Disc brakes on road bikes. Good idea?

daddylonglegs

Right, I'm going to risk it and dare to suggest that the push to disc brakes on road-racing bikes we are now seeing is not necessarily a good idea.

Whenever I read a forum that touches on this topic the pattern is usually the same: lots of excited talk between a few interested posters, all assuming the 'new' technology to be per se a good thing, with the only question being when they'll be forking out the usual wads of cash for this latest bit of gear. Then a lone voice of dissent might pipe up with an objection. He (or she) is then mocked and ridiculed as some dyed-in-the wool old fogey still clinging to their alpaca and toe-clips.

I admit I've been riding, building and fixing bikes for a very long time, but I really am having trouble seeing how, on balance, when everything is considered, disc brakes on road bikes offer any significant advantage to the user. By 'road bikes' I don't mean touring bikes, or commuter bikes, or cross-bikes. I mean road-racing bikes, or bikes that make an excellent attempt at being road-racing bikes.

I briefly made up a pros and cons list to see how the benefits might outweigh the disadvantages of a disc set-up on a road-bike. I also made a brief list for the other important factor in the equation - the industry - and this is what I came up with.

The advantages of discs on road bikes seem to be these:

Advantages for the user:

No overheating of rims on fast, long alpine-type descents,
Better stopping in the wet,
No rim-wear leading to blowouts if the rims aren't replaced beyond a certain mileage
Lighter rims at cheaper end of the market.
Safer for learners and inexperienced riders.
More new things to buy for people new to cycling ('coincidentally' the biggest buyers).

Advantages for the industry:

Adoption of new standards and therefore new products, (eg. disc-specific frames).
Further increase in rate of product obsolescence
Increase in production and cost to the user of consumables (pads, rotors, hydraulic fluid).

Disadvantages for the user seem to be these:

Significant overall increase in weight
Complex serviceability relative to calipers both on the road and in the workshop.
No more radial spoking or many other lightweight/specialist wheel-building options.
Increase in wheel-weight due to lack of spoking options.
Price of consumables - pads, rotors, hydraulic fluid.
Boiling off of Hydraulic fluid on long, fast Alpine-type descents
Poor aerodynamics (Eh? I thought we were all being told trading in our old bike for something more aerodynamic was the way to go...)
Hydraulic brake failure miles from home (on top of Di2, this makes the idea of being self-sufficient as a cyclist soon just a distant memory)
Further increase in premature obsolescence of bike frames

Disadvantages for the industry:

None

Comments?

pride4ever

Neither good nor bad just the latest way to squeeze more money out of cyclists.

maddog 2

depends if you want decent brakes or not.

daddylonglegs

What do you mean by 'decent brakes'? Mine are fine.

antfly

Is there a push to disc brakes ? There don't seem to be many around. Maybe on a winter bike it wouldn't be such a bad idea.

daddylonglegs

There certainly is antfly.

antfly

It's not something I would want anyway, I have enough trouble with them on the mtb. Keep it simple.

daddylonglegs

Well it's looking a lot like they're coming whether you want them or not. We'll all be staring at our bikes fretting about how old-fashioned (and dangerous) they suddenly are. And hence saving up for new ones.

thistle_

I'm not sure I agree they are safer for learners and beginners - you can flip a road bike with rim brakes if they are decent and you brake hard enough. Applying the brakes gradually is something you have to learn and isn't second nature to everybody.

I think they'd be nice to have on a road bike used in all weathers such as for commuting and on my MTB I do find them low maintenance, but in poor weather it's not the brakes on my road bike that govern how quickly I can stop, it's the amount of grip between the tyres and the tarmac.

Ber Nard

Daddylonglegs wrote:

Advantages for the industry:

Adoption of new standards and therefore new products, (eg. disc-specific frames).
Further increase in rate of product obsolescence
Increase in production and cost to the user of consumables (pads, rotors, hydraulic fluid).

Disadvantages for the industry:

None

Well it's up to the manufacturers to make the goods that the user buys so it looks like we're going to get them whether you like it or not.

Personally, although they are not yet perfect, I think disc brakes are the way to go. I always get the sense in these threads that those who have ridden discs (okay, maybe on tourers or crossers) are in favour and those that haven't, aren't.

Rob

smoggysteve

I think sooner or later they will be the norm in some form. If anything from the cost. Problem with normal rim brakes is, eventually they will wear out your rims, carbon or alu. The cost of a disc and pads would be a lot cheaper to replace than a set of carbon rims that can be 3 or 4 grand. They would also negate the issue with carbon clinchers as no heat build up would ever occur.

daddylonglegs

Ber Nard wrote:

Well it's up to the manufacturers to make the goods that the user buys so it looks like we're going to get them whether you like it or not.

Personally, although they are not yet perfect, I think disc brakes are the way to go. I always get the sense in these threads that those who have ridden discs (okay, maybe on tourers or crossers) are in favour and those that haven't, aren't.

