Are cable housings different for road/MTB/urban bikes? I need to get a new kit for the derailleur: cable, housing, and a couple of ferrules.

I know that derailleur cables are the same for road bikes and MTB bikes, but are there differences in cable housings as well? I notice some web sites have different sections for each, as if they are different.

Thank you.

Short answer is no.

In terms of normal bulk housing, it used to be that 5mm shift housings were more associated with mountain/utility and 4mm were more associated with road. Now 4mm has become more the norm for everything, although it's kind of a matter of perspective because there are a lot of bikes still running around with 5mm, and you can still buy 5mm. Either works on both, and the common ferrules both have the same OD (there are weirdo ferrules for weirdo frames that need smaller and larger ones, but that's a tangent).

As you've seen, there are various cable kits labeled as mountain or road, and groupset-specific in Shimano's case. There's a couple things going on here. The dimensions of the parts haven't changed - all the mainstream component groups can accept normal housings and ferrules without any adornment. But, the component makers and Shimano in particular seem to have developed certain really specific ideas about what combinations of nosed ferrules and sealing doodads are supposed to go along with which component group, and that's what their group-specific or road versus mountain distinctions are about. Jagwire and other cable set makers have kind of done the same thing. It's all pretty arbitrary in my opinion, but it's a debatable point. The exception is that Shimano is now pushing their slick coated cables very hard for road, and I think that's as it should because their under-the-tape shift routing STIs can have a lot of issues with excess friction being generated at the bar (and that's more or less the reason for the push.)

Also, as was mentioned in the comments, there's some notion that the pre-cut housing lengths in packaged cable sets correspond to road or mountain. Honestly this in my opinion is the biggest reason not to even pay attention to the kits that come with pre-cut housings; the world we're living in now is that bikes have all sorts of different housing/cable routing schemes even within their genres, and you need to just cut it to length and make it right.


How do you keep from coasting too much on a bicycle? Something that has always confused me about working out on a bike.  I want a Hybrid to ride for fitness.  I do not want the Road bike, mostly because I'm not going to ride on the road (I am too afraid of being run over).  The Hybrid will be on paved trails.  Plus, my back would not survive leaned over on a Road Bike, though I wish I could.

My question is how do you keep from coasting too much?  Whenever I think of biking, I inevitably think of hitting hills eventually.  Granted I have to go up the hill, but then I'm coasting down.  And on flat, how do I keep the wheels moving without coasting?  Just the right gear and discipline?

One can only go so fast, so sooner or later I will have to stop pedaling, and I also don't think I can go full out all the time.

You are correct - keeping the bike in the appropriate gear is important. Generally, you should have a preferred pedaling rpm, or cadence that you try to keep constant. Change to lower gears on uphill gradients, higher gears on downhill gradients.

If you find yourself going downhill at a speed that even your highest gear makes you pedal too fast, feel free to coast. There is no rule that says you have to spin your legs madly to keep pedaling. Hybrid bikes tend to have fairly low gearing so coasting on faster downhill sections is normal.


Differences Between Shimano Ultegra & 105 Drivetrains I'm in the market for a new bike (or possibly a groupo upgrade on my current bike that has 8-speed Ultegra 600 components from the early 90s). I'm trying to determine if the premium for an Ultegra drivetrain is worth it.

I know one of the main differences between Ultegra and 105 is going to be the weight, which I am not as concerned with as much as I am with durability and reliability.

I typically put 150-200 miles a week on my bike with my long rides being 50-100 miles. I am not a serious racer, but I do participate in 3-4 organized race/rides each summer.

If I go with a new bike I'd like to stay in $2k range, but could talk myself into as much as $3k if warranted.

Also, since many builds seem to be coming with mixed components are there any items I want to make sure I don't skimp on? I'm guessing STI levers and derailers specifically?

Any words of wisdom?

If you're planning on doing a reasonable amount of Kms I wouldn't purchase anything with less than 105 on it. The groupset tends to reflect the quality of the bike your purchasing. If it comes with a mix of 105 and Tiagra, then it is probably aimed at the recreational rider who might take it out once every other week.

As for 105 vs Ultegra, some parts may make a difference. I don' know the full implications, but I would really take a 105 and ultegra out for a ride and test the shifting speed and precision. I expect the ultegra will shift a little quicker and smoother.

Personally I run SRAM force and love it. It isn't for everyone though as there is only one paddle that shifts up and down based on the length  of your push. With that said, on the cassette I can shift up 3 gears at a time; taking me from 12 to 32T in 4 throws of the lever.

I know in Australia $2k will get you a reasonable bike running 105; and we are one of the most expensive places in the world to buy bikes.


Training fasted: just about weight loss? Preparing for a 100mile ride in August I was thinking of following a training plan which came in a "Sportive Guide" given away with Cycling Plus magazine this month.

Some of the days on the plan mention training for an hour before breakfast in order to burn fat.

Is this just about losing weight? (If so, I'm pretty sure I don't need to since I'm 6ft tall and weigh about 67kg) Or is there some reason that training before breakfast is somehow better?

Advice in book Racing Weight by Matt Fitzgerald goes something like this, paraphrased:

Yes, training without carbohydrates will train your body to use stored fat better. But your capacity to train will go down (not enough fuel!), and net result will be less improvement.

It references this study, which compares two groups of athletes on hi-carb and low-carb diet during a hard training block.

One of the general themes of the book is, you want to improve your performance and body composition, not your weight per se.


Will I notice the benefits of changing wheels? I've got a 2010 Specialized Tarmac Comp. The wheels are Mavic Aksiums and are pretty well known to be dam heavy (but sturdy)

I'm seriously considering swapping them for something like Fulcrum Racing 3's, that alone should save around 500g

I've never ridden another bike and never changed wheels before so will I notice a reasonable difference and do you think its worth swapping them for something like the Fulcrums?

Interested in peoples opinions pros/cons.

I weigh 80kgs ride a mixture of flat to very hilly terrain and approximately 80-100 miles / week

I think probably swapping your wheels out is just about the single biggest improvement you can make to a bike in terms of performance.

I did this last year and love the new wheels. I too was riding Aksiums (I think) and bought some Fast Forwards. Qualitatively I am very impressed (but then I should be, if you boil everything down to money the FFwds cost 5x a set of Aksiums). Quantitatively, its difficult to say how noticeable the change is. I didn't see my average speeds jump or anything, at least not enough to notice. (I certainly notice being blown across the road sometimes (6cm rims), but that I'm not sure that counts!)

But now the caveat.....it all depends what you swap them for. I have no experience of Fulcrums so can't say how good that particular swap would be. Possibly someone else could help there. All I would note is that they're still toward the lower end of the price range (when you think you could spent thousands on wheels), so possibly they might not make as much difference as you'd hope. But as I say that's based on a hunch rather than direct knowledge.

One other point: not so long ago I had a spoke go on the Ffwds. Was a real pain in the ass to get a replacement (they were fancy bladed DT Swiss spokes and you're always recommended to change like for like). Nobody in the UK could sell me just a handful of spokes, only a box of them at about £100. In the end I found a place in the US who would sell them singly, just for a dollar or two, but it cost in terms of delivery and duty. I'm just saying, whatever wheelset you get it might be worth making sure you can source spares for it easily.


Is cycling with crystal sunglasses dangerous? I'm a commuter cyclist. I have a pair of Persol sunglasses with leaded crystal lenses. Do y'all think this is dangerous in case of an accident? I have terrible thoughts of wrecking and glass shards going into my eyes, but I'd rather not carry two pairs of sunglasses. Thanks in advance for your answers.

Edit to respond to below comment because I can't comment yet: I don't know their behavior when impacted... that's kind of what I'm getting at with this question.

Richard

I have had my glasses damaged when falling off/getting hit on my bicycle, even with a helmet. Since my lenses are polycarbonate, they tend to just bounce on the road if they do come out of the frame. I'd think in some of those hits that my glasses would have broken if they were made from glass (especially when my glasses have hit the curb or rocks).

Based on this experience, I wouldn't risk using glass based sunglasses on a bicycle if I had the option. You can find safety glasses which act like sunglasses for a relatively low price, which don't look bad (e.g. the Uvex SafetyPro line) [but note these are likely not tested for sports, but are designed for some level of safety].

The best person to ask would likely be an optometrist or eyeglass retailer (the former likely being less biased than the latter) on what they would suggest for sports. This article (Cobb, Clark, and Chad Hulsopple. "Eye injuries in athletes." eMedRef (MU) (2010).) suggests use of polycarbonate for sports.


Carbon fibre vs aluminium for racing I've been commuting on a mountain bike these past 3 years. Now I want to get into road bike racing. Is it worth saving up money over a few months for a carbon fibre bike? Or should I just go and buy a good quality aluminum bike tomorrow?

There are two answers to this question:

(Money no object)

Go out and buy yourself a carbon frame with all the trimmings. If you want to race, there is no better hardware option.

(Money important)

you say you haven't even begun to race yet. How do you know you'll like it? How do you know you'll be any good? If you go down a carbon route, you're talking about a serious investment which could possibly end up gathering dust in your garage. Frankly, you should consider a steel bike at this stage. When you're losing races because of the weight of the bike, then it's time to upgrade.

Be careful with something like bike racing, it will eat up your every last penny if you're not careful.


Do I need to change my cassette if I can't see any wear? I bought a new road bike with Campag Athena 11 speed in March last year. To the end of Jan it had covered 9000km.

In all that time I hadn't changed the chain because I don't have the Campag tool, and the KMC chain was not available. I finally got a new chain recently - unsurprisingly the old one was very stretched - so I bought a new cassette as well.

The thing is, the new chain on the old cassette runs very smoothly, and even dismantling them and comparing the cogs I can't see any change in shape or size! I don't know what Campag are making them out of, but it's fantastic stuff.

Everyone I've spoken to is convinced that after 9000km on one chain the cassette will be useless, but the prevailing advice is also to change the cassette when there are issues, and there just don't seem to be any.

That's an impressive amount of mileage on a single chain.  Especially on a narrow 11-speed one.  I'm guessing that you keep everything very well maintained and don't ride in much wet weather?

