carbon wheels

naffets

After posting earlier i am considering getting a pair of fuertebici carbon 50mm clinchers
to replace my mavic ksyrium es sl,s. I mostly ride in the peaks so quite hilly wondered if anyone had any feedback or would it be better to go for the 38mm for everyday use

markos1963

IMO I would stay clear of carbon clinchers. If you puncture and can't stop quickly(going down hill for instance) you run the risk of the tyre coming off the rim and either you or the wheel, will be toasted. I got a set of 50mm carbon tubs which I love but use mainly for TT's and racing.

inseine

Interesting. Why is the tyre more likely to come off a carbon rim?

danowat

inseine wrote:

Interesting. Why is the tyre more likely to come off a carbon rim?

I think what Markos meant was, a clincer is more likely to come off the rim than a tubular.

peter101cycle

markos1963 wrote:

IMO I would stay clear of carbon clinchers. If you puncture and can't stop quickly(going down hill for instance) you run the risk of the tyre coming off the rim and either you or the wheel, will be toasted. I got a set of 50mm carbon tubs which I love but use mainly for TT's and racing.

Rubbish - think you are talking about Tubs, not clinchers as the OP stated.

OP, I used to run a pair of Zipp 404 carbon clinchers and had loads of punctures with them, back wheel, front wheel, high speed, low speed, down hill, etc......never had a problem with the tyre falling off or the wheel being damaged.

I even rode a damaged and partly repaired tire back at low pressure 6 miles at slow speed with 12 stone riding on the back, and still no damage to the rim.

But, I would not go for 50mm clinchers, especially if you are riding in the Peaks. Took my bike upto Sheffield one weekend and it was hard work, especially with the rotational effect round fast descending bends......go for less Aero would be my advice.

I have the DuraAce 7850 CL Carbon Clinchers at 24mm deep I think, they are strong and light and would be ideal for the Peaks.
http://www.merlincycles.co.uk/Bike+Shop/Wheels/Road+Wheels/Factory+Road+Wheels/Shimano+Dura+Ace+7850+CL+Wheels_1492.htm

ugo.santalucia

classic example of downgrade from your current ksyriums

TommyEss

But surely braking performance is a bigger issue, particularly with the OP saying they intend to ride a lot in the Peak District.

Even with good cork pads, the braking on a carbon rim is significantly worse than with alu. Unless we're talking about carbon with aluminium sidewalls for braking, which may be the case if they're clinchers - though that said, are there not potential pitfalls with binding aluminium to carbon in these arrangements, particularly delaminiation with extended braking leading to very high temperatures and pressures?

In short - if I were intending to ride a lot in hilly areas, I'd be aiming for some lightweight, low profile rims with an aluminium rim for braking.

HTH.

MaxwellBygraves

My 2p:
Carbon clinchers are fine, you're no more likely to get grief off carbon rims when you puncture than you will off an alloy rim.
An example - never had an issue with my carbon rims, but once on a descent I had a blowout, tyre was shredded and consequently found this fractured the aluminium rim (Mavic Aksium if ou're interested). Had to bin the wheel.
However, if you're riding lots of hills, get some aluminium clinchers.

cougie

Theres as much risk of the tyre coming off a carbon rim as their is an alu rim.

Deep rims will be more aerodynamic, but twitchier in high winds, and heavier. Also you'll need a decent braking strip on them - so more weight.

All things considered - they wont be the best wheels for your area. Go for lighter low profile alu rims.

markos1963

danowat wrote:

inseine wrote:

Interesting. Why is the tyre more likely to come off a carbon rim?

I think what Markos meant was, a clincer is more likely to come off the rim than a tubular.

Yes thanks for that Dan
I'm sorry I wasn't more clear in my explanation. If you had spent a lot of money on some carbon rims and the tyre punctured then a glued/taped on tyre is more likely to stay on the rim than a clincher(regardless of what the rim was made of) Its just that a carbon rim is going to get more damaged by this than an aluminium one.

Is that a bit clearer?

inseine

It's totally clear now, thanks. Never happened to me personally and I can't remember the last time I saw it, though I have with tubs funnily enough. If it were a problem it would be a good reason not to run clinchers full stop, for your own health as much as the wheels.

rogerthecat

Nice wheels set BTW.



