Is Wider Always Better?

Words Enve Staff
Date Sep 2, 2015

Please read this preamble before commenting.

To be as clear as possible, we did not write this. Enve staff did not suggest we post these findings (nor was any compensation provided), which originally appeared as a blog post on their site. I read the piece and felt it helped me get my head around the least dramatic of the recent changes in rim architecture (when compared to fat or plus bikes). Wider rims have been anointed as the solution to many problems, and our intuition says this makes sense, but what about the evidence?

Before we go further, I’d like to be be sure you realize that Enve staff wrote this piece and it’s clear they have a vested interest in declaring their approach to be the most effective (my wider is better than your wider!). Yes – there is an inherent bias and we all know it’s there. At the same time, dismissing their findings out of hand would be premature. Enve asked their engineers to examine the benefits of rims of various widths, and, despite the aforementioned biases, we have no reason to doubt their findings. We’d love to be able to do this sort of analysis independently but we don’t have access to the equipment, nor the big brains, required to collect the data needed to reach these conclusions.

And yes, Enve rims are expensive. They are also as tough and long-lasting as a honey badger. Despite that, our intention posting this isn’t to persuade you that their rims are the best in terms of value and quality. Rather our hope is that these observations will equip you to ask the questions that will help you decide on your next bike or set of wheels. Now that you are aware of the playing field, feel free to engage with us on social media.

Cam McRae


With the whole ‘wide wheel’ craze seemingly erupting all around us in the media and the popular forums, we asked our engineers, from a scientific perspective: Is wider always better? Let’s knock out a couple of myths about wide wheels.

mtb-is-wider-better-2

MYTH #1 – RUNNING A WIDER RIM INCREASES EFFECTIVE TREAD.

Maxxis High Roller II GeometryM70 Case vs Tread Width

chart-tire-highroller-geometry

As you can see – rim width does very little to affect tread width, assuming you are running an appropriately sized rim for your tire. With the Maxxis High Roller II, a 2.3″ tire, there are infinitesimally small tread width gains (about 1/3 of a millimeter) from boosting internal rim width 10 mm from 25 mm to 35 mm. For you guys doing the math at home, about the same size as 3 strands of hair. So, what are you getting? You are getting casing width and most likely added weight.

MYTH #2 – WIDER RIMS REDUCE TIRE DEFLECTION.
Rim Width to Sidewall Stiffness
chart

On the left hand side, you have sidewall deflection in inches vs pounds of force on the bottom. The takeaway here is that there are diminishing returns above an internal width of 30 mm for 2.5″ tires. After that point, you are only adding weight. Myth busted.

When we launched the M Series 60 Forty, we had a specific tire size in mind for all-around trail riding. We were riding 2.1″ – 2.25″ tires and those wheels, with an internal rim width of 23 mm, provided the best traction, to weight, to durability, to sidewall strength of any rim width we tested. Now that we are riding 2.3″ – 2.4″ high volume trail tires, we have launched the M60 High Volume, with an internal rim width of 26mm. The M70 HV, with an internal rim width of 30mm, is optimized for 2.4″ – 2.5″ tires.

SUMMARY
So is wider better? If you are riding higher volume tires, then yes – up to a point. We now know that there are diminishing returns to increasing rim width when it comes to sidewall stiffness and tread width. As you can see below, the new HV wheelsets are just wide enough to provide the best performance, but not so wide that they get heavy – all while maintaining best-in-class durability.

Reducing Tradeoffs

-

Impact values are achieved by dropping a weighted anvil on the built wheel w/ tire in a rigid fixture starting at 4″ and incrementally increasing the drop height by 2″ until rim shows any visible signs of damage.


How wide is wide to you?

 

Trending on NSMB

Comments

poo-stance
0
Poo Stance  - Sept. 8, 2015, 2:30 p.m.

How can you post this article after posting this a week earlier…

Pick a size and be a dick about it!

Reply

JVP
0
JVP  - Sept. 5, 2015, 6:59 p.m.

Enve is missing the point (of course they are!). Rims don't matter much, they just need to work. Tires matter. A lot. None of the current top-shelf tires work well on wide rims. Too squared, don't corner as they should. I started running the 32mm china's and not super happy with all my favorite front tires. DHF, Butcher, too square. Magic Mary, HUGE and sorta square. Redesign us some rounder DHFs (or similar) and then 30mm rims might be best of all worlds. Love the stability of my 32mm rims in winter, love how they work tubeless, but don't love the cornering or the rate that I'm shedding side knobs. Cornering matters. A lot.

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jeff
0
Jeff  - Sept. 17, 2015, 11:59 a.m.

I've been running the Schwable Hans Damf on 40mm wide Derby rims with good success.

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bs
0
BS  - Sept. 3, 2015, 12:24 p.m.

Yes, this is coming from a company that is on the thinner side of things, however other companies have echoed this, Specialized said the same things when the roval fatties were released: "How wide is too wide, though? Roval says a wider rim means more material and, at some point, you are adding more material (weight) than you are gaining a better riding wheel. They felt and saw massive increases in cornering traction by going from 22mm to 30mm with a minimal weight penalty. As you increase the width another 10mm, you get some benefit over the 30mm but the improvement is much smaller while the weight gain was dramatic. Roval decided that 30mm is the best blend of the wider rim support while still keeping the weight low. "

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naveed-nasir
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Naveed Nasir  - Sept. 3, 2015, 12:20 p.m.

my heart says I understand why you posted this, my head says seo duplication

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cam@nsmb.com
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Cam McRae  - Sept. 3, 2015, 12:36 p.m.

