How do I properly adjust a front derailleur? I have a Shimano FD-TX50. How should I adjust it?

A front derailer is a bit more complicated than it looks, and can be quite complex to adjust if you're starting from zero -- just having installed the unit.

There are five (and a half) adjustments --

Height, sliding up and down the seat tube.
Rotation around the seat tube.
Low limit
High limit
Cable tightness

Generally height is such that the derailer, when in "high gear" position, is just a millimeter or two above the teeth of the large ring.

Generally rotation is such that the long arm of the derailer is parallel to the large ring (though it's tricky finding the right reference point on the derailer).  But very slight adjustments (particularly rotating clockwise slightly as viewed from above) may improve shifting.

Derailers differ in terms of whether they spring out, to the largest ring, or spring in, to the smallest ring.  If it springs out, place the shifter in the position for the largest ring, adjust the barrel adjuster until it's just about all the way screwed together, then pull the cable tight, force the derailer in until it's just off the high limit, and tighten the cable clamp.  (Getting this right the first time takes practice, so don't cut the cable short until you're confident everything is correct.)  (For a "springs in" derailer you essentially do the opposite.)

Next adjust the high and low limits until the derailer centers over the high and low rings when those gears are selected.  Finally, adjust the barrel adjuster so that the derailer centers over the center ring when selected.  Double check the high and low.

Once you have it this far you need to crank the bike on a stand and see how it shifts.  Fine adjustment of the limits and cable tightness may be required.

The cable will stretch some over the first few hours and days of use, so fine-tuning of the barrel adjuster may be required.


New bike: disc brakes squeal in wet conditions when NOT braking! Normal? I just bought a new bike, and a lot of people seem to have problems with disc brakes squeaking when they brake in wet conditions--however, mine seem to squeak the whole d*mn time.  The bike is fresh from the shop, so has no problem with oil/debris from the road.  Is it normal for them to squeak the whole time I'm riding?  Is there anything I can do about it?

Thanks!!! :3

Disc brakes are very precise and the pads run very close to the disc even while not braking. Due to this, even small misalignments might make the pads (or even the caliper) rub against the disk, producing the noise you describe.

A simple test would be to lift the wheel (or turn the bike upside down) and spin the wheel slightly. If it stops quickly, the brake is rubbing. Try to visualize where this rubbing happens.

If it is actually rubbing, you have three alternatives:

If it is a pad, you can adjust the pads yourself. This procedure depends on the brake type (hydraulic vs mechanic) and model;
If it is the caliper, you can reposition the caliper by releasing the bolts attaching the caliper to the rest of the bike (directly or via an adapter), and reposition the system. Sometimes, braking hard is the best way to force the caliper to stay in the position it should, but this often require some fine-tuning.
Take the bike to the shop where you purchased. Since the bike is new, they it is very fair that you have it serviced.

Now if the wheels spin freely, or rub against something else, well that would be another story.

Hope it helps!


What are some other places to buy MTB frames online? I am looking for sites that sell bike frames online. i find many sites list all things (forks) but stop short with frames.

The best places I have found are:
http://www.chainreactioncycles.com/
and
http://www.jensonusa.com/

Open to places that only sell their own brand but more after places which stock many brands.

I am looking at the low-end of the price range too

Also i am located in Australia. Thank you.

In the US http://www.performancebike.com and http://www.nashbar.com are two big online bike outfitters.  I don't know that either sells bare frames, but they do sell a wide variety of stuff.

And of course a number of custom/low volume bike builders sell bare frames.

Here is a pretty good list of bike & frame manufacturers.


Common brake arm length on a road bike? After switching the fork on a road bike I noticed that the brake pads could no longer be adjusted to sit properly on the rim but would sit too low even in the topmost position. I encountered the problem with Shimano 105-style brakes. Obviously brakes exist with short and long arms and I had to switch to brakes that have shorter arms. Are there any standards for the arm length or, equivalently, the distance between the bolt holding the brake and the rim?

Reach is the distance between the center of the brake bolt and the middle of the brake shoe. Generally, brakes are sold with a range of reach (usually written on the brake; this is because you have some adjustment with the pads), like 40 mm - 50 mm or whatever and are termed as short, normal, long and extra long reach (but the actual reach lengths vary based on the manufacturer and time period of manufacturing, so you need to look at the range of reach for the particular brake you're using; for example, a long reach brake today may have been a normal reach brake in the 1960s). People also use drop bolts to use shorter reach brakes when longer reach brakes are required.

Most brakes are probably 40-50 mm ish reach these days, though you need to check the particular brakes you're working with.

To measure the reach needed, take the wheel (ideally, without a tire), and remove the existing brake. Then, use a ruler to measure from the center of the brake hole to the center of where the brake should hit the outside of the rim. If this is 45 mm, pick a brake such that the reach range contains 45 mm (e.g. a 40-50 mm reach brake).


What does this rod inside the my american classic seat post do? I've got an american classic seatpost. I bought it used, and wasn't sure how to properly adjust it initially. I found the bolt on the bottom clamps the seat down. The bolt on the rear underside adjusts the saddle angle.

But the bolt on the front was a mystery. I took the post out and looked at it and you can see that the bolt on the front of the post connects to this rod inside the post.

The rod has a fixed end which is inserted up in to the seat tube, and the bottom of the rod is threaded and has a small alloy knob on the bottom. It appears to flare at the bottom and has a slit in the bottom of the seat tub where this knob rests. I have no idea how you would tighten this from outsidem But it looks almost like you could tighten it like a stem for a treaded headset.

What is this for and why did they include this on the seatpost?

Seatpost

Close up of bottom of Seatpost with Rod (You can't see it, but there is a slit in the font of the seatpost)

Rod Removed from Seatpost

Bolt on front of Seatpost

I had a Peugeot bike once where the seatpost didn't have the usual clamp but a similar system to hold it in the seat-tube. The system was not very practical because if you wanted to adjust the saddle height you could only do so if the saddle was removed. The bolt was tightened from the top of the seatpost. There was a second draw-back: the seat-tube being rather thin walled you had to be be careful when tightening or you could ruin the tube.
Your bicycle has a normal clamp so I would remove this long bolt with the cone and save hassle and weight.


Hookless rim benefits I'm in a market for new 700c road wheels and noticed that, in addition to usual clincher and tubular, some companies sell rims in hookless variant. They don't seem to be significantly lighter compared to clinchers (both listed as 400g by manufacturer of my choice).

What are benefits and drawbacks of hookless rims over clinchers?

Update: I've decided to leave the answer open until wheelset in question is built and tested, as my own experience might be enough for another answer.

You can make a slightly lighter, slightly stronger wheel, and depending on your priorities, it's a cheaper manufacturing process as well (hopefully to be passed on to the consumer), especially when we're talking about carbon fiber.

Bead hooks serve virtually no purpose for lower pressure tires. They're designed to bind clincher tires into the rim only when used with a tube. Without a tube, once you get above ~65-75PSI, a kevlar or wire bead will stretch over the rim and blow off because there's no tube binding the tire bead into the rim hook. That was the biggest hurdle in creating a tubeless road tire, and why the ultimate solution was a carbon bead with virtually no elasticity.

Since road tubeless hasn't really taken off and you wouldn't be able to use a standard clincher tire with a hookless road rim(1), you're unlikely to see a big push towards hookless road rims anytime soon. However, anyone interested in running a mountain bike tubeless setup isn't interested in running that sort of pressure so the stretching off the rim simply from being inflated becomes a non-issue. That combined with the reasons listed above are why you're seeing more and more mtb rims going with a hookless design.

(1)I've read that Alex has a prototype road rim in testing that's for tubeless and standard clinchers, but I just don't see how the latter would work.


Whats the best advice to progress onto TT bars? Ive just started TT on my road bike and looking at slowly adding components to improve my time....aero bars seem next logical step but need some advice on how to progress? Thank you

I followed a similar path.  I was road riding then entered into a couple of TT's.  I soon thereafter bought aerobars off of Ebay.  Riding at that angle is different and takes a little getting used to.  I then decided to get a TT bike, but instead of just buying one, I bought a frame and all parts on line, mostly from Ebay, scouring for the best prices on what I wanted that were either slightly used (mostly) or new.  I ended up saving almost $4,000 doing it this way instead of buying a ready to go bike and I learned a lot in the process.  I did have my local bike shop put it all together for around $100.
Good luck.


List of UK hill climbs Can anyone provide a brief list of some graded climbs in England, Scotland and Wales, please? I tackled a few hills some 30 years ago (as a tourist), which I thought were quite tough - would they be a challenge to a racing cyclist (at racing speeds)? Examples include Berriedale Brae, Carter Bar, Drumochter. I used granny gears and went very slooooowly!

You can use the Strava website to find categorised segments. You'll have to register for an account and I'm not sure how "official" the categories are.

Go to Strava.com
Register or sign in Click on "Explore" menu
Find the region you're interested in using the search box.
The map will then show all segments registered in Strava.
There is a slider along the top that allows you to filter out various categories, so you can see just categorised climbs.


How is the quality of alloy sprocket 10 speed sprocket? I saw at ebay, 10 speed cassette compatible with shimano, it's very light 103 grams, but the material is alloy with ceramic coated, it says, the cassette can be used up to 3000K, is it true? or may be more than 3000K, because if it's 3000K the age for me is only about 3 months or less riding.

Have any of you ever used one ?

Thanks

There are a lot of small boutique-factories machining extra-weight-weenie parts that serve three purposes:

Provide some weight advantage to very high-end racers who reached the limit of their training levels. That could mean positions in a very high-level race;
Satisfy some folks (whose population is increasing) who don't mind throwing money out the window to have the most exotic and customized extra-high-tech bikes;
Feed the Weight Weenie Contest members with lots of ways to shave weight of bikes they don't necessarily ride (but most probably take a lot of pictures hanging from scales to post online).

(ok, that was somewhat a bitter answer, but I think this is not far from the truth)

And, yes, this means 3 months of riding, then to the thrash can, for the cassette you mentioned. How can anyone afford that?!?!?!?


Adjusting brake pads When I use the adjustment screw to adjust how far the pads are away from the rim,
neither side moves the pad.
Is there a fix?