The two main problems you'll get from a worn cassette are:

Skipping chain (either between cogs or jumping on a single cog)
Premature chain wear (as the chain stretches to match the worn cassette's teeth)

If you're not seeing the first problem and visually the cassette looks fine, then you're probably ok to keep using it.  Best case, everything works fine and you've delayed the cost of using your new cassette.  Worst case, your new chain won't last as long and at that point you'll have to change both.

Since chains cost much less than cassettes, I'd suggest running with the old cassette if it's not skipping and shifts smoothly.


Feasability of repairing '70s-era welded-steel luggage rack I've got a '70s Motoconfort (Motobecane) with the original "French randonneur-style" front luggage rack (it looks like a very small porteur rack):

In the photo above, the rack is mounted to the bike frame via a bracket which sits between the front brake and the frame on the brake mounting bolt (highlighted in red). However, this mounting plate has sadly cracked with use:

Although this isn't exactly a "Welding Stack Exchange", perhaps someone here has experience in (trying to) repair this sort of metalwork?-- Is it possible and feasible from an economic and/or usage perspective, and if so, how can it be done? Of course, such a small front rack would never need to carry a truly heavy load, but it should be strong enough to hold a significant amount of weight without bending or breaking (again). It would be a shame to throw it away, since it seems that Motoconfort/Motobecane luggage racks aren't all that common any more.

That looks as though it was chrome plated after it was welded together, which means cleaning it up so you can safely weld it again is going to be tedious. You'll need to clean the chrome off anything that will get hot, and afterwards painting it will not look that great. It would probably be cheaper to build a new rack.

One repair option that occurs to me is to cut a T shaped piece of steel to fit on the bike side of the bracket, bending the bottom of the T out to support the lower part of the rack. Then make a second piece of steel for the other wide, probably rectangular, to actually hold everything in place. Drill holes in both parts to allow the mounting bolt to go through.

If you made that out of ~2mm thick steel, then painted it, you should get another year or so out of the rack. Assuming to can resist the urge to overload it.

A rack like that with one bolt really isn't designed to take much more than a journal and a baguette.


What is the life expectancy of aluminum alloy frames? I learned for the first time that aluminum alloy frames are said to have a "life expectancy".

This is the bike in question, my 2007 Felt Z80. It has an aluminum alloy frame. I really like it and don't want to buy another road bike for a while. But it is almost 10 years old. My specific frame is a 7005 series alloy.

From what I was told, steel frames show their degradation with rust while aluminium alloy may not show any signs at all even though it is still degrading.

How can you tell if an aluminum alloy frame is starting to degrade before catastrophic failure?

How long can I expect an aluminum alloy frame to last?

Material fatigue does happens, it is not caused by time, but due to excessive stress on usage, and/or manufacturing process and/or design fault. If all done under optimal condition, no over stress(e.g. a 120kg person ride it without suspension and under inflate tyre), a aluminium bicycle may last forever.

A bang, a fall, can generate impact that stress the frame weak point. If you are not using it for long time, then the stress is little to none, discounting the stress from introduced from bolts/screw/welding joints/mounting temperature contraction/expansion.

If you search around stackexchange on the same topics, there is advice that you don't put your bike under the snow : i.e. a concern about welding material contraction different than the frame. But this shouldn't be an issue as long as you didn't move the bike from very cold place to very warm place (i.e., temperature different ~ 20 degree Celsius).

Consumer association with loaded funds, such as the German Stifftung Warentest, does indeed test consumer bicycle from time to time, especially for Ebike, due to ebikes are more susceptible to weight stress (the additional motor and battery weight).  As some report I read, in 2013, series of ebikes are not satisfied due to the stress test. However, in 2016, many passed the stress test, except for one bike that had a cracked aluminium seat post.

So it is all about how the manufacture learn to build the bike better.

In addition, it is a myth that titanium will fair better when put on stress : it is all about manufacturing process and design.

About the "metal deteriorate issues"
- A proper maintain steel frame will not rust. Lube and oil them, you will never see the oxidisation
- Aluminium "rust" will stop when oxidation form on the outer layer.

In addition,  steel frame WILL NOT rust, if you maintain it properly.

Update from @Barny :
** Having been the owner of a marin larkspur hybrid 6061 alu frame that has been replaced no less than three times under warranty, each time due to fatigue failure ( i am 5'8'' @ 77kg ) and each frame lasted between 12k - 18k miles, i am of the opinion the lifespan of a 6061 alu frame is around 15k road miles. First failure driveside chainstay split apart halfway along, second failure driveside seatstay split halfway along, third failure crack around downtube / bottom bracket. **


Campagnolo EPS vs Shimano Di? I am tempted in buying a Campagnolo Athena EPS groupset, but I am also eyeing the Shimano Ultegra Di2.

What are the pros and cons of both of these? And don't get me started with SRAM as well.

I'll declare an interest in that my company is the senior (Main) Technical, Service and Warranty Centre for Campagnolo in the UK - but having said that. the Service Centre work that we do for Campagnolo is not all of what we do - we supply general technical training to the industry across the board and I am also part owner and Technical Director of a business that looks after Services de Courses activity for races and spotifs here & in Europe (www.servicecorps.eu), so I have seen the best and the worst of all the electronic and mechanical systems out there.

There are some urban myths around electronic - wet weather performance being one. This is not an issue for any of the systems in the market if they are properly installed. Shimano has slightly greater vulnerability because there are more breaks in the wiring loom than with Campagnolo but if it's assembled to Shimano specs this is not a problem.

Battery life - Di2 and Campagnolo are both around the same - both will give from a full 4 hour charge, something around 1200 km of normal use - it depends how much you shift and how the split is between F and R shifting. F shifting is more power consumptive in both systems. If the battery fails, Shimano defaults to the inside chainring. Campagnolo allows you to manually position the RD under any lower (easier) gear than the one you were in when the battery failed but you can't manually move the FD. In our experience, most people with electronic shift are so paranoid about this that in real life it's never a problem.

Electronic shift won't make you go any faster in and of itself ... it is more accurate though and once correctly installed, it will remain as accurate as it was the day it was installed, unless the user changes something, chain, cassette and chairing wear of course needing to be accounted for. The accuracy of shift remains, however tired the rider. In competition, this can matter.

Cost and cost of ownership - Shimano Ultegra Di2 is at a killer initial price point - the system is robust, spare parts are widely available and expertise likewise. Problems though, can be a headache to diagnose and the diagnostic software also requires (at the moment, anyway) connection through a relatively expensive interface to a PC. Campagnolo Chorus is comparatively expensive but offers a higher-spec, carbon crank set and on-board basic diagnostics. In my general (and genuine) experience, chainring and cassette life is better than Shimano, chain life can be better and I have never seen a correctly fitted Campagnolo chain fail - I have seen one or two instances with Shimano chain that I can't account for by fitting (but maintenance and use play into this and there is also a lot more Shimano "around" so that might also account for it on simple probability rules.

If the cost and availability issues are not the decision makers, then in terms of functionality, there is very little to choose - both shift, shift relaibly and well.

Some users prefer the ergonomics of one over the other, especially when wearing gloves - Campagnolo use a thumb lever to shift one way, a lever behind the brake lever to shift the other way so you are never in doubt which way you are going to shift - that's not always the case with Shimano with their closely-located shift buttons. Campagnolo place the feet closer together on all their crank designs than Shimano - this gives more options for bike fitting (if that is a consideration) and could be said to be inherently more "aero" FWIW.

Most of the choice, costs aside, are going to come down to aesthetics and ergonomics. There is very little bad product from Shimano or Campagnolo in the market now, design and execution from both makers is excellent. IME if SRAM could sort out some of their build-quality issues, they'd be up there as well but conversation with bike mechanics will tell you where their preferences lie and it's not as often with SRAM as with Shimano or Campagnolo - having said that a lot of mechanics are more wary of Campagnolo because they don't see it so often and equate doing things differently, with doing things worse. Not the case - but you do have to know how to set it up & that's not the same was as Shimano.


How do I identify the manufacturing year of a Surly frame? I am looking at purchasing a used Surly Pacer. However, the owner is unsure of the year (he also bought it used). Are there any visual cues that I can use to identify the year of the frame?

From Surly themselves:
"What year was my frame built?

You know that serial number on the underside of your bottom bracket? No?! Ok, so flip your bike over and take a look closely at the bottom bracket shell (the cylinder at the bottom of the frame around which your crank rotates). There will be a code stamped into the shell starting with the letter "M". Sometimes this stamp has a bunch of paint that has collected in it but look closely, it is there, I promise. The following number after the M signifies the last digit(s) of the production year of your frame. So, for instance, M2598144 was made in 2002, M8128666 was made in 2008 and M10034269 was made in 2010. Now write down the serial number and keep it somewhere you can find it in case your bike gets stolen. This might be the only identifiable mark on your frame if it comes back to you!"


Chain not sliding into casette perfectly I have a RD 7900 derailleur and a standard 105 28t casette.

After replacing my wheelset I observed after I put my bike on the workstand that the chain is not sliding in perfectly into the casette cogs in the lowest (28t) gear, all other gears are fine.

It makes some sort of grinding noies because, spoiler alert, the casette teeth are grinding on the chain rings and "forcing them" into place.

The derailleur is indexed and high low screws are properly set. I also dont think the derailleurs bent but I cant make that judgement with my bare eye.

How do I adjust my derailleur so that the teeth on the casette will fit perfectly in the chain ?

By definition, if the chain is not running on all cassette sprockets properly, the indexing and/or limits are not properly adjusted. Low limit setting being off would be my guess.

Run through the full indexing adjustment procedure. Park Tool Company has the best instruction video.

You can check the derailleur hanger by lifting up the rear wheel and looking down a line from the derailleur cage to the chainrings. The cage should look parallel to the rings.


Google Maps for cycling I would like to understand how to find cyclist friendly paths in London using Google Maps on my Windows 10 PC. I can do this using my Android phone, there is an option that shows me such paths in the google map app. These paths are shown in green. However, when I just go to  https://www.google.com/maps on my Windows 10 PC I don't see a setting that would highlight such paths. In fact google maps will propose me a cyclist path (or several paths) between any two points, but I will not be able to see which bits of this path are cyclist friendly and which are not. Such bits would be shown in green on my android app.
So is there some way to see these "green paths" on my Windows PC?

