Alpine Braking - Special requirements?

[Tyrian]

I have got a place in this Etape (the hilly one and not flat version option) While going up the hills i am genrally ok but coming down to describe me as cautious is an understatement!! i have been down a hill on my bike at 50mph and survived fine but feel it is not something I need to repeat having lived the experience. My balance and confidence at in descending are not great now ( a couple of speed wobbles) and as a result generally develop a very good working relationship with my brakes happy in the knowledge that it might take me longer than my mates i do get down safe and sound.

i am just a little worried if on the very long descents if i am permently braking the potential problem that heat build up from the friction might have. You do here about the odd horror story of peoples wheels / tyres exploding from the heat. Any advice would be appreciated both in terms of specific braking techniques and also should i look at different pads? Currently running campag record on Ksyrium SSC's, do I need to look at more of a cork type pad? I did a couple last year in the dolomites and the rims were so hot I could not touch them; not sure if this is normal or danger sign


Thanks


Richard

 

[ColinJ]

Hi Richard - welcome to CycleChat!

From what you have written, I think that excessive caution could get you into trouble, either by you blowing a tyre, or by someone hitting you from behind.

When you brake hard, you convert a lot of Kinetic energy into heat, there's no getting away from that. If your brakes work, the rims will get hot.

If you do long descents dragging your brakes to keep your speed down, then I think you will be in real danger of blowing a tyre, and will also tend to wear your brake blocks rather quickly. So yes, I'd take the hot rims as a warning! If you are going to ride like that, I'd suggest that you at least stop every few miles to let the rims cool down before continuing.

The other problem is that you will be descending slower than many other people so you will have riders shooting past you all the time, maybe on both sides. I reckon that could be an accident waiting to happen in which case your attempts to be 'safe and sound' would have backfired on you.

I can see why you might not want to descend at a crazy speed, but 40-50 mph should be safe. I do that all the time round here and I'm no demon descender. If you have a 2 mile stretch of straight road and there are no crosswinds, or other hazards, why not go down it at 50 mph?

I'd suggest that if you are getting speed wobbles on a regular basis, then either something is wrong with your bike or the way that you are riding it.

I think you need to work on improving your confidence in your bike handling skills. If you lack confidence because you lack those skills, then you need to work on those skills!

 

[yashicamat]

A few things I'd suggest;

- check the mechanical condition of your bike, especially brake cables, pads, rim condition and especially wheel bearings/wheel trueness. Also check your tyres very carefully for any signs of rubber fatigue (might even be worth getting new tyres for the event? Make sure they're at the right pressure too)

- as Colin has said, get some practice in of fast descents; I think 50mph is pretty quick, but if there is no cross-winds or tight corners that you're trying to negotiate at that kind of speed, it's perfectly do-able

- finally, something I find helpful if my bike gets a bit wobbly is to press a knee against the toptube - this seems to smooth the bike out again (I only find this issue on my road bike, my touring bike doesn't get twitchy at speed like my road bike can)

I've never even entered into a proper competition so I appreciate this might be of limited use, but I've done quite a few 50mph descents on all sorts of different bikes so hopefully the (probably fairly obvious) tips above will be of some use!

Good luck

 

[ColinJ]

I think 50mph is pretty quick, but if there is no cross-winds or tight corners that you're trying to negotiate at that kind of speed, it's perfectly do-able

Yes, it is quick and there's no doubt that you could be seriously hurt if you did have a crash at that speed, but if there aren't any gusting winds, sheep wandering about, bends to negotiate etc. and your bike is in good condition, there is no reason for you to lose control.

I'd also add that I'm talking about descents at no more than about 5%-6%. Very steep descents are scary and you'd be stupid to build up too much speed on them because you stand a good chance of crashing if you try and slow down too quickly.

Not taking my own advice ... I descended Holme Moss towards Woodhead once at 50 mph in gusting crosswinds. I got caught by a powerful gust from my left just after a car went past me going up the hill. I was blown straight across the road to where the car had been about 2 seconds earlier!

I did the same descent a few years later on the Kirklees Sportive and caught up with a couple of slower descenders halfway down. For some crazy reason, one of them decided to swing right out into the road without looking over his shoulder first, just as I was overtaking him. I swerved round him with inches to spare ...

 

[dan_bo]

Make sure your rim tapes are in good nick- a scabby old tape is more likely to fail when hot and cause a blow out at high temperatures/ pressures- don't ask me how I know this.

