For once I agree with Lenard Zinn - Road disk shortcomings

[kulivontot]

Road disc thread #3 ftw

[bm0p700f]

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[prendrefeu]

I got caught in the rain coming out of the mountains today. Carbon clinchers, Swissstop pads. It's actually a pretty good combo, as carbon in the rain goes, but I still had very little actual brake power.

Was this on the Bontrager Aeolus 5 D3 Clinchers?

[Zen Cyclery]

I'm not too sure I agree with him. Yeah brake cables are wound which makes them a bit softer, however why not simply swap it with a 5mm shift housing? This will allow for maximum braking power. Obviously hydraulic discs need to happen at some point, but BB7s can be setup to be pretty grabby.

[bm0p700f]

Well as user of MTB discs I do wonder what has taken so long for road bikes to have mounts for these.

I find nothing wrong with good rim brakes but discs on a road bike are something that excites me a little even though I really don't need them in sunny (currently) suffolk.

1. rims that do not wear out.
2. no machined sidewalls means cheaper rims
3. rim profile can be changed providing some (hopefully) aero advantage.
4. carbon rims will become much more propular.
5. rim will surely become lighter in disc only versions.
6. Hopefully 135mm rear hub O.L.D will catch on reducing poor dish and allowing more durable wheels. It is only going to get worse with shimano 11 speed.

Shame it going to be a custom frame to get them now.

1 honestly how long does it take for a rim surface to wear out. (you will need to change pads that might be more expensive and the rotor)
2 just because it is cheaper to manufacture does not mean that manufacturers will pass on the savings to me or to you but
3 if it is a clincher you still need to have structura integrity on walls and you limitation is that not the braking surface.
4 carbon rims will be more popular if they were cheaper ( they are pretty popular for what they cost)
5 or it might become heavier ( more spoke; longer spokes; and beefed up eyelets to resist the pulling force of spokes
6 as it is a lot of fellow weenies complain that some crancksets have wide q factors
let's face it riders like myself and the schlecks will still ride the brakes for too long and overcook the turns. disc brakes are not going to dramatically increase ones ability on the bike, just like di2 did not stop andy from dropping his chain.

1) My current winter wheels are about half worn (~0.4mm of a 1.85mm thick braking surface) due to the foul summer wheather in the U.K up until the end of July. I rode more during this bad spell and it has been killing my rims. They are less than 1 year old with about 4-5K miles on them. My MTB running discs has had the same wheels for 8 years. I would like to have the same for my road bikes.
2) A Velocity A23 with MSW is more expensive than a A23 with NMSW.
3) Then why do we retire rims when they go a bit too concave. It's to stop the rim failing. I have had to do this on my MTB's with v's before.
4) I am refering to the braking performance. There are still many who do not like the braking feel on carbon rims, not a problem on discs.
5) I already ride with more spokes rather than less so no issue for me.
6) I come from MTB riding so a double road crankset feels better narrow to me. I have a road crankset that is too narrrow and would replace it if it was not so nice to look at.

The last point you make I can agree with. No subsitute for reading the road, but with rim brakes the limitations od rim brakes in the filthy wet conditions that I ride in. Discs would help I hope. Were some see problems I suppose I see advantages. Remember the same debate went around the MTB community when discs came in on those bikes. Now try buying a bike with v-brakes and try riding a V-brake on some trails in Wales in the wet. I did once and that experience was enough to make me a disc convert. I would still and do use rim brakes on MTB's (I have one with discs, one with v's and one with canti's) but I do pefer my discs.

[VNTech]

Was this on the Bontrager Aeolus 5 D3 Clinchers?

Yep. Though the pads are left over from a swap to Mavic's new CXR 80; I generally run the Bontys with cork pads or the Cole pink pads (which I really, really like). Glad I had the Swissstops on today, though. Cork + rain = utter crap.

[sugarkane]

Swiss stops and rain= no brakes.. They are well behind the eight ball in the cars on pad game with the yellow pads.. I've been using enve and the new Reynolds pads and they work very well in the wet.
Plenty enough for me to get around hairpins on 9% descents at speeds of over 70kph. A lot of the older pads are not good when it's wet but the newer pads are doing a lot to address that

[ricerocket]

If any of you ride motorcycles or drive cars anything faster than commuting speeds, you'd know that there's a myriad of brake pads that are suited for the purpose of flipping your ass over the handle bars or locking your wheels/brakes almost immediately. Of course there are happy mediums as well.

I don't think all the options for suitable pad compounds have been explored, and we are, as always, too quick to judge. Leonard Zinn included.

[gmitt98]

I finally switched to a disc CX bike for a rain bike (BB7s) and it is amazing. Heavy, but a great improvement. I was wearing through rims every year from 6 months of consistent wet riding in PDX, and that gets old. Not to mention the stopping ability on steep descents with traffic and lights/signs is much improved.

One issue with road disc brakes and aerodynamics is that wheels need more robust spoking. Radial lacing won't work, and 12-spoke wheels probably won't either. Most 29er MTB wheels seem to run 24hr minimum. Couple that with a rotor and fat caliper and I could definitely see a big impact on drag. Although I imagine a brake could be designed that mostly hides behind or in the fork, and the rest of the system will eventually get cleaned up as well. Still, it'll never be as good as current rim brakes.

[Zen Cyclery]

Yeah you can't run radial on a disc hub, but you can counteract this extra drag by lacing with an ovalized spoke shape (such as a Sapim Cxray.) However, I think the slight loss of aerodynamics is more than made up for by the extra braking power.

[Wingnut]

Still, it'll never be as good as current rim brakes.

So after 40 odd years we now have rim brakes at there best...imagine how good road disc brakes will be in 40 years...

[sugarkane]

Shit wears out! You think disks won't wear out if your riding em to death in the rain with dirt and sand in the mix.? Look at what your asking em to do!
I'm sorry but disks won't make you a better descender. Better tires, skills, and less fear wiil.


Disks =marketing sales


I don't need em

[ricerocket]

Shit wears out! You think disks won't wear out if your riding em to death in the rain with dirt and sand in the mix.? Look at what your asking em to do!

You're missing the point.

A $20 disc is 100x cheaper to replace than a $2000 wheelset.

[sugarkane]

Am I


I have 2 wheelsets both full carbon and one of them has over 10000kms on it..
Its far from worn out. Infact I reckon it'll do 10-20 more... And by then I would have sold the wheel set for something flasher and newer..

You show me a mid 5 kg roadie with small (and effective ) ceramic disks and I'll start paying attention..

Other wise why don't y'all just go buy some cross bikes..

Disks won't make you faster if your slow down a hill thats a simple fact. And if your already a fast guy rim brakes won't/don't hold you back

[Wingnut]

Like it or not sugarkane they're coming...