Where did I go wrong with this frame painting procedure? I just painted a bike frame (steel) with the steps outline below. However, every glancing contact with a rough surface immediately strips paint from the frame and I can see the metal shining through. This is the second time I've made this experience. I had expected that DIY paint may not look as great as a factory finish, but I had at least hoped to have it be durable enough that I don't need to worry about scratches every time I lean the bike against something.

Removed one layer of old paint with paint stripper
Removed second layer of paint (not affected by stripper) with sandpaper. Down to bare metal in many places, but not everywhere.
Wet-sanding with 1000 grit for the entire frame to make it easier for the primer to hold firm
Clean with water, dry with towel and air, then use brake cleaner (supposed to leave no residue) and alcohol (the kind you can use for cleaning or making fires or whatnot; 'Spiritus' in German). I was hoping this would remove all grease from fingers and such
Apply 1-2 coats of primer
Let it dry for 24h
Wet-sand frame again with 1000 grit
Wash, dry, clean again, same as above
Apply base coat in 2-3 coats, letting it dry for at least 30 minutes between coats (paint is supposed to be non-sticky after 5-10 mins, dry after 20-30 mins, fully cured after 24h)
Apply several clear coats (same intervals as 9.)

The primer, paint, and clear coat are linked here (in german).

Now I realise this is about the cheapest spray paint you can get, but I had hoped that I did the procedure correctly. The frame has been resting for about 12 hours when I scratched it, but I don't think it'll get much harder, judging from my other frame I painted.

Hypotheses:

The alcohol I used for cleaning wasn't good
I should let each coat of paint dry 24h before painting over it (doubtful)
Paint is shitty

Where else could I have gone wrong?
Here are some pictures of the finish. There are some spots where I wasn't careful enough and it looks like some white powder stains the section, but over all I'm pretty satisfied.

Here is one of the two spots where I touched the frame against a stone wall. It's not well visible here, but it looks very silvery as opposed to gray (the primer color), so I think it's down to the metal.

One shot from the bottom. The gouges are an artifact of insufficient sanding, not of the paint job I think.

Painting is tough and the artist in me (tongue-in-cheek) is never satisfied with finished product. Your prep seemed meticulous enough and you express satisfaction with the finish where it hasn't been marred. Given the work put into the prep, why go with bargain paint and risk the poor quality of it?  Give you props for using the same "brand and series" of paint.  That tip is frequently included in DIY paint tutorials.
The two most popular brands of spray paint here in Midwest, USA are Krylon and Rust-Oleum. I bring this up to share a couple of things common to the directions for use printed on these cans. Despite the myriad of differing formulations and applications within a brand here are some common advisories they share: Priming is especially recommended on bare metal or wood.  Apply multiple, thin coats, waiting a few minutes between.  Apply additional coats within one hour, OR AFTER 24. Some types will state "recoat (or apply clear coat) within one hour OR AFTER 48."  This is under ideal drying conditions of 50% humidity and 70°F.  Finally, it's commonly noted that on plastic, "maximum paint adhesion and durability is achieved in 5-7 DAYS."  I realize your bike is not  likely to be plastic but I think that tip can lead us to believe that the paint will continue to cure and become most durable quite some time after the "ok to handle in such and such hours."  If your paint job is being marred right down to bare metal as you say, the paint is not nearly cured enough. Certainly 12 hours isn't enough time to expect it to hold up.


Do I need to bed in my disc brakes again after I clean rotors with alcohol? After giving my bike a good wash and deep cleaning of drivetrain components, I like to clean my disc rotors as well. I typically use a small spray bottle full of 90% isopropyl alcohol and a clean cotton rag.

After cleaning rotors with alcohol, should I need to bed in my brake pads again? Should I do anything special before riding again?

MY personal opinion, based solely off experience and guesstimations is that they do to a degree but not to the extent that a new rotor and pad combination would.

My reasoning is that one of the main components in brake pad bedding in is heat. The heat build up helps to evenly distribute pad material to the rotor surface. One of the reasons many people say you should not come to an abrupt halt while bedding in new pads/rotors is it can make an uneven distribution of material where the pads come to a stop.

The tiny particles that are transferred, spread and disperse more evenly when heated and become harder to remove once cooled which accounts for the poor performance when the disc pad comes in contact with a non level surface resulting in micro vibrations and horrible noises.

While a full bed in procedure is not necessary, the surface of the rotor has taken on a slight change and will require a few passes of the pad to essentially resurface the rotor on a microscopic level. While the rotor feels clean to the touch and looks shiny and new, microscopic sediment is still left behind where the alcohol has carried it and then evaporated. Therefor a decrease in braking power occurs until that sediment has found its new home in the microscopic nooks and crannies of the rotor and or pads.

This however does not require the same about of heat as bedding in an all new rotor does though as the majority of the surface has already been heated, cooled and smoothed down by the general use of the brake, but there has been a microscopic change to the surface.

So while i don't think it is necessary to go through the entire bedding in process, i would just air on the side of caution and use your best judgement for the first couple of miles/stops ridden/performed after cleaning.


Safe cycling lights red but the man is green At a standard road crossing, the lights have turned red, but the man has gone green for pedestrians to cross. What do you do?

Honestly in the situation I coast through as long as there is room. (i.e not a sea of people crossing)
Now my question is, is this bad cycling? I believe not, but I am interested in the views of other cyclists.

Question inspired by this thread on lfgss  and this video... kinda

If you are in the UK this is an offence. You are traffic, therefore must obey the red.

Consequences could be a pull by the police and a fine!

I am not sure about other jurisdictions.


Shimano Tourney (SL-RS36) 3 speed indexing wrong 2, 3 transfer correctly

1 - not correctly.

transfer switches normally. But the index does not become 1 in the box.I do not even remember how it happened. The effort did not make.
How can I fix it?

add

I'm guessing your cable is immensely too long, and its only by chance that numbers 2 and 3 line up with a gear.

Try putting it on the smallest front chainring, then back off the cable pinch bolt.

Set the handgrip shifter to 1 and pull all the cable slack through, and do up the pinch bolt.

Some tweaking may be required.


What regulations apply to bicycles in New York City, USA I have heard of many incidents where cyclists got ticketed for something small, but I can't find the actual rules for cyclists online anywhere. Where are they?

Ah ha, some how I got it lol. It was a round trip, but hope help those ppl aware of this

http://www.nyc.gov/html/dot/downloads/pdf/bicyclerules_english.pdf


Can I fit a 26x1.25 tyre to wheel with current tire 26x2.1 I've just bought a tacx turbo trainer and want to get a tacx training tyre for my mountain bike.

Can I fit a tacx 26x1.25" training tyre to my wheel with current tire 26x2.1" ?

Thanks

Matt

I regularly run 50mm and wider tyres on narrow rims which is the opposite of what you want to do, but suggests that your actual rim width might be narrower than you think it is. Viz, you might find that you have 25mm or narrower rims, in which case a 32mm tyre is perfectly reasonable.

I have run tyres narrower than the rim in the past but I don't really recommend that on leaning bikes. In this case, the question is for a trainer where leaning isn't an issue. The problem is that when you have (for example) a 45mm rim with a 25mm tyre extreme leaning can make the rim hit the road, at which point you will lose traction and crash. But this is an extreme problem, you're very unlikely to experience it in normal riding.

The increased pressure shouldn't be an issue unless you have exceptionally lightweight rims, but I'm guessing from the question that this isn't the case. If you do have a high-end carbon fibre mountain bike with ultralight, extra-wide carbon rims they should have the maximum rated tyre pressure printed on them or listed in their specifications. You should respect that. But that's not normally done for aluminium rims because the rim isn't the limiting factor for tyre pressure.

I've blown the sidewall off a rim, and running a narrow rim with wide, high pressure tyres was likely part of the cause for that. The manufacturer replaced the rim without questions, however, suggesting that they agreed that it was a weld fault at the join (where the blowout started). But you're not doing that, you're running a narrow high pressure tyre on a rim that is most likely capable of working with a wide, high pressure tyre. I would not worry about this, especially on a trainer where you're more likely to suffer hearing damage from a blowout than major crash injuries.


110mm crank on 73mm BB shell I have a roadbike with a 73mm BB shell and I recently bought a Tiagra compact crankset that has a 110mm bolt circle length. However, I can't get enough of it to come out the other side to properly attach the left arm of the crank.

This is really upsetting because, as far as I can tell, Shimano only makes 110mm length cranks for compact (double) chainrings. The only solution I see is getting a new triple crankset for about €100 and this would mean I have to change my STI shifters and possibly the front derailleur as well... Are there any other options?

EDIT:
You are right i was confusing BCD with spindle length, the problem is that the 110mm spindle wont come out enough to attach the left arm, triple cranksets do have slightly longer spindles tough.

You need a mountain bike specific crankset.  Tiagra is a road group.  Road bikes typically have a 68 mm wide bottom bracket shell, and mountain bikes have 73 mm.  The wider BB shell is used to give a proper chainline with the (usually) wider rear axle spacing (OLD) and will result in a wider q-factor (distance between pedals.)  This frame is an unusual build with the 73mm BB and the 130mm OLD, perhaps to take advantage of the smaller chainring sizes available in MTB cranksets.


1970's Gitane Gypsy: Brakes and types I can Use Shimano: ULTEGRA R8000 I want an updated brake system for Gitane Gypsy (1970's frame). Some braking types have descriptions that indicate "short reach caliper', which, is eponymous with its name I’m sure, however, I want to know if that will affect my tire size I need, (which should be 27'') or other mechanism with respect to braking system or my tires or my mounting position on the bike iteself... I am mounting it on a 1970's Gitane Gypsy..

brake types interested in:  Shimano: ULTEGRA R8000

Long reach brakes are often used on bikes designed to fit larger tires, or if a bike that was built to fit 27" wheels (iso 630 mm) is adapted to 700c (iso 622mm). Based on a quick Google image search, it looks like you might be in the former category, in which case the short reach r8000's probably won't work... But you should measure it yourself.

To tell which brakes will fit your frame/wheels, you need to measure the distance (in the up-down axis) between the center of the bolt that holds the brake to the frame, and the center of the braking surface. If you have brake calipers that work, and you're not changing wheel size, you can just measure your caliper from that bolt to the center of the brake pad. It's kind of a rough measurement because you have to hold the ruler straight up and down and just eyeball it.