Rob

That's what I said - it's likely to happen whether we like it or not. I'm not sure I do though, at least on road bikes. When you look at the overall price to be paid in terms of obsolete bikes and user-dependence on specialist servicing and relatively expensive consumables, not to mention the less tangible benefits that simpler kit has for cycling it seems the advantages are minimal.

junglist_matty

Daddylonglegs wrote:

No rim-wear leading to blowouts if the rims aren't replaced beyond a certain mileage

Is this really an issue? I've ridden 3000 miles on my current wheels, the rims are in perfect condition, the blocks don't have much wear either; maybe someone who regularly descends mountains would suffer this

daddylonglegs

SmoggySteve wrote:

I think sooner or later they will be the norm in some form. If anything from the cost. Problem with normal rim brakes is, eventually they will wear out your rims, carbon or alu. The cost of a disc and pads would be a lot cheaper to replace than a set of carbon rims that can be 3 or 4 grand. They would also negate the issue with carbon clinchers as no heat build up would ever occur.

True about the cost of rims. Anyone know how much life you can expect out of a pair of rotors and a set of pads?

daddylonglegs

junglist_matty wrote:

Daddylonglegs wrote:

No rim-wear leading to blowouts if the rims aren't replaced beyond a certain mileage

Is this really an issue? I've ridden 3000 miles on my current wheels, the rims are in perfect condition, the blocks don't have much wear either; maybe someone who regularly descends mountains would suffer this

It has been for me (twice while riding) and a couple of times while my bike's been leaning up minding its own business. Then again, I have in the past made a habit of riding my rims (literally!) into the ground. By way of general reassurance, rims usually blow apart (it will leave your ears ringing by the way) while riding slowly uphill out of the saddle (it's the pressure on the sides from the leaning that does for them). It's a lot less common for them to go on a forty mile-an-hour descent. If they do however it's unlikely you'll remember much...

3000 miles isn't a lot for a pair of wheels. Start worrying after about 30,000.

junglist_matty

Daddylonglegs wrote:

3000 miles isn't a lot for a pair of wheels. Start worrying after about 30,000.

I agree, 3000 isn't a lot at all, but even so, that's over 6 (autumn/winter) months.... I do about 7-8000miles a year so by my reckoning 30,000 (approx 5 years) is a more than acceptable lifespan for a rim regardless of original cost.

After all, nothing lasts forever

smoggysteve

junglist_matty wrote:

Daddylonglegs wrote:

No rim-wear leading to blowouts if the rims aren't replaced beyond a certain mileage

Is this really an issue? I've ridden 3000 miles on my current wheels, the rims are in perfect condition, the blocks don't have much wear either; maybe someone who regularly descends mountains would suffer this

Obviously never suffered from grit under a brake pad scoring a deep line into your rims.

daddylonglegs

junglist_matty wrote:

Daddylonglegs wrote:

3000 miles isn't a lot for a pair of wheels. Start worrying after about 30,000.

I agree, 3000 isn't a lot at all, but even so, that's over 6 (autumn/winter) months.... I do about 7-8000miles a year so by my reckoning 30,000 (approx 5 years) is a more than acceptable lifespan for a rim regardless of original cost.

After all, nothing lasts forever

All true. Winter riding kills rims far quicker. At that sort of Winter mileage on a pair of good aluminium rims, 5 years is the absolute maximum. I had a pair of Mavic Open 4's (remember them?) on my Summer training wheels. I got ten years out of them before they exploded.

junglist_matty

Daddylonglegs wrote:

True about the cost of rims. Anyone know how much life you can expect out of a pair of rotors and a set of pads?

Unless you bend the rotor or run pads until there's no compound left on the pad, they would likely last for a hell of a long time on a road bike

Pad lifetime on the other hand is like asking "what's the length of a bit of string?"

- I've ridden my MTB and worn out a pair of pads in 20minutes of riding at Thetford forest @ "Dusk Till Dawn 2011".

If you descend a mountain and are heavy on the brakes you could wear them out in only a few descents whereas if you ride mainly flat, you'll probably get at least year or so of riding out of a set of pads.

junglist_matty

Daddylonglegs wrote:

All true. Winter riding kills rims far quicker. At that sort of Winter mileage on a pair of good aluminium rims, 5 years is the absolute maximum. I had a pair of Mavic Open 4's (remember them?) on my Summer training wheels. I got ten years out of them before they exploded.

I wasn't road riding that long ago; started road riding in about 2009, only rode mtb before that, don't know the Open 4's.

I use Mavic Kysirum Equipe wheels.... The rims seem fairly robust to me, I'd be surprised if the rims outlast the hubs to be honest, by which time i'd be happy to replace the entire wheelset.

