Carbon speed cycle wheels review

deano

Likes Dirt
Putting this up as a community service of sorts, would have loved to read something like this when I was purchasing.

I took a gamble on the 29er 30mm internal carbon rims built on novatec hubs from carbon speed cycle.

Price for the complete set was $525aud delivered, carbon rims, novatec hubs, double butted pillar spokes, aluminium nipples, 28 holes. Seriously cheap, hence my taking the gamble.

About one month from order to delivery. Build was excellent, high tension matched to upper rating of spokes. Very even tension. Perfect roundness and true. Weight 1710g for the set. Hubs roll well.

Easy to set up tubeless. Ride excellent, much stiffer than aluminium wheels they replaced (24/28 spoke approx 1800g).

I cracked the first rim after half a dozen or so rides, on rocks that have never ever worried aluminium rims. Carbon speed cycle came good and replaced the rim for free, I had to pay freight of $50. I built this up, it was very easy to do, very even tension at perfect round and true.

Rear rim cracked three rides later. Again on rocks but certainly not an impact that would ever seriously damage an aluminium rim. This time carbon speed cycle did not offer a replacement.

I may have been unlucky in getting two dud rims, or they are all shit. I liked the increased stiffness, particularly vs the underspoked aluminium wheels I compared to. I didn't like the willingness to break at the sight of rocks.

I would not recommend these cheap carbon rims to anyone. While the hubs seem fine, the build excellent and the ride outstanding, there is zero impact resistance. As such they are just not fit for purpose.

Maybe expensive carbon is better. I'm switching back to aluminium. I will reuse the hubs, they seem fine.


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The Duckmeister

Has a juicy midrange
Also what tyre pressures? I've found you do need to be very careful with pressure when using carbon rims; due to the extra stiffness over aluminium you need to drop a little bit to take the bounciness off, but you need to have enough firmness in reserve to minimise the risk of bottoming out on rocks & stuff.

The thing people often fail to understand is that unlike metals which have a springy phase, during which they'l spring back from a hit, then a non-springy phase in which the hit is too big to spring back from, so stays bent but won't break, and then they'll break if it's really bad, carbon doesn't have that non-springy phase. It is exceptionally springy (within the bounds that it doesn't bend a lot), all the way to the point at which it breaks. A hit that breaks a carbon rim will typically permanently bend an aluminium one. Also pick a woven finish over a unidirectional (UD) if available; although the majority of the layers in the carbon layup are still UD, the woven outer layer will have better impact resistance, as the interlaced fibre strands will reinforce each other. Purely UD layups will tend to split between the fibres and shred apart.

1700g is not a particularly light wheelset, and the other comments on the apparent build quality don't really lead to the thought that the rims are shit; straightness and roundness with carbon rims are as much to do with the quality of the moulds as the wheel assembly, so it's hard to belive they'd make good moulds and assemble the wheels well, but turn to shit at the rim layup stage, therefore the breakages are more likely to be attributed to setup and user error.

Oh, and get them rebuilt with real nipples and not horrible fucking shit aluminium. Carbon and aluminium really don't like each other, and those nipples will corrode and fall apart. For the sake of a 50g weight penalty, brass nipples will give vastly more reliable wheels.
 
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deano

Likes Dirt
Weigh 80kg

25-27/30-32 psi with 2.3 exo minions, on a spesh enduro 29er.

UD finish, maybe another finish would have held up better.

Have read many times of the issues with aluminium nipples and carbon, they didn't have an option for brass though so went with aluminium, I may change them in the future.

Regarding the springyness etc this makes me think carbon is a risky material for rims for MTB, impacts are inevitable if there are rocks around. At least with every aluminium rim I have owned in the past I have been able to straighten side wall dings on the occasion they occur. On the other hand I see videos like the Santa Cruz one where they take a beating. So perhaps it's just carbon speed cycle? Or perhaps I got two bad examples from them? I still have the replacement rim they sent on the front so will see how it goes, fingers crossed because it's noticeably stiffer than the 24 spoke roval it replaced.

I agree 1710g is not particularly light but it's certainly not bad for a 30mm internal 29" wheelset, particularly compared to something like a flow mk3 set with similar dimensions at 1918g. Btw I weighed the replacement rim when it arrived, 460g.

This is not meant to be a carbon rim hating post nor a judgement on those who ride them or their riding location or ability. Just an account of my experience. For me, running them at my usual pressures. I was flabbergasted at the way they cracked from very normal riding impacts that genuinely would never have ever damaged aluminium rims I have owned. Again the lateral stiffness was excellent.