As long as that number (the "reach") is within the range of the caliper you want to upgrade to (Shimano ultegra r8000 is 39mm - 49mm) it should work.

Also see this answer: https://bicycles.stackexchange.com/a/29362/37296


Parking a 3-speed internal hub in 2nd gear permanently I recently bought a gently used, not super well maintained Columbia 3-speed  bike from some time in the 80s. It has an internal hub - the dreaded Shimano 333. My eventual plan is probably to convert it to single-speed, but I'm not quite ready to buy new wheels yet. (Yes, there are probably other ways to do it, but that's out of scope here anyway.) In the meantime, I'd like to put the internal hub in 2nd gear ("neutral") and leave it there permanently.

It should have been an easy operation - just shift into 2nd and then stop shifting! But I was out riding last weekend and I suddenly found I was trapped in 3rd gear. Couldn't shift down for love nor money. When I got home, I found this:

I've never dealt with an internal hub before so please bear with me for not knowing the vocabulary. I gather that the back of bit A is supposed to be a kind of bracket that holds the pin in bit B in place, creating a hinge that lets the cable tension do its work. It's a bit tough to see in the photo, but the back of bit A crumbled off in my hand when I went to put it back together. So I can put the shifting mechanism back together, but it doesn't stay together under tension.

No problem: I wanted to remove the shifter and cable eventually anyway. All would be well if I were trapped in 2nd gear. But I'm trapped in 3rd. I'm not completely sure what the ratio is but it's much too high a gear for single-speed use. So, thanks to this guide I've started to work out how this hub works. I've gotten as far as removing the bell crank and have found the push rod, which slides easily in and out, with the expected resistance at the "in" position. What I haven't yet figured out yet, though, is:

How do I determine what position the push rod needs to be in for second gear?
How do I hold the push rod in the correct place to keep the hub in second gear indefinitely?
Bonus question: assuming this is possible and I manage to get it done, how will this arrangement change the maintenance requirements of the hub?

In the 45 minutes since I posted this question, I have developed an elegant workaround using a simple device:

I stuck a pebble in the bellcrank.

Most folks here probably won't be surprised by this solution, but I'll elaborate on how I came to it for the sake of future searchers who might be internal hub noobs like me.

In fiddling with the push rod, I determined that since I have three gears, it probably has three positions: all the way in, all the way out, and... somewhere in between. I took a wild guess that second gear would be the "somewhere in between" gear. I figured that "all the way out" was third gear, since that's the natural position the rod is in when there's nothing in place to push it anywhere else, and 3rd is the gear I was stuck in.

I fiddled with the bellcrank some more - putting it back together, seeing what pieces would push on what if it were working properly - and determined that when the bike is in third gear, the head of the push rod butts right up against the inside of the part of the bellcrank that screws onto the threaded axle rod thingy. (Terminology is hard.) So: I need a way to push the rod into the halfway position while the bellcrank is screwed on in order to jam the system into second gear.

Enter the pebble. I found one in my yard that seemed to be the right size, dropped it into the bellcrank and put it back on the bike. Voila: the push rod is stuck in the "somewhere in the middle" position. I am effectively parked permanently in second gear. (Well, I can also shift into third gear if needed: I just have to stop, dismount, and unscrew the bellcrank a little. If I had a second pebble of equal size I could probably get myself into first gear, too!)

So, this is my workable, cheap (free!) solution. I will leave this question open for a while though because I am hoping someone has something a little less bush-league to suggest!


Seat Stay Replacement - Bridgestone MB-3 I am working to restore my first mountain bike frame, a "vintage" 1993 Bridgestone MB-3. Early on, I swedged the left seat stay so that it buckled a bit & rotated about 15 degrees inward. I have sent it to a welder and am trying to source a replacement seat stay. Any suggestions?

Generic photo of the bike type added by Mσᶎ:

First "a welder" is possibly not the best choice if you have any alternative. If you can find a framebuilder, or a TIG specialist who deals with thin material that will be much better. If nothing else, you need to know that those frames are brazed together (you can see from the lugs in the picture), not welded, and if the welder tries to weld over the brazing the brass will boil off spraying metal everywhere.

The simple, brutal approach is just to cut the seatstay out of another bike and use that.

It's also tricky to weld thin bicycle tubing, so unless your welder has experience of thinner than 1mm tubes they're likely to make big, ugly welds and also damage the bike while discovering that. Blowing through the seat tube is likely to make the frame unusable, because even after you file the inside of the tube clean it's likely that the seatpost will either not go in, or won't clamp tightly.

That said, it can be done, but you really want a TIG/GTAW welder rather than MIG, and doing it with a stick welder is very, very difficult. I TIG weld my frames, and while I know people who MIG weld frames they do it full time and it usually takes an experienced welder a month or so (full time) to become competent at welding thin bicycle tubing.

The replacement seat stay is pretty easy to get. You can either buy a specific seat stay part from any frame parts supplier, or just use 4130 CroMo steel straight tubing that matches the thick part of the seatstay (probably 12mm x 0.9). If you told us what country you're in it might be possible to suggest suppliers.

You will want to recover and reuse the brake boss, and ideally also the rack mount at the top so remember when moving the bent tube that you're grinding the tube off the boss, not the other way round.


Sociable quadracycle build. Disc brake rotor size? I'm building a quadricycle. This sociable is planned to be around 120 lbs / 54.5 kg. The only "Guide" to proper rotor size versus weight is one I found from Magura. Average pilot/rider weight I figure to be around 200 lbs / 90.7 kg. This would add up to 520 lbs / 236 kg. Cut in half to use the guide sheet, (two wheels versus four), and I get total weight of 260 lbs / 118 kg.
Street or off-road use says 160mm rotors all around.
The other consideration I have to take in is, recumbents have most of the weight riding in the back, 60/40. During braking there is a weight shift I know, but does it go over 50/50 during hard braking?
160mm rotors just don't sound right/enough. And I am using duplex dual cable levers, one front, one rear.

You have two considerations, energy dissipation(will they overheat) and braking force(will you stop in a short distance or even stop at all on a steep down hill). I doubt overheating will be an issue, but having 4 brakes will divide the force you apply to the levers. Using hydraulic calipers will overcome the force division issue but may encounter a fluid volume(lever stroke) issue.

The calculations needed are newtons of force times meters divided by seconds equals watts.
Maximum braking force is limited by the tire-road coefficient of friction which is less than 1.0 in common practice, 0.85 is normal, above one is only common in specially selected warm race car tires. So, mass times 9.8(converts Kg mass to newtons under earth gravitational acceleration) times 0.85 gives maximum braking force in newtons. Newtons divided by mass in Kg gives acceleration in meters per second per second. Braking is acceleration, just in the other direction.
So if you have 520kg the maximum braking force is 4332N, acceleration of 8.33m/s^2. From 15m/s to zero = 1.8 seconds (on level ground)
Kinetic energy in joules is 0.5 times Kg times velocity squared. In this case 58500j. Divided by 1.8 seconds is 32.5Kw divided by 4 brakes is 8.1Kw per rotor. Heat capacity of steel ranges from 460-510 j per k, 58500/480=122k temp rise in one kg of steel. 160mm rotors seem to range 50-140g, 100g is common so 400g total, 58500/(480*0.4)=305k increase, this is acceptable, it also doesn't take into account the heat loss to radiation and the air during the 1.8 seconds.

I don't have the formula for continuous heat dissipation of the rotor at hand, this or testing would be needed for long downhill sections or rapid repeated stops. The watts of heat on a long downhill is zero at terminal velocity and zero at a stand still, peak brake wattage occures at 60% of terminal velocity. The range of 42%-72% T.V. is greater than 0.9 peak power, 0.5 peak power occures at 20% and 88% of terminal velocity. And of course the final impulse to stop at the bottom of the long hill is far less at 20% than at 88% t.v. so even though the rotors should be equally hot just before attempting to stop from either speed they certainly won't be equal after the stop.

Joules of potential energy from a hill is equal to vertical height in meters times gravitational force in newtons. (kg*9.8 here on earth) Joules per second equals watts.

Sorry I'm out of time so I can't give hill slope to braking force equation. Its simple vectors, should be easy to look up.


When upgrading from a Claris to an Ultegra crank, the latter has a gap between BB and crankarm I have a Giant contend 2 2017, its been a great work horse but now it needs changing, I got an Ultegra groupset for cheaper than a 2nd hand Ultegra spec bike. I've started with swapping the crank over, but noticed a gap between the BB and crank arm on non drive side that wasn't there on the claris crank. I'm assuming I need spacers but none came with Ultegra crank.
What measurements do I need to take to know:

crank is in right position to too far one side or other.
what size spacers if needed and fitted which side,

Tried looking for build manual but so many different variants can't find what I need.
Thanks
Matt

Some Hollowtech II cranks have a spacer that's supposed to go under the left crank. You need to find the exploded view diagram for your crank model to confirm this. Here's the one for FC-6703 for example, the triple crank for the second generation of Ultegra ten.

If you don't have it, it will probably be okay because these spacers don't interact with the seals in any particularly important way, although they do act as a sort of shield for the seal area to a limited extent. You do need something in its place though, or else you won't be able to preload the bearings. If this is the kind of seal you're missing, the simple thing to do would be get a bunch of scuff washers or whatever other tuneable stack of 24mm spindle spacers you can get your hands on. The nature of Hollowtech II is that as long as the spline engagement is complete give or take some very small amount, the exact dimension of the distance between the cranks doesn't really matter, so you're free in this case to just find something that takes up the gap.


What is the model of my bike? Hi, i can't figure out what the model of my bike is. I know that it's an Orbea AVANT bike, but i can't figure out which series it is.

Any help would be a appreciated thanks!

The frame is made of Aluminium. The fork is carbon fibre. Everything on it is original, nothing has been changed.

I got the bike from participating in a bike tour, they didn't give me any info on what model the bike was. I've asked the people that arranged the bike tour what model the bike was, but they don't seem to have any information about the bike.

This might help a bit, the shifters, front and rear Derailleur has the text shimano 105 on them.

If your bike was a 2019 (which I’m assuming it isn’t) it would be an H30, as that’s the current model that has an aluminum frame and 105 groupset.  It’s probably either an H30 or the equivalent from 2018 or earlier.

when trying to identify a recent bike, If the manufacturers’ web site has an archive section, you can go through it looking for a match WRT frame material, colors, major components etc. I’m writing this answer in a mobile device so I can’t see if Orbea’s main site has a link to an archive section.