Unless you see a very different Google Maps in the UK than I see in the US:


How do you shift your weight when leaning on a turn? When I turn I usually shift my weight on the same side I'm turning to. To ease the discussion let's assume we are turning left, on a paved road (no mud/gravel/potholes/grease/oil/ice/door traps).

I would lower the right foot, move my bottom to the left and this is sufficient to tilt the bicycle to the left.

However I have seen other people doing different things (remember we are turning to the left):

some people do the same as I do, but in addition they stick their left knee sideways. I tried (when nobody was watching) but don't see any advantage.
Some other people instead move their bottom to the right and then (I think using their hands) they tilt the bicycle to the left.

Having given this context (but feel free to add more styles/methods) I wonder what's the best way to take a turn, primarily in terms of speed, but I'm also interested in safety, when I can activate my brain enough (sometimes happens).

I think this relates quite nicely to motorbikes where you corner at very high speeds and I'll give a run-down of the techniques, why they are useful and how they apply, and how they might apply to cycling.

So when turning left:

You shift your weight over on the seat and tilt the bike left. This allows the centre of gravity to be slightly lower, aiding in stability and keeps the contact patch of the tyre to road more central.
Sticking your left knee out also. This is done for two reasons, firstly (if you're wearing knee protection) it can give an indication of when you're leant over too far (your knee touches the floor). Secondly it works like an air brake (for additional braking) and also will start pulling you towards the direction you are going slightly. You have to be going pretty fast for this to be effective, but it can help if you're racing.
I can't see any benefit of tilting the bike over whilst staying more upright. Higher centre of gravity, less control. It might be a sub-conscious impulse to not falling over low-side.

Another tip for cornering fast:

When going into a corner and you feel like you may run wide, or want to tuck into the apex a little more, turn the handlebars in the opposite direction to the turn (right) just a little. This is called 'counter-steering' and will cause the bike to tip over more and turn in a little harder. This can be a life saving technique if there is a car coming the other way or is overtaking you. Don't over do it though ;)

Also, ultimate safety tip: never brake and turn at the same time.

Source: I've been riding high performance motorcycles for about 5 years.


Front caliper rubbing spokes, should I dish the wheel outward? I've a problem with my front wheel.
I have a Velocity Aileron rim (584mm ERD), a Shutter Precision SL-9 dynamo hub(the flanges are not offseted like other disk hubs, but they have a smaller diameter than usual) and 28 Sapim CX-Ray spokes.
I'm using a 160mm CenterLock rotor on it in combination of a flat-mount Sram Force hydro caliper.
I have a carbon fork with a quick release axle.

When on the stands the caliper/pads are correctly centered and there is no disc rub, however the space between the caliper and the spokes is only ~1mm.

Here's a not very clear photo (notice the banjo bolt) :

Under load (when I'm braking while riding), there seems to be some flex and the caliper rubs the spokes.

So the diagnosis I've made is that the distance between the spokes and the caliper is too small, and the symptom is that it causes some rubbing.

Assuming the wheel is correctly mounted (centered and correct tension, I trust my wheelbuilder for now), what solutions do I have ?

We came to the conclusion that I could dish the wheel outward a bit by tightening all non drive-spokes half a turn. Does it sound like a good idea ?

Super frustrating problem. Some brakes are a little notorious for this.

You don't mention whether your pad/piston extension is centered. If by some chance it was biased towards the inside pad being more extended currently, fixing that could fix the whole thing. By the same token, brakes have some tolerance for unequal extension, so biasing it towards the outer pad being a little more extended could also be a workaround. (You would try this be resetting the pistons and adjusting the caliper to a starting position where the inside gap is less than the outside gap, then letting them self-adjust. The brake mount has to be done on the fork such that the caliper has room in the slots to slide over this much.)

Shimming the rotor is also a possible fix. You can buy special centerlock shims for this or you can cut through one side of a freehub/freewheel/BB spacer to bend it on clear of the centerlock splines. This also requires room in the adjustment range of the caliper to work.

If you don't have adjustment room, there are also possible solutions involving lacing the brake side of the wheel all heads-out. You could do it crossed, kind of reverse "race lace," with the spokes you have now bent around each other and more prone to fatigue breakage, or you could half-radial the wheel and rely on the relatively large smallest inscribed diameter of this hub to transfer brake loads to the right flange, a trick that some boutique wheels also play. Both are probably pretty bad ideas that would at least work for a while. (It would be up to you to do the math/research on whether your SP's shell diameter was adequate for the latter plan.) Another path would be lace that side of the wheel one cross, heads out. One cross wheels are usually all laced on one side of the flange, and the cross would be up far enough that it's not awkard in terms of spokes being bent around each other. This would give that side of the wheel some torsional strength to brace against bracing loads. It may be plenty of torsional strength for the purpose in fact, but again doing the math would have to be on you. I believe all of these plans would buy you an amount of clearance equal to the flange thickness.

Putting the wheel out of dish enough to actually solve this seems bad to me.


How should I transport Cannondale Bad Boy 5 INSIDE a BMW 4 Series Coupe? So, I have a Cannondale Bad Boy 5 and I'm LOVING it.

I'd like to understand how to transport it. I have 2014 BMW 4 Series coupe. Even though I folded back seats (to maximize trunk storage), bike won't fit there (well at least not all the way anyway), so I gotta take one of the wheel off. The wheels are 700c discs and the fork is a Cannondale Lefty fork (i.e. attaches only on one side).

my main concern is since i cannot easily take off front wheel due to lefty fork and i can use quick release to take the rear wheel off; What's better way to handle derailleur (without ruining your cloth, car, etc).

Ideally I'd like to:

use quick release to remove rear wheel,
place chain into some sort of container (suggestions?),
place bike along with separated wheel (derailleur up) inside of the car,
go to wherever, and revert procedure.

None of the other answers deal with the OPs desire to keep the bike inside the car, i.e. not on a rack.

To put the bike in the car, you have to take off at least one of the wheels.

Pedro sells a "chain keeper" which is designed to keep the chain on or near the derailleur when the rear wheel is off:

This should help you considerably (along with old towels and maybe a moving blanket) to put the bike cleanly in the car with the rear wheel off.


One stripped post mount on suspension fork I have a suspension fork, which has a stripped lower post mount, i.e. the bolt used to attach the brake caliper doesn't grip the post. Before anyone asks - yes, it is the correct size bolt, as the upper post is fine. Would it be possible to use something like a heli-coil insert to repair the thread or would you consider this unsafe ? FYI I am running a 160mm disc up front, and only do XC/Trail riding - so nothing too mental :-)..Thanks for any advice.

You might consider tapping this thread back out if you have a decent tap-and-die set.  Otherwise, a heli-coil should work for this application.  I would be more concerned with a heli-coil if you were using it on a post-bolt that would experience tensile stress--that is, "pull-out" force.  This bolt will be under mostly shear-stress, which means that the majority of the strength will be derived from the body of the post rather than from the threads.

I'm not an engineer--engineers, please correct me--but this is what my thinking is when I fix a broken piece of metal in a situation like yours.

If you are a little paranoid, you might goop the bolt threads with some JB Weld before threading them into the heli-coil.  This will add a little tensile strength and piece of mind, but should be pretty easy to break out with a breaker-bar if and when you choose to remove the part.

Note also that, in my experience, any use of a heli-coil or JB weld has the potential to be an "ultimate" fix.  That is, once it's fixed... it's fixed for all practical purposes and subject to failure if "fixed" again in the same place.  I might do this to my 90's Rockhopper, but I don't suggest it for your 2011 Santa Cruz Blur that you plan to change everything out on next season.

Short answer:  With the sort of riding you are suggesting, I would do the fix you are suggesting on my beater mountain bike.  On my high-end down-hill ride... I would take it to a frame builder and have the post replaced.


Alternatives to trailers for transporting young children A representative in Oregon has recently introduced a bill that would prohibit children under the age of six from riding in bicycle trailers. While it is far too early to tell whether this bill will pass, and what the final law would look like if it did, I am curious what alternatives to bike trailers people can recommend. I don't have kids myself, but I grew up riding around in a bike trailer, and know people who do have children and use trailers like these. I am particularly interested in suggestions for families with multiple young children, since one reason my family loved bike trailers was because it could easily fit two of us at once. If this law were to pass, what alternatives would be available?

Followed some links from your links and found the actual text of the law, which summarizes the law as:

  Prohibits person from carrying child
  under six years of age on bicycle or
  in bicycle trailer.

Elsewhere in Oregon law, a bicycle is defined as:

  [a human-powered vehicle] designed to travel with not more than three wheels in contact with the ground.

So a unicycle, bicycle and tricycle are all covered by the proposed law.  There's also a wheel-size provision in the definition, which makes me suspect that too small of wheels or 4 of them puts you in a category like skateboards that probably aren't allowed on the road.

So I think you simply have no solution if that law passes as written. Everything I've ever seen for using a bicycle to transport a child constitutes "on bicycle" or "in trailer".  Even if you devised some clever sidecar or push-cart mechanism to get around the letter of the law, I doubt that would work.

But just in case it's useful, there was an earlier question along these lines that I think covers all the answers you could be looking for: Recommendations for Transporting Twins On The Front of a Bike

Basic summary:

Coolest option is a bucket bike (long wheelbase with a big box built in). Common in Netherlands, rare in the US.  Search for "cargo bike" in your area (I know there's bikes of this type made in Portland, OR)
Next best is probably a long-tailed bike, such as an extracycle, especially if you can get seats designed for that use
There's child seats that mount on a bike rack behind you
child seats that mount on the handlebars in front of you (you could combine this one with any of the other options)
Trailers are pretty darned good for carrying children.


Did i buy the wrong derailleur? (mech hanger/direct to frame) I'm a total newbie with bike repair and  I can't figure out this hanger/direct to frame business. Googling doesn't help much.

Here is a picture of the current derailleur and the new one I bought. The mount doesn't look the same. I was wondering if it could still work or if I definitely need to exchange the one I bought for a more appropriate one.

