Giving up with carbon rims on an MTB now, so far i’ve cracked an Easton rim, a 29″ Derby carbon rim & now an Enve.

Never running silly low pressure, as I get tyre squirm, and never flatting, but still cracking a rim due to impact damage. Yes i’m racing DH on an AM bike, but, I need some sort of reliability….

I will build them onto a set of DT240’s, the obvious choice is a Flow, but it’s going to make quite a big weight change on the wheel, so I don’t know if there is anything else out there i’m missing?

The Syntace W35 wheels look great, but they don’t seem to do rim only, which is quite annoying, don’t want a proprietory wheelset, as I want to be able to get spares.

Anything else out there? Or do I suck up the Flow Ex weight?

Saw this on fb. Ouch!

Finally ordered my lb rims too!

Rigida/Ryde do some really nice, super-wide, light, 29er rims with offset spoke holes drilled at an angle – should build up into a very strong wheel and give a nice shape to a wider tyre. Have a look at the Trace Enduro 29.

bike-components.de do the Syntace rims

http://www.bike-components.de/products/info/p37254_W35-Disc-29-Felge.html?xtcr=4&xtmcl=syntace%2035

http://www.justridingalong.com/parts/wheel-parts/rims/w35-rims.html listed as available to order if that helps you.

Would be interested to see your broken rims – you’re giving me second thoughts on the LB ones.

I’ll do some decent pictures with a macro lense. The Enve rim was worse than the Derby, the bead has delaminated, and split the carbon, and it was bulging on the outer wall, when I popped the tyre off at home it’s cracked across the internal rim bed and around the bead. Probably shouldn’t have done the last run!

I have been hammering them and racing DH on the bike, so it’s the extreme end of their use, so I can’t really complain.

Thanks for the ideas so far, I’ll look at those Ryde rims. The Syntace ones are surprisingly heavy, considering the wheelset weight, more than a Flow EX. The hubs must be super light!

The thing is, you’d msot likely break the Syntaces as well…. except they’d bend or get massive flat spots.

My advice is that if you nobble wheels a lot, run Mavics and replace them whenever you break em. At 800 quid a pair, the syntaces will cost you a fortune to ruin as well.

The irony is, until I went carbon, I’d never broken a rim in my life…

What Tom said, im not sure this a carbon V aluminium issue, more a case of fit for purpose and it sounds like a XC / AM wheel is not fit for the purpose you intend.

What about the spank Oozy wheels?

The syntaces have a bit of a rep for weakness from what I’ve seen- not too shocking, there’s not a lot of metal in them and it’s spread a long way.

Haven’t Enve got a five year warranty and trade crash replacement?

Yeah, second hand purchase. To be fair I got lucky on Ebay and paid not much more than a LB rim cost, so thought they may be worth a punt, due to someone not being able yo list something properly.

Even if I had them new, it’s clear it’s impact damage, and the crash replacement is £450, I’m not paying that for a rim!

Bit off topic – I’m now riding a stumpy evo 29er and the flow ex pro2 build are a tad on the porky side and was suprised on just how much they weighed.

What’s the weight of the derbys over flow ex’s as that’s what I was interested in getting to replace the flow’s

Thanks

Yeah, I’m on an Enduro 29.

IIRC the Derby rims are 440g. With the 240’s and some random (heavy) spokes were around 1650g buit.

I reckon with the same hubs, and Supercomps, the Flows would be about about 1800g, which is a couple of hundred less than the Hope Hoops build, mainly due to the hubs.

The Hope Hoops arn’t light at all, but then the hubs are fairly hefty. I think I might just suck it up and build the wheels onto them, I can get the rims and spokes for about £150 and build them myself.

im sure i heard hope have some all new hubs on the way dt40 weight etc

slightly concerned as my LB rims are here now, claimed 410g each for the 650b 35mm wide rim

as for rims, my last set of ally rims died in a a similar fashion to your derbys- tacod and split all the way along pretty much, but they were 717s
my wtb i25s have survived some good dings so far

Just stick a 500 gram rim on your bike and stop trying to use an AM rim for something it wasn’t designed for. My 33mm light bike rims have been fine and I thrash them, but then I chose the correct DH spec.

I’ve seen a lot of cracked carbon rims; seems they are high cost, low weight, low durability. you pays your money…..

Bigrich – I have seen a few cracked alu rims, the point here is the user and not the product. It’s like buying a glass hammer…….

It’s worth noting, when I say in racing DH, I’m not smashing out runs at Fort William, day after day, we’re talking once a month, local & regional stuff. The rest of the time I use the bike for my normal riding, and some enduro racing

The difference is with Alu I would have expected a ding (albeit a fairly decent one) for which there would be a fair chance I could pull it out again. Ding a carbon wheel decently, and it’s scrap.