If you have good guesses for model and year googling for images or past reviews will often yield a hit.


Are 32mm tires ideal for a fast commuter bike? I am considering a faster bike to replace my XC for commuting. I am thinking hybrid/cross/road bike with wider tires. My question is whether 28mm tires are enough or if I should go with 32mm like Trek touts for their CrossRip. I won't be riding gravel roads or other heavier terrain too much, but I will need to jump to/from curbs from time to time.

Where I live I often need to ride over cobblestones and tram tracks, like this, so safety is very important:

I commute on two bicycles:
— a road bike, with 25mm tire up front and a 28mm back.
— a custom commuter bike, with 32mm up front, 35mm back.

I'd recommend you go with the 32mm tires.

The 28mm tires I've used are good for commuting (I think the 25mm I have is too small — I have to give it too much attention when crossing curb lines and such).

That said, 32mm tires offer a lot more protection in urban environments. I ride suburban roads (25mm is fine for those) into an urban environment, and then I go into a college campus.

It is on campus where the 25mm tires get dicey. There are many different surfaces on campus, and each change creates an edge — It is those edges that will get you, either trip you up or cause a pinch flat.

A 28mm tire does OK, but a 32mm tire handles these conditions much better.

Some 32mm tires are heavy, some are lighter weight. For what you hope to do — go fast — search around for lighter weight tires (Panaracer might be a good place to start).

Enjoy the fatties!


Are 52/34 chainrings compatible with an 11/32 11speed cassette Im thinking of buying a Scott Addict 20 supplied with  Ultegra 52/36 rings and 11 speed 11/30 cassette. Could I change this to 52/34 rings and 11/32 cassette?If not would 52/34 and 11/30 be a compatible combination?

The combination of rings and sprockets you can use depends on the specs of the derailleurs, specifically the total capacity of both the front and rear derailleurs and the max sprocket size of the rear derailleur.

Front total capacity is just the max difference in size of the small and large chainrings, measured in teeth.

Rear total capacity is the max (difference in size small and large chainrings) +  (difference in tsize small and large cassette sprockets), measured in teeth, and represents how much chain slack the derailleur can take up. You really do not want to exceed this as large-large rings sprocket combinations can damage the derailleur.

The Addict 20 comes with 105 R7000 series with a medium cage 'GS' rear derailleur. The front derailleur has 16t capacity which means you nominally can only have 52/36 or 50/34 chainring combinations.

The rear derailleur has a max sprocket size of 34t and total capacity of 39t so you could swap the 11-30 cassette for an 11-32 or 11-34.

Some people report that 52/34 is workable, and with a 11-30 or 11-32 cassette you would not exceed the TC of the rear derailleur.


(V-)Brake pad lifespan Just for the record, my rims are brand new (~800 km) and clean.
I have a set of KoolStop salmon brake pads (actually 2 sets, .... well, front and rear).

I installed them ~600 km ago and I already had to tighten them (adjust the cable tension) twice in the rear, once in the front.
And looking at the pads, the rear are obviously thinner than they were when new and same in the front (although less noticable).

The efficiency is still very good but is that kind of wear normal? what is the usual lifespan of pads like those?

I heard only good about KoolStop stuff,... so don't think it could come from the very pads.
The installation was done properly too, the pads do not touch the rims at all when brakes are released (~2mm away).

It all very much depend on your conditions. If you have a lot of dirt and grime on the road, expect pads to wear out quicker.

I'd say adjust pads position after 600km is normal, nothing to worry about.


Lifespan of a bike child seat I know that e.g. bike helmets and child car seat expires, but can't find anything about bike child seats.

There is a manufacture date on mine (Dec. 2014) and it's made of polypropylene (there is this logo on it: , courtesy of wikipedia).

Considering that I took good care of this child seat and that it has never been exposed to a shock, should I still consider changing it, as it has 5 years now?

Barring damage from sunlight or collision, or fabrics rotting from dampness, or abraiding, a child's seat should be usable for decades.

I'd strongly recommend including the child's seat in your periodic M check.  Wiggle it, lift and push on it, look for changes or cracks.  Tug on the belts and make sure nothing's loose.

Store it according to instructions, wash the cloth parts as required and dry them before storage, and you should be okay for an entire generation, and probably the next as well.

Aside - one neat historical record can be to write the child's name and birthdate on the seat in a place where it won't rub off.   I've seen one kids seat with a dozen names on it going back to the late 80s.


Which position adjustments maximize the use of the glutes in a road bike? I usually don't feel the glutes firing when I'm seated unless I'm in a really long and hard climb or if I stand up and move back.

Is there any common adjustment to maximize the glutes utilization? Or a common mistake?

Cyclists often become quad dominant in their movement patterns, where the quads are preferred over other muscle groups, such as glutes, for a task where both can be involved. This can start to weaken and de-conditioning of glute muscles, causing the body to further prefer quad dominate movement patterns (i.e., reinforcement).  A quick test can be to do a squat and then stand, if you find yourself driving from the balls of your feet rather than evenly through your heels and balls of your feet, you are likely favoring your quads over your glutes (or you could have a short torso and long femurs - no test is perfect).

If you have become quad dominant simply changing your position may not be enough to get your glutes firing effectively as you may have: A) de-conditioned the muscle; B) trained your neural pathways to de-emphasize glute recruitment in favour of quad  recruitment; and C) if this pattern has gone long enough lost flexibility which could further inhibit movement patterns emphasizing glutes. As such may also find the glutes only fire when working very hard because the nerve impulse is finally strong enough to get the muscle to contact effectively.

Assuming you can fire your glutes well, a saddle position where you can roll your hips forward slightly allows the glutes to be recruited easier through the bottom of the pedal stroke. Saddles with a swoop profile (i.e., high tail) facilities this position. I also personally find if I focus on supporting my upper body weight from the front of the hip this seems to further encourage the glutes to engage (rather than rolling your mid to lower back which rolls the top of hips backwards). To set up these types of saddles, set a level on the middle third of the saddle and adjust until horizontal, this should be a good starting place, overall the saddle will appear somewhat angled down, but this is a visual trick caused by the swooping profile. Some may find this type of position difficult if they lack mobility in their thoracic region of the back or core strength (e.g., constant slouching posture can lead to a reduce thoracic range of motion making this type of position difficult).

If you are still having trouble, you may also need to strengthen your glutes and train your ability to fire them. Squats, bridges, lunges are some basic exercises that can help, but they require good movement patterns to fire the correct muscles, for example you can compensate in a bridge by recruiting your hamstrings instead of your glutes. As such, it can help to get a trainer to make sure you are doing the exercises properly, otherwise you may simply reinforce compensatory movement patterns in order to get the “task” done.

Finally, improving glute strength will also help reduce repetitive stress injuries as they also are important component of hip stabilization (e.g., gluteus medius are often weak in cyclists - the link has a good exercise for this). In terms of power, I found getting my glutes to fire properly again after years of poor posture was worth about a 20-30 watt advantage on my FTP.

Reference

This passage from "Bike Fit" by Phil Burt (lead physiotherapist for British Cycling and a consultant physio for Team Sky) describes pelvis position and the impact of thoracic mobility.

  POSTURE

  Posture is the maintenance of a certain body position and requires appropriate joint mobility, joint/muscle coordination and muscular endurance.  Limits in any of these elements can result in postural irregularities.  Good posture on the bike required good flexibility through the hamstrings and the glutei muscles:  this allows the pelvis to roll forward, keeping the back in a straight position while reaching the handlebars.

  One major factor limiting the back's ability to remain relatively straight while on a bicycle is thoracic immobility: lack of movement in the middle of the spine normally results in the spine flexing too much.  Excessive spinal flexion while on a bicycle will limit breathing and compromise your ability to stability your spine for torque production to the pedals

  [emphasis added]


Rear tire dragging on rim brake arm Just bought a used bike- it's great, but needed new brake pads. Got new brake pads and now the tire is rubbing on the brake arm. I do not understand! The front brake is with new brake pads is the same make/model and is amazing in every way. Is there a solution to thin? Is there something about brakes I don't know??? The tire is 700c x 25mm

2005 Trek 1500 WSD

It looks like your new brake pads have pushed the right brake arm out moving the top of the arm down, touching the tire. You need the top of the brake arm to move up and give you some clearance.

Options

Get thinner brake pads
Cut the new brake pad down some so that it will be thinner
If there are any washers between the back of the brake pad and the brake arm remove them (I can't tell from the picture)

Hopefully all you need to do is remove some washers.


How are tire sizes measured? I tried getting a good measurement with my caliper, but the flexibility of the tire doesn't help much. Let's say I have a 26"x2.125" tire. I know this fits on an ISO 559mm bead seat diameter rim, and 26" = 660.4mm.
26":

The OD of the tire including the tread?
The OD of the tire excluding the tread?
When aired up or deflated?
Means it fits a 559mm ISO BSD
None of the above?

2.125":

Width of tread?
Width of sidewall?
Inflated or deflated?

Essentially, I'm converting the tire sizes to "height off rim in mm" and drawing them with a wheel in a web application, so I need to know how "tire size" translates to this measurement. I'm somewhat assuming that the fractional sizes can be converted to the same measurement, but I'm aware that they have certain differences - so any help there would be of value as well.
Sheldon Brown's Website has been helpful, but still leaves me with the questions above.

First Number = Nominal Outer Diameter of tire, including tread.

Second Number / Letter = Nominal width of tire at the start of the tread.

Tire size is determined by the outside diameter of the tire, as regards the 26 inch or 700c number. The 2.125 inch number is the nominal width of the tire at the point where the tread starts.

These are nominal measurements, though, and there is no universal standard applied consistently other than bead diameter.

700c x 23 tires from Schwalbe will measure 28mm in width, and about 5 mm extra in diameter. From Conti, its about 24mm and 1-2mm extra. There is no stadard for point of measurement. It is left to the manufacturer to decide, even before the marketing department gets involved.


Why aren’t there more tricycles with rear disk brakes (between the two rear wheels) Just curious if anyone has seen these before, it would be a rare bird.  I'm looking for a trike where the mount for the rear disk brake is mid-axle between the two rear wheels.  What are the technical or marketing reasons these aren’t these more common?

