I’m thinking of trying some wider rims on my Five 29er and I’m tempted by a set of carbons this time around. Have been looking at Arc/Flow/i29/EX471 etc. but started to consider either BlueFlow or Sixth Element. Previously I’ve stayed away from carbon on this bike as I didn’t want to have any concerns about rims when barrelling through a rock garden or sending over a drop-off but I’m assuming these are no longer issues for these rims?

Would you say the extra money is worth the gains in weight savings and stiffness?

The short answer is, it depends.

My own personal opinion is carbon rims have no place on an MTB. For me, they have been unreliable, expensive & have introduced negative ride characteristics over a decent set of aluminium wheels.

Wide rims – well having ridden some 30mm ID (carbon – before I broke them) rims, I struggle to see the point with 2.3” tyres – they square them off too much & flatten the profile, hence why the likes of the introduction of Maxxis WT to combat it. They don’t seem to bring anything to the table for me. Can’t run low pressures as they squirm and burp like mad, and you end up dinging the rims. Maybe if you pootle around they might work.

A decent aluminium wheelset for anything other than XC is of comparable weight anyway.

ide rims – well having ridden some 30mm ID (carbon – before I broke them) rims, I struggle to see the point with 2.3” tyres – they square them off too much & flatten the profile

interested in this, so what would be the optimum rim width for the likes of a 2.3 tyre ? 19/21/25 ?

I have 38mm sixth element on my 5010 and love them, I went from a mk1 solo (with Hope tech enduro) to a 2016 5010 with these wheels, same forks and other gear. The real world differences are night and day. The weight saving plays a factor though it is not a huge saving 200gms across the set.

The real difference is the stiffness in cornering – imagine driving a standard car and then a car with uprated and lowered springs, it feels incredibly direct and seems to fire out of corners much quicker, if you are on it.

It will depend on the trails you ride and what kind of a rider you are, of course, but in terms of ride feel they are the single best upgrade I have ever made (tubeless and dropper posts up there too).

The interview with Graham from sixth element hit the nail on the head, it is all about the stiffness – that is where the benefit comes.

If you are bashing fire roads, just riding along or ride wide open plains then the benefits are reduced, because a light weight set of alloy rims will be better. But if you ride a lot of tight corners, single track etc then I really think you will notice the difference because handling becomes much more important than just weight and comfort.

With reference to Hob Nob’s post: –

Unreliable – not yet, been riding them for a month and all good so far, lots of drops, roots and jumps but no rock gardens (yet)
Expensive – yep
Negative ride characteristics – not for my riding

Love them..!

interested in this, so what would be the optimum rim width for the likes of a 2.3 tyre ? 19/21/25 ?

Rims around mid 20’s seem to create a good tyre profile for 2.3’s IMO.

The interview with Graham from sixth element hit the nail on the head, it is all about the stiffness – that is where the benefit comes.

And that’s also where the biggest negative (IMO, other than the hilarious lack of reliability) is. Below is something wrote about 12 months ago on this:

Carbon has always felt harsh to me on choppy terrain, off camber stuff and flat corners can become a bit of a liability as the wheel is so stiff, it would just deflect, rather than hold the line. High lines became a bit of challenge, and it always felt like I was running too much compression on my suspension due to the harsh feedback.

One ride back on aluminium rims and I’m sold, even excluding the reliability issues I’ve had, the ride is so much nicer. The harshness has gone, the bike doesn’t seem to get unsettled mid corner by chop and as a result, I can corner harder. A bit of Google tells me I’m not alone in my thoughts of the ‘feel’ they create, and there has been talk of considerably faster WC racers than me trying to make their carbon wheels more compliant, as they felt too stiff.

How hard on rims are you? I’ve got a set of the slightly older LB 24mm 29er rims in my Remedy and I trust them as much as I would any alu enduro rim. (I’ve killed a lighter weight LB rim in the past, and it took a lot- I’m comfortable that the same blow would have killed anything short of a dh rim. And I was happy enough to ride around on it for a week after too.

