Disc wheel changes in pro racing

Back before the peleton had changed to discs, I remember one of the main complaints was the difficulty of wheel changes due to variations in horizontal location of the rotor itself. It seems like neutral service is functioning OK - how did they overcome that issue?

Separately but related - it seems like there are still significant differences in speed of wheel changes between axle types - has there been any chasing of marginal gains in this area?

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In answer to the first question-“thru-axles”–allowed for very precise and consistent positioning. As for the second, not much gain in speed, but highly depends on the techie who is doing it, some are a lot better than others.

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Think speed of change also depends on the type of thru axle. Some mechanics use a power tool while others have to hand turn a built in lever.

Speaking for myself, I’m quicker changing my Canyon’s wheels with the built in lever on the thru axle vs the 6mm hex bolt on my Aethos since I don’t carry a power tool when I’m out riding. :clown_face:

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Marketing idea. Super light E-drill to get your thru-axle out quicker on the group training ride so you can save 3 seconds on the flat fix! It could even be tied into a Di2 battery. Maybe at the end of the ride if you had juice left in it you could swap the bit out for a vibrating massage head.

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Or how about a self extracting thru-axle … have a little motor/gear drive on the axle and frame/fork that could be button activated to spin the axle out? :slight_smile:

thru-axles are good, but I don’t think they fix the variation in hubs. The spacing for rotors between shimano pads is something like <1mm per side. 0.25mm could be a tolerance for a hub…then you have have add the rotor tolerance, the frame tolerance, the caliper tolerance. If each part were at the edge of the tolerance, that’s easily 1mm+. This is all predicated on the caliper operating as designed with equal piston advancement and the caliper being mounted perfectly centered over the rotor.

TL;DR There is variation in parts that could lead to rotor rub. It may or may not be enough to prevent the wheel from being mounted (unlikely, I’d guess), but it may be enough to cause rub that is annoying and robs power. But I guess it’s better than being out of the race?

I’d love to hear from a rider, team mechanic, and industry designer to get their take on the “issue,” if there is one.

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Heck, there’s variation on my own bike; I’m always having to adjust the calipers back and forth as things shift for no reason but wear.

Yup. I have to readjust my caliper pretty much every time I remove and refit my wheels.

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(Grandpa voice) - Back in my day, we did not even have fork tabs! Then, when the fools at what ever nanny board decided all forks needed these “Lawyer Tabs”…we would file them off! We could swap wheels in the peloton in seconds…swoosh and in. Never, not once ever did I see a wheel come off during a race due to an improper install (seen a QR shaft or two break).

But, Nanny has taken over as have disk brakes. Wheel changes will never be as fast, nor as safe. And yes, the rotor variations are a freaking nightmare.

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Well, then clearly it never happened in such numbers that lawyer tabs were deemed necessary. The “nannys” were just bored one day and decided that lawyer tabs would be fun to require.

It isn’t like QR’s were installed on almost every bike in the world, including department store bikes, which dominate the market in volume, and those customers are never taught how to use QR’s.

Or that people regularly just screw QR’s tight and never close the cam.

Nope, because you never saw a wheel come off in a race, there is clearly not a safety issue with QR’s.

Or you just relayed an anecdote.

One of those two things is true.

Henri - I love Darwin. Lawyers, not so much. This is almost specifically a US problem and everyone is a victim…again, man, Darwin rocks.

I can assure you, this is not just a US problem.

It has nothing to do with Darwin…when people are not properly advised how to use a QR 9adn the overwhelming majority of people aren’t), you are going to have safety issues.

The problem here is that you are looking at the issue from an enthusiasts perspective…and we make up an astonishingly small % of the cycling population. Lawyer tabs aren’t about us, they are about the general cycling population.

Your anecdotes of not seeing wheels come off in the peloton is evidence of the myopic view you have adopted.

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Survival of the fittest. And yes, this is a US problem (and we are the cause of the lawyer tabs). In most other nations people do not need baby sitters to NOT eat a battery (that now taste bitter - seriously). Oh, and at a high school MTN bike race the other day every person got a trophy and the scholarships had to be give ‘after’ the awards ceremony to not hurt other kids feelings…It is a shame that human breeding is allowed with out regulations like fork tabs.

But, back to the point. Many pro-teams will have almost exact rotor placement as in general they are on the same exact wheels and rotors (and even MFG dates). Not so much when you get a spare wheel of another brand or lower quality hubs and MFG tolerance. All in all, first world problems.

Can you please tell us your experience working with bike distributors in other regions of the world?

I can tell you from direct, personal experience that it is a global issue.

Sure, this is relevant to the discussion…but the real irony is that your feelings seem to be upset by it. Huh.

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I didn’t think thru-axles were about safety around user error (like lawyer tabs), but about the kinds of forces on the on the wheel caused by using disk brakes that QR wheels are unable to handle.

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Disc brakes do put a lot more downward force on the axle, so an improperly secured QR is more likely to come out than with rim brakes. It still shouldn’t be an issue with properly tightened QRs, but it’s certainly possible for an inexperienced rider to mess it up.

Thru axles also offer great stiffness vs. a traditional QR.

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I have 2 wheelsets on my MTB. I set the bike up for one wheel set and then shimmed the rotor on the other wheels. Swapping between wheels is no issue now.

Also these are QR wheels too.

There’s a Peak Torque vid on YouTube that refutes this - I’m not enough of a science bod to understand if he’s right, but he seems to suggest that the main benefit of a thru able is consistent rotor placement, rather than stiffness.