Disc vs rim

[mrandmrspoves]

In the good old days we used to ride around with rim brakes and the rims never ever wore out..........but that may have had something to do with the fact that the brakes were weak and often ineffective. I would opt for discs over rim brakes every time. Perhaps the stangest option was the Magura hydraulic rim brake. As to discs being ugly - I just can't see how anyone thinks they are uglier than callipers.

 

[Mo1959]

After using rim brakes on my other bikes, when I first applied the brakes on my mtb (hydraulic discs) I nearly ejected myself out the front door!

 

[Drago]

Jeez, chrome rims with leather faced brake blocks? How did any of us survive to be adults?!

Discs undoubtedly can perform better and don't present rim wear issues, although at the expense of a miniscule rotating mass penalty. That said, even with rim brakes I can lock the rear wheel in the wet on all my road bikes anyway. Given the choice I'd have discs over an identical bike with rim stoppers, but I don't think the benefit is so overwhelmingly vast that it'd be anywhere the top of my list for essential road bike criteria.

Different story entirely on mtbs where it's desirable to keep the braking surface away from the muck and crud.

 

[cyberknight]

I must admit i was skeptical on disc brake performance but today coming down a hill in the rain i would normally take it gingerly on a rim brake bike, this morning on the disc subway i braked at the normal "OMFG will i stop " distance and was amazed at how much better they were .
Now if i could afford a disc equipped roadie or flat bar road bike i would buy it as apart the brakes the rest of the bike weighs a ton .

 

[DRHysted]

Was reminded of how poor the rim brakes on my Allez were tonight when an Audi brake tested me. I gave up on the wet rim braking and used the escape route I'd seen (it was part of my motorcycle training 2 decades ago to always ensure you had an escape route planned in case something happened in front).

 

[Smokin Joe]

Jeez, chrome rims with leather faced brake blocks? How did any of us survive to be adults?!

Discs undoubtedly can perform better and don't present rim wear issues, although at the expense of a miniscule rotating mass penalty. That said, even with rim brakes I can lock the rear wheel in the wet on all my road bikes anyway. Given the choice I'd have discs over an identical bike with rim stoppers, but I don't think the benefit is so overwhelmingly vast that it'd be anywhere the top of my list for essential road bike criteria.

Different story entirely on mtbs where it's desirable to keep the braking surface away from the muck and crud.

Which is the main problem with weak and inefficient brakes, lack of feedback means a tighter grip on the lever and loss of feel. I used to lock drum brakes on a car from time to time when my foot was on the floor trying to get the bloody thing to stop, never do it with discs because the light touch on the pedal leads to greater sensitivity.

 

[Cycleops]

Which is the main problem with weak and inefficient brakes, lack of feedback means a tighter grip on the lever and loss of feel. I used to lock drum brakes on a car from time to time when my foot was on the floor trying to get the bloody thing to stop, never do it with discs because the light touch on the pedal leads to greater sensitivity.

I think you'll find that's more to do with servo assistance rather than the extra efficiency of discs. Just try coasting with the engine off and applying them.
As with cars discs will become the norm very soon for bikes.

 

[Smokin Joe]

I think you'll find that's more to do with servo assistance rather than the extra efficiency of discs. Just try coasting with the engine off and applying them.
As with cars discs will become the norm very soon for bikes.

That's because modern braking systems are designed for servo assistance (Just as steering is with power assistance, you can barely turn the wheel if it's off). The first disc braked cars I drove didn't have a servo and I don't believe any motorcycle does yet the brakes are still way better than drums.

 

[Yellow Saddle]

Ceramic rims are supposed to offer good wet weather performance.

Supposed to, but they don't Ceramic (glass) is a very poor friction material and equally poor conductor of heat. Ceramic brake tracks save the rim, but at the expense of everything else including performance and pad longevity.

 

[Yellow Saddle]

I don't like the look of discs. On my MTB I have sufficient braking power from the Vs, however, I frequently feel like I need more stopping power on the road bikes - not enough to make me consider a new bike with discs though - I often wonder if I did have more stopping power would I just lock-up my 23mm slicks and crash?

Was reminded of how poor the rim brakes on my Allez were tonight when an Audi brake tested me. I gave up on the wet rim braking and used the escape route I'd seen (it was part of my motorcycle training 2 decades ago to always ensure you had an escape route planned in case something happened in front).

You are far too kind. I call it brake assault.

 

[Yellow Saddle]

I used to lock drum brakes on a car from time to time when my foot was on the floor trying to get the bloody thing to stop, never do it with discs because the light touch on the pedal leads to greater sensitivity.

Drum brakes are notorious for locking up under the conditions you describe. They suffer from "self-servo" where under hard braking, the drum lifts the leading edges of the shoes and suddenly bring on brake force beyond the tyre's capability to maintain grip. Discs don't do that and modulate nicely at all foot pressures.

 

[Smurfy]

Supposed to, but they don't Ceramic (glass) is a very poor friction material and equally poor conductor of heat. Ceramic brake tracks save the rim, but at the expense of everything else including performance and pad longevity.

Glass? The types of ceramics that are blasted (at hyper sonic speed) into the aluminium rim face are carbides. You're supposed to use special pads for ceramic rims that are much harder. Normal pads will be eaten through in record speed.

http://www.sjscycles.co.uk/rigida-a...rim-black-32-hole-rohloff-drilling-prod13269/

Ultra hard wearing Carbide Super Sonic brake surface, allowing fantastic braking and wear characteristics. The carbide is projected at seven times the speed of sound on to the rim imbedding it into the alloy. Unlike a ceramic surface it cannot flake away as it is part of the rim (not a layer).

 

[andrew_s]

CSS rims are not the same as ceramic rims.
I agree with Yellow addle that ceramic rims are not good in the wet. I got a pair (Mavic Open Pro), and, being cautious sort, just put one on the back wheel to start with. The front wheel never received one - I expect the other ceramic rim will go on the back once the one that's there finishes wearing out (about half the ceramic has worn off now, with no flaking).

I've had a disc bike for about 4 years now, an wouldn't get another non-disc bike. It's not so much better braking, as more reliable braking, with none of the delayed reaction you get with wet rim brakes.

 

[mustang1]

I can't wait for hydro disks to become main stream on road bikes BUT I also love the simplicity of regular rim brakes. Overall, yeah disks are the way to go.

 

[Pumpkin the robot]

A guy I cycle with is a good 3 stone heavier than me and can outbrake me in the wet with his (cheap) disc shod bike. Another reason I will be getting them!