It appears from your photo that you indeed have the wrong style derailleur. Your frame appears to have vertical dropouts and a frame derailleur mount. The derailleur you purchased is designed for a frame with horizontal axle slots. Since the derailleur hanger mounts under the axle nut your frame doesn't have a slot big enough for it to fit.


Can I use BMX brakes on my Murray Ultraterrain MTB? I have an outdated 90's MTB that requires single pivot brake calipers. The only brakes of this kind I have found are either for road bikes or BMX bikes. How do I know if they would actually fit before my online purchase?

The features that need to match are reach from mounting bolt to rim and recessed / normal nut. A BMX sidepull brake will probably work, but it's better to check the measurements before buying.

For younger readers, Murray was a legendary BSO brand in the 1990s. They did come with centerpull brakes made out of thin sheet metal.


Changing wheel size on Jamis Aurora Elite to 26"? Jamis Aurora Elite comes with disk brakes on 700c wheels. I am wondering is it possible to put 26 inch wheels on?

Since it has disk brakes, I can't see any issues with fitting the brakes. Only problem might be the ground clearance to the pedals.

The 26 inch wheels are good for touring with load, 700c wheels ideal for daily commute. I am looking for a bike which will fit both needs.

What you don't want to do under all circumstances is make large enough changes to the outside diameter of the inflated tire that pedal/crank clearance with the ground becomes an issue. Geometry will suffer too, but as a rule of thumb, dealbreaking ground clearance problems will arise first. (It's my rule of thumb at least, having observed various wheel conversions where it seems fine at first and then you learn you get pedal strike in turns).

Generally speaking, if the brakes are a non-issue or a solved issue, i.e. a disk brake or switching to a different reach of rim brake, you can do whatever you want with swapping wheel sizes as long as the tire OD stays about the same while avoiding frame clearance issues with the tire. Lots of things about the bike and its ride qualities will change, but it will generally be rideable and functional. Note how 27.5+ bikes interchange with 29x2.3-2.4ish wheels, many people convert 700x23ish road bikes to 650b, downhillers running extra fat 24s in place of 26s, trials bikes with 19"x2.5" subbed in in back, etc. All the same principle.

There might be a better resource, but the lazy way of comparing tire ODs across different wheel and tire sizes is a computer circumference chart and dividing by pi. Tire deflection of course throws it all off a little, but meh.

In the case of a touring bike and trying to go from 700 to 26" (559), you'll usually find that you won't have enough fork/chainstay/seatstay clearance for the width of tires that get you into the right ballpark. There are exceptions, particularly with forks and seatstays because they're less inherently constrained in this way, but chainstays will usually be a pretty major limiting factor in back.

Applying your idea with 27.5"/650B wheels is more likely to work out.


Bike chain worn to 1% according to indicator tool My bike chain is worn to the 1% gauge on my indicator but only on certain links.  I could check a different link and it won't fit at all. However it would drop right through on certain links.

Should I be looking at replacing the chain and rear cassette?

I would replace the chain at such condition (if there are 3 or more places or if there are multiple links).
About the cassette it's another question, and if you can't decide yourself, it should be checked in LBS probably.


Shimano Revoshift twist grip unusably tight Shimano twist grip shifter on Apollo Neo 6 girls bike. I bought this bike 6 months ago for my 7 year old.

After getting it serviced at 99 Bikes the shifter was so stiff my daughter couldn’t change from the 2nd gear into the first.  Took it back & the mechanic checked it & said it was normal.  I insisted on him replacing the gear cable but… no change.  I flooded the handlebar twist grip with lube but no change.  Went back to the shop and the same guy said nothing wrong and that’s how those shifters work.  I demonstrated that my daughter couldn’t access the first gear.  Seriously, it requires a very firm grip and a firm twist even for an adult.  Now I’m quoted $100 to replace the shifter with a thumb shifter.  My daughter is normal strong for a kid.  Is this a design fault or a mechanic needing replacement?

As per AndyP’s comment, I have also heard anecdotally that these styles of shifters can be stiff for children’s hands, but then again some thumb push trigger shifters can feel quite stiff to my adult thumbs.

As you mention it is most difficult for your daughter to access first gear, I would investigate or have the shop check the Lower Limit screw on the derailleur. If this is set a fraction too tight then the shifter is trying to pull tension against this limit. If this screw is set too tight then the shop should adjust it to the correct position as part of the labour you’ve already paid for. It’s probably only a fraction of a turn.

Otherwise, changing to a trigger shifter unit needn’t be very expensive, but I would try models out and find which suits your daughter’s hand strength the best. if you’re quoting AUD price then maybe it includes the part cost and a minimum labour charge and that’s how much it costs to have work done on bikes where you are.

It has been suggested by an anonymous edit, from a person who had a similar problem, to double check the cable placement at the derailleur fixing bolt. For example this extract from the Shimano Tourney Dealer's manual


Are there any clip-on fenders that provide as full coverage as bolt-on fenders? Are there any clip-on non-eyelet fenders that provide as full coverage as bolt-on fenders?

I live in Seattle and am buying a new carbon commuting rain bike. Many of the high end bikes do not offer fender eyelets. On the other hand, there are many new carbon gravel bikes that do provide fender eyelets. I am curious how important of a factor is it to consider a bike with eyelets. I understand clip-on fenders are available for any bike. But I read online that some clip-on fenders have a gap in their coverage or stop halfway down the wheel.

Are there any clip-on fenders that provide as full coverage as eyelet-installed fenders?

No. In fact the language most have settled on is "full coverage fender" instead of something like "bolt-on fender" for just this reason. Clip-on fenders and Raceblades/Speedez/etc offer a lot less coverage. In particular what they tend to not cover well are your face, your feet, and the bike.

There are various ways of making full fenders work on bikes that have the clearance for them but not the eyelets (this type has become my favorite), and also there's the "reacharound" installation style, which can be okay but is somewhat of a kludge.

Honestly it now more than ever makes absolutely no sense at all to buy a bike intended for rain commuting that can't take full fenders. The options just aren't limited like they used to be.


How to correctly mount double-lock grips? I have a pair of PRO double lock-on grips (id est two lock rings per grip). In a recent crash, following an immensely helpful tip from a fellow rider, I clung to one end of the handlebars, turning the other end towards the ground. The handlebar absorbed much of the impact and only a month later I was able to ride my bike again without any pain.

My question is: have I mounted the grips correctly? As is visible, the white plastic part protrudes from the handlebar. And that is exactly where the metal lockring sits. Should the white part be pushed further inboard? It seems to have smaller inside diameter than the rest of the grip and was not sliding in easy - that's why I mounted it as I did.

Short answer, no!

Almost certainly the entire grip should be on the handlebar.

Then the 2 pieces of steel pushed in by the screws will tighten against the handlebar giving much better security.

The steel pieces should go in the cutouts on the hard plastic inner of the grip.

I'm not sure how well the grips will work now that they are missing some of their structure, but it's worth a try.

FYI, the reason that the hard part is more difficult to get on is that the multi part grips can get away with a looser tolerance under the rest of the grip, but not where they are actually attached to the handlebar.


Pedaling not connecting right away I ride a rather usual Merida hard-tail mountain bike.
Recently I've come to notice that when I start pedaling (bike already in motion), it can take up to as much as quarter of a turn for the pedals to click and the chain to start pulling the bike again.
What could cause this and more importantly, how can this be fixed? Is this merely a problem of chain tension?

The parts that Blam refers to are known as the pawls and the ratchet inside the freehub. Slipping can happen for a number of reasons, including worn ratchet, worn pawls, weak springs, or excessive accumulation of grease & grime within the freehub.

http://dirtmountainbike.com/features/work-freehub-body.html has a thorough explanation of the different freehub types.

Depending on the hub you have, a repair consists of either cleaning, rebuilding or replacing the freehub. Some freehubs are rebuildable, others are not and must be replaced as a unit. That said, it's often possible to extend the life of a non-rebuildable freehub by flushing out the old grease & gunk and regreasing.

The mechanic at your local bike shop can almost certainly take care of this for you. If you're more of the do-it-yourself type, http://www.parktool.com/blog/repair-help/freehub-service has step-by-step instructions for several different freehub types.


Install suspension forks on non-suspension bike I have a 1990s Saracen PowerTrax. Is there a way I can install a suspension fork, or will that muck up the bike somehow? I'm actually interested in ways to raise the bars with respect to the seat, so that wouldn't be a problem. My toes rubbing in the wheel, in the other hand, would definitely be a problem.

You might be able to fit a suspension fork on your bike, depending on frame geometry, but I think it’s likely you will not be able to.

Frames designed for suspension forks locate the head tube higher to allow for the extra length of a suspension fork, and to provide somewhere for the top of the wheel to go when the suspension compresses.

In the early-mid 90’s rigid bike’s either had no provision for suspension forks or a ‘suspension corrected’ frame and longer rigid fork that would allow for swapping in a suspension fork. If you have the former you obviously can’t fit a suspension fork. If the latter, there is still a problem because even a suspension corrected frame only allowed for a contemporary fork with something like 50mm of travel. Modern forks have twice to three times that amount.

If you fit a fork that is is longer than the frame was designed for you effectively rotate the whole frame around rear axle and change its geometry. The  head tube angle is increased which can negatively affect the steering, especially of an adjustment in fork offset is not also made. See here for some more information in this. The seat tube angle is also increased pushing the seat rearwards, and the bottom bracket is raised which can affect stability.

Some very inexpensive forks have low travel and may fit, but they are not very functional and mainly add mass.

It's not a good idea to try to raise the handlebars by installing a longer fork (for reasons above). A riser stem or steerer tube extension are simpler, cheaper and safer ways to do that.


E-bike tyres on normal bike I am shopping for tyres for my normal MTB. As I am mostly riding city, some gravel and light offroad I wanted something with good speed on road and some traction offroad. I found Schwalbe E-bike tyres which should offer just that.
Are there any downsides for riding e-bike tyres on normal bike?

