Disc vs Rim brakes

Borderfox

I recently changed to a cx bike for winter and changed to wheels to Askium Disc. I changed the rear caliper to a Trp hy/Rd and find it much better than the bb7 brakes. Running 28mm conti gp4000 and the soak up so much on the bike, the ride is so comfortable but can go fast when you want to

magicbastarder

i'm currently getting my head around hy/rd brakes. i think i have them fixed...

'think' is always good when you're dealing with brakes.

smacl

Borderfox wrote: »

I recently changed to a cx bike for winter and changed to wheels to Askium Disc. I changed the rear caliper to a Trp hy/Rd and find it much better than the bb7 brakes. Running 28mm conti gp4000 and the soak up so much on the bike, the ride is so comfortable but can go fast when you want to

I found with the full hydraulic disc brakes on my CX bike that as shipped the rear brake was far more responsive than the front brake, which led to quite a few skids. Balancing them took a fair bit of mucking about, specifically loosening the lever adjustment screws all the way out, doing a bleed, and then resetting them. This was after already changing the pads and doing a regular bleed. Adjusting cables is so much easier. They work great now, but were such a pain to setup to my liking.

nordicb

Other than rim wear... Are there any more benefits of disc brakes?

Yes, they are more powerful, but what's the point locking your wheels on a road bike. With this little amount of road contact, locking wheels will not slow you down faster, in fact this most likely will lead to a fall, fast and sharp. They are a must on a mountain bikes, undoubtedly, as locking wheels aids the turning and stuff.

Rim brakes give this very wide range of feel of what's going on under you, and the fact it takes more effort to lock the wheel is actually a good thing. Ability to read the road ahead is the skill that keeps us safe and less on brakes. Just my thoughts.

cdaly_

Lumen wrote: »

Are they really better than 28mm Conti GP4000S II ?

200g ish heavier per tyre. That's a lot of spinning mass. I make no claim about whether that matters for performance, but it must have a noticeable effect on handling.

I've never run GP4000s so I cannot say. They're certainly nicer than the 25mm Gatorskins I ran on the Giant.

As for extra weight, I suspect that I have a much greater effect on handling than any weight of tyre I might use. That said, I don't do racing so I'm not after super acceleration. They certainly roll fast and I keep up with the bunch no bother.

smacl wrote: »

Question so. If you're running wider tyres, do you prefer disc brakes or cantis on the assumption that these are your only options? Or do you have some very long armed caliper brakes?

On the advice of Andy Thorn, I run a rear disk brake (avid BB7 mechanical) and a front canti (avid Shorty Ultimate). Thorn reckons you cannot make a light, springy steel fork that will take disk brakes. You have to beef up the fork too much for the forces involved and you lose the springiness.

I'm really liking the setup. Rear brake is a proper stopper alone and the front is needed mostly for emergency stops or steep descending. Reduces rim wear also.

xxyyzz

nordicb wrote: »

Other than rim wear... Are there any more benefits of disc brakes?

Yes, they are more powerful, but what's the point locking your wheels on a road bike. With this little amount of road contact, locking wheels will not slow you down faster, in fact this most likely will lead to a fall, fast and sharp. They are a must on a mountain bikes, undoubtedly, as locking wheels aids the turning and stuff.

Rim brakes give this very wide range of feel of what's going on under you, and the fact it takes more effort to lock the wheel is actually a good thing. Ability to read the road ahead is the skill that keeps us safe and less on brakes. Just my thoughts.

It's not about the extra power, it's about how they allow you to apply that power. You can lock up the wheel with a rim brake, that doesn't mean you do it all the time. Good hydraulic disc brakes allow far better modulation ie from the point that the pad makes contact with the rotor to the point you lock up the wheel gives you a lot more sensitivity to play with.

Also they give far better wet weather performance, in fact there is no drop in performance in wet weather

Tenzor07

Disco's in the pro ranks

Boonen to race on disc brakes throughout 2017

'It's the biggest improvement I've seen in my career' says Belgian

boonen-to-race-on-disc-brakes-throughout-2017

Zen0

One advantage of disc brakes which I have not seen mentioned here, and I realise I'm open to being called a wuzz on this one, disk brakes are a lot cleaner. After a long spin on wet roads with lots of braking, I just have to clean off road spray from the rims, not that awful black gank that brake pads leaves. I'll happily embrace my inner wuzz for that.

youtheman

Zen0 wrote: »

One advantage of disc brakes which I have not seen mentioned here, and I realise I'm open to being called a wuzz on this one, disk brakes are a lot cleaner. After a long spin on wet roads with lots of braking, I just have to clean off road spray from the rims, not that awful black gank that brake pads leaves. I'll happily embrace my inner wuzz for that.

I actually consider this a big advantage. I can clean my disc brake bike in less than half the time it normally takes. Plus I'm not wearimg the rims so the wheels will last longer.

boege

Road biker here and normally use rim brakes.

Hired a bike in Nice last summer (Giant Defy) and was pleasantly surprised to find it had disc brakes, thinking I could really evaluate disc brakes as I am looking at new bike soon.

