Read the review in ST issue 95, wondering about trying. Has anyone any everyday experience? Can they fit in a normal frame, ie not specifically designed for them?

I have about 10mm clearance between my present tyre and chain at its closest so imagine this shouldn’t be a problem.

Depends how Wide you’re going.
The WTB rims they tested, aren’t really very wide at 25mm. I’ve been running 29mm Sun rims for a few years, and had no problems with clearance on 2 or 3 frames.
If you go 35mm or more, you may get a bit more width on the tyre, but you’re more likely to see the tyre profile get a bit squarer. I’ve run 2.4 Chunkey Monkeys on the 50mm rims on my Krampus, and they come up about 6/7mm wider each side than on normal rims.

I’m finding it another bike industry con. My new 30mm are no better than my 21mm. If anything i think they are probably worse. The same tyre on a 21mm has a rounder profile and I can corner harder. The tyre on the 30mm has a flatter squarer top and washes out when leaned over a lot easier than the 21mm. I’m also struggling with tyre pressure on the 30mm rims. On my 21mm rims I use 25psi at the rear. On the 30mm I have to run around 30psi to stop it squirming in hard corners but it feels to hard and lacks the grip of the same tyre on the 21mm rims.
21mm rims are mavic 821
30mm rims are light bicycle
Rear Tyres are 2.35 hans dampf on both

I didn’t buy 30mm for any perceived benefit I just chose the light bicycle because they look good.

They may be better with a different tyre that stays rounder when on a wider rim.

Based on riding the Krampus with 3″ tyres, what makes the difference isn’t the width, but the volume.
So just putting wider rims (IMO this means 30mm +) with the same tyres brings minimal advantages. It starts to make sense when you also put a larger volume tyre on them too.

I’m finding it another bike industry con. My new 30mm are no better than my 21mm. If anything i think they are probably worse

i presume you are using tyres designed for narrow rims, try a proper + tyre (if it’ll fit your frame) before dismissing it

What’s really much bigger than 2.35 hans dampf? It’s the same on the 2.35 magic Mary’s on the front but the difference when riding is less noticeable. Both magic Mary’s I run at around 20psi but any less on the 30mm rim and its squirmy whereas I have run the 21mm as low as 11psi and it was a bit squirmy but not too bad.

A lot of the squirming you describe is down to a combination of sidewall and profile.

From experience (and some pretty extensive testing by a tester I know) there seems to be more work done by the sidewall on a wider rim, so going up from a snakeskin type to super gravity casing will help, as well as being a stronger tyre.

Interestingly enough I swapped out a SG MM this weekend for a different tyre with a “standard” sidewall. Same pressure, same rim etc and got precisely this wallowing effect.

Wider rims definitely give considerable performance gains, but you have to use the right tyres to make the most of it.

Interesting thread as I’m pondering upgrading my original Flow rims with something from Lightbicycle to run my 2.2 and 2.4″ rubber queen/trail king tyres. Undecided if I should use the swap to gain width for the same weight, or save weight for the same width.

There must be a tipping point for the benefits of wider rims. Sure I read somewhere that the Highroller 2 was designed for a 23mm rim. I’m guessing other tyre manufacturers do similar.

Or go down the opposite route as I saw on Geoff Apps’s rather interesting bike.
Narrow rims (Mavic 717s I think), really thick 24″ speedway/MX inner tubes wrestled onto the 29″ rim, and Maxxis DH dual ply tyres. All run at about 5/6 psi! Amazing grip, but really disconcertingly squirmy. No punctures through!

I run 35mm wide Syntace rims with a MM and a Crossmax rear. I had a 717 + Minion up front on the previous bike and I find a massive difference in grip and they way the wheels stay on line rather than being deflected by rocks etc. Run about 18psi. Maybe they are more wallowy on groomed surfaces but try not to ride those.

Undecided if I should use the swap to gain width for the same weight, or save weight for the same width.

You gain **** all width at the tread (there is some talk of squaring off the tyres cross section, but I haven’t noticed any problems), it is at the base of the triangle where all the gains are, and it is **** brilliant. I am running mountain king 2.4’s on lb 38 rims and I love them.

ajantom – Member
Based on riding the Krampus with 3″ tyres, what makes the difference isn’t the width, but the volume.
So just putting wider rims (IMO this means 30mm +) with the same tyres brings minimal advantages. It starts to make sense when you also put a larger volume tyre on them too.

Agree.

Pneumatic tyres work best with plenty volume.

Try a Surly 1×1 with standard tyres and rim, then with wider rims (35-40mm) and 2.8 Dirt Wizards. The improvement is phenomenal.

