Carbon Clinchers in the Alps

First.Aspect

PTestTeam wrote:

Sorry if riders could descend in the Pyrenees in 1910 on bikes like these, then you should be able to get down a few mountains using carbon clinchers

https://janheine.files.wordpress.com/2013/06/lapize.jpg

You don't know that. What if that photo was taken at the top.

First.Aspect

onemoresolo wrote:

I've got a semi-tarty set of carbon tubular wheels but took a set of Khamsins to the Alps for my last trip and it made precisely zero difference to how much I enjoyed myself.

You mustn't have heard - low spoke count wheels and radially laced wheels are dangerous. Using radially laced low spoke count wheels is suicide.

meesterbond

SloppySchleckonds wrote:

I'm thinking of taking 4 bikes to the Pyrenees, just in case like.

You're being silly now... there's no need to take more than three. A nice light carbon climbing one for the way up, a heavier one with discs for the way down and an aero one for the flats. And a car to follow behind you for bike changes.

Actually, probably worth taking a spare, so you're right, 4 it is.

I think there is a tendency to over think things - anything less than the absolutely optimal solution to a problem will almost certainly result in death, or worse, internet ridicule... you've only got to go back 20/30 years to find that most road bikes had brakes there were there in a purely advisory capacity. I don't remember being killed (although do remember some rather sketchy off-road descents on my mate's Kona Cinder Cone with cantilever brakes that simply turned effort at the levers into noise and brake dust and very little else).

bernithebiker

First Aspect wrote:

Cycling "tech" has a history of absolute nonsense and superstition.

Its not so long ago that we were warned against carbon frames, and then seatposts that would break and cut our anuses to shreds. You shouldn't use hydraulic discs because the fluid would boil. Or the discs themselves would be dangerously sharp and hot. Of course, carbon tubulars were dangerous as well, because the glue would melt.

Lets face it, roadies are a bunch of fearful luddites.

All the things you mention above have elements of truth in them, but as you will have seen in the video (and I have heard of plenty of other examples), carbon clinchers can and do fail, so no myths there.

Under most conditions, they'll be fine, but over brake them with a big rider on a hot descent, and a catastrophic failure is a possibility.

dinyull

onemoresolo wrote:

I've got a semi-tarty set of carbon tubular wheels but took a set of Khamsins to the Alps for my last trip and it made precisely zero difference to how much I enjoyed myself.

That bad eh?

fenix

I do remember my mate taking his flash Rolf Vectors (remember those ?) to the Alps. 16 spokes I think ?

He was on my wheel going up the Alpe but then dropped behind. At the top he was nowhere to be seen. Eventually he rocked up. He'd bust a spoke and the wheel was unrideable. So an hour into the break his bike was useless.

Nobody could fix them and he had to buy a new set of wheels on his plastic to keep riding. So if its a special trip - stick to the tried and trusted wheels ! High spoke counts rock.

jdee84

drlodge wrote:

Fenix wrote:

Apart from looking cool - what are the advantages of carbon clinchers in the mountains ?

Indeed, I wonder why we're even discussing this topic. Alloy has some big advantages (not delaminating hence not killing you), so why would you even consider taking carbon wheels to the Alps?

As well as the inherent dangers due to the materials and construction, braking downhill is going to wear out the brake tracks on your expensive new wheels prematurely. I just don't see the point.

FWIW, I plan to take 2 bikes with me when I visit Mont Ventoux for a fortnight next year, one has 50mm carbon tubeless clinchers so will use that on the flatter rides, but the alloy wheels will be for the lumpy rides.

I'm not long back from Mont Ventoux it might be the only really big mountain around there but you will not find a flat ride around there every ride is a lumpy one!

sloppyschleckonds

Dinyull wrote:

onemoresolo wrote:

I've got a semi-tarty set of carbon tubular wheels but took a set of Khamsins to the Alps for my last trip and it made precisely zero difference to how much I enjoyed myself.

That bad eh?

Some serious photo opportunities missed though

robbo2011

Rode the Alpenchallenge in Switzerland yesterday and at a rough guess the number or riders i saw with alloy wheels outnumbered the blingy carbon wheels by about 10:1.

