Interesting article on disc brakes

every year you see guys in the tour lifting the rear wheel when braking on the descents, quality race tyres have plenty of grip

It’d be pretty nasty to have a bunch of searing hot rotors in a group crash, but I guess they could develop covers for them to make them a bit safer (and potentially more aerodynamic).

The shifting of weight away from the outer edges of the wheel is a pretty big advantage I reckon. Developing road specific rims without braking surfaces means they can be a lot lighter where it matters. Who knows, perhaps it’ll lead to a whole new rim design, one with much less rim, and lots more tyre that’s attached to the spokes in some freaky way we haven’t even conceived yet.

this is crap-hot though.

QFT

Still its a long way off before a set of Hydro-Brifters would be even remotely affordable. How much is a TRP Parabox these days? $500+. Forget about it.

Of course in the long run it will happen… Sometime, Just not that soon.

This.

It’s interesting discussing the ins and outs of new tech, but at the end of the day I get on my steel bike with bar end shifters and v-brakes and ride it home. There’s a long way to go before all this gets into production, trickles down to consumer level, actually becomes affordable, and becomes ubiquitous.

I can just tell I am going to be the fucking worst retro-grough. Come twenty years time, I will probably still be using cable gears and brakes.

I spied your bike locked up yesterday (y u no answer my call?), it had neither cable gears or brakes!

i was at the supermarketing location, without phone machine on me! When i spied you had called, i figured the moment was gone.

As for the track weapon, it now boasts clips and straps, rather than spds. This makes my stopping far more difficult and inconsistent. It is very exciting.

I, also, was glad to see the Bike Snob of NYC back on the blogging-horse again this morning.

Re: those disking-brakes, Nik’s link isn’t working anymore, but I do remember reading about the difficulties of fitting a rotor alongside 10 or 11 sprockets, leaving room for a wheel with reasonable dish within 130mm.

Just what we need - more new proprietary standards and non-interchangeable systems.

Road disc brakes are coming for sure. I just hope they design them from scratch based on the actual requirements of road cycling rather than just using off the shelf MTB components and bolt it on a road bike. This would be shit (and overkill).

everytime i think about disc brakes, i always come back to the silly euro’s and the outer edge disc brakes on their motorbikes (and i can’t for the life of me find a pic).

and the reason i quoted, isn’t wheel inertia a good thing for push bikes?

Not when you are trying to accelerate. Great for TTs when you want to keep your momentum.

whoever comes up with a road disc setup is going to have to find a way to make wheel changes really quick and some sort of (reliable) self aligning setup that works better than the mtb ‘self aligning’ arrangement

Nah, rim weight isn’t that significant. Mass near the rim will contribute twice as much, in effect, to your momentum, but who cares? With a difference between a light and heavy rim of about 50 grams, 100 grams in total for two wheels, you’re talking about adding an extra 200 grams of equivalent frame/rider mass. Dropping a turd before the ride will have a more significant effect.

I can get my wheels out pretty quickly with discs and don’t have any alignment issues?

Sure, for slow shmucks like me and (maybe?) you 100-200 grams is not even worth worrying about. For the top end riders however, this is all important. “But you can already make a bike under the UCI weight limit!” Yes indeed you can but the next step is redistibuting that weight for the best possible performance. Lighter rims mean more rapid acceleration, and the removed weight can be re-used in stiffer BB’s, bars whatever. Not only that if the multiplication factor you have mentioned is correct, then you shave 100 grams and get an effective 200 gram saving! - in top end cycling that’s awesome. you’d be hard pressed to find any better way of effectively cheating the UCI weight limit whilst remaining fairly and squarely within the rules.

Can’t think of any euros off the top of my head but Buell did it.

The turd you are dropping doesn’t have angular momentum. Unless you’ve got a corkscrew arsehole and really shoot them out.

Mass on the rim of the wheel provides much more resistance to your effort to spin up than the same mass close to the axle. Angular momentum is proportional to radius squared.

Wikipedia - Introduction to angular momentum
“Illustrating the properties with the example of a flywheel: if two flywheels have the same mass, and they are spinning at the same angular velocity, but one flywheel has a larger diameter than the other, then the larger diameter flywheel has more angular momentum. With a larger diameter the flywheel’s mass is further away from the axis of rotation. The further away from the axis of rotation, the larger the required torque to spin up or spin down the flywheel with in a particular measure of time. Likewise, the larger the mass the larger the required torque, and the larger the angular velocity the larger the required torque.”

do we need to have the ‘rotating mass’ myth discussion again?

Yeah sure, just for my benefit, I’ve only been here 3 days.