[Closed] Carbon rims - are they all they're cracked up to be?

Ridden a few, didnt like it....purely psychological but in the back of mind i was thinking 'please dont shatter, please dont shatter' throughout....not conducive to an enjoyable test ride i'll admit!

Also one thing bugging me is that to get these carbon rims strong enough for AM/Enduro/DH use they're ending up weighing more than a decent Alu set....wasnt one of the advantages of carbon rims light weight?...if the bloody things have to be built up like tanks it kinds of negates any advantage for me.

Finally i've also heard they can provide a harsh ride meaning you fit them and then have to spend several rides buggering about with your suspension settings to soften things off based on your new harsh carbon rims....cant be bothered with that cheers.

I'm sure some love them but the faff, the lack of weight advantage over Alu, having to play with suspension settings to get them working right, the cost etc means i'm more than happy on metal rims cheers.

numpty double post

Numpty post full stop.

If anything it's tyre pressures you have to play with ime.

Been using the Superstar Carbon AM wheels all summer, including beasting them in various enduro races, and have been awesome. Deviant is right, the ride is a bit harsher initially but playing around with tyre and suspension pressures a little sorted that. I love the stiffness the front wheel gives, put it into a corner, load up the bike and it just goes where you want it. I have also hit it hard a couple of times and no issues. Would def buy some more but not at Enve prices when Superstar and LiteBicycle seem to work as well!

Nope, waste of money IMO, from someone who has had, and broken most most brands available.

I have light bicycle 30mm carbons and whilst they look good I can't say they are any better than any aluminium rims I have had (mavic 821's at the moment). I don't think wide rims are worth going mad over either, they come with there own negatives.
I would buy them again though as they look good and are not too expensive.

Hob Nob, which brands did you break?

Flow EX or any Stans rims for that matter are a very good option if funds don't allow for carbon but having a set of carbon rimmed wheels does indeed feel and ride great now I tinkered with tyre pressures but I don't run tubeless and am very much old skool.

38mm light bike 29er rims. Surrey hills riding on an am style hardtail. Massive difference to me, really notice the difference over the p35s on there before. Not broken them yet but there aren't really any big rocky trails round us nor do I do big jumps.

ex471's are £50 a rim from bike-discount. a few extra grams but significantly cheaper to replace.

I use spank oozy 295 trail beads - no point in going super wide and carbon

Definitely a bit harsher but bit less pressure and they are ace
Lb 35mm, lighter than equivalent width ally rims, so very happy

Been riding and racing mine for 16months b4 I cracked my rear, i flattedbut kept on riding at ukge Ae, went bang on a rock garden and cracked it

But stull went up tubeless, rode the rest of the race and 100k of tough trails at dyfi ukge next round, I've got a replacement on the way but I might just keep riding the one until it dies

I've had 3 (2 more being built up) and broken 1 LB rim. Worth it, for me. I just ride them like I would a metal rim, the one I broke way outlasted the alu rim it replaced and yet weighed less and was a little wider. And my 29er ones weigh pretty much the same as a Stans Crest, I wouldn't expect a Crest to last more than a couple of months in my big bike.

If you're not bothered about weight then it's a different matter, and you should probably get something cheap and bombproof, but I like how lighter bikes and lighter wheels work and IMO you just can't get a sub-400g alu rim that's suitable for the job.

Width, well, I like fat tyres so it's a good thing for me I reckon but as long as the tyre's not pinched I'm not too stressed (*). Stiffness, meh, not fussed frankly, it's not a thing that registers on my noticeometer.

(* seems like the biggest advantage of width, comes from tyres that are the wrong shape, like bloody useless hans dampfs. Well designed tyres should already have a good profile on a normal width rim. But going a bit wider doesn't harm that ime)

I have the Light-bicycle carbon rims on DT Swiss hubs and they are the best purchase I have made for my road bike in years!

The feeling of them with 25cc tyres is something else.

We're going to have this thread every other week until everyone has carbon rims.

My LB carbon cracked on the rear in 2 places, NWMTB said that they were way over tensioned on the LB build.

For the 16 miles that it lasted it was great! LB offered me £15 off a replacement. I've gone back to alu for that.

I don't get it then? They cost a fortune, the advantage not being lightness, because they're not, they're stiffer - but that makes for a harsh ride so you lower tyre pressure to make them more compliant which negates the stiffness.

What have a missed?

16 miles is good going. I was riding with someone who cracked an Enve at Glentress of all places.