The brake pads on this kind of brake (V-brake) are adjusted with the screw above the one you've circled. The screw at the end of the pad adjust the positioning of the pad relative to the rim. It's one of the jobs where you ideally need 4 to 6 hands to get it right.
The screw that you circled adjusts the symmetry of the pull, or the timing of the pads touching the rim by adjusting the tension of the springs in the pivots.


Framebag vs Panniers - Pros and Cons What are the benefits of a frame-bag over panniers? I need one for a bike-packing trip (any good value recomendations welcome). I've used panniers in the past but I've seen a lot of framebags about.

If the image above is correct, the frame-bag is great if all you're carrying is a credit card and a puncture repair kit. It's light, cheap, unobtrusive and doesn't add much air resistance. But if you're carrying even a rain jacket, it'll be hard to find a frame bag big enough. The frame-bag is not waterproof either, so it would be best not to carry a phone or cash in it (unless your currency is plastic).

Even if you found a big frame bag, the capacity is limited by your frame size and the width you can fit between your knees as you ride. So a triangle perhaps 500mm on a side and 100mm thick (it will overhang the bottom bracket a little, but most cranks allow that). Call it 12 litres. Bigger than a handlebar bag, but not by much. That's enough for a change of clothes and lunch if you choose wisely.

The advantage of panniers is they come in a range of sizes, from much bigger than a frame-bag to really quite large. You can find waterproof panniers as well as back-pack converting ones, front and rear panniers, and multi-compartment panniers. The disadvantages are that they're big, obvious, expensive, heavy and require racks on the bike as well.

People carry ridiculous amounts of gear in, on, and around panniers. I've toured with people who had 80kg/150 litres of stuff on their bikes, and I've toured with four 60 litre panniers on my bike. There are limits to what you can get into panniers, but compared to the 12 litres in a frame bag the real limit is how much weight you can deal with.


What is the purpose of rollers I have not ever done any bike specific indoor training other than a stationary bike.
I have a rough idea what smart trainers do when it comes to simulating load and terrain.
I am curious though what is the training benefit to riding on rollers?
From what I can tell it does not allow you to vary the load you are working against like a smart/dumb trainer right?
Has anyone who trained with rollers felt like it was time well spent?

While stationary trainers are used primarily to train for raw strength and power, rollers provide training for form and balance.
Because the bike is free to move and weave on the rollers, the rider must keep the bicycle centered while riding. You can't just space out like you can on a regular trainer. Imbalance between right and left legs will often cause you to drift one way or the other, so it provides some feedback to work on that. Pedaling at high cadence also tends to make people start to rock the bike, which will be amplified on the rollers, thus requiring the rider to focus and learn to keep their balance and form.
Regular rollers do provide some resistance training, approximately proportional to wheel speed, but not as much as a stationary trainer. They also don't appreciate sudden bursts of power in sprints, if you blast too hard you can come right off the rollers.
There are 'smart rollers' i.e. computer controlled resistance rollers, but just like dumb rollers, they are limited in how much resistance they can provide. Example is the Nero Elites, which I understand to be the best offering, can only provide 830 watts of resistance. Comparatively, I would expect even the cheapest smart stationary trainer to be well above that. 830 watts is plenty of resistance for just about everyone for steady-state training, but it's not going to work for all-out sprints.
When you are riding around on the street, try to ride right on a line, e.g. the white shoulder line, without moving off of it. See how far you can go. If you can't, riding rollers can be good training for that. It's a surprisingly difficult skills to ride in a perfectly straight line on a bicycle, especially under hard power. That's an important skill if you are riding in a peloton where constantly weaving back and forth, even a small amount, will both slow you down, and make the others around you nervous. With a few hundred hours practice on rollers, you should be able to keep both wheels right on that line virtually indefinitely.
Lastly, they are also a great source for comedic videos of people falling off of them. It happens to us all.


Cycling clothing care products Given a "standard" cyclist's wardrobe (e.g. paddded shorts, jerseys, moisture-wicking t-shirts and socks--made of blends of lycra, spandex, wool, and other "specialty" fabrics) what special-care products are good to have to ensure longevity of the garment and its functionality?

I've so far been using a cold-water delicate-cycle wash with a free & clear detergent and line-drying.  My only issue is I've noticed some base layers still have a bit of odor left-over, certainly not enough to need a second wash--but presumably due to either sub-par cleaning technique or products.

The fundamental problem with synthetic garments is that some of the fibres (particularly early nylon and current polyester) have spaces within the fibres that are perfect-sized cocoons for growing the bacteria that give rise to body odour. 'Boil wash' the garment to kill the bacteria and you damage the fabric. Cold-wash to look after the fabric and you don't kill the bacteria. It means you cannot win on a regular machine wash.

As mentioned vinegar (an acid) works to kill the bacteria. The same goes with a domestic alkali such as baking soda. If this pre-wash is too much effort and you just want the bacteria killed then you can get TAED or 'oxy' add-in for your wash - same aisle as the regular washing powders, smaller packs. This works at low temperatures and with my clothes but there is no way in a million years that I would advise an 'Assos' garment (or equivalent) be washed with TAED.

You can also invest in the base-layers that have silver particles embedded in them. These are up-market garments that cost a bit more but pay off in the no-smells department.

Also of use is a dehumidifier, the DeLonghi DNC65 will work wonders in the changing room at work or at home in the winter months to purge moisture from the air where your clothing develops its pong. A lot of life's problems were solved with the DNC65 for me and my invariably damp cycle attire.

The aim of the game is to not have the bacteria grow, it is therefore best to shower before riding to work (not at work) as fresh sweat does not smell - just the bacteria that develop 12 hours later (when you are home). Therefore, clean body and no bacteria gets transferred to the clothing - it stays that bit cleaner.

I don't think anything can be done with cheaper fabrics that get infested with bacteria - a good set of quality items, washed as per the instructions and kept scrupulously dry in-between rides with a bit of 'oxy' added to the wash is the best strategy. You also want to avoid merely disguising smells - the deodorant strategy - as that does not really work.


Russian "Turist" bike look alike guys! I was wondeing if any of you beautiful people can help me out. My dad's bike just broke :( He lives in Ukraine and has had this "Turist" bike for probably over 20 years. They don't make this model anymore and I was looking around on the internets trying to find a similar looking bike to buy for him. He's 60 and uses it to commute to work and when going on fishing trips. I have attached a picture. If you know where I could find a bike that look like it, or even better, where I could buy one and have it delivered to Kiev, Ukraine, I would greatly appreciate it :)
Please post a model number and I can look into it and where to buy it.
Thanks so much]1

This is Bicycles.SE, we're more aimed at helping you overcome practical problems.  Since its a nice looking bike, why not fix it?

Please tell us more about the problem/damage, with photos of the broken parts.


Problem fitting luggage rack to bicycle I recently purchased a new bicycle, unfortunately I am struggling to fit the existing luggage rack I had to it.

The eyelets for connecting the rack to the bicycle are positioned below the top of the wheel, so unless the rack is positioned at a very severe angle (to the point the legs no longer reach the holes near the hub of the wheel) it will not fit.

On my previous bicycle the eyelets were much higher than the top of the wheel, so there was no problem at all.

Is there any way to get around this problem, or am I going to have to buy a new rack with the appropriate fitting?
I've uploaded two photographs to illustrate the problem:

http://i.imgur.com/cgHSk.jpg
http://i.imgur.com/YHocz.jpg

The front mounting straps on standard luggage racks are meant to be bent as needed to fit the bike.  It appears that bending them down just slightly and sliding them back in their slots should produce a nice alignment of the rack.


GT MTB - New tires - same size front/rear or a mix? (based on my needs below) Probably questions about tires are an everyday-question on this forum.

I own a GT mountain bike. I was running some tires more for dirt/off-road, but where I moved to live now I have also been riding a lot on tarmac/asphalt/pavement. So I was looking for some tires that would give me:

a good speed on these flat roads (gosh, I have strong legs and still cycle fast, but these actual tires kill me)
still a good grip on off-road dirt/gravel.

I came across the CONTINENTAL Race King ShieldWall (this is the upper-intermediate version of Race Kings).

They sound to have a good grip for off-road, but also appear to be fast on road (of course not as fast a road bike, I'm not looking for it anyways).

Now, bearing in mind my needs stated above, a question came to my mind - and when I search I only see topics/posts/answers from few years ago:

Should I run 2.0" on both rear and front wheel?
Should I run 2.2" on both rear and front wheel?
Should I run 2.0" on front and 2.2 on rear?
Or should I run 2.2" on front and 2.0" on rear?

PS: I'm also open to any other suggestions on tires :)

Looks like a good tire for both uses. The speed king would be faster on road, but not as good off road.   If your off road is tending towards non-technical and dry hardpack, consider speed king. Size down not matter - narrow for more road/hard pack, wider for more technical off road conditions.

Consider something like speedking rear and raceking front. With more weight (70%) on the rear, the rolling resistance is relatively more important on there ear. The race king ont he front will provide more predictable traction for steering and control when off road.

One thing to watch is sealed/paved roads, especially when wet.  As you lean into a corner, you transition onto the nobbly shoulder and loose traction when you most need it. Something like the speed king can catch an unwary rider out.

Ideally you have two bikes, second best is two sets of rims, one for off road and other for on road.


Cycling base layers in warm weather? I understand wearing base layers in the colder months, but I see cycling clothing companies (Castelli, Assos, Rapha, etc) also making undershirts specifically for hot summer riding. Given how lightweight and breathable some of the summer jerseys are (like Castelli's Climber's Jersey), why would riders want to add another layer during the summer?

What are the advantages to wearing an undershirt during the summer?

Many of these claim to make you cooler (temperature, not social standing :-)) but whether they actually do or not is another matter. Some fabrics can certainly feel cooler to the touch, and thus may make you feel cooler when riding - which could give you a psychological performance advantage - but whether they physically help cool you down is another matter. Finding information on the actual technology and any sort of scientific testing is difficult.

I ride in Florida and the temperature range can sometimes go from cool in the morning to very hot by afternoon. I've worn UnderAmour Heatgear base layers to keep warm at the start of a ride and found them to be fine when it warms up and they help to wick away sweat if you're not wearing a tight fitting jersey. However that's only up to a certain temperature. Once it gets beyond that I found it just makes you hotter.