And the wheels used by the rider who had an exploding inner tube just after completing the Spluegun pass descent? Yup, carbon clincher. The group i was in got held up by traffic lights midway down and then we had to follow a slow line of traffic around a long series of hairpins on the brakes the whole time.

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

First.Aspect

robbo2011 wrote:

Rode the Alpenchallenge in Switzerland yesterday and at a rough guess the number or riders i saw with alloy wheels outnumbered the blingy carbon wheels by about 10:1.

And the wheels used by the rider who had an exploding inner tube just after completing the Spluegun pass descent? Yup, carbon clincher. The group i was in got held up by traffic lights midway down and then we had to follow a slow line of traffic around a long series of hairpins on the brakes the whole time.

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

1 in 10 riding most expensive product. Check. Bloke with puncture and speculated cause, check. This robust statistical analysis has convinced me to change my mind. I'm going to use my lightweight obermeyers as ornaments from now on.

I was on a sportive last year and I saw the support team repairing a puncture. Blue sidewalls. Avoid blue sidewalls, that's what I say.

bernithebiker

robbo2011 wrote:

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

Absolutely. Good info. All sorts of things can slow your descent far more than you think, causing excess braking and heat; caravans, livestock, crowds, etc.etc.

I use carbon tubs and not sure why anyone would want to chance it with carbon clinchers in the mountains.

mfin

bernithebiker wrote:

robbo2011 wrote:

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

Absolutely. Good info. All sorts of things can slow your descent far more than you think, causing excess braking and heat; caravans, livestock, crowds, etc.etc.

I use carbon tubs and not sure why anyone would want to chance it with carbon clinchers in the mountains.

It is simple why they would chance it, because they turn a blind eye to the fact that carbon clinchers are a flawed design as far as heat dissipation goes, or they can't absorb the logic.

Anyone riding cheap ones in the mountains is risking it, and anyone riding more proven, expensive ones is still risking it. Whether that's risking yourself, your wheels which you think are nice, or risking your holiday being interrupted is up to you to think through but it is actually all three.

Carbon clinchers do provide aero advantages like their tubular counterparts, but are best kept to rides where descending braking could be needed a lot. They may look pretty much the same, but they aren't, it is simple.

First.Aspect

bernithebiker wrote:

robbo2011 wrote:

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

Absolutely. Good info. All sorts of things can slow your descent far more than you think, causing excess braking and heat; caravans, livestock, crowds, etc.etc.

I use carbon tubs and not sure why anyone would want to chance it with carbon clinchers in the mountains.

So, an issue with carbon fibre is low heat conductivity. A knock on effect with clinchers is that the sidewall can blow out. But if you watch the video, and other serious issue is blistering and delamination of the brake track. And in place of spot heating causing inner tube failure, tubs suffer from melting glue causing the tyre to roll off the rim, as we saw in the TdF even this year.... (or was the cause something else. I don't know, so hey lets just speculate.)

But you are happy to use carbon wheels in the mountains? Its an arbitrary distinction based on your preferred mode of catastrophic failure. This is just belief without understanding.

A carbon brake track isn't going to be knackered by having to stop for a passing sheep. IF you are trundling down in a slow group, the energy dissipated is much smaller (square of speed, remember, so stopping from 40 to 20 kph generates three times as much heat in the brake track as going from 20 to standstill, for example).

A carbon brake track is only going to be problematic if you adopt the habit of absent mindedly dragging the brakes for prolonged periods in these situations, rather than pulsing or alternating braking, or braking only when you need to - which is a habit a competent cyclist builds up anyway, after grinding through brake pads and aluminium sidewalls a few times.

Sorry, but that's operator error. Its like complaining that your car's handbrake is broken after you've driven to the shops with it on.

bernithebiker

First Aspect wrote:

bernithebiker wrote:

robbo2011 wrote:

Those who say it is just down to bad descending perhaps don't appreciate the situations that can occur while descending. These things can and do happen.

Absolutely. Good info. All sorts of things can slow your descent far more than you think, causing excess braking and heat; caravans, livestock, crowds, etc.etc.

I use carbon tubs and not sure why anyone would want to chance it with carbon clinchers in the mountains.