You're paying a lot of money for something that has a tangible effect on the feel of your bike. I'm personally not sure if the 'feel' or 'effect' that you get is in any way beneficial other then "woohoo this is different".

Plus, failures are common, potentially lethal and way more expensive to fix than they need to be.

I'm no luddite but they're not for me. Not yet anyway.

2x 3peaks cx on my 60mm road rims v stiff and bomb proof and still strait as a strait thing though i can get a lighter build using alloy and just as tough.

P-Jay - Member
I don't get it then? They cost a fortune, the advantage not being lightness, because they're not, they're stiffer - but that makes for a harsh ride so you lower tyre pressure to make them more compliant which negates the stiffness.
What have a missed?

Bbbbbbbbb-ut...! They look soooooo drool-worthy! 😀

I was wondering about carbon rims.. I've got a Bonty wheelset that weighs 1850g on my 29er, I want lighter wheels.

P-Jay - Member

I don't get it then? They cost a fortune, the advantage not being lightness, because they're not, they're stiffer - but that makes for a harsh ride so you lower tyre pressure to make them more compliant which negates the stiffness.

You don't think they're lighter than an equivalent metal rim? Your post is a bit hard to read but that seems to be what you're saying

Carbon rims *are* lighter, compared to the same strength alu rim.

They're way stiffer than alu, especially on 29ers, so they don't flex in hard corners, and go where you want them to go.

That's pretty much it. Lighter and stiffer.

They do break, but if you don't break alu rims then you *probably* will be fine.

For the same weight you can go wider, an alu rim running at a 40mm width would be much much heavier. This width allows you to run lower pressures without issues.

Some say the being able to run at lower pressures is rubbish I know, but I can now run crazy low pressures that with skinny alu rims the tyre would burp, or fold over, running wider seems to have stopped this.

So they are lighter than my old alu rims, but it's down to a few grams, the weight saving means they can run the same weight and wider that for me is worth it. But say they are not lighter is not apples to apples.

I also like stiffer rims as a concept, the suspension is there to move, the tyre provides some travel, so prefer to be able to work with that. That for me isn't a harsh ride, but it's letting each component do its job, but that's more the geek in me I guess.

I like them and don't really want to go back from carbon. They are not worth missing meals for, they do not make your life better, or any other rubbish. If you can get them great, if not I wouldn't worry.

They are standing up to more abuse than I expected, if bent plenty of alu rims and only the chunky ones were fit and forget, and with those there is more of a weight difference.

Some people will never trust carbon, and that is more of a factor for some people, but my life has depended on carbon more than a bike wheel, so have faith that carbon is workable and here to stay. Don't try to convince yourself to like it.

If you want them try them and see, if you don't like them great move on, if you do buy them, simple

They are lighter than aluminum. That's about it.

The stiffness is the main thing I noticed, the weight was about the same as the wheels I had before, bit lighter, but the rim was nearly twice as wide.

Hob Nob, which brands did you break?

Easton x 1, ENVE x 2, Derby x 3 & LB x 1.

I sound like a broken record, but they just arn't cut out for harder riding with a gravity bias.

For the same weight you can go wider, an alu rim running at a 40mm width would be much much heavier. This width allows you to run lower pressures without issues.

Why do you need a 40mm wide rim? I still remain to be convinced it in real terms makes any difference whatsoever. I can show a picture of the same tyre, one mounted to a 23.4mm internal width rim and one mounted to a 30mm rim & they look exactly the same.

Regarding the lower pressure thing - again if you don't ride hard. Otherwise it feels like a nasty, squirming flat tyre that's more likely to pinch flat & crack the rim. So, in reality, lots of issues.

Once the people who make them stop giving me replacement rims, then i'll never run them again. For me personally, the negatives outweigh the small weight benefit of running them.

I'll rebuild the hubs back onto some EX471's and probably stop wrecking rims again, and get an increase in ride quality 🙂

1600km on my AM bike (Pivot Mach6), my LB 30mm rims are going well inc DH park trips, in fact about to get on a flight to Chieng Mei for a long weekend.
However, an identical set on my Stanton Switchback lasted 200km before I cracked the rear rim, my fault as I popped on a kerb, got it wrong, and my rather thin Ikon just folded under the weight and cracked the left hand side. My fault and they are cheap enough to replace.

I like them, it takes a while to get used to how hard they make the ride feel but I like stiff suspension and high PSI so it suites me and with LB the price it not so bad.
I don't think I would go wider than 30mm though, since I don't run really low PSI the gains in grip against resistance on climbing are low (I ride in a mountainous area with lots of 250-400mtr climbs between segments).