Another reason may be for sun protection. Many cycling jerseys are so thin they don't offer much.

Some base layers offer a compression fit, too. Again, companies market this as performance enhancing. Whether that's true is entirely subjective, IMHO.

Lastly, (and if you choose to wear a base layer because of this then you may want to practice riding more) they offer some physical protection. I hit the deck at 25 mph once. My jersey was torn to bits and my skin underneath would have been too if it were not for that fact that I was wearing a base layer that came away relatively unscathed. (The weather was warm enough that I didn't need the base layer, btw).


Is this just the paint cracks? It is on the dropout of my new tarmac, one month old.

The shop owner said "It's normal for this side to crack it might be from the chain"

But when I did test the chain it didn't touch the frame (there got 5mm gap between). But I don't know exactly that when I ride.

So has this happen to anyone?

And how do I know if my frame has cracked or not?

It looks like a chain jam from a wrongly adjusted rear mechanism. The paint finishes on these bikes tends to be fairly hard and a good smack will chip the paint.

The next question is what's been done to the frame. Without testing, x ray type inspection, history etc. Its impossible to tell. So that just leaves whether you trust it enough not to lay out for a new frame. Me, I'd trust that sort of catch if there is nothing obvious in the carbon layup and it rides ok. Go easy to start, build confidence in it; or not. You decide.


bike racks for outdoor use at a school We're looking for some bike racks for our school, but we're unsure as to the styles of bike racks and what's best. What features should we be looking for? Are there styles of racks that work well for schools?

At the moment, it's looking like these for price, capacity and design:

If anyone else has found something better, then please let me know as we're looking to get some sorted fairly quickly!

Those don't look that great. Students would need a long cable lock in order to lock their bikes. There's no way that they could do it with a U-lock. And the weight of the bike is resting on the spokes, which is not good for them. Also, I'm not sure what level of school you're talking about, but I imagine an elementary school child might have a hard time lifting their bike that high.

Here are some features you should look for:

The bike rack should be firmly attached. Ideally, it would be planted in cement. If this isn't an option, it should at least be bolted down and the bolts should not be easily accessible or removable.
The rack should either have loops to put locks through or be completely enclosed at the top. A pole with a bulbous protuberance at the top, like a parking meter, is not sufficient. If a person uses a longish cable lock, the bike could easily be lifted over the top.
You should be able to park a bike next to it in such a manner that a person could easily get a U-lock around both the frame and at least one wheel, both if the front wheel is removed, like this.
People shouldn't have to lift their bikes up to get them into a rack. Requiring a person to lift a bike to get it into a rack makes them extremely difficult to use for the elderly, children, and people with disabilities.

This design has become pretty standard where I live and works wonderfully.

It's certainly not the only option though.


Does using a DH fork reduced to 150mm (6") make sense on an ebike? I recently found out that you can apparently reduce the travel of 8" DH forks such as Fox 40 to 6". This raises the question: would it make sense to do this for ebikes? I like dual-crown forks because they are stiffer and heavier and somehow seem more suited for an ebike, yet I don't see this approach in the wild as most people seem to be happy with single-crown fork such as Fox 34 or Fox 36.

eBike manufacturers seem to think that single crown forks are strong and durable enough. Double crown forks are likely too heavy and overbuilt for use on an eBike.


In bike geometry, what is 'RC Length'? For example, seen on the Reid Cycles website

Rear Center Length
It’s the distance from the rear hub to the bottom bracket. More or less the chainstay length.
Unfortunately Reid Cycles doesn’t have a diagram of what and where exactly they are measuring. For example top tube length could be the actual tube length or a “virtual” top tube length (like in the diagram below) if the top tube were completely horizontal.


Front derailleur cable suddenly very slack (no shifting), not sure what's caused it I last rode the bike on Sunday. Throughout the ride I noticed the front shifter (grip friction shift, Shimano) was feeling "looser" than normal (hard to describe, it didn't feel "right" and seemed to be clicking louder than usual).  However  nothing seemed out of order and shifting was functioning fine.

Today, haven't not rode the bike since, I went back out on the road with it in 1 (smallest sprocket, left there from Sunday) and immediately found it will not shift at all. After pedalling wildly at a wonderful 8mph for a while to a safe stopping point I found the cable completely detensioned and hanging beneath the frame. Twisting the shifter to "H" (limit of its travel) tensions the cable enough that it is nearly in the correct usual position for "L" when the bike is working. It's impossible to produce derailleur movement.

What could have caused this and what do I do now? Not experienced at bike repairs; last time I tried a front derailleur repair, it went horribly wrong, but I want to know what the fault is and whether it's easily doable.

To the best of my knowledge, the bike has been touched by nobody between Sunday and today. The derailleur seems to be working fine (manually pulling it).

The suspicious shifter behaviour on Sunday makes me think the shifter may be at fault, but I do not understand how the cable has suddenly completely slackened. I don't want to touch anything lest I make it all worse - part of me wants to just retension it with the pinch bolt, but I suspect this may not solve the problem.

Possibly related: I'm aware the H-stop on the front derailleur is improperly adjusted, and I've had the chain fly off the outer sprocket on shifting a few times lately. I really need to get around to adjusting that, but suspect it's unrelated to the sudden cable tensioning problem.

ilmiont

Most likely cause is that the front derailleur cable simply slipped through the pinch bolt. The derailleur cage has to put significant force on the chain when shifting to the large chainring which can overcome the clamping force on the cable.

Another cause of shift cable becoming slack is the housing popping out of a housing cable stop on the frame. As you describe the shifting feeling progressively looser my bet is on the cable slipping. The cable could also have snapped but that tends to happen when shifting and is sudden and obvious.

Couple of things to check: Hold the cable taught and verify that the shifter is pulling and releasing it. Manipulate the derailleur by hand a verify that it will swing through its proper range.

Re-secure the cable and re-adjust the derailleur and you should be OK. It's a good idea to run thorough a setup procedure as front derailleur adjustment can be tricky. Park Tool has a good web page and video with step-step instructions.

https://www.parktool.com/blog/repair-help/front-derailleur-adjustment


Cycling in high traffic roads Riding on roads?

I want to go to the work (in São Paulo, Brazil), by bicycle. But I live in a neighbor city, and I need to get a high traffic road.

What is your experience with this, and could it be safe?

I live in Brazil too (Porto Alegre), and I would adivise you to use only roads with wide shoulders ("acostamento") or avenues. Unfortunately, as the vehicles' size (trucks, buses) get bigger than the lanes, biker safety tends to zero.

The most important device I installed in my life is a big helmet-mounted rear-mirror. It took me two weeks to automate it's use, and another six months to cope with the anxiety of looking all those vehicles coming "straight" after me, something I didn't care so much while I was not able to actually see it. Now I've "mastered" its use, I almost nothing look behind turning the head. But sometimes I look more to the mirror than to the way ahead... VERY useful and HIGHLY recommended.

Also, the faster you ride, the safer you are, specially on saturated/near-congested traffic, because you can choose your lane positioning without tempting the rear drivers to overtake you. So, it's worth to invest on a relatively light bike, with relatively narrow/hi-pressure/slick tires, and a pair of strong legs :o)

But, like Guilherme Santos said, things are getting better, slowly. At the same time, unfortunately, dead cyclist news are not uncommon. But, what choice one has but to ride?


What could be preventing my bicycle from shifting gears? I recently purchased a second-hand bicycle. I found that the back wheel was not spinning freely, and was rubbing against the disk break, so I adjusted the position of the wheel to the right. After this adjustment, my bicycle could no longer shift to all of the back gears. It has 8 gears in the back, but it could only reach the 2nd largest gear.

It has Shimano rear derailleurs.
It has microSHIFT twist-type shifters.
It uses metal cables for shifting.

I found an on-line videos and spend an hour of trial and error adjusting the B-tension adjustment, barrel adjustment, and "L" and "H" screws. None of my results seemed to lead anywhere. I found that if I pushed the derailleur manually, it never could extend far enough to reach the largest gear.

After this tinkering, and learning how the rear derailleur works, and what the various adjustments do, the bicycle now entirely refuses to shift gears.

The gears in the front and back will not shift.
The front derailleur previously worked perfectly. Now it has stopped working, even though I did not make any adjustments to it.
I attempted to manually move the rear derailleurs, and the gears still do not shift.
Manually pulling on the cables does not cause the derailleurs to move, the cables seem unwilling the budge.
I disassembled the rear-gear shifter, and tried manually tugging on the cable, but it won't budge. Should this be really hard to pull?

How can I diagnose why the bike refuses to shift gears?

Update 1:

Photo from top of rear wheel:

Photo from side of rear wheel:

Update 2:

Per the suggestions, I have checked the derailleur and hanger.

The hanger seems to be in good shape.
I was able to fix the alignment of the derailleur by removing the chain and wheel. Now it seems to move correctly.

However, turning the shifter does not pull the cable at all. I will entirely replace the shifter and shifter cable, unless someone has other suggestions.

not sure if these may be the problem but you can get it checked.

Make sure your cables are still in good condition.
Make sure your hanger are not bend.
Make sure your derailleur is not bend as well.

I have a mountain bike with 9 speed and it refuse to change to the largest cog and after taking it to the bike shop, we found out that the cables were too old and after replacing it and adjusting the tension, it worked out fine. Hope it helps.


34.9mm front derailleur on steel frame? Can I fit a 34.9mm front Shimano derailleur on my steel frame? I understand that steel frames are narrower. However, is there some sort of adapter that I can use, or can I even wrap the frame around there with some inner tubes to "fatten" it up? Will this be sufficiently stable?

Any thoughts will be appreciated, thanks.

You need a derailleur shim

The one linked adapts a 34.9 mm derailleur clamp to a 31.8 mm seat tube.  I haven't seen other sizes but I'm sure it could be augmented/replaced with something homemade.


Chain on singlespeed tight, pedals won't turn backwards very freely - is this an issue? A well-known and well regarded shop fixed something on my converted single-speed bicycle. On the ride back from the shop, the pedaling felt "different", and I noticed that the pedals will stop after less than a turn when pedaling backwards.

