Carbon disc only rims

[Paperclip]

As stated will carbon rims hit our market. What are the downsides. Obviously something that will have been posted on the forum before but really interested to see what people think about them now they've been out in the world of MTB for a bit longer. I would be mostly comparing to the double walled 24" disc only rims such as Spank. 

[robkerly]

have ridden a few varieties on 27.5 inch wheeled enduro bikes and found them incredible.  the model i was riding on was just over 40mm wide, running a 2.6 inch tyre at around 20psi so plenty of width / tyre stability and toughness for constant impacts. they also make a great noise when you rim them! stiffness wise they should have the potential to be better than conventional rims. several of the carbon rimmed wheelsets come with straight lacing or 3cross without the overlap and 28 hole as opposed to the 32 on other standard wheels in the same strength / discipline. they actually aim to let the spokes have more flex to keep the wheel more supple for off camber rough cornering as otherwise they are not pliant enough. opens up the serious possibility of running tubeless tyres as well, which seem to give more spring for the same psi, and no more pinch flats!

[Mark W]

I guess that is at the expense of possible tyre fold/burping though, especially on a streetier bike if you're landing spins/taps/whatevers?  I've heard of MTBers riding more tech trails at lower pressures getting little burps here and there, so with trials I'd have thought it would have exacerbated that quite a bit.

My concern would be what would happen where an ordinary rim gets a dent in it.  I've seen a few people with some pretty serious dings in their sidewalls, and it seems like if you've got something like carbon it would f**king hate that.  That said, it could be that it'd totally handle business.

With the prices of them though I can't see any good ones hitting the trials world any time soon.

[Dman]

I'd ruin them

[Greetings]

Wouldn't they just be incredibly stiff and unpleasant to ride?

[robkerly]

the tubeless beadlock systems have massively improved in the last few years, pretty much eliminating burping.  if you're running 25 psi on a bike and racing it for a few hours, losing a pound or two here and there quickly adds up to folding and crashing and broken bones. i think carbon is pretty good at shock absorption, or it certainly can be. they obviously made bash plates and frame protectors out of it, so if you expect them to take a beating im sure it can be designed to take it. cost, however, is definitely a big downer. currently they seem to be 6 or 7 times more expensive than their high end alloy counterparts. i imagine it will take a fair bit longer to be picked up in something as cliquey as trials. 

[craigjames]

It would be their ability to survive heavy repeated impacts on sharp rocks etc. I've read a few stories about carbon wheels 'exploding' on DH bikes.

[robkerly]

yeh, its always a big question mark. i guess everything can be pushed too far. 

[Rusevelt]

The competition scene would certainly benefit of having a Carbon front with alu  rear set-up.

[Jake.]

On 26 January 2016 at 8:05 PM, Greetings said:

Wouldn't they just be incredibly stiff and unpleasant to ride?

[N.Wood]

Natural trials - I reckon out the front they would work well, as long as the width is there. Having said that, you'd have to compare the weight differences between a carbon and existing alu rim because I can't imagine there is that much in it.

 

Street trials - I think these would work pretty well, given the tendency to run higher pressures that should protect them from dents. Would have thought you could make them a fair bit lighter than current alu ones, making spins etc easier? I'd have thought they would stay true for longer and handle side-loadings better then alu too.