Well my new lb rim turned up its a 38mm with a new profile compared to the older 35 mm one its replacing, 460g on the kitchen scales for the 650b.
Will be built up onto my new Bor hub, just gotta decide on spokes

I've been running some widish LB rims for a while now. They're lighter than the Flows they effectively replaced and, I think, more precise laterally. Or probably just have a different feel. I haven't cracked them yet - touchwood - but I am a little wary of breaking them, so I probably run slightly higher pressures than I might otherwise do.

I know things tend towards black and white thinking here, but I suspect it depends a little on what sort of rider you are - if you're an aggressive, serial rim destroyer then possibly not a great idea, if you're a more restrained rider, then they're light and stiffer than an equivalent aluminium rim. If you're somewhere in the middle,which is probably where I am, you'll most likely be fine unless you're unlucky/have a mad moment.

I do wonder if they'd make an ideal partner for a Schwalbe Pro Core set-up, sure you'd gain a bit of weight, but you'd retain the precise ride feel and worry less about smashing the things. And you'd save a lot of weight from your wallet as well...

And yes, they do look nice. But we know everyone here is all about function and performance, no-one cares about aesthetics....

For gods sake just search the forums why do we have to have a new thread on this topic every bloody week arghhhhh...

Out of interest, does anyone run carbon fatbike rims?

I always "understood" that carbon rims were an answer to the problem of 29er rims being not stiff enough at weights that are acceptable, with hub widths being essentially fixed (Trek are looking to change this) changing the material of the rim is the only substantive change you can make. Whether it makes any difference to a recreational rider is probably questionable

With more and more people running lower pressures and tubless and side wall thickness increasing to cope, more weight is added, some of the more aggressive 2.3 width 27.5/29 tyres are well over 1kg. Increasing yet again the need to find weight savings somewhere else.

Look soon for marketing that will tell you that heavy wheels make for a better ride....

ononeorange - Member
Out of interest, does anyone run carbon fatbike rims?

I have a set on my fatbike. They make a huge difference there because it's possible to get the whole bike down to the weight of my old 26"bike.

They feel great.

What I don't like is that they were obviously designed for tubeless because tyre fitting is more difficult. That's no problem at home, but effing miserable in the rain fixing a puncture.

Obviously I should go tubeless, but I'm not doing that until someone comes up with a way to do it without adding a lightweight tube's weight of sticky goo (or sticky goo of any amount).

So, tubeless great, tubed potential PITA.

ononeorange, yes. Game changer, apparently:

http://www.xcracer.com/big-dog-and-elite-fatbike-double-header.html

To me rims are disposable items like tyres or tubes. It seems like a lot of money to spend on something that will only last a year when I can get a nukeproof rim from CRC for £15

I guess if I had a crazy amount of cash and nothing better to do with it I would get carbon.

Do those people who run them and like the stiffness thing have a problem with "flex" on alloy?

Thanks epicyclo. The main reason I would consider carbon rims is indeed to go tubeless (and avoid a lot of punctures).

I assume no cracking issues? What do you run?

[i]Do those people who run them and like the stiffness thing have a problem with "flex" on alloy?[/i]

The answer to this will of course be: "Yes, I did"

I can remember threads about busted rims, but honestly I can't think of many folk starting threads on here about how flexy their 26" wheels are/were

Do those people who run them and like the stiffness thing have a problem with "flex" on alloy?

No, you just a subjectively more precise feel with carbon ime. It's not like aluminium-rimmed wheels are blobby flexible things and carbon aren't, it's more just that they have a slightly more precise feel to them ime, ymmv etc. It's just another one of those small improvements like slightly grippier tyres or better suspension damping or a 10mm shorter stem or whatever.

I like mine, but that's probably because I'm gullible, curious about kit and not a particularly aggressive rider. I also bought into hyped-up stuff like disc bakes, tubeless tyres set-ups, dropper posts etc though not alternative wheel sizes. I don't think carbon rims give as significant a gain as any of those, especially if you get into stuff like Enve with high prices, but I think they do have a distinctive feel which I quite like. Anyway...

The main reason I would consider carbon rims is indeed to go tubeless (and avoid a lot of punctures).

Just stick some Gorilla Tape in your current rims and go tubeless that way. Half an hours work.

No, you just a subjectively more precise feel with carbon ime.

That's about the whole thing. They are noticeably different and it's this feeling that everyone raves about. As I said before I'm not sure this feeling has any actual benefits in terms of energy expended or time against the clock or anything meaningful.