I went back and the mechanic explained that he overtightens the rear wheel in the dropouts. In his experience, within a few days the chain will be back to normal and it'll be fine.

However I wonder if this could cause issues of wear and tear and ruin other, perfectly working, parts?

Yes, overly tight chain does accelerate wear on other parts of the drivetrain. The rear hub bearings are not designed to work under the load described here and if ridden like that for extended periods, it will likely show significant wear.

Chain wear would (and will) cause your chain to gain that desired slack again, but I wouldn't rely on it happening soon enough. Your mechanic supposedly does this to avoid situations where their customers start dropping their chains after their chains have elongated significantly, but from your perspective the trade-off is pointless: setting the correct chain tension is fairly trivial job that needs to be done again anyways if you are to remove the rear wheel for any reason, such as fixing a flat tire or packing the bike up for transportation.

I suggest you ask the mechanic to set the chain to appropriate tightness, or learn how to do it yourself.


Better to go with a longer spindle length bottom bracket or shorter? I have a 1987 Panasonic dx1000 that I am converting to a single speed. I was planning on replacing the bottom bracket. To get the measurements I measured the tube to be 70mm (2 3/4") and the spindle to be 125mm (4 7/8"). When looking for replacements I cannot find this size. Would it be better to go with a 68x122.5 mm or a 68x127.5 mm? It was a double cog and removed one so that it's only a single. Any suggestions?

I have just rebuilt a 1990 Raleigh bike (exact model unknown) and tried several bottom brackets to find the best. This turned out to be the one that brings the smallest chainring (in your case only chainring) closest to the chainstay without touching it. The one I've ended up with is 117.5mm whereas the original was 122.5mm. The front derailleur works perfectly (not applicable for your setup) and the chainline looks great, albeit aimed at the larger cassette ratios rather than the smaller ones.
My logic is that when on the larger sprockets I am putting a lot of pressure on the pedals, so a straight chainline is best for chain strength and wear. When in the smaller sprockets I am usually on the flat or downhill, so a bit of chain angle is not such an issue.
Thus, I would go for the shortest BB you can get away with to keep the chainline close to the chainstay, and minimise flexing forces on the BB stubs (are they called that?)


What are real advantages of brake hose junction connectors? I just received my new brake callipers and handles.  They come pre-assembled with hoses and a "hose junction connector".  These are the same as Dan Lloyd has in the below video:

I understand the advantage of these when there is a need to work on the hosing without the need to unwrap bartape.  However I can't really think of a scenario where I would work on the hoses and still worry about the bartape as well.  I do however see scenarios where these connectors would scratch my frame or just be plain ugly.

Before I spend money to replace something potentially useful: what are some real life advantages of using these connectors?

For your own bike, you would probably only do that one time, when the bike is new (to you) and setup opposite to your preference.

The big advantage in this situation is that you shouldn’t have to unwrap that lovely fresh bar tape to do the job, and you are undoing specially designed connectors, instead of the compression fittings at the lever. There’s less to go wrong, certainly no need to fit new fittings or shorten the hose for them, just a couple of spanners are required. More lay-user friendly.

Otherwise, If you had a rental fleet and foreign customers, you could swap the hoses around if any customer requests it, then back again. I assume; I don’t know how many swaps the connectors could handle, but it would be preferable to swapping at the lever end. (Quicker, easier, no need to shorten the hose for new compression fittings).


Calculate suspension oil needed for a fork? I've got a non-standard 20" air fork (Mekkem SASO) that could use some maintenance, but there's zero info I can find from either the manufacturer or OEM on oil viscosity, volume, or anything else. I've watched many air fork service videos, so  I'm confident I can follow those procedures for disassembly and cleaning since things aren't likely to be very different from a hardware setup standpoint, but after I drain,  I'll be stuck trying to figure out how much oil to put back in. It's got 80mm of travel, so I'm wondering if I should just eyeball it (3ml?) of "standard" suspension fluid (5w?) or if there's a standard way to calculate what you need by measuring the volumes of the tubes and going from there.

Given the lack of info on this item, I assume replacement parts will be difficult or impossible to acquire, so  I figure I should try to stay ahead of the wear to keep them around as long as possible. They don't get mountain-bike type use, just bad pavement and fairly tame single and doubletrack + gravel.

I can't find a specific source, but in my shop we use a chart from RockShox that can be applied to almost every front suspention. Here is a link


Why dual pivot brakes, not longer brake arms? Dual pivot brakes are marketed as having "more braking power", which in technical terms means higher mechanical advantage. Exactly the same effect can be achieved by longer brake arms (ones which are pulled by the cable).
It was pointed out that dual pivot brakes are more convenient to center, which I disagree with, but that's a different question; here I'm asking about getting the same mechanical advantage without two pivots.
Is there a technical reason to use a more complicated construction? By "technical" I mean "not related to marketing". "Dual pivot" definitely sounds "cool" and probably sells well.

The single pivot sidepull design requires a fairly wide pad gap at the rim in order for centering to not be too finicky. It's essentially the widest of all common rim brake designs. This is due to the spring design's two sliding contacts, as Jobst Brandt writes about here. The contacts are hard to keep at the exact same level of friction, and any disparity takes the brake out of center. You need a wide gap to compensate, at least for a normal person not fiddling with their brakes all the time.
You can't just add longer actuation arms to make the same design more powerful because it's still the same human hand at the lever end. If you want the pads to be able to touch the rim, then longer actuation arms with the same pad gap would require either shorter lower arms, which you can't do because there's a tire there, or a lever that pulls more cable. You can make the lever pull more cable, as in a v-brake lever, but note that v-brakes have a much smaller pad gap. That's why they can have a lever that generates much less mechanical advantage. Do the same thing with a hypothetical long-armed single pivot and you get a brake with very low power.
In other words, all brake designs are bottlenecked by the input force. You can't then have one that's also bottlenecked by pad gap and have it compete on power with ones that aren't.
What amount of pad gap should be designed in to the brake to overcome the centering issues is subject to both opinion and potential design advancement. You may even disagree with the premise that this is a design limitation, and that's fine; every real advancement in component design does. If you made a single pivot brake that could happily run with the pad gap of a dual pivot, then yes you could increase the arm length to get the mechanical advantage of a dual pivot. There's presumably some way of doing it with graphene.


My wife has Cerebral Palsy (CP) so can’t balance on a normal bike, what are the options so she can go cycling with me? My wife has Cerebral Palsy (CP) so can’t balance on a normal bike, what are the options so she can go cycling with me?

We don't own a van, the size of any "bike" is important as it will have to fit in a car.

I've seen quite a few older people in my city riding around on 3 wheeled bikes, similar to the ones shown here.  They offer quite a bit of stability, without making you low to the ground like a recumbent.  However, I can't think of how you would get one into a car.  Getting a regular bike into a car is hard enough, have you thought about a roof rack?

You almost might want to look into stabilizer wheels which can be attached to any bike, and you may be able to find some that are removable for transportation.


Converting down from 10spd to 7spd I'm building up a vintage mid 70s AlAn that cannot have it's rear drop outs cold set to a wider width.
I have a nice set of williams clincher wheels which are substantially lighter than anything oem (28/24)
By replacing the shimano freehub with a 7spd and the axel with a 7spd length is it possible shrink the rear hub width to 126mm from the 135?
(I realize I'll probably have to redish the rear wheel)

I kind of doubt it. The hub will still be 10-speed and I'm pretty sure that a 10-speed cassette is wider than a 7, so you won't get back all of the width (in fact I'm not sure you'll get any of it back). Even if you got some back, putting it into a 126 mm frame likely means that the wheel would be "over dished" (there would be a poor bracing angle on the right side spokes).

It seems like you'd do better to go looking for a NOS 7-speed hub so that you could build up a proper 126 mm wheel. If the flange sizes are the same you could probably reuse the existing spokes.


First cyclocross race - strategy Next weekend there is a cyclocross race at a park near my house.
My first organized bicycle race ever.

I would like advice / links on strategy, rules, and protocol.

I am over 50, in good bicycle shape, and comfortable on trails.

I ride a bicycle daily and take a 45-75 minute workout ride at least 3 days as week.
So I am pretty comfortable with what I can do in 45 minutes.

My thought is to try and hold with the leaders as long a possible.
If it only 5 minutes then so be it but I want to know what that pace is.
How do I even know which riders are in my age group?

I suspect I will be lapped.  How do I deal with that?

This is a links to the event information   2014BCRCX2   register

So I did my first race to today and here is my take on first race strategy.

Unless you are a solid road or mountain racer don't even think about
staying with the leaders.  The pace is fast.  It is faster than you
can ride.  It was two gears faster than I thought it would be.  For non a racer I am a good rider and in very good shape.  I got lapped 30 minutes into 45 minute race.  Even on the 4/5 30 minute race I got lapped on my second to last lap so it got turned into my last lap.
Bring chap stick
Don't over eat
Don't drink the night before the race - it was Halloween and I went
on the Critical Mass ride
Bring water as the event may not supply water - it was a well run event
but the park did not have water
On the last 2 or 3 laps they will tell you how many are left.  If you
get passed by the leader then that is a lap.
Ask questions.  Riders are are very helpful.
If you are over 40 and not experience then you don't really have a
good option.  You may have a 1/2 the field Cat 3 or above in
masters.  And in 4/5 you are going against 20 year old legs and lungs.
Just have fun.
If you are in the last race and they serve beer then stash a cup
before the race as once the Cat 1-3 hit the keg they drain it.
If they cheer for you to ride the sand pit or other hard obstacles and
they are not a racer it is because they want to see you crash.
Heckling is a big part of the sport.  Don't wear a yellow jersey -
especially your first race.
If you are coming into a section that you are going to need to hit
the brakes then coast a little longer and use less brakes.  There are
going to be sections of course where you don't brake and go
all out.  Use the downhills to recover.
When you get passed they will tell you what side they want.  And you
will hear them.  On a corner just go wide.
Once you get passed is when you can learn.  Watch their lines.
Watching from the sidelines is not the same.


Can I swap Semi-Metallic brake pads for Sintered Metal Brake Pads? I'm running disc brakes on my cyclocross bike with semi-metallic brake pads.  I find that I'm constantly having to keep my rotors cleaned off to ensure optimal performance.  I'm used to my mountain bike which uses sintered metal pads, and still works well in muddy / dirty conditions without needing excess maintenance.

