Originally Posted by stoneageyosh

The wheel change bit was in response to the video link in a previous post.

Originally Posted by ummed

Crit racing usually allows for a wheel pit. You put wheels in the pit and if you get a flat you can change out your wheel but you only get one free lap. You have to be quick and get back in.

Maybe the best mechanics in the world can change a disc wheel as far as a rim wheel but most mortals can't. That's assuming you can even get two wheels to have the disc perfectly aligned in the first place.

Originally Posted by PeteHski

I don't personally find it any faster or slower changing disc wheels. My through axles have built-in levers so I don't need tools. Flats are a non-issue for me anyway since I moved to tubeless.

Originally Posted by merlinextraligh

ever try to do it in the middle of a crit, where you’ve a minute or two to get back to the Pit, get your wheel get it installed and get put back in the race.?

Originally Posted by merlinextraligh

I’d say it’s about 30 seconds longer, particularly if you file down the lawyer tabs. You’ve got to screw and unscrew the through axle, and it can take a bit of time to get the disc in the caliber, particularly rushing in the heat of battle.

Normal circumstances that doesn’t matter much, but when you’re trying to get back in a crit, ( the subject of the thread) it could be critical.

Also trying to get a wheel from the wheel truck and chase back on in a road race, every second matters.

Originally Posted by PeteHski

Pros can change a rear disc wheel in about 20 seconds. So if you are taking 30 seconds longer than a normal wheel change then you are doing something wrong. But I haven't had a flat in the last 3 years of road riding, so it wouldn't factor in my choice of brakes. I wouldn't even bother with a spare set of pit wheels.

Originally Posted by PeteHski

I wouldn't even bother with a spare set of pit wheels.

Originally Posted by maxants33

Ah, if you look back at the original question and subsequent clarification - hitting the brakes/brake force was not part of the query. Nor was wheel changes ( I don't take it so seriously that I'm going to carry a spare wheelset). Crit is just fun for me and an opportunity to improve on technical skills.

Improved modulation/feathering was the original query; can mech discs improve on this. Sure in an ideal world, modulation is of no interest, because you're so awesome that you never need to actively reduce speed. But really, if you're at my (lesser) level, and riding the courses I ride (tight, technical, hairpins) - modulation is super important. Its always a topic our coaches focus on at training.
I was amazed how much more fun I was having when I used my hydraulic disc CX bike at crit training, since I could so much better feather the brakes and make small speed adjustments, which helped me to work on improving my cornering technique. My current flexy Athena calipers are inferior to my Rival hydraulics concerning modulation. But I did get some good suggestions here about new pads and potentially better calipers.

I think to further my point regarding modulation, it might be worth seeing the this video from GCN and UK crit champ Alec Briggs: here

At around the 6 minutes mark, they actually focus on the benefits of discs for modulation.

Originally Posted by merlinextraligh

1) you’re talking a pro mechanic, not an amateur racer. In the context of this thread we’re talking about a racer who just crashed, or had a mechanical, and has to get back to the wheel pit, get a new wheel, change the wheel themself, gather their composure, and get back in the race, all within one lap, which may happen very quickly depending on the size of the course.

2) if it’s not slower, then why did pro tour teams essentially give up on changing out flat tires, in lieu of whole bike changes?.

I will admit I’ve never changed a disc wheel in a race. But having changed disc wheels, raced a hundred plus criteriums, gotten wheels in the wheel pit, and taken wheels from the wheel truck in road races I absolutely believe there is a speed advantage in not having to deal with a disc brake and through axle, particularly in the heat of the moment.

Originally Posted by merlinextraligh

Have you actually raced crits? I’ll admit my last crit was a few years ago but pretty much every serious crit racer puts wheels in the wheel pit. It’s not just flats; it’s also crashes.

So perhaps if we’re talking about the equipment for racing crits it would be helpful to hear from people who race crits.

Originally Posted by merlinextraligh

I have no doubt that many people, if not most are racing crits with disc brakes, simply because most bikes sold today have disc brakes. That doesn’t answer the original question posed in this thread however. And certainly does’n’t suggest there’s a need to switch from rim to mechanical discs to race a crit.

Originally Posted by Kontact

40 years ago, some racers preferred the flexy Modolo single pivot calipers because - lacking stopping power - they made speed modulation easier. Now everyone talks about speed modulation as the same as power.

Campagnolo had the right idea when they put double pivot calipers in front and singles in the rear.

Originally Posted by Kimmo

I don't think flex is helpful with modulation

Originally Posted by PeteHski

This is true. Modulation is a combination of lever travel, weight, power and consistent feel. Flex in the system just masks the actual feel and reduces overall power. I think it was the latter that Kontact was referring to i.e. those old brakes had relatively low power (because of all the flex) so you couldn't accidentally brake too hard. Not something I would see as a positive feature, but there you go.

Originally Posted by Kimmo

But he was also saying the lack of mechanical advantage of a single pivot is a good thing on the back, and he's totally right about that.

And you can extrapolate on that, that a hugely powerful front brake might even be a bad thing, if it never takes much effort to lock up.

Originally Posted by Kimmo

I don't think flex is helpful with modulation; it tends not to be linear. Having only as much mechanical advantage as you need is the main thing, closely followed by rigidity of all the components.

So beefiness is good for both modulation and stopping power, but you're on the money with the single pivot rear; I've never mounted a DP on the back, because it's worse than pointless. Too much leverage on a brake is like putting too much throttle body on a car engine; when half throttle works the same as wide open, it feels super responsive but you've lost half your modulation.

I'd like to play around with different pad compounds to find something less grabby, but with carbon rims I'm uncharacteristically inclined to stick to the manufacturer's recommendation; that's some serious voodoo right there.

Originally Posted by msu2001la

Speed of wheel changes? Sure maybe a few extra seconds for disc, but we're talking about local crit racing here, not a grand tour. It has no impact - you're getting a free lap regardless.

Originally Posted by tomato coupe

Realistically, it's also makes very little difference in amateur road racing. Most races don't have wheel support, so you're effectively out of the race if you get a flat. Even if there is wheel support, it's going to be slow, and it's going to be pretty difficult getting back to the peloton.