LOL. If I knew what that was maybe you'd be right. What is that exactly? Are you saying we did this to help Enve's reach for this article? Or maybe something else? We asked them if we could post it, not the other way around FYI.

Reply

naveed-nasir
0
Naveed Nasir  - Sept. 3, 2015, 12:55 p.m.

This is how it's done -

It's about the distribution of links, man, now I feel middle aged and boring!

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republicmalcolmisland
0
RepublicMalcolmIsland  - Sept. 3, 2015, 10:36 a.m.

What's next? 24 inch rear tires?

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craw
0
Cr4w  - Sept. 3, 2015, 9:05 a.m.

Stop with the science. The anecdotal evidence is irrefutable!

Reply

bogdan-m
0
Bogdan M  - Sept. 3, 2015, 5:44 a.m.

I went from a 26mm internal Flow EX to a 31mm internal Woven rim (cheaper carbon rim) and running similar tires Maxis DHFs 2.3 I def feel like the 31 mm rides better. I seem to be able to run a bit less tire pressure but the tire stays put better. That is on the flow at 30psi I would ding rims but on the wider rims I'm riding around 25psi and the tire feels like it has more air in it when hitting things but at the same time it's more supple, haven't damaged my rim yet … though I'm trying very hard, since I have a 1 year replacement warranty on mine, no question asked.

To be honest it's not apples to apples I went from a 26 to a 27.5 in this comb but I thought it was def something I noticed. Now I guess I'm staying within the parameters of this article … 31mm rim … not going to a 35 or 40 …

Pretty happy with my wider (though not mega wide) rims.

Reply

jeff
0
Jeff  - Sept. 3, 2015, 12:45 a.m.

Running wider rims decreases tire roll/squirm while cornering, allowing a lower pressure to be run for a given amount of tire roll. In turn the lower pressure increases tire contact patch, increasing grip. This is important for riding situations where grip is hard to find, typically black diamond or double black trails, or in the wet.

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neil-carnegie
0
Neil Carnegie  - Sept. 3, 2015, 12:59 a.m.

The trouble is if you are a decent fast rider, running low pressures and then battering through demanding terrain with a carbon rear rim is a bad plan for entirely different reasons. Wide might let you run super soft in theory, but carbon stops you in practice.

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david
0
David  - Sept. 3, 2015, 5:21 a.m.

^^^ Ding Ding Ding.

If you are a half fast rider then you're going to want the opposite of lower pressure. I know that there are plenty of folks that feel more comfortable with a softer setup, but frankly when you start pushing your limits, using a system with lower pressures does not provide consistent support. This is somewhat analogous with suspension setup and the same BS was pushed down our throats when tubeless tech started making its way into biking. I can't run under 28 psi on 2 ply casing downhill tires without having those 'moments' of squirm and tire collapse in certain cornering and leaning scenarios and I'm no better than a midpack Cat 1 bum on a good day. It's truly amazing that the real fast guys manage to keep their tires on their rims for an entire run.

We're all a bunch of introverted donkey's playing with special big boy toys in the woods so if someone wants to buy wider whatevers then that's all good and if certain 'technologies' or types of bikes allow some riders to be more comfortable and personally faster then I think it is a great thing. Interesting that ENVE would put a stake in the sand on this issue. Reminds me a bit of Specialized doing the same in claiming (correctly I'll add, based on all empirical evidence) that there really ain't no difference in speed between 26 and 650b wheels.

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whatyouthink
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whatyouthink  - Sept. 3, 2015, 6:59 a.m.

I enjoy your rant. I happened to have done this to an extreme i went from 21mm internal rim to a 35mm internal. running basically the same tires. I used to get a lot of squirm at 30+ psi on the narrow rims. Now I un 30 and dont get the same roll. I am not some crazy fast person either but I hate the feeling of thinking my tire is going to fall off in a berm.

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brizzy
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Brizzy  - Sept. 3, 2015, 7:54 a.m.

Yup, I'm definitely NOT that fast but this has been really noticeable for me (especially on a hardtail). If I set my tire pressure based on comfort and amazing cornering traction I end up bottoming out on the rim constantly in chunky sections.

And honestly, when I'm trying to really pin it and corner at speed I need a fair amount of pressure to prevent squirm anyway. I used to ride around on like 22 psi all the time… but I was freaking SLOW back then. I don't feel confident below 28 now.

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poo-stance
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Poo Stance  - Sept. 3, 2015, 11:31 a.m.

What size tires were you running? Narrow rims work better with narrower tires. Trying to mount a massive Schwalbe 2.35 or 2.4 Maxxis onto a 19mm IW rim isn't the greatest idea

Reply

whatyouthink
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whatyouthink  - Sept. 3, 2015, 12:09 p.m.

I think that was part of it for sure.

Reply

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