I considered buying new brake pads and swapping them out. However, If I do that, will the new metallic pads work well with the rotor that has been bed-in using the semi-metallic (part resin) pad?  Do I need to get new rotors or do anything to bed in the rotors again with new pads? Would it be any different swapping from sintered to resin based pads?

Yes you can do this, and no, you don't need new rotors.

I had the same issue with my CX bike in that it didn't brake as weel as my MTBs, so I swapped to metallic pads.  They do work better, but IMHO, the biggest difference is whether you are using hydraulic or cable disc brakes.  Cable are simply not as good as hydraulic.


Breaking spokes very often at J bend I have a urban commuter bike. Since last couple of months, the spokes at the rear wheel keep breaking after each ride. I changed the broken spokes couple of times. Also I replaced all the spokes. Same thing keeps happening. I weigh around 90 Kg. I have had the bike for 2 years and covered only 6000 Km. I check the spokes before going for a ride. Almost never have I found a loose spoke and yet after the ride I find one broken. Should I replace the whole wheel or just the rim/hub? Is my weight the problem here?

Edit- 1) Being a complete amateur in the field, I didn't know what details mattered. The wheel is Double walled 36H with double cross lacing (Both sided).(This is an assumption. I am attaching photographs to make things clear.)
2) I didn't change the spokes myself. I had it done from a shop.
3) I go over the curb or rather potholes  (We have a lot of those here in India) moderately hard.

This is not normal. A properly built wheel with quality spokes will not break spokes like this. The likely culprits are build quality (spokes over-stressed?) of spokes quality. Take your wheel to a bike mechanic and ask if the spokes tension looks right and if the cross-pattern is OK. If it does, then you are left with poor quality spokes; change them.


Sekai 2000 tire and rim? I have a Sekai 2000 bike and the rims are bent very minutely. If I turn the wheels front or back and put my fingernail in a fixed position close to the rim, it is less then 1mm. Is that anything I need to worry about? I will be riding out in the country on asphalt and then down a gravel lane.

I am considering replacing the rims and tires. I kinda of want yellow tires and rim since the bike is blue. All the running gear is brand new and some brand I cant recall at the moment. I know the tires are 27x1 1/4 or 630 x 28. Do they have yellow colored rims for that size? I know the rims aren't that important but I like to admire the little things. either that or black or white rims that will contrast between the blue and yellow.

Some general advice:

The bend/wobble is likely nothing to worry about and you can search this site or Google for how to true a wheel. If there's less than 1mm of un-true-ness, I wouldn't even worry about truing it.

A new wheelset will likely cost more than the bike, and since it sounds like you have a perfectly good one on the bike already it's hard to recommend doing. That said, if you want colored rims and tires, you're likely going to have to perform a 700c conversion to take a modern wheel since hooligan colored stuff wasn't reasonably common on road bikes in the pre-1980s as far as I can tell (and 700c became popular after that). The 700c conversion essentially requires the ability to move the brakes down about 4 mm and spreading the frame (cold setting it) to fit a modern hub. Then you can buy some (generally low quality) 700c wheels which are colored to your liking, along with tires provided they clear your frame (you're going to have to measure it).

As for handlebars, note that changing the handlebars may change your fit. Make sure the bar has the right diameter for the levers to clamp to as well as your stem.

There are a lot of fenders on the market, so go find something you like - make sure you have the eyelets or mounting method for the fenders you choose.


Can I combine SRAM Rival 22 Levers and Shimano 105 Rim Brakes? As the title asks, is it possible to combine SRAM Rival 22 levers (for mechanical rim brakes, of course) with Shimano 105 rim brakes?

For BR-5700, BR-5800, and BR-R7000 they run off the various new school Shimano not-quite-short-pull cable travel numbers. SRAM road levers are all basically traditional short pull, which is less cable pull than Shimano Super SLR et al.
The mismatch in this direction results in less pad movement but with more leverage than intended. It can typically be made to work, but needs to run with commensurately smaller pad gap, which usually means the caliper QRs won't open up enough for an on-trend tire. Feel will be mushy and indecisive but power will be good as long as you can get the pads close enough that you don't bottom the lever. By the same token, you have less ability to use the Doubletap reach screw.
It does function, but it always feels like a way of making a mediocre system out of good components. The pre-5700 brakes are normal short pull.


inner tube width range relative to tire width: reliability effects? [Apologies if this seems like a dup: I see there are lotsa tire+tube questions, but this one does seem to be slightly different, in that it strives for generality and concerns choice between alternatives.]

question

Suppose one is buying tubes for a given {rim, tire} tuple. Assume the following data/constraints:

The tire fits the rim's bead seat diameter (BSD) appropriately and has tire width w1.
Tubes ta and tb match the rim/tire BSD and are identical in all meaningful1 respects except width: identical cost, material, thickness, valve, etc.
ta specifies a width range w0-w1 (with w0 < w1)
tb specifies a width range w1-w2 (with w1 < w2)
One is a competent tube changer with lots practice.
One's primary concern is tube reliability over time: i.e., one very much wants to have fewer flats.

Given the above,

Are there empirically-valid reasons to choose ta (i.e., the tube for which the tire width is at the high end of the tube's width range) over tb (i.e., the tube for which the tire width is at the low end of the tube's width range), or  tb over ta? Or is there no reason to prefer one over the other?
Are there other data/constraints which are significant for the decision? E.g., whether one typically runs at high or low tire pressure?

motivation

I drive recumbents with 20-in/406-mm front wheels, currently running unbelted 20x1.35 Primo Comets. (FWIW

tire make/model is irrelevant for the rest of this question, so feel free to ignore.
I don't drive a trike: I have 2 nearly-identical SWBs with swappably-identical wheels. I like to have spares :-)

) I bike for transportation, so reliability is very important to me. Unfortunately

I recently moved to an area with much more puncturing road debris.
The area is also less dense, causing longer mean trip distance which exposes me to more debris.
Recent flats have now consumed my stock of 20x1.35 tubes. FWIW, I replace tubes rather than patching them (assume that preference as given :-), and I like to keep a few spare tubes (as well as ... everything else).

Fortunately there are some 20x1.5 Kevlar-belted Comets locally available at a decent price, which I intend to try. However the 406-mm tubes I'm seeing (and on which I now need to stock up) are either 20x1.25-1.5 or 20x1.5-1.75. Which raises the more general question.

possible answer

I bought the 20x1.5-1.75 for the Primo belted Comets. After 3 months: no problems installing, no flats, hold air well (i.e., takes a long time to go from 90 psi to 80 psi). Granted, this is not much of a test: n=1, not enough time for testing, change of tires is a confounding variable. But WTH.

1 Assuming both tubes have the same material and thickness, the wider tube will be heavier, but consider the mass difference negligible. (In this specific case, the mass difference=26 g, which is negligible for me.)

If you're getting flats regularly, my guess is that its not the tube's fault, but you to need to make sure that you have sufficient tire pressure and switch to puncture-belted tires (e.g. Schwalbe Marathon). A tube is just a balloon, and you can often put a tube marketed for a not too different size tire into one which slightly different without problems (so long as you don't have the extra width bunch up; e.g. don't put a 29x2.5 tube in a 700x18 tire; I normally do this with 700x23 marketed tubes in a 700x28 tire without problems). Just like most balloons, even the smallest prick will deflate it, so you really need to protect the debris from getting to the tube in the first place. The thickness difference between the rubber in the bigger and smaller tubes will likely be too small to make a difference. And in this case, since the tube is designed to work for tires of your size in both cases, you should expect to have perfectly acceptable behavior with both sides (that is, dumb luck should determine which works better).

Empirically, if anything, the brand of tube might have a slight effect. I've had bad luck with tube reliability from one manufacturer in particular, so I don't buy their tubes anymore.

If you're really paranoid, they make tubes which have extra thick rubber called puncture resistant tubes (useful if you have goatheads) and you can fill your tube with tire sealant (Slime). These will be more resilient to punctures compared to other tubes, but they are more expensive and Slime is messy. But I'd start with some puncture resistant tires. In short, if you don't have these speciality tubes, its likely the case that it doesn't matter which tube you have.

I'd suggest avoiding using tire liners, since they can actually increase flats unless you're really not in good shape. A puncture belted tire is a better idea for most people.


Road bike for brevets Until today I've been doing 200km brevets on a trekking bike. It was quite comfortable, there was no ass pain after that, but the average speed was low (24km/h). Also if the wind blew, I had problems riding further, or arms were aching from taking more aerodynamic position.

So I bought a road bike, and it's great, but after doing 50km on it:
- ass pain became unbearable (I had pants with a gel diaper)
- my back and shoulders were aching from road bike position

Is road bike really a good choice for 200km brevets or longer?

Triban 520 c1:

Riding long distances comfortably has very little to do with whether you're on a 'road' frame or a 'trekking' frame and much more to do with the tires you're using and the seat you're sitting on. Wide, plush tires will go a long ways toward absorbing the bumps in the road, and the seat is your most important point of contact with the bike.

For starters, try swapping the seat from one frame to the other, swap out the tires for wider touring tires, and see if your problems don't go away.

Edit: and for Pete's sake, make sure the bike fits you. If it doesn't fit you, nothing else really matters. Have a professional fit performed if you need to.


How to measure and cut chain I am currently building a road bike. I measured the chain using the largest ring and largest cog method, I counted two extra links and cut the chain using a chain tool.

Both ends of the chain now have narrow ends. I want to use a power link, I understand that if I use the power link to join the ends, the chain will be one link longer than necessary.

How can I remedy the situation?

Appreciate any help.

You put the powerlink on the chain and move on with your life. Provided the chain is not insanely too long, it's going to work fine unless you're on the boundary of what your shift system can handle in capacity (which almost nobody is) and you're abusive at this boundary.

Note that the article clearly states how to size when accounting with a master link:

  MASTER LINK NOTE: If the bike chain uses a master link, it is necessary to account for the link. Install one half of the master link on one side of the chain. Size the chain by cutting the other end of the chain.