So, an issue with carbon fibre is low heat conductivity. A knock on effect with clinchers is that the sidewall can blow out. But if you watch the video, and other serious issue is blistering and delamination of the brake track. And in place of spot heating causing inner tube failure, tubs suffer from melting glue causing the tyre to roll off the rim, as we saw in the TdF even this year.... (or was the cause something else. I don't know, so hey lets just speculate.)

But you are happy to use carbon wheels in the mountains? Its an arbitrary distinction based on your preferred mode of catastrophic failure. This is just belief without understanding.

A carbon brake track isn't going to be knackered by having to stop for a passing sheep. IF you are trundling down in a slow group, the energy dissipated is much smaller (square of speed, remember, so stopping from 40 to 20 kph generates three times as much heat in the brake track as going from 20 to standstill, for example).

A carbon brake track is only going to be problematic if you adopt the habit of absent mindedly dragging the brakes for prolonged periods in these situations, rather than pulsing or alternating braking, or braking only when you need to - which is a habit a competent cyclist builds up anyway, after grinding through brake pads and aluminium sidewalls a few times.

Sorry, but that's operator error. Its like complaining that your car's handbrake is broken after you've driven to the shops with it on.

I think you don't really get the issue here. It is that CC's are by their design, very thin at the top of the rim. There is little material here, far less than in a tub wheel. Less thermal inertia = more rapid temperature increase.

This is why, (as the video explains), manufacturers have tried to move the brake surface down lower, where there is more material.

A properly glued tub is fine; the surface area of a glued tub is far greater than the thin sidewall area of a clincher. I doubt the pro peloton would be using so many carbon tubs if they feared constant tub roll off. I only use 1 layer of glue on my tubs, but they are always really quite difficult to get off, even un-inflated. Sore thumbs.

You also don't get that situations DO arise where even a good descender may have to descend on the brakes. Sh*t happens.

And even you would surely accept that there is a big difference between a good 60kg rider descending an 'easy' col in 15'C and a 90kg rider beginner descending a 'tough' col in 30'C? The heat difference at the rim will be enormous.

Noone's saying that if you take your CC's to the Alps you're guaranteed to come back in a coffin, but you are potentially opening yourself up to problems in a small %age of cases. It may just be that when you get back you notice your wheel is slightly out of true, but you don't remember hitting anything.....

First.Aspect

No, I get it. I don't deny that there have and can be problems with these wheels, I just don't think its quite as bad as the hyperbole would lead you to believe. I also think that there is an awful lot of selective judgement goes on in cycling.
Btw, you aren't one of these people who think that 30C is twice as hot as 15C, are you?

bernithebiker

First Aspect wrote:

No, I get it. I don't deny that there have and can be problems with these wheels, I just don't think its quite as bad as the hyperbole would lead you to believe. I also think that there is an awful lot of selective judgement goes on in cycling.
Btw, you aren't one of these people who think that 30C is twice as hot as 15C, are you?

No, because I have a degree in mechanical engineering and I know that 0K = -273'C.

Nonetheless, high ambient temperatures will exacerbate the problem.

So the heaps of melted CC's in the video aren't enough to convince you then?

pblakeney

First Aspect wrote:

Btw, you aren't one of these people who think that 30C is twice as hot as 15C, are you?

'Scuse the ad...
https://www.youtube.com/watch?v=bbjGdgtscDA

bernithebiker

PBlakeney wrote:

First Aspect wrote:

Btw, you aren't one of these people who think that 30C is twice as hot as 15C, are you?

'Scuse the ad...
https://www.youtube.com/watch?v=bbjGdgtscDA

That video is SO fake.....

pblakeney

bernithebiker wrote:

PBlakeney wrote:

First Aspect wrote:

Btw, you aren't one of these people who think that 30C is twice as hot as 15C, are you?

'Scuse the ad...
https://www.youtube.com/watch?v=bbjGdgtscDA

That video is SO fake.....

You would hope so, but I think she is genuinely that thick.
There are a whole series of them. I was the one about Brexit that first got my attention.
Scary thing is, she has a vote.
https://www.youtube.com/watch?v=nZO9JGSScMQ

paul2718

robbo2011 wrote:

And the wheels used by the rider who had an exploding inner tube just after completing the Spluegun pass descent? Yup, carbon clincher. The group i was in got held up by traffic lights midway down and then we had to follow a slow line of traffic around a long series of hairpins on the brakes the whole time.