I ride (almost) every day (been a bit less the last couple of weeks due to slight illness), through all weathers, never had a stone score my rims, but maybe that's because I've always run alu rims.... I guess if you use carbons they will not last as long due to rim brakes.

smoggysteve

junglist_matty wrote:

Daddylonglegs wrote:

True about the cost of rims. Anyone know how much life you can expect out of a pair of rotors and a set of pads?

Unless you bend the rotor or run pads until there's no compound left on the pad, they would likely last for a hell of a long time on a road bike

Pad lifetime on the other hand is like asking "what's the length of a bit of string?"

- I've ridden my MTB and worn out a pair of pads in 20minutes of riding at Thetford forest @ "Dusk Till Dawn 2011".

If you descend a mountain and are heavy on the brakes you could wear them out in only a few descents whereas if you ride mainly flat, you'll probably get at least year or so of riding out of a set of pads.

Disc brake pads can be changed in a few minutes, keeping a few spare sets on you could make sure you always have grip on them. I know where you are coming from with running out in a short space of time. I used to do downhill and you could almost get a disc glowing with heat after a steep decent.

daddylonglegs

By the way, this sort of long-lasting rim-related talk is poison to manufacturers and importers. They've been busy over the last few years convincing everyone that they should be changing their entire wheelset every two years. Even if it's only to replace them with a new colour.

goonz

i think discs are a great idea, knowing their stopping power, I would be a little wary if on 23's so would take getting used to but their are many advantages as already highlighted. If weight is not a massive issue then they are a safe bet on all bikes.

daddylonglegs

junglist_matty wrote:

Daddylonglegs wrote:

All true. Winter riding kills rims far quicker. At that sort of Winter mileage on a pair of good aluminium rims, 5 years is the absolute maximum. I had a pair of Mavic Open 4's (remember them?) on my Summer training wheels. I got ten years out of them before they exploded.

I wasn't road riding that long ago; started road riding in about 2009, only rode mtb before that, don't know the Open 4's.

I use Mavic Kysirum Equipe wheels.... The rims seem fairly robust to me, I'd be surprised if the rims outlast the hubs to be honest, by which time i'd be happy to replace the entire wheelset.

I ride (almost) every day (been a bit less the last couple of weeks due to slight illness), through all weathers, never had a stone score my rims, but maybe that's because I've always run alu rims.... I guess if you use carbons they will not last as long due to rim brakes.

Open 4's were the standard rim of choice for many roadies not using tubs. I think it's been superseded by the Open Pro now and the wide availability of good factory wheels has complicated things significantly. As far as decent factory-built road wheels go, Kysyrium Equipes are excellent. All the Kysyriums are good. But don't try finding spares for them - another example of manufacturers reducing user seviceability. When the rims wear out, you'll just have to throw the whole wheel away. Really outrageous in my view.

maddog 2

Daddylonglegs wrote:

What do you mean by 'decent brakes'? Mine are fine.

Fine like CRT monitors, Ford Escorts, V-brakes...

I already run discs on my winter bike/trainer/commuter. Night and day. As soon as a decent disc frame comes along I'll make the shift on the good roadie. If you want to stick with your rim brakes that's fine. I'll see you at the bottom...

thegreatdivide

daddylonglegs

maddog 2 wrote:

Daddylonglegs wrote:

What do you mean by 'decent brakes'? Mine are fine.

Fine like CRT monitors, Ford Escorts, V-brakes...

I already run discs on my winter bike/trainer/commuter. Night and day. As soon as a decent disc frame comes along I'll make the shift on the good roadie. If you want to stick with your rim brakes that's fine. I'll see you at the bottom...

Well this is always the standard response - 'listen to the old git stuck in the past'. I know what you're saying, but I'm wondering what it is people are throwing away here to get their extra inch of perceived health and safety. I've been road-racing and training for nearly twenty years and I've fallen off dozens of times. Thing is, I can't think of a single time it's been due to inadequate brakes.

Strith

Road bikes is a broad term too. I don't think your average crit bike would need them :!: , but a commuter or tourer might be different.
Either way we'll get them when the manufacturers see fit.

bernithebiker

Just to further muddy the waters;

Carbon rims - braking is mediocre at best, downright shabby in the wet.

If I could improve braking power whilst keeping a lightweight tubular carbon rim, I would be interested.

daddylonglegs

Strith wrote:

Road bikes is a broad term too. I don't think your average crit bike would need them, but a commuter or tourer might be different.
Either way we'll get them when the manufacturers see fit.

I qualified 'road bike' in the original post. I mean a road-racing bike or bike that makes a very good job of being like one.

I agree, I think the manufacturers can do what they like once they have a market sufficiently motivated, loyal and often ignorant to buy anything to do with bikes.

smoggysteve

If there was a stigma about discs on a road bike, I dont think Colnago and any other prestigious brand would sell bikes with them already. Only the UCI rules are preventing them being used in competition. If that were to change I am sure more manufacturers would invest more into getting weight down and balancing aerodynamics etc.