My friend's trike has some terrible hub/band-brake on the rear axle.  I put on on a front 180mm disk brake, that helped immensely, but I'm very curious about a rear disk brake too.  A fully loaded trike plus the unloaded weight of a trike can be quite significant.  [NB:  looking for a non e-bike trike]

Check out the Atomic Zombie plans for "deltawolf"    These are do-it-yourself plans, they don't sell completed bikes.

Here's someone's bike from the rear

There's nothing to stop you putting the caliper mount further out for a 180 or 203mm rotor.  You could also set up the same on the left-hand axle.

Note this design is a single driven wheel rather than a solid axle or a differential.

Someone's build: http://atomic-zombie-extreme-machines.blogspot.com/2010/08/building-deltawolf-recumbent-speed.html


Alternative for campagnolo rim brake release I bought a used road bike for a great price, it came with a shimano 105 groupset, but the brake it's a Campagnolo centaur.

It's a wonderful brake, but every time when I need to remove the wheel it's need to tighten the barrel adjuster to open the brake.
I am aware that the campagnolo rim breake release system it's a button in levers, but I would like to know if it is possible to place a release lever directly on the brake, just like the system on the shimano brakes.

Closest thing out there is the Shimano SM-CB90 in-line brake QR, which exists to be paired with direct mount road calipers but would solve this problem too.


Performance difference between 700x28 vs 700x25 tires? My bike originally came with 700x26c tires so I assume I can easily go to either 25 or 28

Actually the Shimano WH-R540 is 19mm which supposedly doesn't go below 28 but there is 25 on there now anyway and it seems to fit properly.

I assume 28 will be slightly more comfortable, especially at "only" 100psi vs the 125psi on the 25 (though that's max, so it could also be run at 100psi)

Is there any way to calculate the performance difference for the same brand of tires?

ie. Are we talking 0.5 mph loss or 1mph loss?

It looks like 28's also need their own width tube because the 25 tubes are not recommended to stretch that far, so I assume there is slightly extra weight there.

Rolling resistance is complex and not easily calculated. Fortunately, the people at bicyclerollingresistance.com did actual measurements for different width versions of same tire. The short summary is that

Wider tire has lower rolling resistance at same pressure
The maximum and useful pressures are lower on wider tires
When each width is inflated to correct pressure (which is far above 60 psi for 23mm tires), there is very little difference in rolling resistance between different widths.
EDIT: At their test setup, 18 mph and 94 lbs load, the power lost to rolling resistance per tire is 12.9W for 25mm@100psi and 12.7W for 28mm@80psi (pressures picked based on what I use). The total difference, 0.4W for both tires together, makes approximately 0.02Mph difference in speed if everything else (including air resistance, which isn't exactly true) is kept the same.


Are all the Ultegra brake pads the same? I have a road bike with Shimano Ultegra Di2 6870 goupset. Today it was my first long ride with it and alsmost instantly I noticed that the brake pads are not for carbon rims. I tried searching on the internet brake pads for ultegra 6870 but with no luck. Are other ultegra brake pads compatible with my brakes?

If you have carbon rims (with a carbon braking surface) you will need appropriate brake pads, so as not to damage the rims.  You do not have to use shimano brake shoes- most (possibly all?) rim brakes will take any brand of shoes.

There is a carbon rim insert for Dura Ace, which might fit the ultegra shoes.  However if there are no compatible pads for your brake shoes/ rims, you may have to buy a new set of shoes - not especially pricy, and they will come with pads.


Alternate mount for Kryptonite U-Lock? My wife's bike doesn't have room on the upright to mount the Krytonite U-Lock she was given as a gift. The plastic mounting bracket sticks out way too far. She has a small framed Specialized Vita.

Is there some alternate bracket that can be purchased that would allow it to be mounted via the existing holes in the frame where the water bottle bracket would go?

Is there some alternate bracket that can be purchased that would allow it to be mounted via the existing holes in the frame where the water bottle bracket would go?

First, Kryptonite makes more than one U-Lock (at least 6 models) and more than one mounting. So, my first impulse would be to check the Kryptonite site or inquire at a local bike shop that carries the Kryptonite product line.

Second, Does the lock really need to mount on the frame? If the bike has a rear rack, the lock could get bungeed there. Or perhaps in a pannier? Or backpack/messenger bag? Jersey pocket? And, just sayin, the hipsters around here keep U-locks in their back pockets and that's for fun. ;~)

Not to be rude, but U-locks can be mounted or carried in a few places. Personally, I don't carry the U-lock on the water bottle mounts...mainly since I actually do want water bottles to be on the frame mounts. But hey, it's up to you.


What are the possible upgrades for a 40-year-old Bottecchia 10 Speed? I have a 40 year old Bottecchia (entry level model) that I took for ride yesterday after letting it sit for 20 years. Just inflated the tires and oiled the chain and off I went.

The tires and brake pads obviously need to be replaced and I was thinking of getting some cross tires for some dirt road and short trip riding, but yesterday's ride reminded me how bad the old derailleurs were and the huge gap between gears.

Some components had been upgraded (wheels, cotterless crank) but I'm wondering what gear clusters I can use without changing wheels.

I'm also open to other ideas ... other than making it a fixie.

Bottechia frames from that period use an italian threaded bottom bracket. I assume also down tube friction shifters?

The simple answer is that you can upgrade the bike all the way to current standards, if you are willing to spend the money. But it is not what most would consider to be cost effective to do so.

Upgrading the rear freewheel beyond a 7 speed cluster isn't likely to work, without new wheels, and if you only upgrade to a 7-speed freewheel, you will need to change your chain to match. Changing your chain requires changing your derailleurs, both of them, preferably, although you might get away with leaving the front derailleur.

If you spend the money to go that far, a whole new bike kit, which should be possible to make work on the frame, isn't that different in price, depending on your choices. A SRAM Apex Kit should cost around $1500 dollars, including new basic wheels, and current standard wide range gearing.

But if you want to keep the original wheels, you will be very limited in how far you can change things.


Giant Revolt 2 vs Giant Anyroad 2 drag/roll resistance I own two bikes:

Giant Revolt 2: http://www.giant-bicycles.com/uk-ua/bikes/model/revolt.2/17270/72372/#specifications
Giant Anyroad 2: http://www.giant-bicycles.com/uk-ua/bikes/model/anyroad.2/17256/72374/#specifications

Experimentally Revolt has a better roll than Anyroad. This really bugs me because:

Anyroad has a stiffer fork.
Anyroad tyre width 32, Revolt - 35.
Revolt weights slightly more.

I've perfectly adjusted cones for Anyroad, experimented with tyre pressure, switched riders.

The only thing I didn't change is the hubs. Revolt has Formula [F] DC20 [R] DC22, alloy disc hub, double-sealed, Loose Ball Bearing, 32H. Anyroad has sort of noname Giant, [F]24h, [R]28h.

Does anyone know anything about this mysterious Giant hub? Could it be a culprit as the Formula hub gives better roll?
Are there any other suggestions how to make Anyroad roll better?

If you're measuring on downhills, the Revolt will roll better because it weighs more, not despite it. While objects of different mass will free-fall at the same rate (all else being equal), the mechanics of coasting are different due to the effect of air resistance. A great explanation is available here.

There are better ways than roll to measure a bike's efficiency--like given the same energy input, same speed, and same wind profile (for the rider at least), which one goes farther on a flat surface? Or, given the same energy expenditure and the same flat distance, which one arrives first?

If you're concerned with efficiency, hunching over a bit more for aerodynamics will have much more of an effect than minor differences in rolling resistance, or slight differences in the weight of the bike.


Shimano BR-R650 long reach calipers compatible with Paul Components Canti Levers? The Shimano BR-R650 caliper brake uses the Super SLR system.  I believe Super SLR relates to the amount of cable pull necessary to activate the brake.  Does anyone know if the caliper is compatible with Paul Component's Canti Levers which are short pull brake levers?

Super SLR mismatches in this direction result in mushy feel and needing to get the gap between the pads and rim smaller than normal to avoid bottoming out the lever. You'll get brake rub from wheel flex and out of trueness that would otherwise be negligible. It's a lesser version of the problems you'd have putting a v-brake on a short pull lever. It's enough to notice but not so bad it doesn't work. You'll have to live with having taken two nice components and made a mediocre system out of them. It will feel and perform way better if you just get a Tektro brake of the same reach and call it a day.


Is a sprung saddle the answer to the saddle problems on my commuter bike? The current saddle on my bike is getting past it use-by date, so I will shopping around for a new one. I use my bike for commuting to work, about 40-45 mins, 50% on seal roads and the rest on forest trails.

My current saddle is a non-sprung version with a high density foam padding.

My bike is a Giant Cypress from a few year back. Here is the 2011 version but it is pretty much the same.

I have seen saddles that are spring loaded and are tempted to go for them. However, I fear that I will be bouncing too much as I ride along. My current saddle is not spring loaded but I I get a very small amount a numbness around the crotch area.

I used to despise the antiquated look of sprung saddles - then I got one on my retro-bike. Despite all of my preconceived opinions I immediately took to the sprung seat.

Clearly not for the road-racer, the sprung saddle has its place in regular riding, where roads are not exactly smooth. Given the choice of a couple of springs in the seat or a Kona-tractor-style-rear-suspension setup, the couple-of-springs has elegance in how it delivers comfort. Energy lost through compressing the springs is actually returned with marginable 'pedal bob'. The weight of the springs is negligible, your back wheel will thank you for them, even though only you and not the bike is being suspended.

Given the roads you describe I would definitely recommend a sprung saddle. You would not drive those roads without the weight being suspended, on the bike your legs are the suspension, it would be nice to give them a break after a hard day's work, so why not go with the sprung seat.


Can I secure a 12v battery to my bicycle to charge it? And then attach a 12v horn to it? I'm from the Netherlands, so I mean a Dutch style bicycle, as in:

Then I want to attach a 12 volt horn to it. I could just put it in the basket. It doesn't necessarily need to be charged while pedaling, or it can just be partly charged, but just that it runs out of power a bit slower. Then I'd like to attach a horn to it.

Would this be possible?

I think you're on the wrong track looking at batteries because they're heavy, stealable, fragile, and bad ecologically.

Firstly, you already have an airhorn installed in the middle of your face.  Its steerable so it always sounds in the direction you're looking.
Plus it needs no batteries, and best of all it plays a customised noise, from "OI!" to "LOOK OUT!" to "STOP!"