This situation isn't really a problem, because the speeds are low.

The thing here is that 'alloy clincher' is the right answer to 'what's the best wheel for an English winter?', and the reason is that punctures are quick and cheap to fix. The right answer to 'what wheels should I ride in the mountains?' is 'something tubular' and in present market conditions that something is probably carbon. Although Mavic still make a nice alloy tubular rim for a very modest sum. That's where I'd be if I routinely rode up and down mountains.

Paul

DeVlaeminck

Disagree, the kind of situation that will cause a problem is where you brake to keep speeds between sort of 25-35 mph on a descent where a confident descender on a clear road will be doing 40mph plus and braking for corners only. It's riders new to the mountains or if you get stuck behind traffic.

First.Aspect

DeVlaeminck wrote:

Disagree, the kind of situation that will cause a problem is where you brake to keep speeds between sort of 25-35 mph on a descent where a confident descender on a clear road will be doing 40mph plus and braking for corners only. It's riders new to the mountains or if you get stuck behind traffic.

This scenario has to be in here somewhere....

robbo2011

paul2718 wrote:

robbo2011 wrote:

And the wheels used by the rider who had an exploding inner tube just after completing the Spluegun pass descent? Yup, carbon clincher. The group i was in got held up by traffic lights midway down and then we had to follow a slow line of traffic around a long series of hairpins on the brakes the whole time.

This situation isn't really a problem, because the speeds are low.

The thing here is that 'alloy clincher' is the right answer to 'what's the best wheel for an English winter?', and the reason is that punctures are quick and cheap to fix. The right answer to 'what wheels should I ride in the mountains?' is 'something tubular' and in present market conditions that something is probably carbon. Although Mavic still make a nice alloy tubular rim for a very modest sum. That's where I'd be if I routinely rode up and down mountains.

Paul

Not sure, Paul. coming to a virtual stop from 25-30mph for 5 or 6 hairpins in close succession with a gradient of around 10% in 25degC temperatures seems like an awful lot of braking to me.

I have to say, I still have the what if I get a puncture fear factor with tubs. don't think I would like my ride ruined or have to dick around for ages trying to fix a new tub which would take up loads of space in a back pocket, space that is needed for gels and additional clothing.

Having said that, on my road bike, I have done about 25,000 km since being here and only had one puncture, so maybe the fear is an irrational one.

pinno

robbo2011 wrote:

paul2718 wrote:

robbo2011 wrote:

And...time.

This...Paul

...being here....

Where's 'here' ?

robbo2011

Switzerland

pinno

robbo2011 wrote:

Switzerland

Have you got a number plate on your bike?

DeVlaeminck

https://www.youtube.com/watch?v=bFdG2NgIc7s

paul2718

robbo2011 wrote:

Not sure, Paul. coming to a virtual stop from 25-30mph for 5 or 6 hairpins in close succession with a gradient of around 10% in 25degC temperatures seems like an awful lot of braking to me.

It would be good to have proper measurements of this. It is all speculation and one off personal experience.

I remember last summer sitting in a café on one of the Alpe d'Huez hairpins, a couple arrived from the up side, leaned their bikes against a wall and started to walk away. Followed by an explosive bang as a tube exploded. Alloy clincher....

Perhaps tyres get pumped up to quite hard in a cool morning and then in the heat of the day after excessive braking something pops.

I have to say, I still have the what if I get a puncture fear factor with tubs. don't think I would like my ride ruined or have to dick around for ages trying to fix a new tub which would take up loads of space in a back pocket, space that is needed for gels and additional clothing.

It's an issue. I usually carry a spare tyre. I've never used it. I think changing it is quick enough, if you can get the old one off.

Having said that, on my road bike, I have done about 25,000 km since being here and only had one puncture, so maybe the fear is an irrational one.

I have some sealant in mine, I think this takes care of most 'normal' punctures and generally you don't notice. I've had one certainty and one maybe in the last two and a half seasons.

Paul

pinno

Warning, Way off topic:

How many recruits do you actually think you'll get on here DeVlaeminck? -

"sign for Mickleover Sports FC U15 girls"

DeVlaeminck

It's about building the brand - I've got a squad of 17 anyway so not really looking - though if you fit the bill and can play centre forward ... ?