Considering it weighed as much as a Stans Olympic but had done an EWS round, half a SES season in a hardtail, and done a load of uplifts inc fort william, that’s ridiculous- I’d never dream of doing all that on an alu rim of the same weight, in fact there just aren’t many.

Stiffness? Can’t say I’m very aware, I have a set of Frequencies for my spare wheels and they don’t feel less stiff. Certainly never felt there’s any harshness, other than the weight I’d struggle to tell you which of my wheels I was riding tbh. Build has to play a part here. TBF on paper I’d rather have a less stiff wheelset, as long as it’s strong, all this obsession with stiff everything seems daft to me but in practice, I just don’t find any interesting differences.

But at the end of the day you don’t want to be chopping them off sharp edges constantly- any rim’ll get beaten up with that so it just makes sense to buy something more disposable. I have a spare wheelset for this reason, not because they’re stronger (I’m pretty sure they’re weaker) but because the rims on it were £40.

Hob Nob – Member

A decent aluminium wheelset for anything other than XC is of comparable weight anyway.

200g pretty much, I don’t think that’s comparable personally (XM481 vs LB 30mm 29er, but that’s pretty typical). Course, not everyone is all that bothered about weight which is fair enough.

Agree with you on the potential harshness of the carbon rims. I say ‘potential’ because I am riding a full sus, on a stiff hardtail and carbon rims…yeah I can see that not being a great deal of fun!

As for holding line, so far so good!

200g pretty much

You sure? My 38mm (30mm internal) LB rims are about 440g each and XM481s are listed as 490g (maybe not true?) which would only be 100g for the pair.

I like my LB rims but they cost more now the pound is weak and it’s just enough to tip me back to aluminium. That’s a cost thing, I love the LB rims.

they square them off too much & flatten the profile

is a fair point but tyres will probably change to suit wider rims

Rubber_Buccaneer – Member

You sure? My 38mm (30mm internal) LB rims are about 440g each and XM481s are listed as 490g (maybe not true?) which would only be 100g for the pair.

I was comparing 29er for the OP- XM481 is 510g, 35mm (30mm id) LB is 415g.

(the 38s are 31.6 internal aren’t they?)

I’ve rode 38mm light bicycle rims for 2 years.

Built with light gauge spokes by my lbs, overspokes, so they are not harsh.

Yep, they square the profile a bit, I use hr2 and minion Ss and it doesn’t affect the huge side knobs traction.

Light, no issues with them. Can’t say I notice a serious advantage over the previous wheels with flow rims. They do look huge with a 2.4 front hr2 front.

I ran the rear down a descent at dyfi with a blown out ardent. No lasting damage.

The rear has been retensioned once, and the front has never needed it.

(the 38s are 31.6 internal aren’t they?)

Just checked, you are right. Still a comparison of what I’d be choosing between though and the money would sway me given the better selection of wide rims available now. If I’d not scratched the carbon rim itch and was feeling flush…I’d probably shell out the extra

Interesting and mixed feedback, thanks.

What type of rider am I? This bike gets used for trips to Wales, Afan, BPW etc. So not a fire road bike but I’m more of a Red run rider than Blacks, so far 🙂

Good points about the wide rims and tyre profile, I was a bit concerned about this also. Most of my tyres are in the 2.3-2.4 range so until I upsize the tyres perhaps a mid point of 27mm internal might be better. Having just put a set of Easton Arc 27’s on my P7 and they seem pretty good but I was keen to try wider.

I’ve used LB rims before and been very impressed with them but now the exchange rate is rubbish, they are no longer a cheap alternative from what I have priced up recently. BlueFlow seem to be the cheapest alternative for UK supply of Carbon wheels, obviously the rims still coming from China. Even cheap you are still looking at £680 or £800 if you spec them up a little.