If your chain is too short, you can jam your RD in large-large. If your chain is too long (as in this case), it may droop a little bit in smaller cog+chainring combos, but with 1 or 2 links too long, it will likely be insignificant (and occur in combos you don't use anyway).


Why do my handle bars wobble from side to side? I am a gramma with my first electric bike.  When I ride I notice my handlebars and wheel tend to flip from side to side a lot.  Is this because I am out of practice riding or does something need readjusted?  It is a Nakto Skylark 22" ebike with no shifting gears.  I am 5'2" over 200lb.s and generally riding on uneven side walks but it also happens when I am just going straight.

I had the same thing on my 20in viking ebike. Mine was down to the folding tensioner on the handle bar release handle.I tightened that and it sorted out the problem.


OnGuard U-Lock key mechanism partially activated I have a mini U-lock from OnGuard.
The lock is not attached to the bike, so that's not a factor is this question.

I can see the locking mechanism jutting out partially into the key hole, which is preventing the key from being fully inserted into the key hole--it only can go about 1/2 in.  How can I get the mechanism to go back in to place so that my key may be fully inserted? Or is it time to finally break down and get a whole new lock?

You can rotate the key back and forth while you insert it, That should help realign the cylinders. This actually a common problem and doesn't mean that the lock is broken.

Take it to your bike shop if you continue to have problems. They are experts at the jiggle-dance sometimes necessary to get the key in.


Route mapping tool - INSERTING a point I'm kind of frustrated by this, because after long time of internet searching, I found none that would satisfy my needs.

The problem is that I want to HAND-DRAW my route by first clicking it's endpoints, then refining the route in between.  So, I need a tool that will have ONE feature that all other tools lack - INSERTING a point between two points already in place.  Of course, it has to work ON google maps in satellite mode, so I can map across the fields and so on.

I don't care for an algorithm, since it is useless - I'm not following charted roads.

BTW: HAND-DRAW above means to draw it by hand on a computer, not on a paper :)

You could use ridewithgps to build your map. It allows you to drag waypoints off the main route and re-routes (can be used without auto routing as well if you prefer).  You'll have to pay if you want to print from their site.  However, you can print a cue sheet free or export the saved map in GPX or TCX format to print with another application or website that accepts these uploads.


Shimano Sora 3400 shifters with Shimano Alivio M430 rear derailleur? I'm thinking about a touring built with just spare parts I have.

I have a rear Alivio M430 9 speed derailleur and Alivio 9 speed 11-34t cassette already. I want to have drops and Sora 3400 is the cheapest 9 speed road shifters I could find. I don't think there is a difference between the cog spacing between road and MTB so it should work if my assumption is true.

Yes, with 9-speed this sort of combination works because Shimano mountain and road rear derailleur actuation was the same until mountain 10 came out.


Rear axle sizing for wheel set, compatible with both 142mm thru axle and 135mm quick release? Attempting to buy a new wheelset and I am getting a bit confused on whether the wheelset - or I guess more specifically the hub will fit my bike. I have a Salsa Journeyman Apex 1 and it has quick release dropouts.  The specs on Salsa's website say the rear spacing is 135mm. So I would need to select a wheel set suitable for QR x 135mm.
I am looking at this rear wheel which lists compatibility with 12mm thru x 142mm as well as QR x 135mm. However a lot of sites don't list the QR compatibility for this wheelset, like this one.
I will be getting the wheel with a SRAM XDR so final question would be, does a SRAM XDR 142mm thru fit a bike with 135mm QR? Do I need to get different end caps to fit a QR system if so or will it come with thru axle end caps and QR end caps?

135 QR and 142x12 thru axle are two wholly different standards with no intrinsic cross compatibility.
They both locate the cassette in the same place relative to the frame centerline, or in other words they give the same chainline. 142x12 is essentially the iteration of a thru axle rear end that didn't change anything else about the parts that would play nice on the rest of the bike, coming out of the long period where 135 was the only game in town for a disc bike.
All that said, it's extremely common for aftermarket 142x12 wheelsets and hubs to have 135 QR adapter endcaps either included or available. These are all proprietary to the hubs they're made to go in. It's pretty common for them to be included and I believe that is the case for the DT wheel in question.
Whether the freehub body is XDR or XD or HG or Microspline or whatever is immaterial to the frame the hub is going in. All that matters is either endcap availability or native compatibility with the standard the frame is made to.


How much tolerance is acceptable on the chainline of a fixed gear conversion? When converting a geared bike to fg/ss, at some point there will be adjustments to be made regarding chainline. Without getting into details about what could be made to make it better (bb axle width, hub spacers, different cogs, whatever), how much disalignment can we have between chainring and rear cog?

Currently, I am building a fixed gear out of 90s MTB frame, track rear wheel and road crankset, and I am sure it will work eventually, because I've done this before and I don't care about the hassle. What I hope is someone could give this question a final answer, to enable (or not) people who are into that "DIY fixed gear spirit" to have some confidence (or to know the risks with more certainty) before starting a new conversion project instead of simply buying new stuff.

There is no hard and fast limit. The farther off the cogs are, the worse vibration and wear you will get. My personal experience is that a couple of millimeters off is still smooth and at 5 mm the chain will be noisy but still work.

On a singlespeed it's virtually impossible to throw a properly tensioned chain without breaking cog teeth, but bad enough chainline will wear them out and make that easier.


How to seamlessly upload to Strava after a ride using a Garmin Edge 500? I have a Garmin Edge 500. Records everything I need, but the pain is uploading and managing the data into Strava.

I just want to walk in from my ride, have a shower, have breakfast and see my ride stats straight away in my iPad or PC. In other words, I don't want to touch the device until the battery is about to run out. I don't want to plug in my device to anything either (usb, etc).

I know the Edge 500 cannot do this automatically as it does not have Bluetooth or Wifi, but it can connect without cables to the Cadence Sensor, etc. So why can't there be a hack or something to be able to "force" it to download the FIT file once within range of your internet at home?

The reason I ask this here is because I usually ride with my partners very early in the morning, and when I come home I have a lot to do before I go to work - have breakfast, get ready, kids to school, etc. By the time I get to work, and if I have time, I then upload the ride's stats into Strava usually around noon. By then it's "too late" as my ride buddies have already given Kudos to each other and I hardly get any, plus the ones I do get are days later from other people I don't even ride with. I know this sounds egoistic, but that's beside the point of the question and subjective to each one's needs of why we ride, etc.

Thanks

I personally use a Garmin Edge 810 which can connect via Bluetooth to your smartphone and then automatically upload rides to Garmin Connect. The auto-transfer from Garmin Connect then allows your ride to appear in Strava almost immediately, however, this isn't without it's short-comings.

As per my comment on Mac's answer, I have found the auto-upload functionality very hit and miss ever since owning my 810 in April last year. Recent firmware updates have significantly improved the reliability, but it's still not perfect. Saying that, the fact it doesn't hit my phone's battery life is the winner for me.

There are lots of different devices on the market, but a quick look on Strava's own store has highlighted the Wahoo RFLKT which connects to your smart phone. Without a connection to your smart phone, the Wahoo is essentially useless. However, it would appear to be quite good as it allows a direct connection with your Strava app (displaying data that the app outputs), only costs $99 and then you have the piece of mind that your data will ultimately end up in Strava as soon as you finish your ride. This again has it's own cons as you need to use your phone as the main cycle computer, ultimately draining your battery quite rapidly.

It then really comes down to an argument of which appears more useful. A standalone bike computer with the ability to auto-upload when paired with a mobile phone, or a computer which simply displays data outputted by the Strava app at the sacrifice of your phone's battery life.

Wahoo RFLKT on the Strava store

Other alternatives on the Strava store


Help on calculating spoke length I am going to replace my bent hub on my MTB. The hub is Novatec D042SB and the rim which I am going to order is Sun Ringle Inferno 25 29er. Since my hub is not so popular there are not any default dimensions available in online spoke calculator databases. I cannot take apart all the stuff on the wheel for precise measurements and that's why I have to ask for your help. I have used several calculators and all of them gave me different result ranging from 290mm to 294mm.

Here are the dimensions of my hub in Novatec's official website.

Flange to Flange 58.4mm

Flange Diameter 58mm

Over Locknut 135mm

Offset of centers 6.8 mm

Rim ERD 602 mm

If anyone has experience with building a wheel, please help me to determine the exact length of the spoke

Thanks in advance

Rather than quoting figures for the right and left flange distances from the Locknut centerline distance, they quote a "flange to flange" distance, along with an offset, for some mysterious reason.

This image: http://issuu.com/novatectaiwan/docs/novatec_hub_dimensions should help translate their "Flange to Flange" and offset figures to be right and left flange distances. In the case of this hub, your left and right flange distances are:

Wl = (F.T.F/2 + Offset) = 36.00mm
Wr = (F.T.F/2 - Offset) = 22.40mm

Using the dt swiss calculator, I calculate 292 and 291mm spokes for building a triple-cross wheel with your selected components.


Shifting 1>2 does nothing, shifting 2>3 puts me into 2nd. What's wrong? I'll be in first gear on my front derailleur, and shift up to 2nd. Nothing will happen at all. Then I'll shift up to 3rd, and I'll finally switch into second. 3rd gear is inaccessible.

What could be the cause of this issue? Cable too slack? Limit screws in wrong positions? What should I adjust to try and fix this? I've been trying different things but I'm clueless here so I thought I'd ask for advice from people who actually know.

If it was me, I'd release the gear cable so there is no tension at all on the front mech.

Then move the gear lever / changer to the position the changer would be in if you weere in the 1st chainring.

Then make sure that the adjusting screws are set correctly, so that when you look at front mech from above, it is centred over the 1st, smallest chainring. You might need to tweak the screws to get it to line up properly. I can't remember which screw does what but trial and error will tell you.

Then I'd get some pliers and put lots of tension on the gear cable, and clamp it tight in the front mech.

Now you have a nice tight gear cable. Try again with changing and see if it works any better.

If it goes up to the 3d, biggest chainring, make sure you can't overshoot on the changer, you might need to adjust those screws again - but don't touch the one you used to set the position on the 1st, smallest chainring.

It can take a bit of testing, but usually this approach works for me.


How can I warm up/cook food while cycling? I've been doing lots of long-distance cycling this year (150+ kilometers). With that much riding, there's obviously a need for some sustenance, and I'd rather not stop just to eat.