Do those people who run them and like the stiffness thing have a problem with "flex" on alloy?

It's the same principle as the change from QR to 15mm front axles. Did I particularly notice flex before - no - but I did notice how much stiffer the new set up was.

I like mine, but that's probably because I'm gullible, curious about kit and not a particularly aggressive rider. I also bought into hyped-up stuff like disc bakes, tubeless tyres set-ups, dropper posts etc though not alternative wheel sizes. I don't think carbon rims give as significant a gain as any of those, especially if you get into stuff like Enve with high prices, but I think they do have a distinctive feel which I quite like. Anyway...

Single most honest paragraph about new kit ever written on STW, should be the reference answer to every new kit thread...

I recently cracked a Nextie fatbike rim with a pretty mild knock off a rock. That's the real problem with carbon imo. It's massively strong and stiff, but a knock in the wrong place can trash it alarmingly easily. My old Rolling darryl ally rims soaked up loads of harder hits, they were ful of dents and flat spots but are still working perfectly fine.

[url= https://drj0nswanderings.wordpress.com/2015/09/09/hed-whats-the-big-deal/ ]I'm not the only one.[/url]

Tubeless set up on the Nextie is fantastic though, really easy and secure.
The other rim on the front has just done a week of rocky hammering in Spain with no issues, but I feel I'm always waiting for that next hit at just the wrong angle which will take it out...

Why do you need a 40mm wide rim? I still remain to be convinced it in real terms makes any difference whatsoever. I can show a picture of the same tyre, one mounted to a 23.4mm internal width rim and one mounted to a 30mm rim & they look exactly the same.

Regarding the lower pressure thing - again if you don't ride hard. Otherwise it feels like a nasty, squirming flat tyre that's more likely to pinch flat & crack the rim. So, in reality, lots of issues.

I like the feel of them, so far in the 6 months I have been riding them I have had zero burps, compared to one every couple of weeks on flows. I can show you a picture of a tyre, one mounted to a 23.4mm internal rim and another mounted to a 30mm rim and they look completely different - all it points to is tyre selection becomes important when you go to wider rims.

Low pressure on flows feels like a flat just as you described, but on a wider rim it doesn't the squirm is gone - and its for those reasons I like them. For others you might not lend importance to these factors, so justification becomes even harder.

They will not revolutionise riding in anyway, but they make small marginal improvements FOR ME (not measured in seconds but feel) and I can, so I will - simple really.

Riding my old bike with flows etc now feels like a lumbering beast. Did I think it felt like that at the time, of course not it felt great. But on that level my first car felt like it was amazing at the time, going back to an E reg fiesta nowadays doesn't feel so great - doesn't mean it doesn't work as a car, but my reference points have changed

Last year we were at Afan & found a mashed up rider at the end of one of the trails (can't remember which one). His carbon rimmed front wheel had disintergrated on the descent. It put me off ever trying them anyway, at least ali bends!

Northwind - Member

P-Jay - Member

I don't get it then? They cost a fortune, the advantage not being lightness, because they're not, they're stiffer - but that makes for a harsh ride so you lower tyre pressure to make them more compliant which negates the stiffness.

You don't think they're lighter than an equivalent metal rim? Your post is a bit hard to read but that seems to be what you're saying

I was referring to Deviant's post above - the claim being that for an equivalent built (AM/Endruo/DH anyway) that they're actually heavier than an Alu rim - I suspect especially if you're talking the same price because they're really expensive.

My question was this, if they're no lighter, and the stiffness they offer can be a drawback that requires lower tyres pressure to over-come, and they by reducing tyre pressure you lose the stiff feel - what exactly is the point other than 'bling'?

You can have light 40mm rims in alloy too.
[url= https://www.syntace.com/index.cfm?pid=3&pk=3560 ]syntace w40[/url]

I've been very impressed with these.

andywill - Member

Last year we were at Afan & found a mashed up rider at the end of one of the trails (can't remember which one). His carbon rimmed front wheel had disintergrated on the descent. It put me off ever trying them anyway, at least ali bends!

I agree with the sentiment, but whilst I've dinged a few rims in my time and knocked a few out of true - if you suffer the 'full taco' which I have once or twice you're going to crash hard.

I Like my lb 35mm dh rims.

Done a lot on them and they're sound.

Will be buying a second set soon I reckon.

I'm light and ride very aggressively, coming off a flow ex that I cracked in 3 places and was flat spotted everywhere.

