Road bike brakes - do they actually work?!

Surf-Matt

With MTBs getting ever more powerful brakes, I'm rather suprised that road bikes still have piddly little side pull calipers or at the most small cantilever brakes.

Now these were ditched by MTBs years ago - because they were useless.

So how come road bikes, which go a lot faster, still seem to have brakes that use very old technology and can't have much more power than dragging a flip flop on the ground to slow down.

It's one major factor that puts me off road bikes.

Of course I'm glad to be proven wrong - any takers?

el_presidente

Road bike brakes are fit for purpose. The limit is not the braking power but the tyre adhesion. I can lock my back wheel (or put myself over the handlebars, for that matter) on any surface even at low speeds.

homercles

I suppose it could be said also that in road racing (the intended purpose of these bikes, in theory), there is not often much requirement for emergency stopping. If a crash happens it's usually unavoidable (peloton all go down right on top of each other etc), regardless of how good the brakes might be.

Braking is more about modulation, speed control, etc, rather than stopping dead, whereas on MTB it's often a lot more technical.

So as el_pres says, they're 'fit for purpose'.

rhext

I have an MTB (with disks) and a road bike with rim brakes. Brake shoe compounds have improved to the extent that the rim brakes now seem quite reliable in the wet, and my wheels run true, so I don't have the alignment problems I used to. Things have come on a lot in the rim brake world since disks were invented, and they're now far from useless. The only time when I find myself wishing I had disks on the road bike is descending a local 1 in 7 which finishes at a T junction on a busy road. I have to stay on them all the time to be sure I can stop reliably at the bottom.

I'd also point out that, while you might go faster on a road bike, you don't tend to go down such rough, steep slopes. MTB brakes need to be powerful and easy to use because you'll often find yourself having to brake hard to stay in control.

I'd not let the lack of disks on road bikes put you off getting one. But I must confess if road bikes with disks were more common, I'd happily pay the slight weight penalty.

cee

are the side pull jobbies like V-Brakes then?

if so, then they should be plenty powerful enough and if not, can you get v-brakes for a road bike?

I tried a mates mountain bike with v-brakes and was stunned at how good they were. i could still lock up both wheels without my hands turning purple!

The last time i tried rim brakes before that was cantilevers on an old emmelle mtb....they were pretty poor

Parkey

I thought road bike brakes weren't very good until I tried pulling them from the drops during a descent... then I knew otherwise.

Surf-Matt

Cee - nope. Side pull caliper brakes are pre V brake and even pre cantilever brake (although V brakes are actually a sort of side pull brake).

My old (1997) Stumpyjumper has decent Avid V brakes and they do work fine, but the bikes I've used (a long time ago) with side pulls are very slow stoppers.

Just using simple physics, I can't see how a side pull brake can give enough leverage to give much stopping power against a narrow braking area.

tardington

Surf-Matt wrote:

Cee - nope. Side pull caliper brakes are pre V brake and even pre cantilever brake (although V brakes are actually a sort of side pull brake).

My Tricross Sport has V-brakes, and drop bars! It seems to stop pretty well - it has the 'safety' levers, if that makes a difference?

My sister has a cannondale touring, with cantis, it's a beast to stop she says. She getting near to fitting butterflys or a flat bar just to get proper brakes...

Underscore

Surf-Matt wrote:

Side pull caliper brakes are pre V brake and even pre cantilever brake (although V brakes are actually a sort of side pull brake).

But aren't the ones on road bikes now dual-pivot side-pull? That should give you (in theory - I've not ridden a bike fitted with them) much better mechanical advantage than the old single pivot things of my youth...

fossyant

Decent road brakes are fine - and I've got the older single pivot (all be it good ones) and they will stop my road bike far faster than needed - again - it's more down to keeping adhesion to the road.

Good brake blocks help as well and they offer good modulation and stopping in all conditions.

jpembroke

Why are people obsessed with locking up their brakes? Try an 20km Alpine descent on a disk-equipped mountain bike and then you'll find why road bikes have caliper brakes. There is such a thing as too powerful.

jpembroke

oh, and I have disks on my Inbred and they are fantastic - wouldn't go back to Vs on an MTB - but I wouldn't want disks on a road bike.

cee

jpembroke wrote:

Why are people obsessed with locking up their brakes? Try an 20km Alpine descent on a disk-equipped mountain bike and then you'll find why road bikes have caliper brakes. There is such a thing as too powerful.