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99_FGT

Likes Bikes and Dirt
It's not just them, I've done it to a zelvy. Shredded a tyre sidewall, no damage to rim, put on a 2.1 that I had sitting there, didn't check pressures, and there goes a rim.
 
Z

Zaf

Guest
Do you have any pictures of the damage?
Are we talking cracks that occurred from impacts coming in from the tyre side onto the bea, or rocks flinging up onto the side of the rim?
Preemptive follow up question; how many times do you suspect you hit a rim (of any material) onto rocks per every 100km of riding?

I'm yet to have actually had a carbon rim fail on me (Bontrager, ENVE, Roval, Light Bicycle and Zelvy to date), so matter of curiosity from people who have managed to. I've seen a mate write off an ENVE rear rim, but even that stayed inflated and rode him out, just had a nice big hold in the side of it where he'd sent it into a rock.
 

link1896

Mr Greenfield
Do you have any pictures of the damage?
Are we talking cracks that occurred from impacts coming in from the tyre side onto the bea, or rocks flinging up onto the side of the rim?
Preemptive follow up question; how many times do you suspect you hit a rim (of any material) onto rocks per every 100km of riding?

I'm yet to have actually had a carbon rim fail on me (Bontrager, ENVE, Roval, Light Bicycle and Zelvy to date), so matter of curiosity from people who have managed to. I've seen a mate write off an ENVE rear rim, but even that stayed inflated and rode him out, just had a nice big hold in the side of it where he'd sent it into a rock.
Regardless of speed down a trail, the smoothness difference between riders is staggering. I've mates who go through rims like they are hot dinners, and I've never trashed a rim. Bucked one once at Halls gap when I went OTB. (I'm not counting second hand wheels I've bought that had a 50% tension difference on the one side to get it even remotely ok.)
 

deano

Likes Dirt
Here are some pics, damage was from ground through tire, the same sort of impact that would cause a pinch flat.

I would estimate I would bang a rim hard enough to notice it (where you wince and think I better check that) once every few rides, so probably 1 in 100km.

It seems this thread could be heading towards internet judgement from afar on smoothness etc. To reiterate this is a record of my experience that will hopefully benefit others. I have dented, buckled and flat spotted plenty of aluminium rims in the past but never rendered one unserviceable from the relatively insignificant impacts (not even the wince type mentioned above) that fubar-ed these particular carbon rims.


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Z

Zaf

Guest
That's proper fucked.
No judgement from me, sometimes it's just luck of the draw. The guy I saw write off an ENVE is one of the smoothest riders you'll catch on the trail, on this occasion was off his line and the wheel (and then his handlebars, brakes, and body) took the hit. It's always good to know more details is all, style and terrain are big factors in longevity of components. You have to try really hard to find a spot to put this kind of damage on a rim in a place like Rotorua, even with someone wanting to test it to failure.

Still worth noting. The price was a double take as well, I thought you paid that for the rims alone, but wheelset is impressive at the cost.
 

deano

Likes Dirt
haha, I always knew it was a gamble at that price

I am really hoping I had two duds, I'm quite enjoying the remaining rim on the front, I just hope it lives a longer life. I have seen a mates nextie implode with little impact too but at the price I thought these were worth a punt.
 

creaky

XMAS Plumper
Potentially just shit quality rims. I’ve done that and broken a couple of no name carbon rims riding xc trails early on in the Chinese carbon fad.

I’d really be checking your pressure gauge though. That could well be the problem. Couldn’t imagine impacting a rim with a decent bag tyre at 35 psi.
 

teK--

Eats Squid
All the maybes surrounding carbon rims lead me to go back to aluminium after I cracked a rear carbon on a rock garden. Mind you that was after many many other hard impacts and square edge hits for over a year, so quality certainly does vary from brand to brand or even batch to batch.

For the extra 400g for whole wheelset (including Huck Norris in the back wheel) I now have piece of mind to charge into all matter of rock gardens without a worry.

That and all the various babyhead rocks etc that end up airborne and smashing into the rims from some tracks have left the rims quite battle scarred but still run dead straight and no dents.
 

deano

Likes Dirt
Calling all carbon experts here, this has been eating at me so I cut up one of the busted rims. Every cut revealed small pores in the carbon lay up as pictured.

Is this normal or shit carbon? Could this be why they implode at the sight of rocks?

And on a brighter note the rims I am replacing them with arrived today and built up nicely.


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