But, I would not go for 50mm clinchers, especially if you are riding in the Peaks. Took my bike upto Sheffield one weekend and it was hard work, especially with the rotational effect round fast descending bends......go for less Aero would be my advice.



About the best bit of advice here though. 30mm max imo

markos1963

inseine wrote:

It's totally clear now, thanks. Never happened to me personally and I can't remember the last time I saw it, though I have with tubs funnily enough. If it were a problem it would be a good reason not to run clinchers full stop, for your own health as much as the wheels.

A properly glued on tub should stay on the rim compared to a clincher. Its probably the reason the pro teams still persist with tubs, enabling the rider to carry on after puncturing until a team car can catch up with a spare wheel. For non racing applications I would always choose clinchers but not with carbon rims for me.

rogerthecat

Why would Carbon rims be considered bad? I am happy with possible over-heating when breaking, is there another reason?

inseine

It seems like there are some incidents of blow outs (tubs and clinchers) due to heat build up. The other thing is braking is probably not so good especially in the wet. I've only used carbon sprint rims and I didn't have carbon specific blocks but the performance was good enough for TTing but not great. They can be a bit 'grabby' aswell as lacking a bit of ultimate stopping power. Doesn't seem to bother the pros.

TommyEss

inseine wrote:

It seems like there are some incidents of blow outs (tubs and clinchers) due to heat build up. The other thing is braking is probably not so good especially in the wet. I've only used carbon sprint rims and I didn't have carbon specific blocks but the performance was good enough for TTing but not great. They can be a bit 'grabby' aswell as lacking a bit of ultimate stopping power. Doesn't seem to bother the pros.

I wouldn't worry too much about my brakes racing on closed roads either - back in the real word, where cars/pedestrians/crows/cows - whatever - can jump out unnanounced - I'd want to know my brakes would stop me quickly and consistently - not slowly and a bit grabby.

rokkala

The guy that does the Fuerte Bici wheels is about to offer them with an optional ceramic coating treatment on the braking surfaces. Apparently the difference against the non-treated rims in dry and wet is very marked.

Think it will add on ~£100 to the wheelset price though

http://fuertebici.com/site/?p=1722

Down the Road

I personally would make sure someone riding these wheels was behind me.£500 for a pair of Carbon clinchers - really Ever wonder why none of the serious wheel companies get no closer that twice this price at best????

In carbon Clincher rims are not easily manufactured and as such this adds considerably to the costs

MaxwellBygraves

TommyEss wrote:

inseine wrote:

It seems like there are some incidents of blow outs (tubs and clinchers) due to heat build up. The other thing is braking is probably not so good especially in the wet. I've only used carbon sprint rims and I didn't have carbon specific blocks but the performance was good enough for TTing but not great. They can be a bit 'grabby' aswell as lacking a bit of ultimate stopping power. Doesn't seem to bother the pros.

I wouldn't worry too much about my brakes racing on closed roads either - back in the real word, where cars/pedestrians/crows/cows - whatever - can jump out unnanounced - I'd want to know my brakes would stop me quickly and consistently - not slowly and a bit grabby.

I respect what you say, but have to disagree.
Granted, they don't work as well in the wet and I said as much in my earlier post, but you allow for this.
On the other hand, I think everyone reading this would be chuffed to get remotely close to the speeds some pro's reach on alpine descents - not saying it can't be done, but a decent cyclist, living in chilly ol' Britain would really struggle to heat up their wheel rim enough to blow a tyre.
Conversely, a pro giving it some beans down some mountain descent in the height of summer, where every second counts I think is more likely to blow a tyre.
I would encourage you to try them out if you haven't already and don't live somewhere like the peaks, they're great!

cougie

I've blown a front tyre descending Alpe D'Huez.

It wouldnt have happened on a normal day - but this was the day after the tour and there was a lot of traffic around so more braking than usual. Plus I think I used to run my tyres at too high a pressure. 140PSI with my Vredesteins ! :oops:

Monty Dog

Original Zipp 404 clinchers were notorious for blowing tyres due to overheating due to the heat build-up in the aluminium brake track.