Would I be better looking at the Stan’s Arch Mk3 or another set of Easton/Raceface Arc 27’s as opposed to the Flow/EX471’s if I’m sticking with 2.3/2.4 rubber?

Coming up for 3 years on my 35mm LB 29er rims. 2.3 Minion DHR2 is about as narrow as I’d want to go on the rear, but for proper width tyres the extra support and tyre shape they give is excellent.

I love the stiffness, and apart from a quick tighten of the spokes after the first few rides I haven’t had to do anything to them (32h build on Pro2 hubs with DT Comps and brass nipples).

I have another pair on order, 28h this time, which will go on the hardtail.

Very pleased with my LB rims 38mm all mountain 650B
Fitted to a full sus bike ridden in mostly the Lakes.
Typical riding Borrowdale bash Ullock pike,Helvellyn, Whinlatter, Torridon.
Im 80kg in my riding gear and quite happy crack on a bit on the rocky stuff.
Was slightly nervous / cautious about the carbon rims when I first got them. Dont even think about them now.
Like the stiffness, like the tyre profile (2.3) WTB Vigillantes. Avoid tyre presure below 30 PSI as I will pinch a tyre.
Had mine over a year and at least 1600 miles off road in the conditions above.

Durability wise think carbon wheels have come a long way, if you
are a bpw red rider would say perfect.
Have ridden finale on reynolds carbon, the rockies on reynolds carbon, and industry nine carbon in colorado/moab, would consider
myself a smooth rider not a hucker smasher.
A friend recently bought some wide light bicycyle wheels and loves them, defo worth a shout imo.

Hob Nob has pretty much hit the nail on the head.

My experiences are exactly the same.

Great in good berms, jumps n hardpack but put them into choppy stuff or off camber and they suffer.

On hope enduros now which are rather flexible compared but better all round for sure

Wide carbon on the front, alloy on the back. Rocks and carbon don’t mix in my experience.

andyjh – Member

Would I be better looking at the Stan’s Arch Mk3 or another set of Easton/Raceface Arc 27’s as opposed to the Flow/EX471’s if I’m sticking with 2.3/2.4 rubber?

Whisper it- it probably doesn’t matter much. Going from a narrow to a wide rim does make a big difference, pinched tyres just don’t work that well. But going from a wide to slightly wider is diminishing returns, going up or down a couple off mm from a 27mm rim isn’t a gamechanger. (you can do rough numbers pretty easily to see how much difference adding a couple of mm to the circumference of a tyre makes- it’s not quite that simple as tyres aren’t perfect circles, but it’s indicative)

And even if you feel the difference is significant, it’s still not better/worse- some people think the tyres get too square but not everyone, there’s no perfect shape or volume (depends on your tyres, too)

Pick a wheel width, and be a dick about it.

I have the alloy Roval rims on my stumpy which are listed as 29mm inner width, I ride schwalbe tyres and havent noticed any squaring, I ride a hans dampf up front 2.35 and either a racing ralph 2.25 or a hans dampf 2.35. I wouldnt say 30mm rims would be an issue for these tyres.

So it seems like 30mm is the step up from my current wheels that’s worth trying from what people are saying here. Today I run Hope Enduro’s which I believe are 23mm internal so this would be a reasonable size up. Also from what I’m getting here 30mm should be ok to carry on running 2.3/2.4 rubber but will also give me a good platform to use wider rubber when it becomes available.

I would happily go for the LB rims as I’m confident in them as a company and product but the price is no longer compelling.

Therefore I’m considering Flow/EX471 (approx. £500) for aluminium rims or BlueFlow 35’s (£680) for carbon.

Lb 35mm rims on both my bikes for approx 2.5 /3 years now. I’ve blown 1 rim running my rear tyre too soft down Sticks pass. In terms of parity to my previous alloy rims, their durability seems pretty similar.