That was a serious suggestion, but if you want a horn consider an airhorn something like http://deltacycle.com/airzound-horn
It refills from a bike pump and is lighter than a battery, plus no drag from a generator/alternator.

My own experience - I put a small 1.2AH 12V battery inside a disposable 600 ml bottle, and used a small car battery charger to charge it.   I also put a car 12V-->USB adapter in the mouth of the bottle to run my camera and cellphone.  This worked well, but loses a drink cage.

My electric bike has 3x 7AH SLA batteries.  They are in a frame built from light angle aluminium and rivets.  This replaces the main drink bottle cage and works fine, but probably overkill for your requirements.


Adding gears to a single speed Cycle I have a single speed cycle and i want to have minimum of six gears on it, Is there a cheap and good way so that i can get gears on it?

If you're willing to accept 5 gears, it's really not that difficult. The main issue is finding a hub that's narrow enough to fit the dropouts.

Sturmey Archer make a wide-range 5-speed geared hub, with or without coaster brake, with 120mm OLD spacing. There used to be a 5-speed SRAM hub with 122mm (?) OLD, but it might be a job to track one down. If it's a steel frame with thin stays, you have a couple more mm of leeway. But most hub gears are 135mm OLD. Depending on the hub, it may be possible to remove axle spacers, but don't bet on it... anti-rotation washers don't count; they mustn't be removed!

Unless your current frame is a conversion, you may have a few cable-routing headaches too (although clamp-on cable guides aren't difficult to find).

It only really makes sense if you love the frame. Part exchange would probably be your best bet, but if you have a good reason to keep the bike then I say go for it.

My partner is very short (5'), and standover height is an issue, so she rides a kids' Fuji track. The cost of the Fuji, plus that of building a new wheel around the SA hub, was significantly lower than any WSD we could find.

Afterthought: A cheap and good way (albeit one that requires some tinkering, swearing, and an awful lot of luck):

5-speeds from the 50s tended to be 120mm OLD, so you might be able to swap out the SS freewheel for an old-fashioned thread-on 5-speed model. There are quite a few caveats, however. For starters you'll need a fairly narrow hub shell. Then you'll need enough free threads on the axle to shuffle the cones and locknuts off to one side, so there's enough axle showing to fit the wheel securely. Then you'll need to re-dish the wheel.

Then you'll just need a rear mech with a bolt-on hanger claw (assuming the frame doesn't have a threaded hanger on the dropout). If you're friendly with a local bike shop / junkyard, you might be able to blag these bits and pieces for free.


Inner tubes - if two tubes match the tire, is bigger or smaller better for durability? Some of the inner tubes tire thickness ranges overlap. For example Schwalbe often offers tubes in 1.5"-2.4" and 2.1"-3.0" width ranges. Given a tire that fits both ranges, like for example a 2.15" tire, is it better to buy a larger or a smaller tube when it comes to durability?

My intuition tells me that a larger tube will be better, because it will be less stretched, hence thicker, but that's just an intuition.

Really good question. It's hard to answer because manufacturers play games with how far in either direction they decide they can get away with stretching those numbers. Sometimes what they're basing those decisions on might be something rational and expertise-driven that has to do with wall thickness or seam construction or whatever, and other times it's two brands calling the same tube 700x18-23 versus 700x18-25 because the latter knew they could get away with it and wanted to have one less tube SKU to worry about.

In general you're safer choosing the tube where the upper end of the printed range matches the printed size of the tire. This tends to give a result where the tube, when inflated just enough to give it shape but not stretch it, fills out the tire nicely give or take a negligible amount of stretch, and is easy to install. That last point should not be underestimated; damage or blowouts from difficulty installing the tube is one of the major ways things can go wrong here, and it happens more when the tire is in the smaller end of the tube's range than the larger. Once it's in there, tubes really don't care that much about being a little stretched or a little large. It's true that the distinction is non-zero, and stretched is probably worse for durability in that sense, but it really is pretty close to zero as long as it's within the printed range, and meanwhile the extra rubber is extra weight and extra hassle/risk during installation. Having extra rubber per se really doesn't add durability and shouldn't be aspired to.

So the literal answer is probably that, given exact perfection is impossible, erring on the larger side is marginally more durable, but in practice it's more complicated than that because some much more meaningful percent of tube issues happen as a result of difficulty cramming in a bigger tube, which isn't likely to be an issue in the case of putting, say, a 23-25 tube in a 23, but can come into play in a more major way in some instances. And likewise, in actual practice, having a tube that tops out at the tire size you've got will virtually never cause issues, and has other advantages.

Manufacturers/brands tend to make more falsely optimistic choices when it comes to choosing what to print for the lower end of the range. A tube box that says "2.1-3.0" is a code from the manufacturer to the retailer for, "This may physically work in a 2.1 once you finally get it crammed in there, but it's going to be inconvenient and heavy, and we basically only did this to have fewer SKUs, plus 2.1 is way out of fashion and only needs to be catered to as an afterthought so who cares." Or they may have just put 2.1 on there instead of 2.5 because they thought the appearance of stocking versatility would give them an edge over the competition and they didn't care about damaging their credibility because everyone in the bike industry is always going broke, which encourages short-term thinking. That 2.1-3 is a huge range. If it's going to be an optimal fit for a 3.0, or even if it's optimal in a 2.8 and can be stretched to a 3.0, you're safe inferring they only got the other end of the range down to 2.1 by straight fudging the numbers.


Is there a way to remember pedal, crank position before taking sharp turns I had a nasty tumble yesterday when doing a sharp right turn into a side road.
A car was giving way to me at the junction.

I turned right and I was basically thrown of my bike. flipped onto my left side ending up on my back.
It was so quick a violent I can't say for sure what happened.

The only thing I can think what caused it was my right pedal may have been in the down (6 o'clock) position.

These things must have been natural when I was younger, as I've never had a incident like this before.

Outside pedal down and your weight on the outside foot, that 's how we were taught at the cycling school of the cycling club. You may angle the inside leg more or less away from the bike if you want to turn faster (cf. moto GP racers).


Front Disc Brake not braking to it's full potential Today, I got a new disc for my front Clarks Hyrdaulic brake. Before the change, whenever I pressed my front brake, I could almost do a front flip but that's only if I pressed it fully. Now, when I press it fully, the lever goes all the way down but it feels like the tyre should stop but instead, it goes for slightly longer. It's almost as if there's grease on my brake pads but I know that's not the case.

So my question is, why did replacing the front disc cause my front brake to lose effectiveness? Do I need to wait it out cause it's a new disc or?

The disc could be a little smaller, so you need to press your lever further. Normally a hydraulic disc-brake will do a correction on this, but it's worth to re-adjust your brakes.

Most likely, cleaning them will solve the issue. Make sure to clean them correctly. If your pads are greasy, then you might need to replace them.
See: What do I clean disk brakes with?

Also, if they are brand-new, you might need to break them in. See user manual for that as brands specify other methods. (Generally you need to do several hard stops).


Can I use a 7 speed shifter on an 8 speed cassette I am currently upgrading my mountain bike and have bought a set of wheels that accepts 8,9,10 speed cassettes but my previous wheels used a 7 speed freewheel. If i install the new wheels with an 8 speed cassette would having the standard shimano 7 speed trigger shifters and 7 speed derailleurs cause a problem or would it work fine?

The 7 and 8 speed cassettes have slightly different spacing (see http://sheldonbrown.com/cribsheet-spacing.html), so the derailleur will be slightly, almost unnoticeably, out of adjustment at largest and smallest cogs. And of course you won't be able to shift to one of the cogs.

If you can't change the shifter to 8-speed, you can install a 7-speed cassette on 8-speed hub with a spacer.

The 8-speed hub is wider than 7-speed, so you will also need to bend the rear fork slightly to install the wheel.


Visual chain identification I have a second hand bike and the chain doesn't seem to work well with the 11 speed cassette fitted.
It almost seems too wide to fit in the sprocket gap. Are there any visual signs on a shimano chain which indicate whether it is 10s or 11s?

With accurate vernier calipers or a micrometer, measure the width of the outside plates.
https://en.wikipedia.org/wiki/Bicycle_chain#Width shows this table of chain widths.

Speeds
Width

6
7.3 mm (9⁄32 in) (Shimano HG), 7.1 mm (9⁄32 in) (SRAM, Shimano IG)

7
7.3 mm (9⁄32 in) (Shimano HG), 7.1 mm (9⁄32 in) (SRAM, Shimano IG)

8
7.3 mm (9⁄32 in) (Shimano HG), 7.1 mm (9⁄32 in) (SRAM, Shimano IG)

9
6.5 to 7.0 mm (1⁄4 to 9⁄32 in) (all brands)

10
6.0 to 7.0 mm (1⁄4 to 9⁄32 in) (Shimano, Campagnolo)

10 (Narrow)
5.88 mm (7⁄32 in) (Campagnolo, KMC)

10 (Narrow, Direction)
5.88 mm (7⁄32 in) (Shimano CN-5700, CN-6700, CN-7900)

11
5.5 to 5.62 mm (7⁄32 to 7⁄32 in) (Campagnolo, KMC, Shimano CN-9000)

12
5.3 mm (13⁄64 in) (SRAM)

So if your chain is 5.8mm wide then its probably 10 speed, and 5.6mm is likely 11 speed.   The difference is small, 0.2mm is about 8 thousandths of an inch, you're not going to see that on a ruler.
However if you had known 10 or 11 speed chain laying flat on a tabletop, and your current chain flat beside that, you should see a visual difference, or at least feel one with your fingers.

Another idea is to look for a quicklink or master link.  Many of them have 10s or 11s stamped into the sides.  You're unlikely to get an 11s master link to close on a 10s chain, but the opposite is certainly possible.


My helmet had a bad fall. Is it still good? I just stupidly dropped my helmet on the floor from a quite high distance. I know (or rather, heard of) that motorbike helmets must be inspected in such cases.

Is it the same for bike helmets? How can I tell if it is still safe?

BHSI.org says the following:

Did you drop it hard enough to crack the foam? Replace.