Sorry....I wasn't sugesting that locking the wheels was the desired effect. although on re-reading it it does lok a bit like that. :oops: It was meant to be a statement of if I can lock the wheels, disks aren't going to give me any more than that. I would need to pul less hard on the lever though.

Clearly its better to slow the wheel down to the point just before it breaks traction.

Alibran

On my second ride on my road bike, I decided to "see what the brakes are really like on this", and pulled them on pretty hard on a nice, straight stretch of downhill. I was on the drops at the time, and it was the first time I'd ever come close to putting myself over the bars, despite having ridden bikes with V brakes up until that point.

My only complaint about my brakes is that they don't stop very well in the wet, which I think is down to poor quality pads as standard spec, and I'll definitely be doing something about that. There's no way I'd ever put discs on a road bike. One of the most important aspects of a road bike is its lightness.

boybiker

The reason that you don't get disk brakes on a road bike is because the frame is much stiffer than on a mountain bike and it cannot handle the torques generated by the disks.
Having said that the brakes on my allez are more than strong enough to stop me, the limiting factor with road bikes is the fact that they have thin and often slick tyres which do tend to loose traction under heavy braking.

whyamihere

boybiker wrote:

The reason that you don't get disk brakes on a road bike is because the frame is much stiffer than on a mountain bike and it cannot handle the torques generated by the disks.

That's a load of rubbish I'm afraid. It's not a particularly good idea to fit a disc adaptor onto a non-disc road frame, but it's also not a great idea to do it on a non-disc MTB frame. Neither are designed for the purpose. The reason MTBs can take the forces is that they've been designed to do so, and if road bikes ever got discs, designing them to do so would be trivially easy, especially for the companies that make MTBs too.

redddraggon

My dual pivots stop me fine. Modulation seems fine, power is easily enough.

The only time I have problems stopping is on slippery surfaces and then it doesn't matter how good the brakes are I won't stop if I've lost traction.

meanwhile

Surf-Matt wrote:

With MTBs getting ever more powerful brakes, I'm rather suprised that road bikes still have piddly little side pull calipers or at the most small cantilever brakes.

According to the road bikes faq, a standard road bike can brake at 0.6g. The bike would endo at 0.68g. More powerful brakes would be pointless. Riders who know how to use them would be nice, and brakes that keep their power in wet weather. After that a road bike would need geometry changes to brake better - more top tube and less stem.

Now these were ditched by MTBs years ago - because they were useless.

MTBs use cantis etc because of the need to cope with wide tyres.

So how come road bikes, which go a lot faster -

They don't. Marginally faster than a slicked rigid MTB on the road, and not at if the MTB has drops. Where a road bike will excel is in the handling for peleton riding.

It's one major factor that puts me off road bikes.

My Sirrus has geometry almost the same as an Allez racer, but it has v-brakes. Cyclocross bikes also have cantis, v's, or discs.

Of course I'm glad to be proven wrong - any takers?

I think I have. That said, I can't see why road bikes don't use v-brakes anyway. It would give them more versatility. If you really want to criticize road bikes, start with the silly 700c wheels that make them less agile, increase aero drag, and mean that you need a narrower tyre for the same contact patch size. reducing the air gap distance between the rim and pavement to stupidly small levels. A 17 inch wheel Moulton is closer to an optimal road design but it's banned from racing as unfair competition.

meanwhile

boybiker wrote:

The reason that you don't get disk brakes on a road bike is because the frame is much stiffer than on a mountain bike and it cannot handle the torques generated by the disks.

The torque argument is VERY silly.

1. A road bike's ability to handle braking is set by its flippability - which calipers reach.

2. A disc on the rear couldn't exert high torgue, because the rear wheel lightens during braking: there's a limit of about 0.1g on rear only braking, compared to 0.5 for the front brake.

3. You can buy, quite easily, a 700c disc fork to add to most road bikes. It's not a problem.

4. The rider's weight and the reaction to it via the wheels will exert more torque than the maxim braking than most ride bikes can take before flipping.

Squaggles

In answer to the original question , yes , road bike brakes do actually work . The disk brakes on my MTB work as well but I wouldn't want disk brakes on a road bike , just as I wouldn't want suspension forks .

Shimnolo

Don't be so sure discs aren't on the horizon for racing bikes. Log onto Velo News, the American magazine, and you can read several articles forecasting not only small discs but also suspension.
Seems to me the buggers never run out of ideas for parting us from our money.

gavintc

My road brakes do the job perfectly well - dont see the need for stronger brakes.