E-bike tires are designed for heavier loads, and faster speeds. Comparing Marathon Plus regular with e-bike version, e-bike has deeper tread, two layer puncture protection, and rubber mixture optimized for higher speed. E-bike one also has max load 6kg higher. For 28 x 1.75 Shwalbe says that regular weights 1100 g and e-bike 1150 g. When I was choosing tires for my bike (about a month ago), e-bike ones felt much heavier, so I am sceptical about this data point.
My conclusion is, you would be paying money and using more mass for some features you would use, like enhanced flat protection, and some you will not, like optimization for heavy mass at high speed.
That said, I am really heavy and I can and want to go relatively fast, so I ended up choosing Energizer Plus Tour, designed for e-bikes, for my regular bike. And I am happy with that choice. Like you, I am mostly riding city, some gravel and light offroad now, and it works all right.


What is the most effective way to upgrade my Cervelo S2? I bought my Cervelo S2 2013 model a few years ago.

It has Shimano 105 groupset and brakes, and originally Fulcrum Racing 7 wheels which I have upgraded for Planet X Carbon 45mm wheels. The rest of the components is general aluminium stuff that does the job and I often stick a pair of aluminium Profile aerobars on.

I mostly race short 10-40km as part of triathlons, but I also use it for longer rides and even "touring" (with a rucksack rather than panniers).

I know the standard thing to upgrade is the wheels, but since I've already done that, I'm thinking maybe a better groupset?
My question to the world is: what would be the most effective upgrade to make me faster?

To get faster times, your options are:

Accelerate faster
Cruise faster
Decelerate faster

To accelerate faster, reduce rotating weight and increase bike & component stiffness. Reducing non-rotating component weight will not have much effect unless your races involve a lot of climbing, especially as lighter components are usually less stiff unless you're swapping cheap alloy for good carbon fibre.

To cruise faster, reducing drag, rolling resistance and drivetrain friction will help, in order of impact. Your body and clothing are currently the greatest contributors to your drag, especially since your frame doesn't use round tubes, has internal cable routing, and your rims are deep. Rolling resistance can be decreased by increasing your tyre width, since you're not racing on perfect surfaces (such as wooden velodromes). The current fashion in the pro peleton is 25mm.

To decelerate faster, use soft-compound brake pads. Reducing rotating weight also decreases the load on the brakes.

This review of a bike which I think matches yours lists the weight as 8.08kg. This isn't bad, and losing 1.3kg to get down to the 6.8kg UCI minimum will be far more expensive than eating less and riding more to lose body weight.

Things I would consider upgrading:

Tyres. Easy upgrade, quite cheap.
Chainset. The Praxis Turn M30 crank is about the same weight as Shimano Ultegra, but is surprisingly stiff. Praxis make a matching bottom bracket for most shells, including "old-school" BSA threaded 68mm shells.
Stem. Thomson Elite X4 is heavier than their X2 "road" model, but you'll struggle to twist the stem and the 4-bolt clamp is nice and wide.
Carbon bars, but not a superlight model, since you need them to be stiff for acceleration.

Of course, you still need to train more.


Is a road bike good for an Ironman race I am a race bike beginner and I am considering to buy a road bike. Is it doable to ride a road bike for an Ironman race or should I consider a Time-Trial bike?

I suggest buying a regular road bike, have it properly fit and ride it.

It will be good enough for a couple of years in all situations, not just triathlons.

You can upgrade it with some aero bars, better wheels and tyres.


Are tubeless tires the solution to frequent flat tires? I have owned a Trek FX3 for about 6 weeks and I have suffered 3 flats in the last 4 weeks (front and back tires).   All my cycling is on road (almost exclusively in the cycle lane). The shop I bought from have recommended that I go tubeless with sealant which I am a bit nervous about.

With all the flats I have managed to get home by simply inflating the tires with CO2, and I would have the tube replaced after that (not repaired).

I have 3 related questions:

Will the tubeless tire setup generally be more reliable?
Will I know when I get a flat with the new setup?  I worry with this setup that I might not realize that something has punctured my tire and end up with catastrophic tire damage from not removing the cause of the puncture.
I notice that the CO2 is very cold and was wondering if this might make the sealant less effective?

Thanks in advance.

UPDATE

I opted to try tubeless and the new tires would not fit on the rims no matter what the bike shop tried.  It turns out that there was a "tolerance issue" with the wheels on my bike.  This might explain why I had so many punctures (or maybe not?!)    I ended up getting free replacement wheels which are supposedly a lot better than what I have (They cost more than my entire bike!!)  Not sure what benefit this is to me other than the ride does feel a lot more comfortable.

I wouldn't go for tubeless as a first attempt to solve the problem.  Tubeless might be a good solution for skinny racing bike tyres, which are rather prone to puncturing.  But you really shouldn't be having much of a problem with punctures on a hybrid bike with 32C tyres.

Tubeless usually requires new tyres.  If you're going to buy new tyres, there are plenty of options such as kevlar-lined tyres that are very puncture-resistant. (Schwalbe make various kinds such as Marathon that are well spoken of by cyclists in much rougher environments than the road; other brands are available.)
You might want to consider tyre liners as a first line of defence.
Honestly, that many punctures in such a short time suggests that you're doing something wrong.

Are you making sure that whatever caused your puncture has been removed from the tyre before you fit a new or repaired inner tube?
What do the punctures look like? If it's on the inside of the tube, it's a problem with a spoke. If it's two separate holes on the sidewall (a "snake bite" or "pinch" puncture), it's because you hit a kerb or pothole too hard with under-inflated tyres and pinched the tube between the rim and the road. If it's a single hole on the outside, you ran over something sharp. If it's at the valve, either the valve hole in the rim has sharp edges or you didn't install the tube properly (the valve should be at right-angles to the rim, for example).
An unfortunate feature of cycle lanes is that road debris naturally migrates to the side of the road, where the cycle lane is. Cycle at least a couple of feet from the kerb to avoid the worst of it.
Avoid potholes as far as possible; ditto drain covers, manholes, etc. Make sure you always know what's behind you so you know when you can cycle around them. If you can't avoid a pothole, lift your bottom slightly off the saddle and cushion the impact by letting your knees flex.  Avoid puddles wherever possible – you don't know what hazards are under the water.
Speed bumps are just potholes in reverse so be careful there, too.  A common arrangement in the UK is to have the cycle lane bypass the speed bump, with a raised kerb between the cycle lane and speed bump, to force vehicles over the bump.  The kerb means that street sweepers can't get to the cycle lane so, again, it fills with puncture-causing debris.
Make sure you're running your tyres at the correct pressure.  Too soft and you'll get pinch flats; too high and minor damage can turn into a flat.

Also, you should definitely consider repairing your inner tubes. It's easy, saves a lot of money and the repaired tube is just as strong as the original. Also, it helps you diagnose the problem, as discussed above.


Shimano Dura-Ace 1st Generation Brake adjustment I am trying to get my rear brakes to work properly but I do not understand how it works.

I dissembled the caliper, cleaned each component (since the brake raked (?)). But now I have the problem that the side where the brake cable attaches is stiff and only the other side moves properly. I can provide two pictures of how I reassembled the brake

From another perspective:

On that second picture only the right side of the brake moves the other one does not when I pull the lever. Anyone who can help me?

Your spring is not right - its one or more of

bent unevenly
lost springiness with age
pinched
mounted not square in the retainer.

I've tried to show the difference I see here:

To be honest unless originality is a big thing, consider moving to a dual pivot brake caliper.  The old single pivot side pull caliper was always sub par.


Trouble balancing when starting I recently starting riding again (stopped for 10 years) and am having balance problems when starting.  Using the proper starting technique causes me to wobble and lose my balance, tho' I haven't fallen yet.  As a result I've got my saddle low to the point where my toes touch the ground and I have too much bend in my knees.  Knees don't hurt, but I know this is not the right way to ride.  Any suggestions other than switching to a trike?

The more speed you get, the more balanced you will be, so at the beginning give a hard pedal stroke to get quickly some speed. You can also practice in a slight downhill road, this gives you speed easier.

I recently taught a friend to ride a bicycle (30 years old!), and the solution was the slight downhill.

Another trick is to look far ahead (dont look at your front wheel) and stay upright, so you should put your saddle higher than you describe.

Good luck!


Is pressure of presta valve hard to read by design? I have dual system floor pump. When I use it with auto valve it is no brainer to use -- after attaching the pump I get the reading right away, I pump, with each stroke there is small spike in reading, but then pressure readings drops to around pressure in the tube. In other words oscillation is very small and it is easy to read pressure just after attachment or during pumping.

However with presta valve it is completely different story (I was wondering if it is my pump fault, but after some googling I see others face the same problem) -- after attaching the pump I have no reading (i.e. pressure is supposed to be zero), with each stroke there is huge spike in reading the pressure, and then the pressure reading drops to nearly zero again.

Two completely different worlds. I already read some tips about pumping, like slow, smooth, strokes so you could have time to read the peak pressure, but this does not suite me (I already blew one tube with presta valve due to misreading the pressure).

My question is this -- is this problem systematic, by design, or are there some pumps which can give the readings as nicely as for auto valve?

The problem is your pump's valve chuck. Some valve chucks press the valve's center pin, which lets the pressure from tire to pump and allows reading the pressure. Some other chucks, such as the one you have, do not do that feature. If pressure drops to near zero after every stroke, there may also a leak somewhere in your pump.

Replacement valve chucks are available, you can replace it if you do not want to buy an entire new pump.


Rear derailleur hits spokes when switching to largest sprocket I accidentally ran a bungee strap through my old rear deraileur and it tore it apart. I have fitted an identical replacement but cannot work out how to adjust it so that the tension pulley does not collide with the spokes of the rear wheel.

The original rear derailleur, damaged

(hi-res version here )

Originally I bought the bike new from the LBS, who built it. It looks like they may have bent deliberately the metal frame that holds the guide pully but I'm a little anxious about trashing a brand new derailleur without confirmation that this is the best solution.

I ride a Surly Crosscheck and this rear derailleur is the standard spec so it seems more likely that the crunch has damaged another part or I have misfitted the rear derailleur.

What is the likely problem that is causing the guide pulley to collide with the spokes when I switch to the large sprocket?

I guess the derailleur hanger or the bit of frame it connects to must be bent. These can be bent back. Of course Sheldon Brown has some advice, but I'd be afraid to do this myself and instead take it to the LBS who will have the tools.