 

[Tyrian]

Gents,

Thanks for all the input so far. Perhaps I over egged my descending ability (or lack of). I should be fine fine for 35 mph on lower gradient hills like that and was not planning on doing the whole thing at 15mph. Yes as always i could do more to improve my bike handling skills and the previous major speed wobble was more a result of play in the forks but as with all these things a lot comes down to confidence. I have some general balance and vertigo issues which effect me all the time and not just the bike. Last year near lake Garda I experimented with letting the brakes go and then put on harder or using just back and then front. I hope this type of thing will help and then it was a question of whether you can get specific brake pads that help dissipate the heat better could be an option. I vaguely remember cork blocks being good for this but I could well be wrong and got this round my neck.

Thanks again for all the advice. I have gone down Home Moss before as part of Phil and friends ride and cannot say i would fancied that at 50mph

 

[ColinJ]

Thanks again for all the advice. I have gone down Home Moss before as part of Phil and friends ride and cannot say i would fancied that at 50mph

There's definitely something in the combination of hill, bike and rider which can lead to speed wobbles (shimmies). I descended Holme Moss two years on the trot (Kirklees Sportive, rebranded as the Brian Robinson Challenge the 2nd year) and my riding partner got a major speed wobble both times at the bottom of the descent! He was very shaken.

To be honest - Holme Moss is a bit steeper than I like for fast descending because the speed builds up really quickly as soon as you stop braking. I prefer descents like the A6033 to Hebden Bridge. It's fast, but I feel that I am better in control on that. I prefer to pedal up to speed rather than have gravity doing it for me whether I like it or not!

 

[heliphil]

I'll add my twopence worth here - get some decent brake blocks - I did an Alps ride last years and the standard Shimano blocks gave no confidence in stopping .......

 

[Tyrian]

Thanks again everyone. as for the brake blocks, I bought a brand new pair of campy record skeleton brakes about a month ago. i would that the brake blocks supplied would be of good quality. I have no complaints so far and they certainly stop me rapidly, concern is that I don't start a major pyrotechnics show half way down the Col du Telegraphe or Col du Galibier

 

[Fiona N]

....
- finally, something I find helpful if my bike gets a bit wobbly is to press a knee against the toptube - this seems to smooth the bike out again

...

It also might be worth learning to descend off the saddle with the top tube clamped between your knees. One way to avoid speed wobbles for definite, although you do tend to go faster But the main thing is that it's easier to absorb bumps in the road without your weight on the saddle and this makes high speed seem a lot safer. But basically descending at speed needs practice - even the daredevils often aren't that good at it, they just take greater risks. Safety lies in being in control and relying on overheating brakes to keep your speed down isn't a very good way of maintaining control compared to learning how to corner, how to float the bike on rough sections etc.

 

[david1701]

I'm not a very good (well not very experienced) rider but I agree with Fi I descend all the short sharp hills round here out of the saddle because I feel I can avoid the crap in the road/roles in it better.

 

[TheDoctor]

I've found that if I sit upright on the bike - hands on the tops or the hoods, arms straight - it slows me down a lot.
I'm hard pressed to get above 35 mph like that, and that's before I touch the brakes.

 

[ColinJ]

I've found that if I sit upright on the bike - hands on the tops or the hoods, arms straight - it slows me down a lot.
I'm hard pressed to get above 35 mph like that, and that's before I touch the brakes.

I also use air-braking on gentle descents, but it's not much use once the downhill gradient is over 15%!

 

[buddha]

I've found that if I sit upright on the bike - hands on the tops or the hoods, arms straight - it slows me down a lot.
I'm hard pressed to get above 35 mph like that, and that's before I touch the brakes.

A half-unzipped jersey acts like a parachute - well, kind of. Can get a bit nippy though after a while, and looks daft - so I've been told.

 

[Tyrian]

As always thanks for the extra advice, went out last night and tried the knee clamping bit and that seemed to help. I often get off the saddle anyway and shift my backside back which I also find helps. Not sure the world is ready for my ripped v shaped torso with my top undone!! not to mention the 12 pack I can boast (as if). We have had a lot of cross winds here in Derbyshire / peak district and I find that effects me. Have got a Pinarello Prince SL which I absolutely love with the Onda forks but they do seem to get caught more by the wind and be quite twitchy. As you have all said, it is a confidence thing and I used to hair down quite happily. However with age comes greater caution and awareness of risk, throw in a nasty scrash on black ice and a couple of wobbles and it has just set me back. I do not mind going down slowly and feel no shame in this but I just want to be sure that this will not result in an heat explosion. Once I have got underway then I can hopefully feel secure move about the same speed as others. if I do not feel happy with this then will just stop every couple of miles and let the rims cool. They cannot get any hotter than when I did the Fred whitton and was coming down hardnott pass at probably a slower speed than I rode up if that was at all possible.

All advice well appreciated