If the width gain is only at the base of the triangle, where there is no contact with the ground, how do wider rims aid grip?

Not going to try and explain the science but my mate has just got a mojo hd3 with the ibis 41mm rims. He is running hans damf 2.35 at about 18 psi and the grip is ridiculous. They are so good that I am going to try them in my switchback to see if they will fit.

With the wider rim the tyre can move further side to side and still have the centre of the tyre between the rim edges. The tyre section is U-shaped rather than horseshoe shaped so the tyre wall is more perpendicular to the downward forces making it less likely to ding your rims.
This adds up to: More grip, less being chucked off line by obstacles and less chance of pinch flats.

continuity – Member
If the width gain is only at the base of the triangle, where there is no contact with the ground, how do wider rims aid grip?

Don’t get bogged in the theory.

It works. 🙂

I’d say it’s largely b*llocks.

I’ve got some wide carbon rims, and some ~24mm ID aluminium rims & can’t run any different pressure when riding in general, or racing.

Out of curiousity, I ran the same tyres on both sets of rims, with the same pressure, and no noticeable increase in grip.

Amusingly, no faster either with my super posh carbon wide rims either. Don’t get how people can supposedly run super low pressure either, they squirm all over the place when cornering hard, and I started getting pich flats on a tubeless setup when I started running less than 25psi.

Think is, once wide rims and tyres designed for them take off, the system will be lighter and better performing. It’s just whether or not wide rims compromise the current tyres.

My motorcycle rims were almost as wide as the tyres on and off road. They never squirmed.

My motorcycle rims were almost as wide as the tyres on and off road. They never squirmed.

Did they have paper thin sidewalls to keep the weight down?

Just ordered some Ibis 941’s for my new build. Not ridden any yet, but hopefully soon will be able to report back. They’re going on a bike with plenty of rear wheel/tyre width clearance and a 1×11 setup, would be very wary with more than one chainring and/or tight clearance frames.

Currently riding some 30mm external (24mm internal) Light Bicycle Carbon rims, and been very impressed. Had been used to 21mm internal width rims for a while. Used to really like my old EX729 rims on a 26″ bike I had a while ago for their width and the tyre profile they afforded, just didn’t like the weight!

jam bo – Member

My motorcycle rims were almost as wide as the tyres on and off road. They never squirmed.
Did they have paper thin sidewalls to keep the weight down?

Nope, but both the rim designer and the tyre designer knew what the other one was doing.

Alot of differing opinions above. Here my practical experience.

Got two different rims with the same tyre on it conti race kings 2.2″

One i can run 20 psi in the other i cant because the tyre squirms. One rim is a velocity blunt sl internal width of 20mm. The other rim is a ryde trace trail internal width 25mm. You guessed it the wider rim and it the internal width that makes a difference that offer the lower tyre pressures.

Wider rims work by better supporting the sidewalls thus reducing flex. Lateral grip is related to ammount of sidewall flex. Also the contact patch becomes wider and shorter. this improves lateral grip and reduce rolling resistance slightly. Physics does not lie. This is what wider rims do the wider the better really.

I know which wheels i prefer riding.

There seems to a a general vibe that wider rims are a panacea for improved grip, better bottom out resistance because of greater air volume and better rolling speed and puncture resistance, but rims are only a component part of what forms a wheel.

Generally, a wider rim allows you to gain more air volume for a given tyre, which in allows lower pressure to be used, with less fear of burping the tyre due to tyre bead leverage, but, lower pressure gives a more flexible tyre – good for rolling resistance, but not so great for keeping the sidewalls stiff, so they squirm, even with the added support from a wider rim, which only really helps to stop the tyre bead pulling out and helps the tyre contact patch to be bigger. You either have to up the pressure to get rid of the squirm, or get stiffer sidewalls, which necessitates a new tyre.

This is not rocket science, but you do have to give some consideration to how these factors inter relate to one another. Seems to be a bunch of people putting old, excessively flexible tyres on new wide rims and then blaming the rim for the tyre squirming a lower pressures. It’s like listening to a replay of ‘I’ve done my tubeless wrong so it must be shit’ that’s been so common over the last five years.

This is not rocket science, but you do have to give some consideration to how these factors inter relate to one another. Seems to be a bunch of people putting old, excessively flexible tyres on new wide rims and then blaming the rim for the tyre squirming a lower pressures. It’s like listening to a replay of ‘I’ve done my tubeless wrong so it must be shit’ that’s been so common over the last five years.

Which is why, when I put a carbon Wheelset on my bike, I used some brand new tyres, which arn’t floppy, skinny XC tyres.