I’ve found them stiffer, but not too stiff, but that is probably off-set by me running stiff sidewall, large volume tires, which I expect also mitigates against smashing them up to a degree.

Alloys over this period of time would be full of flat spots and re-straightened bead walls, but apart from rock scrapes, they’re still perfectly good running at approx 18-20psi.

People don’t seem to understand the failure mode with carbon rims. Below a certain impact, they just shrug off anything, and when pushed above it just break. The reality is that an equivalent hit on an alu rim would have totally spannered the beads anyway.

Back then, my first set I brought in direct were 120 quid each, but they’re alot more than that now, and there’s much greater choice in wide alloy rims. Once I’ve blown through my spares, I’ll be back on alloys, but I expect it to be a good few years yet.

Do wider rims make the tire profile wider? If so, swingarm tire clearance could be an issue.

We are running LBs, Rovals and Sixth Elements of various widths on our bikes, 26″, 650b and 29ers. All are run with the same tyre combination of Butcher front and Purgatory rear.
They have been used in most conditions from the Peak to weeks in the Alps and none of the rims have let us down.
We did have some Superstar ones which needed rebuilding after a month in the Alps but they were fitted to two bikes that were stolen last year.
Abigale competed last season in Enduro with a set of 650b Sixth Elements on her S Works Enduro, the bike and the wheels have been passed to her sister for this year.
If you are ever in our area you are welcome to come and have a look at the condition of them, apart from a few scratches they are smooth, and true.
Give Graham a ring at Sixth Element, its well worth the chat before you decide.

Therefore I’m considering Flow/EX471 (approx. £500) for aluminium rims or BlueFlow 35’s (£680) for carbon.

you can get EX471 with hope pro4 for £420

Hand built Hope Pro 4 hubs with DT Swiss EX471 rims

Given the current tyres I run, using wider rims wouldn’t give me anything extra. comparing HR2 on my 24.5 Vs the 30mm on my bro in laws heist you can see a major difference in tyre profile and its not for the better. Plus my rims say spank on them lol

Hi, I noticed this discussion and here’s a usefull link that might help choosing a rim/tire combination. Tire witdth to rim overview

Thanks for all the advice. I bought a set of Stan’s Flow mk3 today and having them built up on Hope Pro4’s, DT spokes and brass nipples 🙂

Hob nob has hit the nail on the head for me. I too bought some sixth element wheels. Firstly they are a thing of beauty and the tart in me was happy. But I just couldn’t get on with them. There really is a thing as too stiff and I was getting pins and needles in my right forearm after about an hour of hard riding. I was fiddling with my suspension to compensate for this when I realised I was trying to compensate and make them feel like an alloy set would. So changed them for a set of DTSwiss 30mm rims and I am a happy lad now.

Set will be going up for sale shortly. I kept them incase I was just being a diddy but I can’t see Mr ever wanting carbon wheels again.

Some people swear by then and each to their own. Just not for me.

Loved my carbon rims initially… until they cracked doing nothing adventurous at all, and they’re a write off, and American Classic refuse warranty, and I know a few others who’ve cracked theirs too.

Then finding out their alloy wheels are actually lighter, and I can build up some pretty tough alloy DT wheels for not much more weight.

And I notice zero difference in carbon vs alloy wheel “feel”.

So carbon wheels are off my radar now. Frames, bars and cranks yes (as I have already). Not wheels.

p.s. EX471 are tough stuff. Very nice. Just had a set built up for my old Nomad.

The Moonglu builds seem to have just gone up to £500……….

Check out ptcycles.co.uk

Got a 26er DT EX471 with 350 hubs for just under £500. Same rim with Hope hub is one of the recommended builds for 650/29er (i.e. stuff in stock or prebuilt) – £475

Ah, seems that I was mistaken, the £500 is an interest free credit price and there is a 10% discount code for cash purchases…….

Still a price increase – give Al at wheelcraft a phone to see what price he can do you wheels for.