Saddlebag clamp on carbon seat post? I think Mr. Fusion seems perfect, except they don't recommend it for carbon seatposts
https://porcelainrocket.com/collections/store/products/mr-fusion

Q : Why is Mr. Fusion not recommended for carbon seatposts?
A : Some folks tend to get a bit ham-fisted when tightening bolts on
their bicycles, and Porcelain Rocket cannot be held responsible for
damage to expensive carbon seatposts, due to over-torquing of the
clamp bolt.  The clamp bolt is meant to be tightened to NO MORE than
4Nm.  This is about the same torque that you would apply to MTB brake
levers; tight enough to hold the stabilizing rack in place reliably,
but not so tight that the rack cannot rotate on the seatpost, in the
event of a crash. If you do decide to install Mr. Fusion on a carbon
seatpost, this is done at your own risk.

Does it say long as you don't tighten the clamp bolt too tight, you should be fine? (English is not my first language and can't say for sure what the above lines means)
Has anyone used Mr Fusion on carbon seatposts ?

The item in question appears to be a bikepacking seat bag which has a set of struts below the bag. Those struts clamp onto your seatpost.
Without having used this clamp myself, my reading of the language is that Porcelain Rocket, the manufacturer, think you are likely to be fine clamping this to a carbon post if and only if you don’t over-torque the clamp. This requires a torque wrench, and 4 Nm is not high torque (the clamp on my carbon gravel bike says 5-8 Nm, and I think I use about 6-7 Nm to prevent slipping). The manufacturer is clearly saying not willing to assume any responsibility for damage to your carbon posts, which seems prudent and reasonable. They clarify in the last sentence that if you clamp this to a carbon post, this is at your own risk. Had they meant to prohibit this saddlebag on carbon posts entirely, they would have said something like, “Do not mount the Mr. Fusion to any carbon seatpost.”
This is nitpicky of me, but ultralight carbon posts may not be safe to be clamped in that fashion. Their wall thickness might not be sufficient for that purpose. I don’t know if any posts are made with variable wall thickness, but it seems possible that someone could lay up a seatpost with less fiber in the area where it will not be clamped. Of course, this is a thought exercise only, since a you probably aren’t mounting a bikepacking saddle bag on a road racing bike with that light a seatpost.
One thing you could consider is to inspect the clamp for any burrs or sharp edges when you get it. It does seem possible to me that a sharp edge on the bottom side of the clamp could eventually start cutting through fibers in the seatpost, which would naturally be bad. You could just sandpaper the edges of the clamp until they are smooth. This statement is admittedly not based on any practical experience, just on my general (and limited) knowledge of how carbon fiber can fail. I would not expect there to be any burrs or sharp edges, as this should have been caught in quality control, but I suppose it's not impossible.


Buying bicycles online What are the advantages and disadvantages of ordering a bicycle from a large online retailer, for example Bikes Direct (i.e. not Walmart's website)? What should an inexperienced bicycle shopper be aware of when buying online?

It's a legit company. Many of the bikes they sell are not really name-brand bikes—they're house brands. As I understand it, Mercier and Windsor are old bike marques that went defunct, and BD bought the names and sell their bikes under those names. There is a certain misplaced snootiness about this, since almost all these name-brand companies outsource their manufacture to a few giant factories in China or Taiwan and slap their own decals on. BD's other bikes are remainders from other companies, I think.

Many of their bikes skimp on the specs, substituting lower-cost parts in places you won't notice (like the bottom bracket). Of course, lots of name-brand makers do the same.

Finally there's the assembly. I don't have direct experience with BD bikes, but I've read unkind things about the quality of assembly. Since you're buying a pig in a poke when you buy mail-order, you don't have a chance to see if the wheels are true and evenly tensioned, that sort of thing. In that respect, you really are getting something worse than you'd get from a reputable local bike shop.

If you know what you're getting when you order, they're fine. But you could be buying a bundle of problems caused by poor assembly. You're definitely not buying name-brand cachet. And might not be buying a bike with quite as good specs.


Are there substitutes for chain lubricant? With long journeys and particularly during winter I have noticed that the salt erodes the chain very quickly, even when I have lubricated the chain beforehand. When you are missing proper chain lubricants, what would you use as a substitute? Could you use cooking oil if you are missing the right stuff, or should I keep a small bottle of oil with me on my rides?

Related

Vegetable oil to oil a bike?
How to clean consumable metallic parts cheaply while touring?
Chain lube for winter riding?
Best chain lubricant for road bikes?

One option would be to use a cheap chain during winter and discard it in spring.

Another would be to not have the chain be salted in the first place, try a hermetic chain guard system.

If your bike doesnt have a dereailleur, you could try a chainrunner, but I have my doubts it protects against water getting into the lining. http://de.wikipedia.org/w/index.php?title=Datei:Chainrunner.JPG&filetimestamp=20100223153843

The Teflon-based lubricants are pretty good in summer, but dont help in winter.

Cooking oil is not suited for mechanical parts. (It chemically changes over time, contains acidity, etc)


Going from a 1x8 to 2x10 setup After using my bike for a year I feel that although I enjoy the simplicity of a single chainring setup, I would prefer a more versatile 2x10 setup and would like to move to it. Currently the two cranksets I am looking at buying are the SRAM Apex White 50-34t & the Shimano 105 5700 52-39t.

What else apart from one of these, a new set of shifters and front derailleur would I need to buy as well, should I also replace the rear cassette & derailleur?

To go from a 1x8 to 2x10 drive train you will need:

Replacement shifters for 2x10 drive trains
Front derailleur for double 10 speed crankset
Double 10 speed crankset
10 speed chain
10 speed cassette
10 speed rear derailleur
Cable outers for front derailleur


How to mount a compact pump onto a full-suspension frame? Many FS mountain bikes have a weird shaped seat tube. I have managed to strap tube to the bottom of the down tube with electric tape, but am now struggling to purchase and mound a small pump. As is evident from the picture, the bike lacks water bottle mounting screws, where compact frames are typically stored.

What would be a secure mounting option for a pump?

Electric tape is a bad idea because the adhesive can mess with your tube.

Other suggestions

Many off-road riders carry a hydration pack instead of bottles/bidons.  Carry your spares in the pack.
Jersey pockets have worked for roadies for many decades.
Do you have bottle cage mounts?  Either store your tools inside a bottle in the cage, or many mini pumps are sold with a mount point to go between the bottle cage and the frame.
I have a small triangular frame bag that fits inside the main diamond of my bike.  It carries tube and tools, and a USB battery to power the camera on longer rides.  It straps around the top and down tube by velcro.
Likewise you can use a top-tube bag, which velcro-straps to your top tube and around the steerer.  Often found with a clear plastic panel on top to hold your phone.  Sometimes referred ti as a Bento, because it can hold food for snacking.
Not on your bike, but Time Trial bikes with Aerobars can have stuff mounted in the middle of the forearms, with relatively little aero impact.
Any sort of smallish cloth bag can carry your spares, and then use 2 or 3 velcro cable ties to fasten the bag to the frame where its out of the way, and not going to get dirty.  People who ride downhill would want the weight rear, so on the seatpost or seat.  Those who ride everything prefer weight low in the middle or forward if you do steep climbs.
Its also possible to load some tools inside handlebars, replacing the end plugs.  Although this can lead to accidental loss of tools and is no good for tubes.
I read somewhere that the latest Stumpjumper frame has storage compartments in the downtube, which sounds like an interesting idea.
There are frame pumps that are designed to wedge between a corner and a peg, but your frame probably won't have that.
Finally - consider not carrying it.   Instead you could carry a smaller CO2 inflator or add sealant to your tyres and trust it will do the job.  Not really recommended.  Further, there's little point carrying tools you can't use, don't fit your bike, or are broken/worn.  Weed out your loadout and take what you need not what you might need.
If you're out with mates, you don't all need a pump and a multitool.  Just stay together and avoid being separated.


How can I print a map with my GPS track? I have tracks from a bike tour in GPX format. Is there an easy way to create printable topo maps with these tracks? Waypoints should be visible and labelled as well.

QGIS might be an option, but it's very technical and the print features are limited. Any other suggestions?

Inkatlas lets you create printable PDF maps with GPS tracks and waypoints (on multiple pages if needed). You can select a map style with terrain. Smaller PDFs (6 pages or fewer) are free.

Full disclosure: this is my project.


Why should I wear bicycle clothes made of spandex? What's the reason for wearing biking clothes made of Spandex (Lycra)? They sure look pretty strange.

I thought spandex shorts looked weird too, until my wife bought me a pair with the padding. Now, I can't ride in regular shorts at all!

The shorts with padding help protect your sensitive groin parts, as well help keep you cooler and drier (preventing nasty sores) by wicking the moisture (sweat) away from your body. There's no binding or rubbing in the wrong areas, and all your jiggly parts are held securely in place.

And a big, important point about bike shorts - you wear them without underwear.

Jerseys also come in tight and loose fitting material - I personally prefer the loose-fitting jerseys (I'm not exactly skinny enough to wear the tight jerseys). Other than the moisture-wicking they provide, they also come in extremely visible colors, which is nice when you're out riding by yourself, especially if visibility is low.


Should this wheel be fixed or replaced? So, I have this tire with a factory sealed bearing.  It has a few broken spokes.  TO get these off, I'd need to remove the freewheel.  Sadly, the "studs" on both sides seem to turn independently, suggesting the axle is broken.  As a result, I don't know how to brace the axle so I can unscrew the freewheel and get it off.  Or should I even ride it like that at all?

What I'm asking is, is this wheel repairable, or should I buy a new one?

Your freewheel seems busted from what you say, it happens when the cogs are worn, nothing much to do there.

Everything is reparable but it sometimes takes a lot of time for not a lot of gain. Question is what is the value of your wheelcircle and from picture i'd say that's and old aluminium one. I don't know how that is where you live but in my neighborhood you can get a "brand new" used one for under 5 bucks. If the freewheel is busted you have to replace the entire bearing, meaning you have to take the entire wheel apart and then do the spoking from scratch. If you have a bit of experience and tools that is a good 1-2 hours of work, if it's your fist time count merely your sunday afternoon on it.