I’m not blaming the rim for squirming under low tyre pressure, it’s because i was trying lower pressures than normal (~25psi).

It’s the same for me when running similar pressures on normal width rims. Around 25psi they seem to turn into a floppy mess when riding harder.

I swapped wheels back and forth for a while, to see if I could notice any real difference, and I still can’t. Certainly not the ‘considerable performance gains’ mentioned above. If that were the case, a whole load of contracted professionals would be circumnavigating their contractual requirements to benefit from this ‘free speed & grip’.

Maybe even the new non floppy tyres you bought still didn’t have thick enough sidewalls. Let’s face it, there’s no guide to this stuff anywhere.

What tyres are ypu using hib nob because your experience is certainly not mine but your alloy rims are already quite wide. Your carbin rims may only be a bit wider and maybe with your tyre choice the tyre does not come up any wider.

Measure the tyre width on both rims is there a difference if not you wont feel any difference. Some tyres do not spread well others do. Tyre choice is probably your problem.

Possibly, but I’d hope a Super Gravity Schwalbe would be plenty stiff enough. Somewhat defeats the object if the requirement is to run massive, heavy tyres to make it work…

im don’t dispute the science fact that it should be beneficial, but in my own experience of running them in the field is its a borderline un-noticable difference.

Then I have a similar feeling towards running carbon wheels in general on the sort of bikes I ride, but that’s a whole other discussion 🙂

2 wheeled vehicles need a tyre that’s got a crown on it, otherwise it can’t corner effectively, and won’t transfer onto the side knobs carefully designed into your tyres…

Not at all saying that wider rims are a bad thing, there’s benefits such as lack of burping, and perhaps some stability, but there are downsides as well, stiffer tyres and more material on the rim, especially for Aluminium 29er rims which can be a hell of a weight gain. But at 2.3″ current tyres that are marketed now (how I love standard unit measurements) I reckon a 28mm internal rim is as far as you want to push it before the tyre shape is compromised.

I’d say it’s largely b*llocks.

I’ve got some wide carbon rims, and some ~24mm ID aluminium rims & can’t run any different pressure when riding in general, or racing.

Out of curiousity, I ran the same tyres on both sets of rims, with the same pressure, and no noticeable increase in grip.

Amusingly, no faster either with my super posh carbon wide rims either. Don’t get how people can supposedly run super low pressure either, they squirm all over the place when cornering hard, and I started getting pich flats on a tubeless setup when I started running less than 25psi.

Perhaps because you seem to be a pretty handy rider and are fast you can see through the bullshit.

As far as I am aware most DH and Enduro pro’s are not riding super wide rims so that tells me it is industry cobblers.

Maybe if a rider is pretty slow then really wide rims and super fat tyres are the emperors new clothes 😉

As far as I am aware most DH and Enduro pro’s are not riding super wide rims so that tells me it is industry cobblers.

Oh dear, not the old “DH pros don’t use it so it can’t be any good” argument against. We went through this with, “DH pros will never stop using 26″ for a bigger diameter” & look what happened there.

Oh dear, not the old “DH pros don’t use it so it can’t be any good” argument against. We went through this with, “DH pros will never stop using 26″ for a bigger diameter” & look what happened there.

Unlike the average joe and the MTB industry, DH racers actually test things against the clock before deciding that they are faster.

Why don’t Dh riders use 3.0 inch tyres for DH? Because they tried them and they are not as quick.

When the top guys racing ANY discipline start using super wide rims I will believe they are better, until then a bunch of stw semi fat bike lovers and industry whores telling me they have so much more grip and are faster is not going to convince me.

You can pull science theory out of your arse til the cows come home, but until I have seen proof at the top level it is faster then it’s just waffle.

When the top guys racing ANY discipline start using super wide rims I will believe they are better, until then a bunch of stw semi fat bike lovers and industry whores telling me they have so much more grip and are faster is not going to convince me.

Good point. I wonder how much of the positive reports we hear on these forums are from people who have convinced themselves they’ve gained all this super grip because they’ve just gone and spanked £500 on the credit card for wider rims.

It would be interesting to do some social research on mtb riders along the lines of looking for a correlation between those who read the bike mags and those who perpetually upgrade their bike with the latest kit and trends.

This “squaring off” and compromising on profile, really?

You do realise the tread is flat at the point it contacts the ground?

What’s the sort of average tyre width, about 55-60mm? When people have measured to change in width due to the wider rim, maybe 5-6mm i’ve seen somewhere, so ~10% change in width, that’s going to have naff all squaring effect, especially on the bit of tyre that in in contact with the ground.