The protein/carb bars have been getting incredibly boring... especially for my second meal on the road, so I've been experimenting with different foods like sandwiches and soups in a thermos. That's worked just fine, but it got me thinking... is there any system that I could use to cook or heat-up food while I cycle?

It's crazy, I know, but when I was a kid, my father would cook food on the engine block while we drove... and I was thinking, that's almost a reason to start driving again :). Any thoughts on what I could do to heat-while-I-ride? Chemical heat? Electrical? Propane?

The latter (propane) seems dangerous and not so environmental friendly, but I suppose it couldn't be that bad?

I don't think it would be convenient or practical to use any kind of stove or hotplate while you are actually riding. If you are carrying a backpack or have things on a rack a propane backpacking stove can be very fast for creating a hot meal on a break.

To cook/warm while you are actually riding I think your best bet would be to use a Flameless Ration Heater like you find included in many military-style Meals Ready to Eat (MREs). I think you would still want to assemble the FRH and MRE into a packet and attach them to a rack while you ride because the packaging can get pretty warm.


How much distance can I put on drivetrain components? I figure the jockey wheels on my derailer will last nearly forever, but what about the rest: cassette, chainrings, and chain?  How many miles, kilometers, or furlongs do they normally last?

I know that there are definite signs of worn out sprockets—what sort of mileage is typical before the point where the wear is significant enough to require replacement?

This is for a commuter/touring bike with Shimano 105 components that is reasonably well maintained.  I clean & lubricate the chain every few weeks.

Mileage will vary greatly depending on the riding conditions and component maintenance. Personally, I've never tracked the mileage of my drivetrain components. But I do know that I replace chains far more often on my commuter bike than on my road bike.

Ok, I pulled out my copy of Zinn and the Art of Road Bike Maintenance...

Chain life: 1,000 - 1,500 miles in dirty conditions or infrequent lubrication. Lighter cyclists riding on clean, dry roads might expect 2,000 - 3,000 miles with poor maintenance and up to 5,000 miles with a daily high-quality lubrication.

Zinn also says that he gets almost infinite life out of his chainrings and cogs! He said that in the section on checking for chain elongation.

Here in Portland, commuting year round, I'm probably near the bottom end for my commuter bike.

wdy


Low power while maintaining high cadence I just started using a Tacx Smart Flow in combination with TrainerRoad to try maintaining and getting up my fitness level over the winter.
My problem now is that TrainerRoad tells me to keep a power level off around 60 in my workouts while having a cadence of around 80-90. When i have a cadence of 80-90 i'm either over a power level of 60 or in a very low gear and are bouncing around on the bike to keep the cadence. If i try to keep a power level of around 60 im mostly at a cadence of around 60.
Is there anything i'm doing wrong or should i just ignore either the power level or the cadence?

64 watts is well within the margin of error of 60w target.

Don't be afraid of going to your lowest gear on the trainer.

You should be working up to your target cadence, if you can't hold 90 without bouncing then you should aim for something lower. It will take time to get up there.

60w is relatively low for most people, it may become easier for you to hold a higher cadence at more watts.

Trainerroad philosophy is to focus on the power, especially in your intervals.

Bouncing and poor form won't help you get faster.


E-bike drivetrain demagnetization I've heard conflicting reports that demagnetizing drivetrain parts to prevent metallic debris sticking is a real thing I'm supposed to care about when servicing e-bikes, but I can't find anything written about it or any instructions on how to do it. I do know that some of the more bling systems such as Bosch and the Copenhagen Wheel have magnetic torque sensors that are sensitive to external magnetic fields so I imagine care has to be taken there if this is a thing.

This is the first time I've heard of such thing. Here's my analysis of it.

I'm assuming the magnetising of the drive train is referring to the chain and rear sprocket (if it's a hub motor). These components could theoretically become magnetised through rubbing if they travel through a magnetic field in one direction (either north to south poles or vice versa). They have to contain iron for this to work.

Ebike motors are mostly brushless, which have permanent magnets inside. And also the chain and sprocket is often made of stainless steel (more below). So it sounds possible that those components could be magnetised as you would mostly pedal forwards.

However, here are some doubts to whether it needs to be demagnetised:

Magnets made from rubbing are only temporary. They lose their magnetic field over time and knocking.

The magnetic field around a brushless motor is complicated, as there are multiple permanent magnets inside arranged in a circular fashion. So any rubbing may be cancelled out by this arrangement.

Some stainless steel actually can't be magnetised. I haven't checked yet but you can by holding a fridge magnet and see if the chain and rear sprocket reacts to it.

The only debris that would stick due to magnetism is ferrous materials. Most debris in cities are not. But that  would largely depend which geographical area you're in.

In conclusion, I'm very doubtful whether this is needed at all. And as you've mentioned, there are magnetic sensitive sensors on some Ebikes. Demagnetising could potentially damage them and the motor.

Some sites I used to confirm my understanding:

https://sciencing.com/magnetize-things-6377.html
https://www.google.co.nz/amp/s/m.wikihow.com/Magnetize-Steel%3famp=1


Choosing the proper bearings for replacement Hub and wheel bearings: Xero 6902 and 6903 LBLU. I can find 6902 and 6903 bearings, usually 2RS, but I can't find that brand (Xero) and type LBLU (what does it mean?).

Can I safely replace these bearings with others the same size (6902 and 6903) but different brand and type (2RS instead of LBLU), and expect the same performance and compatibility/suitability, provided they are equivalent in quality? In other words: is any 6902/6903 bearing good enough?

I'm aware that there is a whole science about bearings, with concepts like tolerance and standards like ABEC. It seems to me that bearings for bicycles are usually ABEC 3. But I am afraid that maybe hubs and wheels manufactures choose the bearings that for some reason perfectly fit their components. Or maybe it has nothing to do and all I have to care about is choosing the right measurement.

This is one of the bearings disassembled, which will not be reused:

Bearings are of standardised dimensions. In your case 6902 is 15 x 28 x 7 (inner diameter x outer diameter x width) and 6903 is 17 x 30 x 7 (which you probably got from Google).

Thus, dimension-wise, as long as you stick to the original dimensions, you're good to go. In other words, you can safely replace these bearings with others of the same size (6902 and 6903) but different brand and type. For the types, those are used in the industry (full source obtained from https://www.astbearings.com/bearing-closures.html):

ZZS - Removable non-contact metal shield retained in the outer ring with a snap wire.
ZZ - Non-removable, non-contact metal shield retained in the outer ring via crimping, or pressing.
2RS - Molded rubber seal. This type of seal is Buna-N bonded to a steel insert.
2RU - Molded rubber seal, non-contact. This type of seal is Buna-N bonded to a steel insert.
2VS - Molded Viton seal. This type of seal is made of Viton bonded to a steel insert.
TTS - Glass reinforced PTFE seal is retained in the outer ring with a snap wire.

You would want to have 2RU or 2RS since they provide the best protection against moisture at the affordable price. The "non-contact" (2RU) means that the seals are not making contact with the inner ring ("shaft" part) - less friction but less protection against dust and moisture.

Concerning the ABEC scale you can read on https://www.astbearings.com/bearing-tolerances-precision-levels.html - there are apparently more parameters than ABEC rating only that determine the longevity of the bearings. Nevertheless, what I've heard from the rollerskates world - not always the higher ABEC class, the better. The bearings rated higher have slightly more resistance but they benefit from less play. Rollerskate riders recommend going not higher than ABEC 5 as going higher introduces too much resistance in rolling.


Why is there a stitched hole in the back pocket of my new jersey? I just finished a charity ride and found that the brand new jersey bought for it has a hole in the back center pocket.  It is neatly cut, with stitching around it to prevent fraying, so I'm sure it is a feature rather than a defect.  What is the intended purpose?

My best guess is the hole would allow a headphone cable to run down the collar, through the inside of the shirt, and into the pocket.


Can someone locate my missing derailleur hanger My brother broke derailleur hanger and he doesn't bothered to pick it up. So I'm asking you guys if you can identify the missing fragment. Bike brand is unknown same as frame.

Your bike doesn't have a separate hanger.  The hanger is integral part of your frame, and is the metal "drop" hanging down below the axle nut.
What has been lost is the bolt and spring mechanism of your rear derailleur.  I've never seen these as spare parts, so you're up for a replacement rear derailleur.

Separately, the thread inside that large hole looks somewhat chewed up, which could explain how it came out.  I'd advise cleaning up the thread with the appropriate tap or the mech will fall off again.
Its up to you and your brother to figure out who's paying for the replacement part.  To be fair, even if he did pick up all the parts it might be unrepairable.  You should always return loaned items in the condition they were lent.


How to turn off segments on edge 510 Recently I've been getting notifications on my edge 510 of an upcoming segment (& and display when riding through it) - I can turn this off by hitting the red cross on screen when it comes up, but I'd like to completely disable this function and can't work our how. Any ideas?

This works with firmware 5.0.

From the start screen, click the "folder" icon on the bottom left

Click "Strava Live Segments"

Click the Menu button on the bottom right (the three rows)

Click "Disable all"


Can I upgrade my 2007 front suspension? I just bought a 2007 Trek Fuel EX5 used but the front suspension dial is cracked and makes it difficult to change the give. The current forks that are on there are RockShock Tora's. Would it be possible to change this out knowing the tire and tread size?

Edit: Thanks for the input guys. You make a good point Matt, I paid $350 for the bike so it might not be worth it, but the front suspension is at nearly full give so I’m a bit worried I’ll constantly bottom out.

Knowing that I’m not eligible for the upgrade program, how much do you guys think it would cost to buy the parts used/new and which one of those is the best option?

Short answer: Yes easy.

My recommended process:

If you are the original owner of the bike check out SR Suntour's upgrade program.

https://www.srsuntour.us/pages/upgrade

The RAIDON XC-LO-R 26 with a straight steerer would be a really good fork for that bike at $199 down from $299 with the deal.

If that isn't appealing you'll want anything that has support for a 26" wheel, 100mm of travel, and a straight 1 1/8" steerer. I doubt you'll be able to fit anything over a 2.3-2.4" tire in there.