So my conclusion is : get a new wheel and recycle this one into an artistic project of some sort :)


Using non-brand oil for cleaning brake pistons I am having some problems with rubbing disc brakes and came to the conclusion that it might be because of "sticky pistons". I would like to clean and lubricate them, as here.
This video instructs to use the same brand oil for cleaning them as is used in the hydraulic system. These brakes use mineral oil. Questions: 1. Is it safe to use another brand's mineral oil for this task? 2. Is it safe to use different mineral oil, e.g. watchmaker's oil?
This question is only about cleaning and lubricating the pistons, not about adding more oil to the system. I am aware that using DOT fluid is not safe—the question is about using other kinds of mineral oil.

Probably yes.
I am expecting them to have very different viscosity and boiling point, so I would rather not.

The idea is to have an homogeneous oil if some droplets are left over after the cleaning process (same oil in same oil).
However, it should be no problem if you use a different mineral oil. At worst, the different oil will hamper your braking effectiveness, at which point you will need to flush out all the oil from the brake circuit.


Why don't couriers use rear racks? I've noticed that lots of courier companies prefer their riders to use messenger bags or backpacks.  When a rack does get used its often a porteur rack of the front wheel?  Does anyone know why these are the preferred tools of the trade?

A big reason to use panniers around town is that it keeps you from getting a sweaty back on a commute. If you're dashing around a city all day couriering you'll get sweaty with our without a backpack, and you're not smartly dressed to start with.

But loading and unloading a rack takes time, and the whole point of bike couriers is to be quick. A few seconds at each end of each job adds up. You've somehow got to get the delivery to and from the bike as well, so loading food into a backpack or parcels into a messenger bag should save time.


How to determine correct bearing size for Quando hub? I'm servicing the Quando hubs on my single speed/fixie bike. This hub uses a cup and cone type bearing assembly. When I removed the cones I noticed that one of them is chewed up badly at the end. I have good reason to suspect that the last owner may have used the incorrect bearing size when they attempted to service the hub. The cups still seem to be in good shape though. So, I want to replace the cones and bearings, and be sure that this time I'm putting in the correct sized bearings.

Given that I don't trust the size of the bearings that I'm taking out, how can I determine what is the correct size of bearing to use for this hub? Googling "Quando hub bearing size" hasn't turned anything up for me.

The vast majority of OEM hubs for adult bikes are 3/16" front, 1/4" rear, usually ten per side in front and nine per side in back. Exceptions do exist, but if nine 1/4" bearings comfortably fit in the cup with little to no extra space, that's very probably what it takes.

Quando is a line of Kun Teng, or KT, one of the largest hub manufacturers. By doing enough homework, or maybe just emailing them a picture of your hub and asking what bearings it's supposed to have, or asking them if they've ever made any singlespeed/track rear looseball hubs with anything but 1/4", you may be able to get a definitive answer.

If one had to figure this out without any external information, it becomes a matter of making an educated guess based on looking at:

How the different sizes of bearing mate with the profile of the cone
and/or cups. The radii won't be exactly the same, but they do
complement each other (a bearing engineer would put that better I'm
sure), and by knowing what's normal you can pick up on incongruities.
Also if a bearing's radius is way too large for the cup/cone, it will
be apparent by the fact that it's making contact at more than one
point.
What installing the different sizes does to the positioning of the
cone relative to the rest of the hub, i.e. whether any sealing will
be sitting at the right level and able to work properly, or whether
any of the race is exposed that one would normally expect to be hidden.
Where the ball track (the line the bearings clear away in the grease)
sits on the cone race. If it's at an extreme end of the race's curve,
that's a sign of the wrong bearing size. Being somewhere near the middle is a sign of the correct size. Likewise, in some cases one would be able to make inferences based on where the ball track is falling in the grease relative to where existing wear lines are on the races.

All the same considerations, especially ball track, apply to determining appropriate replacement cones.

Wheels Manufacturing makes replacement cones for many common KT hubs. I have no idea if they'd be applicable to your track hub, but maybe.


Difference between high and low pressure air springs? I've just been adjusting the spring pressure on my
Rock Shox SID XX fork and then adjusted my Manitou Minute Expert because I had the pump out. The SID has the solo air spring and needed 115psi and the Minute has the ACT spring and only needed 20psi. Whats the difference between high and low pressure systems and what is the benefits of each?

To add to Daniel's comment, there is no real benefit/detriment to one vs the other, but you are going to find that rear shocks are typically higher pressure for a few reasons:

rear shock pistons are typically smaller in diameter and therefore require more pounds per square inch (PSI) to push back against load.
front shocks (ie your fork) are acting directly against the weight you're loading them with. For example, if when loaded the front wheel is supporting 50lbs, then the fork just needs to push back against 50lbs (minus the weight of the stanchions, front wheel, and front brake if you want to get technical about it). With many rear suspension designs, the linkage that hooks the shock ip to the rear triangle acts like a fulcrum, with the shock being on the short end of pivot, and thus it's not a 1:1 ratio of weight that the rear wheel is supporting vs the pressure with which the rear shock has to push back.
finally, weight distribution across a bike of the type in question is not 50/50 front and rear. The rear tire must support more weight when not under heavy braking. Therefore the rear shock is supporting more weight and must push back harder.


Can I use this chainlink? I bought this SRAM PC1091 chain for my compact chainset and have been running it since January. In order for the chain to fit properly I cut a few links from it.
I am now getting a standard chainset, so I think I will have to add some links back on the chain.

Can I reattach this link to my chain to make it longer? This is how I left it when I chopped it.

Yes, you can, but it leaves the chain weaker on that link.

The SRAM chains are designed to work with a master link. If you use that one, it's not reusable, but it comes in a pack of 4, so you can open and close it a few times for cleaning.


Saddle bag for food container I have a ~2 mile/~20min cycle to work and currently take a rucksack with me that generally only contains my food for the day in a standard take-away container measuring about 17cm x 12cm x 4cm give or take.

I end up with a sweaty back in the morning which is a little annoying; so I'm wondering if there are any good saddle bags or similar that I could fit my food container, wallet and phone in (so something with a depth of maybe 10cm) to relieve the issue of sweaty back.  Does anyone have any good recommendations because at the moment my rucksack seems a little like overkill.

It sounds like you need something like a handlebar bag or a rack trunk like these:

rack trunk

handlebar bag

The rack trunk would require adding either a seatpost mounted rack or a full rear rack. Either one would allow you to move to panniers in the future if you needed to carry more goods like a laptop or a change of clothes, but a full rack would be able to handle more weight and is generally recommended for stability and versatility.

The handlebar bag may or may not require a front rack, depending on how big it is. Some come with enough of a mount that you don't need anything additional to support the weight.


Do OnGuard MinPin Locking Skewers provide adequate security? Do OnGuard MinPin Locking Skewers provide adequate security?

I read one review (http://www.rei.com/product/842891/onguard-minpin-keyless-3-piece-locking-skewer-set) saying that the skewers can easily be defeated. Another review (http://www.amazon.com/review/R3CTA0K40XLP1K/ref=cm_cr_pr_perm?ie=UTF8&ASIN=B0077T7CR6&linkCode=&nodeID=&tag=) said the skewers could probably be either broken or defeated w/ a magnet or pliers.

For anyone who has used these skewers, how would you describe the security that they provide?

I haven't used them myself, but I've been asked to remove a broken set. A customer came back to their bike and discovered that a thief had tried to force them and failed. But not before breaking both front and rear lever mechanisms. I got both off without damaging the rest of the bike at all, with a cutting disk in the grinder they come off in seconds. Anyone can buy a battery grinder for $99 and youtube has a collection of "bike thief being ignored" videos so I'd rate these as "casual thief" resistant.

Also, the "locked" mode is exactly like the "stuck" mode of a normal set of QR skewers. Unless someone knows that they're the special locking ones they'll just apply more and more force until something breaks. So every time you take it into the bike shop or put it on a vehicle you will need to attach a note to the bike to that effect. I hope they come with stickers or something.

Given that you're looking at spending money at all, I suggest something more effective. A  set of Pitlocks cost about $105 from Peter White (US) or 95 euro from pitlock.de. And they're made from hard stainless steel so a cheap battery grinder will take a long time to grind one off.


Front disc brake rattling noise I recently purchased a brand new Scott Genius 950 at a local bike store.  After bedding in the brakes, I noticed a rattling noise while riding coming from the front disc brake.  I brought it back to the bike shop, they disassembled the front brake and put it back together, but the noise is still there.
I was told to bring the bike back when the head mechanic is in, but I thought it would be worth posting a video of the noise here.  It seems to act up the most when I turn sharply left or right.  It doesn't always rattle, and it does it when I am not braking.
Maybe it isn't the brake, but the spokes?  I am not really sure.
YouTube Video:

Any suggestions?
UPDATE 1
I just got back from the shop, the head mechanic took the front brake apart and put it back together. I rode it around the parking lot for a while, and just now around the neighborhood. Seems that the noise is gone (for now!).
I asked what he did, but I don't remember all of the technical details. Definitely re-aligned everything, tightened everything, mentioned something about [retracting?] the spring, etc. I wish I remembered more of what he said so I could share it here.
UPDATE 2
I just got back from a test ride around the neighborhood. I can still get a slight rattle out of it when dropping the front end after doing a wheelie. Since the front brake has been rebuilt by the shop mechanic, I am not too worried about safety. From the feel of it, nothing is loose, and I have full stopping power. I suppose I will just have to learn about it on my own, and continue to investigate.
UPDATE 3
So, I am able to reproduce the noise (only for a fraction of a second) when dropping the front end down, hitting a curb at an angle, and turning sharply.  It makes a very quick, very quiet ching noise.  From this, I am now thinking that it may be from the flexibility of the fork causing the rotor to make brief contact with the pads.  After learning how the disc brakes on my bike really work, I am not concerned that this will be a safety issue, and may wear in with time if my conjecture is correct.
I found some interesting information after looking at the dealer's manual for my brakes: SHIMANO Hydraulic Disc Brake 4-Piston Caliper Model: BR-MT420
https://si.shimano.com/pdfs/dm/DM-MBBR001-04-ENG.pdf
On Page 8 about a third of the way down the page it reads "The 203 mm and 180 mm disc brake rotors have a larger diameter than the 160 mm disc brake rotor for cross-country bicycles, and so the flexing of these disc brake rotors is greater. As a result, they will interfere with the brake pads.".
Very interesting, as those are the exact size of the rotors on my bike.  So maybe this is normal and expected?
Thank you to everyone who has responded, and if anyone has any further ideas or experience with this issue, please reply :)

The rotor might not be perfectly true. Although the shop should fix it as it's a new bike, do be aware that big MTB rotors get out of true really easily and at some point you just need to live with it. This can be somewhat mitigated with two-piece rotors utilizing a beefier spider, but in the end you're riding trails; stuff breaks all the time.