I have seen a few cracked alu rims

yes, everything breaks, but then they cost 50 quid to replace, not a grand.

Yup Alu dent’s, Carbon cracks. But from my experience of DH racing (brother used to race Juniors and would place in the top 10) and carbon wheels – the level of impact that cracks a carbon rim tends to completely ruin an aluminium rim. If you really want you can mend cracked carbon….

You pay your money and take your choice, for All Mountain riding I run carbon rims because I like the weight and stiffness. For downhill/dh racing I would be running aluminium because I can’t afford to replace more than one carbon rim a year, if I could afford to I would as carbon rims offer a hell of a lot of benefits in terms of outright performance.

Any level of DH racing tends to destroy parts, as I said, my brother raced about 2 to 4 times per month. He would crack downhill frames but has never cracked any trail bikes or bmx’s.

Do you run tubeless? I’m not convinced tubeless offers enough support against impact damage…..

Just coming back to this, as i’ve started stripping down the wheels to use the hubs to build them back up again.

Plan was to just sell the rear rim as that would more than cover the cost of the replacement aluminium ones.

No such luck, rear wheel is also junk. cracked around 3 of the spoke holes!

So, not a great carbon experience – considering i’ve raced tougher Gravity Enduro stages than the 3 DH races i’ve done on them, it’s probably a good job I found this out now rather than a Pinkbike style Enve failure.

That takes me to over 50% failure rate. Fairly conclusive that carbon wheels don’t work for me on an MTB 🙂

That takes me to over 50% failure rate. Fairly conclusive that carbon wheels don’t work for me on an MTB

How do your stats compare on alloy rims? Presumably by 50% failure rate you mean premature failure because rims never last indefinitely on hard ridden MTBs!

It’s about time somebody made a tubeless tyre with a double lip on the bead – like specialized evil twins were. One lip hung over the outside of the rim; that might prevent burping and rolloffs as well as protect your £500 rim

If they were secondhand are you sure the rims weren’t battered to death before or the spokes over tensioned?

How do your stats compare on alloy rims? Presumably by 50% failure rate you mean premature failure because rims never last indefinitely on hard ridden MTBs!

Tough to say, in the last few years, i’ve taco’d a couple of front wheels, and dinged the hell out of a few (and pulled them out again), but never terminally cracked an alloy rim to the point where it’s unsafe to use.

If they were secondhand are you sure the rims weren’t battered to death before or the spokes over tensioned?

Local collection, built by a local (decent wheelbuilds) shop. There is always the chance when they were build someone was having an off day, but i’d be surprised, given their reputation.

The guy who I bought them off, lets just say he was a spender, rather than a user. They were unmarked, which for a carbon rim is quite hard to do, as they seem to pick scuffs and scrapes from just looking at them…

Tough to say, in the last few years, i’ve taco’d a couple of front wheels, and dinged the hell out of a few (and pulled them out again), but never terminally cracked an alloy rim to the point where it’s unsafe to use.

Thanks! I have a 26 hardtail on Flows which have lasted a few years but the rear is now a few mm from circular (despite truing) after a pinch flatting a UST tyre incident and my new 27.5 full-sus is on Flow EXs but I was wondering if I’d missed a trick by not jumping onto the ‘cheap-ish’ carbon bandwagon. I don’t mind spending more if durability is increased but it seems it’s the reverse with carbon rims…

hob nob what wheels are you running now?

If you really want you can mend cracked carbon….

Hmmm, has anyone looked into this with carbon rims yet?
Genuinely interested as there is a thriving trade in patching up carbon frames, could the same be done with rims?… Discuss.

Toons – I’ve built some wheels up with some E13 TRS+ rims I had spare. No longer on a 29er though.

Hadn’t thought about getting them repaired, they were going to be some expensive wall art 🙂

Ryde trace enduro or trail methinks. Well, I’m getting some

Cracked spoke holes I’d have thought it may be worth a call to Enve, you never know. They’ll take very high spoke tensions, so it’s a slightly odd failure mechanism. I suspect they may be interested.

I would have tried but they were used, albeit only just….

Hob Nob – Member

They were unmarked, which for a carbon rim is quite hard to do, as they seem to pick scuffs and scrapes from just looking at them…

For whatever it’s worth, my LB rim that I’ve been using for about 6 months has much less marks and scratches than I’d expect from an alu rim of the same vintage.

My LBs scratch quite easily, I’d say more so than the Stan’s rims from before. Only very light scuffs in the lacquer though.

hob nob what you riding now?

building some wtb i23 kom for my 29er, I?ll get some picts sorted. Never had any real problems with wtb rims, dinged a bit, but nothing major.
I’d get the beefier i25 team ones for your use though.