Edge 68 Clinchers + braking downhill

[r_mutt]

carbon clinchers - i know most of you here are purists, and scoff at the idea of running carbon clinchers, but i like having the convenience of changing a flat on the spot, and being able to charge downhill without worry on an half-glued tire.

my question is - what is braking like with a carbon clincher? are you worried about warping issues when going down long descents on the brakes for extended periods? i've read a few things on the internet concerning warping and exploding tires due to heat build-up on the braking track when braking for long periods.

anyone have any experience on this?

[Tim]

I've been using carbon clinchers since last spring and the braking is excellent. As for descending issues I can't tell you- no huge hills around here for me to test out.
I rode some long descents last summer in France in the Pyranees on Alu rims and, it's true, the rims get hot from the braking- but the tires never came close to coming off. I imagine it would be similar with carbon rims.
One thing: good brake pads are essential- I'd go with Swiss Stop yellow pads.

[rockdude]

carbon clinchers - i know most of you here are purists, and scoff at the idea of running carbon clinchers, but i like having the convenience of changing a flat on the spot, and being able to charge downhill without worry on an half-glued tire.

my question is - what is braking like with a carbon clincher? are you worried about warping issues when going down long descents on the brakes for extended periods? i've read a few things on the internet concerning warping and exploding tired due to heat build-up on the braking track when braking for long periods.

anyone have any experience on this?

I have seen quite of few Edge clincher on ebay with the warped braking surface. No personal experience with the problem but it is an issue.

[srice]

I've actually seen a carbon clincher destroyed by braking generated heat. I have no idea what brands it was and it was in 2006. I was riding BMB and there was a tandem that had come down off Middlebury Gap. They managed to overheat and destroy their front rim. After seeing that wheel, I have no idea how they walked away from it. Granted it was 4 years ago, a tandem and a 8+ mile downhill.

[SoCalSteve]

I believe the conditions have to be just so for this to happen.

Very hot day
Very steep hill
Lots of very hard braking
Bigger rider (so it takes more umph to stop him-her)

I imagine that you can avoid this by just being careful on VERY hot days. Pull over to let the braking surface cool down if you have any doubts.

[LegendRider]

A little off-topic, but I recall descending Brasstown Bald after the Tour of GA stage. The road was crowded with fans and as a result I had to brake a lot. The upshot was two blowouts from overheating my alloy rims.

I wonder how carbon would have fared? Presumably worse, right?

[Charles M]

for folks with genuine mountain riding as standard, I would simply go in another direction.


It's not an "EDGE" problem, but extended braking and heat warp very simply can be a problem with most current carbon clinchers.

I've blown a tire. I've seen a a few. I've been on a junc with others testing a single brands bikes and a couple of people had blow out's alomst at the same time after long drops and riding the brakes...


Right now a couple of companies address this. A few use a coating and that coating will simply wear off. I hate to be back on that band wagon, but I think Zipp have a better carbon clincher with regard to heat build up and also with controling side wall size so that tires are less likely to come off.


A lot of the current carbon clinchers are just fine for most folks. But if you're in warm climate and have genuinely long descents (miles) I would simply not run most carbon clinchers.

[false_Aest]

I would down shift


or


use my jersey as a wind brake.

[Geoff]

as an aside how is this issue different irt carbon tubulars? Why worry about clinchers but not tub? is it becasue of the bead and pressure holding the tier on? if so then the real issue is heat and outward pressure on teh brake surface?

[hokoman]

I'd go with Swiss Stop yellow pads.

I think this is the reason why my front Bonty xxx lite clincher is warped. You have to use cork pads.... my wheel was not under warranty from Trek because the yellow residue from the swiss stop pads were on my wheels. I switched over to cork pads, and no problems.

[Steve K]

Does Zipp sell the new 404c as a 24 or 28 hole rims only? The 16/20 wheel seams a bit low in the spoke count for a 200 pounder.

[Charles M]

as an aside how is this issue different irt carbon tubulars? Why worry about clinchers but not tub? is it becasue of the bead and pressure holding the tier on? if so then the real issue is heat and outward pressure on teh brake surface?



clincher tires press out against the side wall with a pretty good amount of force.