Running a flat on an all-carbon clincher is asking for trouble IMO - anyone that's survived is just plain lucky - I've seen carbon tubular rims 'toasted' by an expansion crack. I've seen plenty of crashes due to sudden punctures on clinchers regardless of materials - a thin edge has sod-all grip on any surface.

Never experienced or heard of heat-build up problems with tubulars - one of the reasons that pros still use them, along with the run-flat ability.

For general riding I'd stick to a medium profile rim - most people down ride fast enough to warrant the benefit but only ride them because they think it looks 'cool'

inseine

Never experienced or heard of heat-build up problems with tubulars - one of the reasons that pros still use them, along with the run-flat ability.

I have read of heat build up softening the glue enabling the tubs to rotate and ripping the valve off. i guess if heat build up with clinchers it could be with tubs too.

MaxwellBygraves

cougie wrote:

Plus I think I used to run my tyres at too high a pressure. 140PSI with my Vredesteins ! :oops:

Jesus no wonder she blew! Having said that, have been guilty of the same thing myself.

TommyEss

cougie wrote:

I've blown a front tyre descending Alpe D'Huez.

It wouldnt have happened on a normal day - but this was the day after the tour and there was a lot of traffic around so more braking than usual. Plus I think I used to run my tyres at too high a pressure. 140PSI with my Vredesteins ! :oops:

Wow! I only go that high on the track! So was it a big crash?! :shock:

kingrollo

Not an expert in this area. But I have been looking at carbon wheels (and yes I admit - just for the bling value) - whilst I have nothing further to offer on the in depth technical debate - If I ever had £700 that I was struggling to spend - the Mavic Cosmic Carbone - would seem to represent the best of most worlds

Reasonably Priced
Quality Brand
Alu braking surface (can use normal blocks)
Reasonable weight.

Anonymous

Down the Road wrote:

I personally would make sure someone riding these wheels was behind me.£500 for a pair of Carbon clinchers - really Ever wonder why none of the serious wheel companies get no closer that twice this price at best????

In carbon Clincher rims are not easily manufactured and as such this adds considerably to the costs

Ive been racing on 60mm carbon clinchers from fuerte bici and they are excellent. I don't use them for hillier rides as I have been using Kysrium SL's as well not one bit of trouble for 4 years with them. I think the low price of the fuerte bici wheels is due to the fact that large companies like zipp etc have insurances and warranties on an international level to contend with and this is factored into the price.

TommyEss

inseine wrote:

Never experienced or heard of heat-build up problems with tubulars - one of the reasons that pros still use them, along with the run-flat ability.

I have read of heat build up softening the glue enabling the tubs to rotate and ripping the valve off. i guess if heat build up with clinchers it could be with tubs too.

True - you get heat build up whenever you use the brakes - the bigger issue with carbon clinchers is you have two different materials (alu brake track mated to carbon rim) - the difference in heat capacity of the two materials leads to a build up where the two meet - spiking the temperature - whereas an all carbon rim, or all aluminium, would see the heat continue to move away from the braking area more evenly.

Zipp seem to have put some thought into this with their latest rims, if the false colour IR photos are anything to go by - the heat dissipiation's much better than it used to be.

Still - we're talking Alpine descents cooking rims - not a trip to the shops/local club 10 - even a descent on a sportive is unlikely to generate enough heat - just remember brake on, slow, brake off, turn - don't drag the brakes.

wildmoustache

140psi in the mountains - daft!

the jury is still out on carbon clinchers with respect to heat disappation which is relevant to steep / long descents. there are plenty of reports of problems and manufacturers have invested a fair bit of time and effort attempting to overcome these problems. the new zipp clinchers are pretty much state of the art in this respect, but expensive

wicked

oops wrong thread

inseine

True - you get heat build up whenever you use the brakes - the bigger issue with carbon clinchers is you have two different materials (alu brake track mated to carbon rim)

Many of the carbon clinchers are full carbon.

balthazar

inseine wrote:

It seems like there are some incidents of blow outs (tubs and clinchers) due to heat build up.

Tubulars don't blow off the rim due to pressure increase from braking heat (as can clinchers). They can withstand much higher pressure than that without consequence.

You're not off the hook if you prefer tubs though- that heat can melt the glue, allowing the tyre to gather at the valve, eventually ripping it off. You can't prepare for that as clincher riders can (by lowering pressure beforehand).