The load on the tyre from your body weight is having a way bigger effect on the contact patch shape and bits of tread in contact than a little change in tyre width.

Well that’s my verdict on that matter anyway.

Most downhillers and enduro riders will be riding wide rims.

Anyway here is an explanation of some of the advantages.

http://www.pinkbike.com/news/Tech-Tuesday–Wider-Rims-Are-Better-and-Why-Tubeless-Tires-Burp-.html

With regards what the pros are using:

Ibis EWS team all on 35mm internal rims
Specialized Enduro team all on 30mm internal rims
Quite a few others too spring to mind, and lots on what look to be prototype wider rims right now too.

Bear in mind there is a development lifecycle for manufacturers, and most riders are in a 2 year deal, typically signed at Eurobike. My prediction is that we’ll see lots more on wider rims next season as product development catches up and contracts renew.

The number of riders of all levels who experience the performance gains, coupled with the theory behind it, strongly suggests factual accuracy rather than (as some on here love to believe about any new development) some Illuminati style industry conspiracy……

When the top guys racing ANY discipline start using super wide rims I will believe they are better, until then a bunch of stw semi fat bike lovers and industry whores telling me they have so much more grip and are faster is not going to convince me.

This.

It’s not that I don’t believe anecdotal accounts from people on here or that I’m skeptical about ‘the industry’ but I also like to see ideas proved against the clock and tested at the highest level before spending my own cash.

These guys are paid to be guinea pigs, development is part of their role, I’d rather not pay out for something on the basis of Internet hype and then realise I’ve just spent a load of money for no discernible improvement to my bike.

‘Racing improves the breed’ as the expression goes, I like to see a consensus among racers, there’s nothing wrong with that approach.

A lot of the stuff on any forum is guff from people trying to justify their purchases or new bike syndrome so you’ll excuse the ‘I’ll wait and see’ approach.

‘Racing improves the breed’ as the expression goes, I like to see a consensus among racers,

people think the wheel size increase is all marketing BS when the entire XC world has moved

Ibis EWS team all on 35mm internal rims
Specialized Enduro team all on 30mm internal rims
Quite a few others too spring to mind, and lots on what look to be prototype wider rims right now too.

Bear in mind there is a development lifecycle for manufacturers, and most riders are in a 2 year deal, typically signed at Eurobike. My prediction is that we’ll see lots more on wider rims next season as product development catches up and contracts renew.

The number of riders of all levels who experience the performance gains, coupled with the theory behind it, strongly suggests factual accuracy rather than (as some on here love to believe about any new development) some Illuminati style industry conspiracy……

And here is the crux of it – none of them are going any faster for it. They haven’t started winning races all of a sudden, ACC still got smoked by Tracey on a skinny rimmed 29’…

I have no doubt we will see lots more riders on wider rims over the next few years, but not for the reason you suggest of people jumping contracts because they are a must have product, but because lots of people will be making them, and sponsors want riders on the new, latest, greatest flagship product.

As you cited above, you believe the wider is better mantra, not just claiming it’s a little bit better, but considerably so – maybe you’ve just been hitting the industry Kool Aid a bit hard recently, rather than us luddites who don’t believe it makes a real world noticeable difference…

I’ve been running Derby rims now for a little over a year, built up by my local shop on Chris king hubs and they’re 40mm exterior so around 35mm interior width. They don’t really make clearance an issue as they don’t massively change the outter profile of a tyre instead they make the tyre box section more square so less of a pinch on the tyre. I recently rode another bike and with a combination of the wheels and tyres it had on it I hated it. Nowhere near as grippy and handling of a ride. I always try to describe it like if you run alongside a root and then want to swap sides a pinched tyre normal width rim will roll before eventually yielding and having to flip over to the otherside but the wide rim due to its boxed profile will just run straight over it. They have a sort of steam roller effect in regards to that. I run 22 psi with magic Mary’s and a combo of high roller and purgatory and all are spot on with zero squirrelling. Any higher psi and the tyre is so rock solid you can’t get a feel for the terrain and it’s a harsher ride.

…..or maybe, as in all her interviews, Anne Caro found the course didn’t suit her.

As for contract shifts – if a brand hasn’t got a product ready, the rider won’t be on it. But come Euro bike I reckon we’ll see that change is what I’m saying.

As for Kool Aid etc – its an easy & cheap shot to think that is all it is. Have you spent much time a/b testing wider wheels against standard, or is this just scepticism? I have spent a good amount of time on both, and also did the same for 26 vs 650, with timings backing up what I could feel. But obviously its all not real…… 😉