  For starters, most people are aware that you must replace a helmet
  after any crash where your head hit. The foam part of a helmet is made
  for one-time use, and after crushing once it is no longer as
  protective as it was, even if it still looks intact. Bear in mind that
  if the helmet did its job most people would tell you that they did not
  even hit their head, or did not hit their head that hard. And the thin
  shells on most helmets now tend to hide any dents in the foam. But if
  you can see marks on the shell or measure any foam crush at all,
  replace the helmet. (Helmets made of EPP foam do recover, but there
  are few EPP helmets on the market. Yours is EPS or EPU unless
  otherwise labeled.)

  You can also crack the helmet foam or damage it by dropping the helmet
  on a hard surface. The cracks may be small and hard to see, so you
  need to look carefully. Cracks in the foam always require replacement
  of the helmet.

  You may be reluctant to replace a helmet that looks almost as good as
  new, but if you did hit, you don't want to take chances on where you
  will hit next time. If the foam is cracked under the thin shell, it
  will be more likely to fly apart in your next crash. Many
  manufacturers will replace crashed helmets for a nominal fee, and most
  will also inspect crashed helmets to see if they need replacement.
  Call them if you are in doubt.


Is my Trek FX2 really toast? I have a 2016 or 2017 Trek FX2 (if critical I'll look up exact year). Ride it daily for shopping, going to the gym and such. Store it outside, unprotected from rain.  Took it to the store I bought it at to have new pedals and break pads installed. Guy at the shop noticed that the headset was loose. After opening it up (lots of rust inside) he's basically saying it's toast and he wouldn't recommend repairing it. Why? Because combined with the other things that need to be done, the total bill will come to about half the price of a new bike. Better to go with a new bike because this old one will just cause exponentially increasing maintenance and replacement costs going forward.   I don't know the first thing about any of this and there is also a language barrier. I speak the local language where I live reasonably well but for technical discussions like this one it leaves a lot to be desired. (Thus it's also possible that I might have misunderstood parts of what he told me.)

My question here is first whether this sounds plausible, or whether the guy is possibly trying to pull the wool over my eyes.

And secondly if it does sound plausible, is there a better option than simply going for a new bike? How about replacing the frame and headset with a new one?

The fact that you've left the bike out in the rain the whole time and that the chain is rusty suggest that you've not been looking after it. It doesn't surprise me that it would now be damaged beyond economic repair.

I used to have a Trek 721, which I think is a predecessor model to the FX2.  Mine was kept under a roof and lasted longer than yours but, after several years of use, it too hit the point where enough stuff needed replacing that it wasn't worth doing so.  From the way it's been treated, it sounds plausible that your bike would now be at that point, too.

I suggest that you take it to another bike shop for a second opinion and then decide how to proceed.  Assuming that they say essentially the same thing, you have two options: either pay half the cost of a new bike and have a bike that will work for maybe another six to 18 months, or pay the whole cost of a new bike and get a new bike.


Beginner bicyclist question about purchasing a new road bike Completely new to biking, and am considering purchasing a decent road bike that'll be comportable for 25 mile outings. Came across a used "KHS Aero Turbo" for 325 bucks. It looks like a nice bike, but like I said, I have no experience or frame of reference for what qualifies as a decent bike. Could anyone help me out in regards to if this is worth the money, or perhaps what other brands/makes to look out for?

Thanks!

Welcome to cycling. 325 bucks is really not too much for a complete bike (you'll understand this better later on). So, go for it as long as the sizing is correct for you. If you are not sure about sizing, take the bike to an LBS and have them do a (paid) assesment and fit in case you buy it.


upgrade my road bike, compatible parts to upgrade in phases? I received a used road bike that functions, but not well.  I completed a triathlon and lots of practice rides, but wanting to upgrade the components.

The crankset is ultegra 6500/170m.  The shifters and FD are ultegra (prob 6500 too?) and the RD is tiagra. Not positive about the cassette (is there models markings there somewhere?)

My goal is to slowly upgrade (based on budget) to either 105 5800 or ultegra 6800.
1) can I upgrade the shifters, FD, and RD and keep my existing crankset and cassette for upgrade later?
2) is there an upgrade path that lets me upgrade a few components at a time to eventually get me to a modern groupset?
3) best place to get affordable parts?

The frame is in great shape.  Aluminum with carbon fork.  Bike weighs in at 19 lbs, fully loaded.  Shimano rims, etc.  Would prefer to upgrade this bike.

Thank you

I received a used road bike that functions, but not well.

Just to point out: If shifting works bad it’s usually a problem with friction in the cables, bad adjustment, bent hanger or worn chain/cassette. Even a relatively cheap Tiagra group works flawlessly when properly installed and adjusted.

I don’t see many options for a partial upgrade because the cassette-spacing has gotten narrower from 9-speed to 10-speed to 11-speed. So you can’t use 11 or 10-speed shifters with 9-speed cassettes or vice-versa.

Anyways, you’d probably have to install new cables and re-adjust for every step so it doesn’t make much sense.


Can I measure my bottom bracket size without removing the cranks? I don't have a LBS (there are BS, but not L), so I generally order everything I need online. I need to replace the bottom bracket on my commuter bike, which I know is a VP-BC73 but that BB's available in sizes from 107 mm to 127.5 mm and I'm not sure what size I'll need. The bike has a 28-38-48 triple front chainring.

I plan on using a Sunrace BB as the replacement, which is available in 103, 107, 111, 113, 118, 122, 124, and 127 mm lengths (italics are out of stock at my preferred supplier).

The obvious answer here is to take the BB out and measure it; trouble is, there's no crank puller or BB tool available—I'll be ordering these with the new BB. I've also tried contacting the bike's manufacturer (a bicycle chain store—I know), but they've been non-responsive.

The best I've managed so far was an attempt to measure the distance from the outside of one crank to the other (at the BB), then remove the crank bolts and subtract the distances from the outside of the crank to the end of the bottom bracket axle. This gave a (rudimentary, at best!) measurement of 129 mm.

I can possibly order a couple of BBs and return one, but I'd really like to be able to narrow it down that much, at least. Is it better to be too long, or too short (or does it really need to be exact)?

UPDATE: I measured the chainline yesterday, it's 53 mm at the front (I know that's wide, but that's what it is) and 48.5 mm at the back. The rear cassette is a 7-speed Shimano 14-28.

As, if not more important than length, is the chain line.  Obviously related, but enough variation to cause problems, as I found out not when I got into my own bike maintenance. Sheldon (as always) shows a way to measure chain line here. The same page has  table of various Bottom brackets and the length and chain-line measurements.

Essentially you measure from the center of the chain rings (triple is easy, double measure half way between the rings) to the center of the seat tube to get your chain line. Then you should be able to match up a BB that will suit.


Rode on a flat tire - how do I check for possible damage? Took quite a fall today while riding, big divot in a gravel path right over the peak of a small hill. After replacing the chain and doing a quick inspection, I resumed the 10 mile trip to the car.  I did not press on the tires.

I noticed for the remainder of the trip that traction was suboptimal, which I thought was due to the fact they put down fresh, but finer than normal gravel. Anyway, towards the end of the trip I had a major traction issue while doing a slow turn which made me scratch my head, and turns out the rear tire pressure was 0. I have no idea how long or short it was like that.

What should I keep in mind to restore that wheel to safe, usable condition?

The wheel is unlikely to have suffered any damage, unless you experienced a really hard bump (for example from going over a big stone at full speed). Just to be safe, check the rim for damage (such as dents) and make sure the wheel is still true.
The tire itself is most likely to have suffered. By running on a flat tire, the tire is subject to much more flexing than when inflated - in the long run, this will damage the tire. If the tire has deep creases or is torn, especially on the flanks, you will have to replace it. Otherwise it is probably ok to use.
Finally, make sure the inner tube did not suffer a puncture, and replace it if it did.

With these precautions, you should be ok.


Wilier oversize bottom bracket bearing cups for Shimano crank My bike frame is a Wilier Imperiale with Campagnolo crankset. I am changing the crank to a Shimano 6800. The bottom bracket does not fit to the Shimano one. It is old version WILIER OVERSIZE BOTTOM BRACKET. I searched it but someone says it is BB94 while someone says it is BB90. I am quite confused about the real specification of the bearing cups. Now I don't even know what key words I should use to search the replacement item to buy. Thanks.

You stated that your frame is a Wilier Imperiale. I'm not certain what year this applies to, but it is very likely to have a proprietary bottom bracket standard known as the BB94 or BB93 standard. Per the Cyclingtips link:

Wilier designed its BB94 (later re-named BB93) around Campagolo’s Ultra-Torque cranks. Seats for the bearings were moulded into the frame à la BB90 so there was no longer a need to install cups. Wilier was able to provide two bearings sets, one to suit Shimano’s Hollowtech II cranks, and another for SRAM’s GXP axle, that could be pressed into the seats so that those cranks could be installed. This design was subsequently replaced by BB386EVO.

As you may know, many modern carbon frames have press-fit bottom brackets. With threaded BBs, you would buy the bottom bracket as a unit. That unit has both the cups (metal cups that are threaded, and you screw those into the frame), and the appropriate cartridge bearings are pre-installed into the cups. With press-fit BBs, the cups aren't threaded, they may be made of plastic, and you press them into the frame, but the cups also contain bearings.
However, Wiliers using their BB93 or 94 standard have a different arrangement: the bottom bracket cups are already molded into the frame. You press cartridge bearings directly into the frame. You would buy appropriate bearings directly. You should be able to follow similar extraction and installation procedures as for the Trek BB90 bearings.
Why your crank doesn't fit and what bearings you need
The reason you can't just slot your Shimano crankset into the Wilier is this: Campagnolo Power- and Ultra-Torque cranksets have 25mm diameter spindles, and the bearings have an internal diameter of 25mm. Shimano Hollowtech II cranks have 24mm spindles, and fit too loose in the bearings. Also, SRAM GXP cranksets have 24/22mm spindles. Wheels Manufacturing sells a number of replacement bearings. All you need to do is to select the ones with internal diameters of 24mm. A side note: don't get a crank with a 30mm spindle, as your frame appears to be incompatible.
This isn't a recommendation to use Wheels specifically. Other manufacturers like Enduro may also produce replacement bearings. If you wish to source your own bearings, you'd want an outer diameter of 37mm, an internal diameter of 24mm, and a depth of 7mm. I believe this corresponds to a 2437 bearing. (A previous version wrongly stated that this is a 6805 bearing; that bearing has an internal diameter of 25mm and will accommodate Campagnolo cranks.)
Is it a good idea to seat bearings directly in the frame, rather than in cups?
From what I've read, I don't think it's a good idea to seat the bearings against a carbon surface. Kogel, a manufacturer of bottom brackets and pulleys with ceramic bearings, contends that

Another problem that I have seen is that the BB shell ovalizes over time from repeated compression of the carbon under pedaling forces. Trek’s solution for either problem is to send out a custom sized ‘V2’ bearing, which is a slightly larger version of the 6805 size that should have fit initially.