Lif30057840

set up properly road brakes work fine - as good as v brakes.
my RS100's work great on my tourer, Weinman centrepulls work great on my carlton corsair (about 20years old )

nwallace

When I switch from Zaskar (M535 160mm rotors) to Giro (Tektro dual pivot calipers) I remember the following.
1) The speed may feel the same, but the side of the trails are a lot closer than the side of the road, it may be 4x more than I think.
(I find 30mph on a forest road a bit hairy, 20 is about enough on singletrack)
2) Best leverage is from the drops, with cables there is a lot more movement in the lever.

The Sardar is another issue, Oryx Cantis on that with shimano Wet and Dry paper pads, don't think i have them set up right, tends to oscilate a bit in the wet on steep hills, can certainly stop at the bottom of steep hills with a commuting load.

I recently changed brake pads on the giro, original tektro pads on the frotn were heavily worn. I had a set of Dura Ace pads sitting around so fitted them, the are dire.

What made the biggest change to my braking was getting the technique right.
Front Brake stops you not the back one

NWLondoner

I find that my callipers (Shimano R450) are good enough. If I pull my back brake too hard the wheel locks and I just skid, which does not help in stopping. Jut a gentle squeeze is enough to stop me. God help me if i ever snatch the front brake :shock:

Belv

I was surprised by how good my road bike brakes were first time i used it. So much so that i changed the pads and cables on my mtb so they felt as powerful. I can't quote numbers and bicycle physics, but i know they stop me as quick as i feel comfortable trying to make them.

Surf-Matt

Thanks for the answers all.

Wasn't trying to have a pop - just interested really. They look just like old caliper brakes I used to have on early bikes which really weren't great!

I think there is a big difference between locking your brakes, and having the power and modulation to stop quickly. Something disk brakes really excel at.

El Gordo

Even if disc brakes could be made light enough to appeal to roadies you'd have to beef up the frame and fork to withstand the high torsion at the brake mount.

You'd also have to build a significantly torsionally stronger wheel for the same reason loosing the radial spokes in the process and reverting to triple cross lacing or similar.

It would all add a whole load of weight, particularly rotating mass which is undesirable on a road bike designed for climbing and acceleration.

Why you don't see V-brakes on road bikes though is another matter. I guess they are a bit less aero and maybe a bit heavier and as everyone has already said there is no real need as the wheels will slide long before the V-brake realises it's full potential.

Surf-Matt

You can get sub 18lb MTBs with disk brakes - but they cost a fortune.

Agree with the reinforcement thing though - we have two steel MTBs, both quite old, one with cantis, one with V brakes (quite a high end steel Stumpjumper), and two with disks - the disk braked frames are a lot chunkier than the others - although they are aluminium framed rather than steel.

Also MTB disk ready forks are all pretty beefy.

meanwhile

Surf-Matt wrote:

Thanks for the answers all.

Wasn't trying to have a pop - just interested really. They look just like old caliper brakes I used to have on early bikes which really weren't great!

Look closely and you'll see that modern designs are usually dual pivot, which I doubt your old bikes had!

I think there is a big difference between locking your brakes, and having the power and modulation to stop quickly. Something disk brakes really excel at.

Yes, I keep hearing how good the modulation is with discs. I've also heard that they're better braking in the early stages of a corner - I'd guess because rims will flex slightly, messing up braking. Have you noticed any difference?

Surf-Matt

Meanwhile - I have indeed - my disk braked bikes wheels feel a lot stiffer.

I was a real luddite with MTBing - thought disk brakes were unnecessary, thought suspension forks were pointless.

Finally relented and to be honest, I was underwhelmed at first - the disks (decentish Avid Juicy 5s) really squeaked and juddered. No amount of fettling helped. Then I discovered how to re-align them and love them to bits - no amount of rain will hinder them (even if the bike is fully submerged!), they are much easier to clean (no awkward areas to clean around the brake stays) and need almost no looking after.

I now struggle to motivate myself to use the other V braked Stumpy - very stripped down, light and fully rigid. Any water spoils the brakes and I'm always aware that a very important structure, the wheel rim, is constantly being worn down by the brake pads.

However if I was on a major expedition, I'd consider it as V brakes are much much easier to "bodge" fix if needed. And they aren't filled with highly corrosive fluid.