Death in the mountains

I've ridden carbon rims for a while now, but the type of brake in use has defined the type of tyre and mounting system - tubular rims and tyres for rim brakes, clincher tyres (most recently tubeless) for disc brakes.

The distinction is driven by my fear - possibly unjustified - that rim brakes will overheat the epoxy/carbon structure under heavy braking (for e.g. in the mountains) leading to a clincher tyre being spat off the rim and a horrible death, remarkable only for the duration and intensity of the pain and concomitant screaming.

However, fairly recently ENVE released their 2.2 SES rims as being both (primarily designed for) tubeless tyres, and with a braking track for rim brakes.

I therefore decided to use them for the Gravity Shadow, a bike that will be ridden in the high mountains of Europe and America, and see if my fear was justified - agonised screaming is still very much on the cards, I'm just hoping that the pace of technological change will make this unlikely. I may be wrong.

I ordered the rims built onto Chris King R45's and they arrived a little while ago, this morning I mounted the tyres, Schwalbe Pro-One Evo in the fashionable 25mm width (they have to clear an ENVE 1.0 fork crown).

This is the first time I've ever purchased carbon wheels new, which was quite nice as they were clean and came with lots of bits, plus a five year warranty.

Here's a rim showing the new tubeless profile:

And here's the very Euro man-bag that came with the wheels, with it's contents:

I won't be using the rim strips pictured above:

Instead we'll use the contents of this box:

Note the isopropyl cleaning pad, I didn't think it was going to do much more than take finger grease off - I was very wrong:

Supplied tape was just over 28mm wide:

And went on fairly easily:

And then make a small cut in the rim tape and mount the valves - I liked the inclusion of an O-ring which fits into a recess in the lock-nut:

Up to this point the install has been remarkably similar to installing tubs - clean the rim, apply an adhesive layer to the rim, but now we have a difference, namely mounting the tyre.

It wasn't the hardest clincher tyre I've ever muscled onto a rim but it certainly wasn't easy - without a tyre lever it would have been impossible. It always strikes me at this point how much easier it is to get a tub onto a rim than it is a modern clincher. Anyway, tyre mounted it was time to deploy the secret weapon:

With the aid of which getting the tyres to inflate was fairly trivial, with the standard nerve-shattering bangs that mark the bead seating properly. The wheels are now going to spend 24 hours at 100 PSI as is, in order for the tape to adhere fully and them to have their chance to explode in the peace and quiet of my kitchen:

Then tomorrow I'll put the sealant in, presuming everything is still fine:

All being well I'll be riding these on my Talbot Frameworks Gravity Shadow in California, then Colorado, second week of July - if I stop posting around mid-July you'll all know why.

I had similar concerns, but with the cheaper light-bicycle versions.
Did 10 days in Majorca with no issue last month and confident enough to take to Pyrenees next week.
Spares to take away include valves, rim tape & sealant.

Just swapped my 25mm pro ones for Vitoria Corsa speeds but on 23mm.
The Pro Ones seem like tractor tyres in comparison

I shall follow this thread, for some virtual retail therapy.

Just swapped my 25mm pro ones for Vitoria Corsa speeds but on 23mm.

The Pro Ones seem like tractor tyres in comparison

I was concerned about the robustness of the Corsa Speeds - they're pretty much a TT tyre, which given that all of the rides I'll do in Colorado will involve fairly long gravel sections didn't present them as the optimal choice for my application.

I've got a puncture kit specifically for tubeless tyres which I'll take, which includes a valve core and valve tool - I don't generally take a spare inner tube, which of course may one day come back to bite me.

The wheels are now going to spend 24 hours at 100 PSI as is, in order for the tape to adhere fully

You're probably better off doing this with a tube in the tyre. I'm not sure air alone will do much to help. Might be wrong though.

In keeping with the thread title, I'm disappointed this wasn't a 'bung some roughly cut Gorilla tape on it and pray' kinda install.

Intriguing title, nice pictures, good read. Learned a bit about tubeless tyres.

'concomitant' - if that's real it's cheered me right up.

Both tyres have gone flat, in deflating news.

rim brakes? what is this? 2003?!

did you shake sealant around and cover the inflated tyre in soapy solution to identify where air was escaping so you could shake the sealant to those spots?

ha!

Let's see whose ante-diluvian bike is ready first eh?

Can't comment on carbons and heat transfer :)

Alu 26" rims though.
Never heard of anyone shedding a tyre, although mountain bikes on tarmac so a bit slower than a 700c on slicks.
Usual format was heat build up in the rear rim, heat transfer from rim to inner tube, inner melts, tyre deflates.
Always seemed to be rear wheels.

Last one i saw many many years ago, coming down Dunkery Beacon in somerset (not far from Porlock Hill)
At first there was the smell. (The village of Porlock smells of clutch and hot brakes and coffee)
We warned the rider he was over heating.
He ignored us.
We dropped back to wait excitedly for something to happen.
Smell got worse,#Gentle pop, rider wobbled to a halt.
Quite boring.
v-brake pads had melted, as had the inner tube. Tyre stayed on, we waited several minutes before changing the tube.
The smell though, that's the big give-away something is going to happen, sort of hot rubber burning brake smell.

Milk the brakes. Will not die.

Was teaching milking to 30+ kids & adult riders, touring coast-to-coast across the lakes & north pennines, last week. Got the feeling people didn't really believe it was necessary (except maybe to relieve stress on hands applying levers) until after one particularly long and fast descent, some kids burnt their fingers touching their rotors.

One clincher tyre did pop a hole near the rim with cantis, wire showing, think it was a bit mashed at install. Luckily I was carrying a 700 folding.

Have there been any tests done on how the heat build-up affects tubeless tyre sealant?

I have a friend who tested the freezing point of various sealants in prep for the Rovaniemi 300, turns out it's lower than it gets in the race.

What sort of temperatures does a carbon rim get up to during braking on a descent, typically? Anyone managed to measure it?

The truth about carbon wheels. Interesting chap. (good thread by the way)

https://www.youtube.com/watch?v=ET1jRVynOBA

https://www.youtube.com/watch?v=bFdG2NgIc7s&t=39s

that guy reminds me of:

Was there sealant in them yet?

Nope, I'll chuck some sealant in tonight, take the wheels for a Rumba around the room, see what happens.

We have a winner!

Hadn't realised they'd have seen installed without sealant!

They aint gonna hold air without sealant

The new braking surface are massively more powerful, in theory this allow you to only do short quick braking as oppose to dragging them.

Just be wary of the cost of Enve brake pads!