Think I'm gonna run flows in whistler next year though.

Definitely lighter than an equivalent alu rim, dunno if it's the lighter weight or the stiffness but they feel like they accelerate quicker

I'm trying to break my cracked rear lb rim and it just won't die !

Those syntace are light but still 100g heavier than carbon equivalents for the same price, strongr? I don't know

The disintegration factor is really a question of design rather than a C/F problem, but obviously there's plenty C/F rims that simply are too lightweight for the job.

Rims need to be both stiff and impact resistant.

I'm trying to break my cracked rear lb rim and it just won't die !

Please stop riding your cracked rim.

Have a read of this,
[url= http://www.pinkbike.com/news/Enve-Composites-DH-Wheels-Tested-2013.html ]LINK[/url]

The full story emerges in the comment section

P-Jay - Member

I was referring to Deviant's post above - the claim being that for an equivalent built (AM/Endruo/DH anyway) that they're actually heavier than an Alu rim

OK, I've no idea what Deviant was talking about tbf. Personally, I wouldn't put carbon rims on a dh bike any more than I'd fit an XTR mech, everything on my dh bike was picked to be strong enough to work and cheap enough to not worry about when I throw it in a cattle truck or ride it into a tree, or ride off the hill on a flat- my carbon wheels fit the former but not the latter 😆 The light weight just isn't worth it for that job, for me.

Isn't it funny how people argue so vehemently about carbon rims, but generally, the MTB community is falling over itself to get hold of the newest and greatest carbon vunder-bike frame, and doesn't bat an eyelid about carbon forks or bars?

Not a fan of the bars either to be honest.

I snapped a Pro-taper carbon bar in a feeble crash. A mate of mine got ejected into the woods at high speed when his Burgtec let go on a DH track.

Nah, you can keep them.

To be fair though, those bits aren't really impact parts whereas in normal use (and not just crashes) rims will sometimes get thumped. So I can see why people have a different attitude.

And to make it realistic for most folks it means "cheap carbon" which understandably people shy away from. Whereas a top end carbon bar isn't thousands of quid.

I've broken a couple of alu bars and a bunch of alu rims so it's not like I think carbon is indestructible, I just don't kid myself that alu is either. And I don't put anything on a mountain bike that I can't deal with breaking. But then, my old easton monkey dhs proved way stronger than the answer alu dh bars they replaced.

Isn't it funny how people argue so vehemently about carbon rims, but generally, the MTB community is falling over itself to get hold of the newest and greatest carbon vunder-bike frame, and doesn't bat an eyelid about carbon forks or bars?

Nope nope and nope again....Renthal Alu bars on my bike (proven in the Motorcycle industry), Giant Alu frame (admittedly worrying light to pick up but i reckon it wont suffer a catastrophic failure)....it may bend, dent etc but should give me some warning....metal crank arms too, really really get nervous and twitchy about my ankles and carbon cranks just make me feel nauseous thinking about them letting go on a descent....maybe i'm old fashioned but i think if i'm chucking it down the side of a hill at 40-60kph i want total faith in the components and carbon isnt quite there for me yet....its still in the new/beta phase for MTBing in my opinion....i'd go out of my way to avoid a carbon frame, i did just that with the Trance i bought...could've got the 'advanced' version (carbon) instead chose the metal one....i just dont see the carbon one sitting in my shed in 5 years time ready to be ridden like i assume the metal one will be.

I'm even more of a luddite with HTs where i want the least amount of maintenance possible and that usually means steel!

I disagree, frames are bounced off rocks routinely and bars are prone to digging into the ground on virtually every stack. Theres some high point load impacts and twisting moment right there, just like a rim.

deviant - Member

Renthal Alu bars on my bike (proven in the Motorcycle industry)

Different product made to a different design with a different process in (I think) a different country. So is it the company you trust? But then they also make carbon bars. And other people make bad alu bars.

So presumably it's the brand you trust? But they also make carbon bars.

Indeed, i dont think they'd ruin their carefully built reputation for tough bars by putting crap out there for MTBers....you only have to see how few crop up second hand on ebay to appreciate that owners buy them and keep hold of them....if i was going to try carbon bars it'd probably be theirs.

Carbon Fibre has a better strength to weight ratio than alu.

So as long as the likes of Enve, LB can do a descent job of turning this material into a rim then you should be able to run lighter carbon wheels without sacrificing strength.

So this us where the real advantages kick in from having a lighter wheel. 100g lost from a wheel has more of an impact than 100g lost from the frame.