Did an 80/90km route up by Col d'Èze and Col de la Madone and descended off the Madone into Monaco. I am an experienced descender, and comfortable at speed on long alpine descents.

I wont exclude the possibility that i had a duff bike setup but I hated the disc brakes. Lack of feel was a big issue but more uncomfortable was the inertial mass of the dics/brake/fork (fork is heavier) which made sudden change of directions slow. I was extremely uncomfortable descending as a result and yeah descending off the Madone the way I did is hairy even with good brakes.

Have taken up MTB lately and would not argue against discs but for road biking I will be slow to change.

I could see Boonan using them in Spring Classics for sure (close to MTB conditions) but will be interesting to see if he persists throughout the year. Cav tried discs for a while but reverted back to rims.

Tenzor07

Ah the first Pro race win on Discs... I guess they are here to stay now!


tech-milestone-boonen-wins-first-race-with-disc-brake-bike

nordicb

Just love the clean sharp finesse look of hubs and exposed cassette.

07Lapierre

Tenzor07 wrote: »

Ah the first Pro race win on Discs... I guess they are here to stay now!


tech-milestone-boonen-wins-first-race-with-disc-brake-bike

I assume Tom won the race by NOT using his brakes as much as everyone else?

Tenzor07

07Lapierre wrote: »

I assume Tom won the race by NOT using his brakes as much as everyone else?

Nah, they were just more aero than caliper brakes...:pac:

wanderer 22

07Lapierre wrote: »

I assume Tom won the race by NOT using his brakes as much as everyone else?

Exactly - who came last? That guys brakes are the ones we want :pac:

xxyyzz

Tenzor07 wrote: »

Nah, they were just more aero than caliper brakes...:pac:

Nah, they let him off because all roadies know that if you get to close to disc brakes then this in inevitible. If I had a euro for every time it happens on a mtb spin...

Tenzor07

xxyyzz wrote: »

Nah, they let him off because all roadies know that if you get to close to disc brakes then this in inevitible. If I had a euro for every time it happens on a mtb spin...

Lovely, makes great lunchtime viewing!

xxyyzz

If only poor Simon knew how wrong he was about disc brakes https://www.youtube.com/watch?v=8Il8XV61yLQ

Cookie_Monster

Discs without question. Rim on the road bike, discs on the cyclocross. I hate using the road bike now after a week of commuting on the cycloX, it feel like it has no stopping power. My next road bike without question will have discs, for me the single best improvement on bikes in recent years.

xxyyzz

Something that's not mentioned often is that disc brakes allow wheel makers to build rims without having to compromise by putting in a braking strip. It gives them more leeway to design more aero rims, also with the trend towards wider tyres, you can now have a wider rim which gives the tyre a better profile and makes it less likely to roll off the rim.

outfox

Zen0 wrote: »

One advantage of disc brakes which I have not seen mentioned here, and I realise I'm open to being called a wuzz on this one, disk brakes are a lot cleaner. After a long spin on wet roads with lots of braking, I just have to clean off road spray from the rims, not that awful black gank that brake pads leaves. I'll happily embrace my inner wuzz for that.

Certainly the wheels are a lot cleaner. But I find that a fair amount of brake dust builds up around the disc brake housing and the forks/chainstay. And given its location, it's hard enough to clean. I invariably touch the cleaning rag off the rotor without noticing, which of course transfers the cleaning product to the pads...

Lumen

xxyyzz wrote: »

Something that's not mentioned often is that disc brakes allow wheel makers to build rims without having to compromise by putting in a braking strip.

What compromise? Weight? That only applies to tubulars. Clinchers have the braking strip on the part of the rim that resists the pressure from the tyre bead, so there is no extra rim material.

xxyyzz wrote: »

It gives them more leeway to design more aero rims, also with the trend towards wider tyres, you can now have a wider rim which gives the tyre a better profile and makes it less likely to roll off the rim.

Clinchers can be wide too, but you know that. There is possibly a tiny advantage from being able to have a rounded rim profile, but that won't offset the aero losses from all the extra spokes or the sticky-out rotors and calipers.

jamesd

I've discs on the road bike and this morning they were a joy on the wet, dirty roads.

xxyyzz

Another roadie claiming to have had his shoe cut by a disc brake today. The footage makes it look unlikely that any contact was made with Kittel's bike but the internet has gone into meltdown similar to the Ventoso shambles.

https://cyclingtips.com/2017/02/owain-doull-marcel-kittel-disc-brake-crash-abu-dhabi/

doozerie

I've yet to be convinced by arguments in favour of, or against, disc brakes for road bikes. To me it seems entirely subjective and there are so many variables that I'm not sure there is a winning generalised argument either way.

For what it's worth, my experiences are:

* cantilevers (various brands and models) on an MTB off-road - I've had good and bad ones, influencing factors included the size and shape of the brake lever, probably the quality of the cantilevers themselves, and definitely the quality of the brake blocks I used. The good ones worked well in the dry, and well enough in the wet.

* Shimano XT v-brakes on an MTB - when tuned well they were better than the cantilevers, when not tuned well they were the same or worse than cantis. Again, brake lever shape and brake blocks influenced their quality, as did quality of cables and how they were routed. Worked well in both dry and wet, although I did have a few hairy moments on off-road descents in the wet, but I just adjusted my riding accordingly and never had a serious fall.