Note: For the fork from SR Suntour I mentioned, it has a 160mm flat mount support for brakes, so you'll probably have to upgrade your front rotor to a larger size as well.


How to roll-start with a back-pedal coaster brake? I have a bicycle with a coaster brake. It is very "handy" to brake even without hands. But somehow I can only do a stand still start. This means if have to get on bike first and then start pedaling. With other bikes step on the pedal and push my bike till got like 5km/h and then hop on. If I do that with my Dutch-bike, I always trigger the brakes and hence fail to quick start.

Is there any way to avoid this?

There's only one solution I can think of, but it's a sweet one.


Disk brake squealing after bike shop changed my pads. Is it enough reason to ask them to re-service (for free)? I recently took my bike to the shop, since it started making a weird metal on metal (not squeal, just hard brushing sound). After checking it out they saw that the back brake pads were really (REALLY) worn down, so they changed them.

Now my bike is doing a really loud screechy sound when I use the back brakes, and the bike doesn't even stop that fast, I remember my back brakes being pretty strong, completely stopping the back wheel even if I was going fast (of course, if I was going fast it would drift a little.. but the wheel was locked). Now it's making this loud sound and just kind of slowing me down slowly, but not fully breaking.

I didn't know if this was normal.. but after reading a few question here like this, it seems like it is definitely not. (Fixing noisy V brakes)

Is this a legitimate reason to take the bike back to the shop and tell them there is something wrong with their work?

Thanks!

This isn't necessarily unusual for fresh disc pads.

Give it a solid 20 miles. Then if you still have problems coming to a stop, take it to the shop and have them look at it. Even still, it's not necessarily something wrong with their work. It might be, if they were clumsy and didn't align things properly or left oil on the pads. But a little noise isn't enough to convict them.


Individual cassette gears and swap a 10 speed for a 9 speed Why can't we buy individual cassette gears? Probably 90% of my riding is on just 4 to 5 of the gears on the cassette. The rest of the gears are used much less. I have a X0 SRAM derailleur 9 speed set up. Since I need to replace the chain and cassette very soon I'd like to swap for a 10 speed set up. Other than cassette, chain and shifter will I have to replace the derailleur and the rings?

Thx

A long time ago some bike shops stocked single cogs, but that was when there were 5 speed cassettes and few choices. Back then few people seemed interested. Today with 6,7,8,9,10,11 speed options, three major manufacturers, often with multiple materials in each width as well as other variations, there would be too many options. I suspect even the really big online shops would struggle. For comparison, look at spokes - few places stock more than the most common types in the most common sizes, let alone 2mm increments from 100mm to 400mm (Rohloff 16" wheel to front 36" wheel)

Think about what's required: you want a replacement cog for the particular cassette you have, out of at least 10 options for your particular combination of manufacturer, number of cogs, material and cost. Sure, you would probably accept a cog out of the next step up or down in the manufacturers range, as long as it was compatible (hint: it probably isn't).

Look online: Wiggle have 84 cassettes listed, ChainReaction have 69 MTB and 56 road cassettes, Starbike have 80 options. Assuming they average 9 cogs per cassette and 20% are duplicates/compatible, that's over 400 different cogs to stock.

(too long for a comment).


Why would one put tennis balls in the spokes? I see this once in a great while around the city: two or more tennis balls stuck inside the spokes, right up against the hub. It usually seems to be on older-looking mountain bike commuter/beater bikes, but I think I saw it on a newer fixie a while back, too.

Does this server some function to which I am not privy?

I believe it's a stylistic choice, and doesn't actually serve any function.


broken presta valve confusion Not a big bike person so my information could be wrong. My bike tire leaks air whenever I fill it and I know its coming out of the valve hole. I did some research and found that its a presta valve so I looked up how to replace it on youtube and for all of the videos the smaller threaded part is a separate piece from the larger diameter part but mine is all one piece.
Is there any way to fix this or do I need a whole new tire/wheel?
Thanks!

The valve is broken.   You need a new inner tube.  A new tube will cost $5 to $10, and most bike shops will charge $5 or so to change it for you.  It's something you need to be able to do anyway. They'll probably show you if you ask.


measuring a spoke that's already in a wheel i have a wheel, and i want a spare spoke to take touring. (it's a front wheel with a disc rotor, i have one for the rotor side but have lost the one i had for the non rotor side)

is it possible accurately measure the spoke when it's in the wheel? i've attempted to use some strings but i'm not clear on where you'd measure to. i understand that you start at the centre of the j bend, but presumably some of the nipple/spoke is inside the rim. perhaps i should remove the tyre and rim tape, and measure the amount of spoke protruding l.

is there a reliable technique i can use for this?

edit: i'd like to avoid removing a spoke out if at all possible. the rim was built by a professional wheel builder, it's running true and i have only minimal wheel trying skills

If the hub flanges are the same diameter, a slightly inexact but highly likely to succeed rule of thumb is that the calculated lengths for a conventional three-cross 26", 27.5", or 700C disc wheel are likely to give you a difference of right around 1mm in optimal length between the right and left side, so if you know your existing left spoke is optimal than just getting 1mm longer is likely to work. (The number is right around 2mm for non-disc rears). Unfortunately there are some stumbling blocks. Usually the actual difference in calculated length is more like .9mm-1mm for fronts and 1.2mm for rears, which means that there are corner cases where if you did this in front where the left you had was at the stone limit of thread length and you added 1mm, you might run out of thread length and the spoke wouldn't work. If the spare you have is the same as what's in the wheel, you could pull off the rim strip and check how the thread engagement is looking to preempt this. That would also let you know whether to get the same length or that length +2mm if you went to buy the spoke and found they only had 2mm increments, which is pretty common. Note this rule of thumb doesn't work the same for smaller wheels or cross patterns other than 3x.

You could just calculate it using a published ERD (effective rim diameter), and if you had an accurate ERD then that would work well since you can measure the hub, but the problem there is that published ones often aren't quite right, sad but true.

A pretty exact length can be found by reverse-calculating the ERD if the left spare you have is the same as what's in the wheel. You can pull off the rim strip as above and do a careful measurement to determine its exact difference from optimal length, probably easiest done by counting visible threads and multiplying by the thread pitch. Measure the spare, add or subtract that difference from optimal thread engagement, then measure or estimate the left side tension on the wheel and use either math or something like Machinehead Wheelcalc to get the amount of spoke elongation the ones in the wheel currently have and factor that in, and the result should be the ideal "stretched" left side length. After measuring the hub, you then have all the tools you need to use a spoke calculator like Damon Rinard's spocalc.xls to reverse-calculate the ERD of the rim by plugging in different ERDs until you hone in on the one that matches your measured optimal stretched left length, and then the calculator will also be telling you what the ideal right side stretched length is, from which you'll then have to compensate for elongation. (Good spoke length calculators use the classic spoke length formula that works off the pure geometry of the wheel as though it were just a bunch of circles and lines, and leave it to you to compensate for elongation.)

If you wanted to just measure the built wheel to get an ideal spoke length, use a tape measure, piece of string, etc to get the most accurate measurement you can from the inside of the J (the actual point of contact with the hub flange) to the point where the spoke inside its nipple intersects the inside surface of the rim. It can be tricky to measure so do it a couple different ways until you're confident. From there you want to add the thickness of the rim including eyelets if present and the thickness of the head part of the nipple, and then subtract for elongation. You can get the base thickness of the rim by snaking the depth gauge part of a Vernier caliper through the valve hole. 2mm is a good general number to use for the nipple head height; that errs low but that will result in spokes that are slightly short rather than slightly long, which is what you want so that you don't run out of thread length while trying to change a spoke in the middle of nowhere. For the elongation, .5mm on the less-tensioned side and .8mm on the full-tension side are pretty safe general purpose number for either 2.0 or 1.8mm spokes, but there are more exacting approaches that can be taken.


Do headset and frame metals need to match, or will a steel/aluminum headset get stuck on an aluminum/steel frame? Will a steel headset get stuck on an aluminum frame bike?

Will an aluminum alloy headset get stuck on a steel frame bike?

I am not asking about carbon frames, by the way.

I ask because I have seen some questions about aluminum alloy seatposts getting stuck in steel frames, and I wonder if the same kind of "galvanic pair" issue would cause a steel / "chromed steel" threaded headset to get stuck into an aluminum frame.

Would doing this make the headset impossible to replace?  Does it even matter if it is impossible to replace if the bike is not extraordinarily fancy?

I'm not worried about the  short term, but am wondering about best practices when assembling old bikes from scrap parts.

Seatposts have a relatively long length inside the tube, and no way to get a tool to the bottom of the post to hammer it. If you have a proper headset remover tool, I doubt a headset would ever get so stuck. (Even without the proper tool, it's unlikely to be a problem.)

Also, I don't believe there's such a thing as a headset with an alloy bearing race. So if it has alloy cups, they probably have replaceable bearings that fit inside it, so the cups shouldn't ever need replacing.


Chain/rear derailleur off I haven't been on a bike in years, and just picked up a used one to get into riding (2013 Specialized Hardrock).

The rear gears aren't shifting properly, it seems to only move between the 2 smallest, and I noticed that when the shifter shows it in 1st gear, the chain is actually on the smallest cog.  Am I right that something is wrong here?  And what's the easiest fix for this?

Almost certainly the gear shift cable has slipped through the pinch bolt that holds it onto the derailleur, so there is too much slack in the cable, and the shifter cannot pull the derailleur onto the larger (lower gear) sprockets. This is pretty easy to fix:

Note which side of the pinch bolt on the derailleur the cable goes. Undo the cable pinch bolt and remove from the derailleur.
Make sure the cable and housing are seated correctly in the shifter and frame stops.
Check cable and shifter by shifting gears while keeping tension on the cable - the shifter should pull and release the cable as you shift.
Shift to highest gear number, pull cable taught, screw the barrel adjuster on the derailleur all the way in, then back out a turn, do the same for the adjuster on the gear shifter. Attach cable back to the derailleur. Now the shifter should be able to pull the derailleur onto the largest sprockets.

Now you can adjust the limits and indexing so the derailleur places the chain onto each sprocket properly. It's hard to describe how to do that briefly in an answer here so check see this Park Tool page which explains how it works and walks you through the process.