Heat that sidewall and soften it up and...


Tubulars dont have a side wall at all.

[palincss]

carbon clinchers - i know most of you here are purists, and scoff at the idea of running carbon clinchers, but i like having the convenience of changing a flat on the spot, and being able to charge downhill without worry on an half-glued tire.


Are you suggesting that the majority of people on this forum use tubular tires? I'd be shocked if 1 in 20 members used tubulars exclusively.

What benefit are you hoping for from carbon clinchers? Or, to put it another way, what will you be giving up if you decide not to go in that direction?

[r_mutt]

Are you suggesting that the majority of people on this forum use tubular tires? I'd be shocked if 1 in 20 members used tubulars exclusively.

What benefit are you hoping for from carbon clinchers? Or, to put it another way, what will you be giving up if you decide not to go in that direction?


from some of the responses, i'd guess that a fair number here use tubulars as an everyday ride. conversely, i don't know anyone who trains or rides on tubulars. the only time i see tubulars when i'm riding, i'm in a race.

i want to run carbon clinchers for racing. i want to be able to ride to the race, race 50 miles, go for a 50 mile muffin run afterward, and not have to worry that i'm going to flat my tubular 35 miles out. i'm doing it for convenience, and to have an aero wheel to race on.

i'm worried a bit about decending in a pack, and having to apply the brakes for long periods due to riding in the downhill slipstream of 40 other riders.

[palincss]

i want to run carbon clinchers for racing. i want to be able to ride to the race, race 50 miles, go for a 50 mile muffin run afterward, and not have to worry that i'm going to flat my tubular 35 miles out. i'm doing it for convenience, and to have an aero wheel to race on.


And you can only do this with carbon? Sounds to me as though it's the "clincher" part that meets your needs, and that "carbon" doesn't bring much to the party.

[zap]

Steve, think breaking away in a race. Only way to get good aero clincher is with a carbon rim.

[r_mutt]

indeed -i'm looking for an aero wheel that doesn't weight 1,700+ grams.

[djg]

No first hand experience with edge. I have a set of Reynolds carbon clinchers, the rear housing my powertap so they get a good deal of use. I sorta regret the commitment to clinchers for my daily wheels, because I really prefer good tubular tires (and end up not using my powertap for a week at a time because of that), but the wheels themselves are pretty good and . . . maybe finally something pertinent to your question, the braking is just fine. Not awesome in the rain, but ok in the rain and totally good otherwise -- good brakes and good pads and you should be fine.

[palincss]

Steve, think breaking away in a race. Only way to get good aero clincher is with a carbon rim.

So every other aero clincher ever made is no good?

[r_mutt]

So every other aero clincher ever made is no good?


well, there are no 65 mm (or even 50mm) aluminum clinchers that weigh less than 1700 grams. not exactly a lightweight option.

[Charles M]

Yes there are.
and I would look at more than depth...




If I were buying deep clincher it would be an oval shaped 50



Budget (with side rim tech)
Bontrager Aeolus 5.0 ACC. 1785 grams

semiBudget
Zipp 404 Clincher 1658 grams

Best on market
ZIPP 404 Firecrest 1550 grams


Any of these with their shape will perform very close to a standard v shaped 68...

None will have heat blow issues.

One is all carbon

[zap]

Yes there are.
and I would look at more than depth...

One is all carbon

I still consider them carbon rims even if they have a light al clincher section bonded to carbon.

Problem remains. Al bonded to carbon. Not long ago it was not unheard of for the bond to break due to overheating as a result of bombing down some massive hill.

Maybe the new carbon clincher rims from Zipp are better in this regard.

[Charles M]

Neither of the zipps are bonded carbon to Alu.

One is solid carbon and the other is a structural carbon rim co-molded to an alu extrusion.

There's been virtually zero issues with Bontrager / HED carbon fairing coming unbonded from the structural Alu rim.

This is the internet, so being "unheard of" is a non starter





The question might remain for you, but it's never been a problem in practice for either of the companies mentioned.

[Steve K]

Zipp support stated current 16/20 spoke wheels support max rec rider of 225 pounds.

This fall they will come out with a Clydesdale and power tap version.