BBinfinite, which also makes bottom brackets, seems to agree with this, but they think that the issue occurs when the bearing is not installed tightly. If it develops movement, it will gradually enlarge the BB shell by fretting against it. The bearing will thus fit loosely in the shell, and it will creak. BBinfinite advocates applying loctite to the bearings, which stops them from moving. This Slowtwitch thread, contains a report of the BB shell becoming out of spec, likely due to the phenomenon described above.
In most other press fit arrangements, the shell is at least protected from wear like this by the BB cups (which can be plastic or metal). In addition, the Wilier in question may have had an aluminum tube bonded into the frame to serve as the bearing seat (see comment by Robert). That said, even regular press fit systems are notorious for creaking problems. We could revert to threaded BB shells, and Trek appears to be replacing BB90 with the T47 oversized threaded system (note, their 2020 model year Emonda and Madone frames appear to still use BB90, but the Domane and Crocket bikes switched). However, this involves bonding an alloy shell into the carbon bottom bracket. This process can also be imperfect, e.g. the shell might not be bonded properly. It does add weight as well, but the amount of weight actually in play is of little consequence (and it can be safely offset by light parts in other areas, if you must play the weight weenie game).
Miscellaneous comments
One original Wilier owner on Slowtwitch.com reported that they received a bag of hardware with their Wilier. This bag may have contained bearings for the bottom bracket. If you have this bag, it might be worth checking it for the Shimano bearings.
Do recall that you can service your bearings without replacing them. This involves gently prying the seals off, flushing the interior with WD 40, and then re-greasing the bearings. I'd probably recommend this, in fact. It's cheaper than replacing the bearings, and it avoids wearing out the carbon when you press out the old bearings and press new ones in.
Trek does sell BB90 bearings whose outer diameter is oversized by 0.1mm as a fix if the shell becomes slightly enlarged. In principle, if this ever happens to your frame, I believe you could use those bearings. Trek's BB90 specifies a 37mm internal diameter. The dimensions of the BB90 bearings that Wheels Mfg. lists for the BB90 seem identical to the ones listed for Wilier's BB94. The BB90 shell is a couple mm narrower than the BB94 shell, but this appears not to affect the bearing dimensions. If you suspect this, you should measure the diameter of the bearing seats with a pair of calipers  in several places to make very sure that they conform to the specified 37.1mm diameter of this oversized bearing.


How do I achieve a lower gear on a Norco Bigfoot with a 9 speed cassette? I have 2015 Norco Bigfoot fat bike which has a Shimano HG-20 11-34T 9 sp cassette a with a  Shimano Alivio RDM 4000 SGS 9 sp Rear Derailleur and a  Shimano EZ-Fire EF 51 9 sp Rear Shifter. As I live in a particularly hilly area and intent to most ride this bike off road along animal pads in the bush I would like to reduce the gearing by having a 42t cog on the cassette. From reading I understand this can be done by
- removing a small cog and installing an 42T extender cog in the cassette,
- by replacing the current cassette with a wide range 9 sp cassette (hard to find),or by
- changing to a wide range 10 speed cassette with a change of derailleur, chain and shifter.

Please provide advise as to the best, most economical option. Could I install a 10 speed cassette and just use 9 cogs?

  From https://www.norco.com/bike-archives/2015/bigfoot-62/

Looking at the spec, your bike has a double front chainring.  Are you shifting into the smallest front ring when climbing?  If not, then do so.

You can possibly buy a smaller front chainring too, that will leave the higher gears alone for faster/road usage, like downhills.

The single cheapest solution is to pace yourself by slowing down, harden up your muscles and climb at a rate that you can sustain.   This is the most economic option.

Is the grade steep enough that you physically can't ride it?  Consider taking an alternate route, or changing a straight climb into a series of switchbacks.

A 9 speed cassette is still available to buy - simply look for one with the biggest big cog and see how it goes.  You will need a new chain too.  Converting your existing cassette won't work if its a one-piece unit, or if the smallest cog is the lockring.

Example http://www.wiggle.com/shimano-alivio-9-speed-cassette/ is a 11-34 tooth for quite cheap.


Using a much heavier rear tyre than in the front For the last 3 years I've been using light (800grams) tyres front and rear.

Since I've been having too many rear tyre pinch flats (tried everything: high PSI, tubeless, heavy duty tubes) I'd like to switch to a real double ply DH tyre for the rear which weights 1200 grams.

Is running a heavier tyre only on the rear suggested?
Or should I switch both front and rear at once? Maybe for bike balance issues while jumping etc?

p.s. I ride mtb all mountain and downhill

There is no need to have equal tires on both wheels, except for aesthetics.

Just make sure that front tire has enough grip so you can remain in control.

As for getting pinch flats - make sure you mount tubes correctly and they are not trapped between tire and rim. Having high pressure should help you avoid pinches. More durable tire will help with punctures, not with pinch flats.

P.S. My own experience is limited to MTB XC marathons.


Help identify my bike frame Please help me identify a mystery bike that I purchased at a garage sale and have grown to love.

I am not sure what is original to the frame but the bike has a 56cm frame, Shimano SFR rear dropout, a sticker on it that says 'Champion NO.2 Tange Industries', 26.8mm seatpost, serial number on lower non drive side seat tube that I believe says 'S0S5140'. It has braze-ons for one bottle cage on down tube and on top of bottom bracket a cable bridge.

The components on it are first generation Shimano Dura-Ace cranks, bottom bracket and brakes. Suntour Cyclone front and rear derailleur with Shimano 600 Arabesque shifters, 3TTT stem, Tange headset, KKT pedals, SR seat post Concor S. Marco saddle. Campagnolo hubs with Fiamme tubular rims.

It fits me well and rides great, it just would be great to know who made it.

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That's definitely a Japanese frame and my guess is the wheels were an upgrade somewhere along the line.  The mix of Shimano and Suntour also is unlikely to be how the bike was sold. My guess is the Cyclone derailleurs were an upgrade, but since it's friction shifting it all plays fine together.

A web site with a lot of experts is the "Vintage Cream" Facebook group.  I would suggest adding more closeup pictures of the lugs, fork and bottom bracket. Tange #2 and Shimano forged dropouts are clear indicators of a very well made frame.

Vintage Cream FB Group

Good luck in your search,
Greg


What can cause narrow disc brake gap in TRP Spyre-C? I have mechanical disc brakes (TRP Spyre-C), second year. Last year I removed and mounted wheels without problems. This year I am all surprised because I cannot adjust the rear brake.

Front -- no problem, plenty of space between brake pads. I can insert 2.5 hex key between pads and even tilt the key a little. Next I can screw in pads-screws, and then fine-tune it with the barrel.

Rear -- I cannot even insert 2.5 hex key between pads (in their neutral position). So basically I can barely put the wheel on, but I cannot adjust brakes at all.

Did I damaged something? Is there is some element extra to adjust?

I already checked and rechecked:

cable tension -- cable is completely loose
barrel adjuster -- all way in (meaning it cannot be shorter)
pads-screws on both sides -- (un)screwed outwards
pads wear -- I just put an identical pair on front and rear

I also removed pads, cleaned the interior (I was thinking about some sand grain), no change.

Granted, last year rotors where 1.9mm thick, current ones 2.0mm, so maybe this explains why I was able to put the rear wheel (but I am sceptical), but the problem remains -- why such a difference between gaps? Could it be my rear brake is faulty (by manufacturer) and I simply didn't notice? Or there is some magical screw (to fix it, or disassemble it)? Is there a way to remove the brake lever (the one at the brake, not at handlebar)?

Any help in solving this mystery is welcome!

Background details:

I upgraded in the rotor diameter as well, front from 160 to 203, and rear from 160 to 180 with appropriate adapters, just as sanity check I unscrewed brakes from adapters and it didn't change a thing.

Last year -- Sudden gap between disc brake and pads? -- I got mud (?) in front brake which had curious effect -- it didn't damage anything, at least I didn't notice, it didn't peel off the pads, yet it widened the gap of the front brake. So from current perspective it looks like it was a fix-therapy and I wonder how I can perform such fix-therapy for rear brake on demand.

That's an uncommon problem for mechanical disc calipers and I have a guess what's going on.

Spyres and Spykes are generally good brakes but they have the quirk that the pad adjusters can get a little stuck. When this happens, the adjuster will feel seized, but if you're only trying to turn it out, that could be mistaken for it being retracted all the way. Try turning it both ways to confirm it's moving freely.

If it is stuck, what's always worked for me is take a higher-leverage 3mm wrench in very good condition (to minimize the risk of rounding the wrench flats) and just pop it free. It can take more force than you'd normally want or expect to be putting on a 3mm allen, and when it frees it makes a scary 'pop,' but then works normally again.

If both pad adjusters are known to be moving freely and all the way retracted and the cable isn't even attached and the arm is known to be all the way in its starting position, that kind of only leaves some kind of internal problem with the brake, and I don't know what that would be.


B-screw hitting derailleur hanger I have a Schwinn Super Sport circa 1966, that came to me as a single speed, so I have never seen a derailleur on it. When I put this SunTour derailleur on it - mid 70s I think, came off a Peugeot - the b-screw hits the Schwinn's derailleur hanger body, not the b-screw stop, as you can see in the picture. The stop seems way further forward on the Schwinn than the Peugeot. However, a modern Shimano XT derailleur seems to fit the Schwinn fine . . . I just was hoping for something  approximately period appropriate. What's going on here? Are the different style derailleur hangers? How can I know what derailleurs will fit the Schwinn?

Here's the mismatch:

I can rotate it so it hits the stop, but the derailleur position looks like it would not work, the b-screw is all the way out, not really hitting the stop dead-on, and the derailleur cage is hitting the seat stay:

However, this Deore XT derailleur seems to have a longer or slightly further-out b-screw that hits properly. I haven't put a chain on it to check, but this looks like it would work. So I want something that works like this, but is from the 60s-80s, 10-speed road era.