Is your thru axle tight? I know that with 9mm QR forks, violently turning and braking can sometimes be enough torque to momentarily twist the hub/dropout interface out of alignment, resulting in noise. A similar effect might manifest if your TA is not done up properly.


What's the pedal spindle size for the NordicTrack GX 4.7 R exercise bike? I am trying to find out pedal spindle size for the NordicTrack GX 4.7 R exercise bike. Is it 1/2 or 9/16?

I want to replace the pedals with larger more substantial ones with a strap.

Thank you!

The Nordic Track GX 4.7 comes with a three piece crank so it has 9/16 pedals.


Identify year of specialized s-works tarmac? Can anyone identify this specialized s-works tarmac? The seller says it's a 2013, but I haven't found it.

Looking on bikepedia.com, I can only find listings from 2012 and 2013 for Specialized Tarmac SL4 Pro, or S-Works Tarmac SL4. The frame in the photo seems to have decals for both 'S Works' AND 'Pro' (on the seat tube). This seems inconsistent with any photographs I can see on google images. SWorks frames tend to have 'SL4' on the seat tube instead but I have only seen photos taken from the drive side.

Also, the colour of the red decals on the bike seem a suspiciously similar shade to those on the wheels, which makes me skeptical even further. I haven't seen any google images results in this paint scheme, and expect that you haven't either, hence the question here.

I would ask the seller for more information, for warranty documentation, proof of purchase, a frame number that you can check with Specialized etc. Maybe it's all legit and original, or maybe it's been resprayed. If so, the owner shouldn't have any issue with answering your questions. But if it seems too good to be true, be prepared to walk away.


Upgrading 3x9 to 1x12 Shimano I have an old 26" hardtail that I want to convert to Shimano SLX 1x12 (M7100) from its current 3x9 drivetrain. As the new 1x12 uses a micro spline hub, I am thinking of changing my rear hub from M475 to
FH-MT500 (micro spline QR 135). Would I be able to use my old wheel and spokes with the new hub, as both the hubs are Shimano and have almost same dimensions/flanges, etc. I can't find new 26" wheels that have the microspline hub.
Or is it better use a Sunrace 11-51T cassette that uses the old Shimano HG hub? If I go this option, I am guessing I won't get the Shimano HyperGlide+ smooth shifting.
Also, is it possible to use a 32T narrow wide 104BCD chainring in place of my current middle chainring keeping the same crankset/BB. I can remove the smallest and largest chainring from my current crank.

Be careful about the expense. 26" makes this a 10 year old bike. While each change over that time has been small, end result is geometries and performance of bikes have significantly changed in that 10 years,  My sons entry level $1k softtail is in many ways a better bike than my 9 year old Carbon Scott Spark 10. The cost of the upgrades and selling the old bike would go a long way to a new bike.
Unless the old rim is in excellent condition, threading a new hub onto an old rim can be difficult to get a good build. Personally I would avoid doing if at all possible. You would be better to buy a new (new old stock) 26" rim. (The rim cost will be small compared to the labour of wheel building and new spokes. In the unlikely event the  old spokes are the right length, reusing 10 year spokes is not recommended.)
The Sunrace 11-51T cassettes are not bad, provided you use the right one. Ideally stick to the same manufacturer if you want bet performance, which means micro spline if you want 12 Speed Shimano
Have you considered 11 Speed?  You can get an 11-51 in Deore.
You can replace the middle chain ring, you may need short chain ring bolts.  With narrow/wide you can probably remove the front derailleur and not drop the chain - but as always, YMMV.  The chain line will be correct.


Front Derailleur Wont Shift I'm not too sure what to call this but basically someone whilst riding my bike shifted up too much (basically they mustve pulled on the lever while already being in the big gear) and now as a result both the lever and the button are both jammed and I have no clue what I should do to fix it (being a novice cyclist xD)

Usually the red line is in the middle (big ring) or to the far right (small ring). I've tried applying a lot of force to the button but it seems completely jammed.

Lastly here is a picture of the front derailleur.

I don't have a way of knowing absolutely this is true, but it sounds like a severe case of the unnamed phenomenon where the shifter gets pushed into its (presumably) last click, and the system is set up such that this position pushes the front derailer to the absolute limit of what the limit screw and the stretchiness of the cable allow. The cable then statically has a very large amount of tension on it (much more than what the FD return spring provides, which is what the shifting mechanism is designed in mind for), and this makes shifting back take a lot of force, or in rare cases not work at all.

If this is what's going on, the main clue would be that cable has an inordinate amount of tension when you pluck it with your finger. The fix is to take a screwdriver and back out the front derailer high limit screw a couple full turns. Then you should be able to downshift as normal. After this you should ideally set the derailer back up again from square one, because if this can happen at all then something isn't quite right. If that's too much you can just reset the high limit back to the normal .5-1mm or so of chain clearance, but you might have to repeat the episode in the future, and this is one of the main contributors to STI levers failing early.


What is this device on all the Tour de France riders' bikes? What is the device behind the saddle on all the riders' bikes in the 2015 tour? I'm seeing it on almost every bike. It looks standardized and electronic.

This is a special device that gathers the following data, according to this article:

  the stage winner’s top speed, average speed and time per kilometer
  the fastest riders up key climbs
  the speed of the winner at the finish line
  the top speed achieved by a rider on the day
  average speed across all riders


Which jockey wheel on top? I've just bought a new pulley set for my rear derailleur but do not know which one goes on the top (nearest derailleur) and which one goes on the bottom. The
wheels have arrows on them;vI suppose they indicate the rotation direction for the pulley wheels when rotating 'normally'.

PS : I see that one pulley wheel is beefier, thicker than the other one
Derailleur is a M970 XTR

Here's a photo of RD-M970 from behind. As you can see, the slotted (guide) pulley goes to knuckle and solid one (tension) to the bottom of cage. I'd align the arrows with chain movement direction that happens when you pedal forward.


(Serious): Male genital protection for mountain biking/BMX and for common falls I want to start using a protection like a helmet for is for the head, but for my penis and testicles.

Why is important? It would give me much more confidence when triying new tricks and tecniques to not fear my genitals will be hurt, simply falling  in the wrong way could hurt me very bad.

I shouldn't worry? Well I do and maybe others don't, however I'm not neither the best biker that never falls, neither I think nobody should put others to that standard. If others don't want it ok, I need it.

Genital protection is rarely (if ever) used in cycling because it generally means putting some kind of hard surface in play (or excessive padding).  Either of these can easily lead to some very uncomfortable chaffing problems.  For less "pedalcentric" disciplines this might be acceptable (flatland, downhill, etc).  But, for the rest of the market there just isn't a benefit to loss ratio to justify it.

Many other sports have genital protection equipment that is used regularly.  Like winter cyclists who have to use mountaineering equipment to stay warm, you may have to dip into some other sports equipment cache to accomplish / try what you are suggesting.


Is it possible to shorten a chain? I have the following chain/gear setup:

I like to get rid of the rear wheel gears. However I don't want to buy any new parts. That is why I am wondering if I simply can remove all the parts from the rear gear shift, and simply shorten the chain?

NO

The derailleur holds chain tension.

At a minimum your would need a chain tensioner.
And it would need to line up with A gear.

Single speed and fixie have horizontal dropout to adjust tension.


Replacement timing: bottom bracket after gear and chain I am planning to do a massive replacement on my city bike: chain, gears (both front and rear) and also bottom bracket, as I noticed the pedals tend to oscillate to the sides when I load them.

While I can attempt changing chain and gears on my own, I prefer to let a workshop do the bottom braket. This mean that I will probably have some time inbetween the two replace actions.

Since I have read here that it is not a good idea to replace only chain or gear, I wonder if a wore bottom bracket does have a bad influence on newly mounted gears and chaing?

There are good reasons to avoid using a very worn chain for to long as it can wear the cassette requiring both to be replaced.

I doubt that a small amount of play in the bottom bracket would move the chain enough to cause unusual wear to the chain, rings or sprockets. There may be more chance of a problem on a single speed or fixed gear bike where the chain has less give.

There's a small risk of poor shifting with a wobbly bottom bracket, so perhaps take care and avoid any gears which rub.

Otherwise, as long as the shop replaces like for like, you shouldn't have a problem. Likewise, worn gears should not adversely affect your bottom bracket.


Are thru-axles generally hollow or solid? Need to know if these thru axles (of any size) have an internal diameter or are completely solid. How common is each type?

Thru Axles are a standard for wheel fasteners that was introduced fairly recently for MTB and later for road bikes. Today thru axles come typically in 15 mm or 12 mm diametres.

If you mean thse, they are indeed always hollow. Any solid bolt with such a large diametre would be excessively heavy. Even when using light magnesium alloys.

The whole innovation of thru axles revolves around that when having a structural element of sufficient size one may do without its core. In other words, a tube of a large radius is under many loads stronger than a slimmer rod of the same mass and material. In the case of a hub axle one can rule out loads (e.g. shearing) where a rod would be stronger.


Is the Specialized Sectour Double 2014 a men's bike. Can a women ride a men's bike? I am looking for a woman's bike. And I found a 2014  Specialized Sectour double. Is this a men's bike? If so what are the disadvantages of a women riding it ?

I sold Specialized bikes for a lot of years, they do make gender specific frames, women's bikes have shorter top tubes relative to the seat tubes, this is because women on average have shorter backs and longer legs than men do, they also come with womens saddles, and sometimes women specific grips (for feminine hands). The Sectour is considered a men's frame. Not everyone is built the same though, my wife rides a men's frame because she is really tall in the body. The only other difference between men and women's Specialized frames is that women's frames sometimes have "girlier" colours and paint details.