* Shimano XT hydraulic disc brakes on MTB - one ride only, and on a full suspension bike for the first time, so quite different from my previous hardtail (and non-suspension fork) MTB's above of many years ago. A 200mm (I think) rotor on the front, 160mm on the back so plenty of stopping power in theory. Hard to tell if they inspired any more confidence during the damp ride given the other variables I was adjusting to. They might well have helped but if so the difference was not huge. Plus the rear pads were pants, I could pedal while they were full on so I'm guessing the pads are contaminated. Even with a rubbish rear brake I stayed upright bar one slightly comical off, the brakes I consider a small factor in my staying mostly on the bike.

* Shimano 105 calipers (from the 90's) on road bike - work very well, and even better with the 105 levers as they suit my hands well. Work well in wet and dry, how well they work is hugely influenced by choice of brake shoes.

* Campag Chorus calipers on road bike - these are 1999/2000 vintage and work as well as, and perhaps better than, my Shimano 105 brakes. Choice of brake shoe makes a huge difference, as does choice of tyre (compound, width, etc.). Very wet weather influences their performance, but by adapting my riding style accordingly that doesn't tend to be a problem.

* Campag Record calipers on road bike - the best brakes I've used, without a doubt, disc included. I'm using stock Campag brake shoes and they work extremely well in both dry and wet weather across a number of wheelsets. One of my wheelsets has a shallower braking surface and I notice a slight loss of braking effectiveness in the wet with those, but I've raced on those in the wet and adapting my riding style has meant they've not been a problem at all. Still my favourite brakes, they've saved me even when I've overcooked hairy bends on a descent due entirely to rider (i.e. me) failure.

* Hayes Expert mechanical discs on road bike, 160mm rotors front and back, Sram Apex levers - when tuned well, including fitting them with decent brake cables, they are on a par with well adjusted v-brakes, otherwise on a par with cantilevers, and sometimes worse. For me they are not an obvious choice over rim brakes. They do allow you to fit significantly wider tyres, but so do cantilevers and v-brakes. I wanted wide tyres (32mm) on this bike but it's my unloved commuter and I also wanted to do without the fiddly nature of fettling that cantilevers and v-brakes sometimes require, hence I chose manual disc but I wouldn't sing their praises.

Make what you will of that. To summarise my experiences, choice of rim (material, braking surface area, etc.), choice of brake lever (shape, hinge mechanism, etc.), choice of brake pad/shoe/etc., choice of rotor size, choice of tyre (material, width, etc.), choice of inner tube (I'm a fan of latex), etc., all influence how effective a set of brakes are since brakes are part of a greater whole. I can't draw any definitive conclusions from that, it always surprises me when I see others making incredible claims for or against disc brakes, they rarely fit with my experiences.

When it boils right down to it, I think that recognising the changes in riding style that you need to adopt according to the strengths/weaknesses of your brakes, and other components, and the conditions, counts for more than the brakes themselves. That's assuming you have half decent components to start with of course, you'll struggle to have any decent braking at all if you compromise on the components or just choose poorly for the conditions.

Chuchote

A small, ditsy dog in Milltown Park has reason to be grateful for my disk brakes. I was going past a group of people with dogs on leads when this little housemop suddenly wandered right into my path. Rim brakes and it would've been toast. The disk brakes stopped me like a brick wall. Mop continued wandering. "Oh, sorry," said the doggy people.

(Sorry, missaid. Of course I meant the dog had reason to be grateful for my disk brakes (now corrected) not my rim brakes. Not only the dog ditsy.)

Rokta

I have hydraulic disc brakes for over 5 years now on different bikes. The only negative thing about them is once you rode on them, you never want to go back. The constant performance you get as well as the modulation and that they are far superior in the wet outweighs them against rim brakes.

I used them on MTB and touring bikes/commuter, I did not manage to slice anything open with them so far. They are used for years on MTBs and I never experienced anybody hurting themselves on disk brakes. Trees, stones all kind of other things yes....but not disk brakes.

Tenzor07

:pac:...:pac:

OleRodrigo

Disc brakes are:

1. Ugly
2. Unnecessary ( unless you have significant problems with muscular coordination and spatial perception, or in other words, are shyte )
3. Freddish
4. In conjunction with electric gears - two peas in a pod tbh - ensure a disconnect between the rider and his bike which will logically culminate in a robot riding the bike on your behalf while you sit on the couch enjoying the ride with a VR headset .

5. See number 1.

xxyyzz

OleRodrigo wrote: »

Disc brakes are:

1. Ugly
2. Unnecessary ( unless you have significant problems with muscular coordination and spatial perception, or in other words, are shyte )
3. Freddish
4. In conjunction with electric gears - two peas in a pod tbh - ensure a disconnect between the rider and his bike which will logically culminate in a robot riding the bike on your behalf while you sit on the couch enjoying the ride with a VR headset .

5. See number 1.

This post is

1. A load of utter me bollocks
2. See point 1