Upon further research it seems that in 1966, Schwinn was using Huret dropouts, which have a different configuration than modern derailleur hangers, which are based on a Campagnolo design. So the options are to get a Huret derailleur, or make an adapter like this one made from a washer or look at this thread for some other options.


What size of slick tire should I buy? I purchased a mountain bike and I ride on the road most of the time and I was looking at slicks for my bike. My tire size that I have now is 26x2.00 and the rims. I have on are AT-550 26inch what size slick tire would be good for me to purchase?

Everything you could want to know about tire sizing is here, including recommendations of how wide a tire should go on how wide a rim. In your case, you will look for tires made for 26" rims (ISO 559), but generally, narrow rims should have narrower tires than wider rims. These tires will be marked 26 x decimal number (by decimal number, i mean a number written with a decimal point).

Schwalbe makes a 26 x 2.00 inch Marathon Plus which would probably make a good replacement (the fatter the tire, more cushioning), as well as 1.5 and 1.75 inch variants. A bit smaller of a tire will technically reduce weight (and lower the bike slightly) and give a bit better handling. If you go down to your bike shop, they probably have a bunch of tires which work for the road well. Look for kevlar belting for puncture protection.

Also, if you're pretty much always on the road, and are running a suspension fork, you may want to swap it out with a suspension corrected rigid fork, since you don't really need suspension beyond the tires on the road unless you have a back problem or something.


Generally can I fit 650b wheels on a modern CX frame? I know this depends a lot on the model and the shape of the stays and fork, but on the average CX disc frame would it be possible to use 650b wheels with thicker tires, for a more comfortable offroad (gravel) experience?

Wheel size swaps in bicycles are generally not possible, but this particular  rim and tire size swap is possible with disc brake equipped bikes, if you have the lateral tire clearance.

700c rims are 622mm in diameter at the bead seat. 650b rims are 584mm. The difference in radius - what has to be made up by a bigger tire - is 19mm. Assuming tire width is approximately tire height, going from a 28mm tire to a 42mm tire makes up most of that difference (42mm-28mm=14mm).

As an aside, changing rim diameter without a change in tire size is not recommended. Frames are designed around a certain wheel size and fitting a smaller rim size wheel negatively effects steering geometry and crank-ground clearance.

See this Sheldon Brown article.


aluminium fatigue how to know if some thing is going wrong? I have an early 00' road bike with aluminium frame. I have read some stuff about aluminium having life expectancy of ten years. What it exactly means? I cant see any thing wrong in the frame (there are some crack noise coming from stem) how I can know if my frames have problems ?

I have a 1998 aluminium road bike, and it made creaking noises in the stem when pedaling hard.  Could replicate this by siezing the bars while stopped and wiggling.  So I tightened the quill stem and the noise went away.  Its just a bit of play in the steerer tube/quill stem fixing.

Since you're asking, a frame should outlive you, assuming no crash damage and its garaged/treated well.

Give it a good wash and then look over the frame for any cracks... but try and see if they're paint cracks or frame cracks.

Then run your bare fingers over the surfaces - you should feel only flatness, no ripples or bends.

Your bike is probably welded, not lugged, so have a close look at the welds.  Ideally they should be smooth and flat, but some bike welds look like beginners (cheaper MTBs are chronic for the industrial weld look)

Forks can be measured to make sure they're not bent too, but this is fiddly and normally only done if the bike doesn't track right, or there was a frontal impact.


Does new chain on old cassette damage chain? I know that a new cassette can be damaged by and old chain. What about the opposite? Can a new chain be damaged by an old cassette?

The main problem with an old chain is that it's stretched. As a result, it won't sit snugly on all the covered teeth of the sprocket, but only on the ones with the main load, and as you pedal the contact point slips a bit. Just fractions of a millimeter at each tooth, but with the considerable load and many thousands of revolutions, that's what wears out both the chain and sprocket much quicker than a properly fitting chain does (which doesn't slip on the sprocket but simply “peels off”, the only friction being inside the chain-link bearings themselves).
An old sprocket can cause a similar problem too, but only if it's quite extremely worn. Usually, the more pressing problem will be that the chain doesn't properly shift between gears anymore, or shifts/skips when you don't want it, because the tops of the teeth and the fine-engineered ramps on the sprockets' sides are compromised. This skipping and mis-shifting under load does then again put wear on the chain, but mainly it's just super annoying for the rider. It's not like the stretched-chain issue, which stealthily grinds on the parts while the gears still seem to work fine.
So, no, using an old cassette with a new chain is generally fine, as long as the gears are working well.


Resealing bearings in chinese OSPW I am currently rebuilding an old steel bike with some modern parts and am searching for a OSPW because it looks quite cool. However a "real" one from CeramicSpeed seems way to expensive for just looking cool.
So I checked AliExpress for some cool looking ones and obviously found some.
After some research I found out that the main Problem with them is, that the inner bearings are non sealed bearings meaning they get dirty extremely quickly and therefore are not a good upgrade because they probably break before the standard one and cost me more watts than its worth changing them (source for the open bearings is this video here from Trace Velo)
To fix my Problem I was thinking of either adding seals or just saving the ceramic balls and transplanting it into a steal ball bearing housing with seals.
Henceforth my Question is firstly: Is this even possible? I am aware that you can rebuild and therefore change parts when you are using cup and cone bearings however I never heard from anyone that they done it with cartridge bearings.Secondly is this feasible and doable without specialist tools and experience?
Thanks for your help
Edit: Weiwen Ng's Answer pretty much sumed it up already. Getting replacement Seals would be quite impossible especially because one of the bearings had nylon races and both had no groves cut out to hold any seals. My other idea of reusing the ceramic balls was proven impossible as well because they where running out of true (probably because the balls aren't really round). I therefore pretty much went with Weiwens idea and just bought new 689 ball bearings with proper seals (I luckily had a small shop specialized in sealing bearings that had cheap bearings available) and pressed them in. That all worked quite nicely and therefore I am now the "proud" owner of an OSPW with fully sealed ceramic bearings for round about 15€. I'll give another feedback when I need to replace the bearings on how long this hack worked out.
For now I can just thank everyone who gave his answers/comments to help me with this idea.

While I have no practical experience trying to do this, I doubt that what you propose is easy, and it may not be possible.
Rubber seals require a lip machined into the inner and outer races. This retains the seal. I suppose you could check for a lip. If the bearing were designed specifically as an open (i.e. un-sealed) bearing, which is sensible for a low-contamination environment, then it likely wouldn't have a lip. If it did, you would then have to source a seal with the correct dimensions to fit the lip. There are probably a number of different geometries of seal lips. I don't know the descriptive terminology or important measurements for seal lips and grooves. If you found these out, I expect you'd then have the problem of buying just two pairs of seals - the entities selling those seals probably aren't set up for retail transactions, since really what consumer does this? So, it might be several hundred seals.*
It should be difficult, and it may be impossible, to extract the balls from the cartridge. The balls fit tightly in the races, and in many cases, I suspect they sit in grooves in each race. For example, see the second picture at this link. If you can’t pry the bearings out, you would need to disassemble the cartridge to get at the balls. Furthermore, cartridges aren't designed to be disassembled, so I think this process would be destructive, i.e. you'd need something like a hacksaw. Getting the balls into a new cartridge could require industrial machinery like a hydraulic press. And finally, remember that a bearing series number like 689 just describes the outer diameter, the inner diameter, and the depth. The race thickness can vary - so, thinner race means larger balls and vice versa. You'd need to find two pairs (again, consumer vs industrial scale problem) with all the important dimensions matching your ceramic balls.
Finally, ceramic is relatively hard. I believe that best practice might need you to specify an appropriate race hardness as well (it may be more important in wheel bearings, since as you go over bumps the balls might indent softer steel races). I am not sure how this quantity is parameterized in the industry (i.e. maybe it's Rockwell hardness or something like that, and you need to specify a minimum hardness, and I don't know the appropriate minimum). On another tangent, be aware that the quality of ceramic balls does vary, and I suspect cheap ones are low quality. Plus the quality of the steel used in races also varies, with cheaper races probably having poorer material qualities (probably stemming from more impurities, poorer manufacturing processes) and probably looser tolerances.
This answer is written with no practical knowledge of manufacturing or remanufacturing cartridge bearings. Basically, I learned from a podcast. I could be wrong! And if I am, you should free to let us know. However, hopefully this post has given you some idea of the possible pitfalls you would face.
*I am aware of one company that sells replacement seals for its own bearings: Kogel, which coincidentally makes jockey wheels and bottom brackets with ceramic bearings. Kogel's instructions suggest annual regreasing, which is why they sell replacement seals (although they have communicated to me that if you carefully remove the seal, it's usually reusable). I haven't asked, but I would suspect Chris King sells replacement seals for its bearings, although they have seals that are designed to be repeatedly removed for regreasing. The issue is not that no seals for cartridge bearings can be bought in consumer quantities, it's that you will probably only find seals matched to specific bearings that are designed to be serviced, and this seems like the minority of sealed cartridge bearings.


Will trailer be my best option? If not, what is? I need to take a  backpack with me that's literally wider than my body and about as tall as my torso and neck, it weighs around 15-20kg.

What I'm concerned about is roads that aren't so good or places where I might even need to go offroad (I don't know) as well as be essentially having less mobility and being wider.

I'm going to travel (mostly on my bicycle) through various countries, which includes central European countries as well as northern countries, including their northern parts (so northern Sweden for example).

I'm low on budget though, keep in mind, so it isn't going to be something super fancy. Do you think a trailer will be my best option, and if not, what kind of attachment is?

From your other question - your budget for the bike was 300 euros.  You'd spend that much on a trailer alone.

Trailers more than double your rolling resistance, and increase your windage area a lot.  Riding long distance with a 2 wheel trailer is unpleasant.

You might build your own trailer, there are many plans around the web for this, using a square of metal or timber, two wheels and either a seatpost or a rear-axle hitch.

Another possibility is a single wheel trailer, which carry a bit less but are more useable on singletracks and narrower roads.

Making a trailer with a locking bin could solve your security problem, but it still needs locking closed and locking up to something when unattended.

In order of preference, top of the list would be front and rear panniers, then a frame bag, then a trailer, then a rear rack with your pack on it, and lowest on the list is a backpack on your back.