Question on matching rim - tire width

[Ash]

Velocity has a 'optimal' tire width specified for their rims.

A23:  23mm - 35mm

Atlas: 28mm - 45mm

Cliffhanger: 45mm - 65mm

and so forth.

What's the effect when the tire is in outside of that range?

For instance, what type issues or degradation in riding experience might  I face if I mount 47mm tire on A23s?

I've been using 650bx50mm tires on Atlas without knowing that's not recommended.  The ride has been fine.  Is there a risk?   My + cargo weight has never exceeded 180lbs by the way.  Perhaps the tire might have popped out of the rim if the weight were to be a lot more?  Is that the  concern?

I'm interested in getting a pair A23s built for my future AHH.

What's the widest tire you've been successfully using with A23s?

[Nick Payne]

Early MTBs used cut-down MA2 rims (13.5mm internal width) and ran 2" wide tyres on them without problems. My touring bike has been running 38mm wide tyres on MA2 rims for years - never had any problems with that - and at the other end of the scale, I have some DT Swiss XM401 rims (22.5mm internal width, according to DT intended for tyres up to 2.5" wide) on which I've been running Schwalbe G-One 30mm wide tyres without problem.

Nick

[tc]

Ash,
I have Dyads on my MIT AHH. It’s a nice, strong rim, and plenty wide to accept the max rec. tire width (42) for the AHH.

If you have any concerns, talk to Rich!

Tom

[Chris L]

I also have Dyads and my experience is that I much prefer the handling of the bike with 40'ish mm tires over 50-60mm tires.  I don't know how much of that is tire width, tire shape or quality of tire and how much of that is tire/rim width mismatch.  I just know that with 40mm tires, the handling is much, much more confidence inspiring.  

Based on my experience, I will us Velocity's ratings on any wheels I buy in the future.  

[tc]

Yeah, if you think about the physics of it, you can relate to holding a balloon only by the knot at the bottom and pushing it from side to side with the other hand....compared to holding it with your whole hand over a much wider surface area.

Smaller cross section of the holding area allows more wobble.

The 42 Cazaderos I’ve mounted on my Dyads are only 2mm over Velocity’s recommended max, and I can assure you that’s insignificant, from a holding and performance perspective.

Wider tires on smaller rim widths will increase the roundness of the tire’s profile, which is insignificant unless the tread pattern changes markedly towards the outside of the tire. You may get a more abrupt change in steering as you lean that tire over in sharp corners because the tread is different. But not so on a consistent tread.

Lastly, lower tire pressures will amplify the above. But again, only if you’re talking about tire widths way over the max recommended.

Tom

[lconley]

I have Snoqualmie Pass 44mm on A23s on my Sam. No problems for 2-3 years. All on pavement except some rough brick roads on the Cross Florida Ride - perfect tires for brick roads.

Laing

Cocoa FL

[esoterica etc]

Anybody have experience with narrower tires on wide rims? I’ve got Velocity Cliffhangers which are optimally rated between 45-65mm, but I’d like to try running tires between 38-43mm on them. 

~Mark 

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[Chris L]

This is a major problem with 2" Maxxis Torch tires on my Dyad rims.  They are fine for normal, mostly straight, riding but the tires have a square profile, like a mountain bike, and in sharp turns, they are all kinds of squirrely.  If the weather wasn't so bad, I would have already retired them to backup status.  

[Mark Schneider]

I ride 42's (Compass) on A23's but 650B, Jan Heine states width isn't an issue for his tires. I ride Antelope Hills and Schwalbe G-One 50's with Dyads on my Atlantis but I purchased some Cliffhangers for the Atlantis so I can run other wide tires tubeless. I see no issues with the A 23's for a Homer, they're great rims.

Mark

[Wilson Wilson]

Wider tire on smaller rim yeilds smaller overall tire width, but increases height. i.e. WTB Nano 700x40 on a vintage Rigada 1320 yeilds a tire width of 30-32 depending on pressures. A narrow tire on a wide rim increases width of tyre, but decreases height. Velocity Dyad with Conti 700x28 yeilds 32-34 in width. 

[aeroperf]

The best explanation I've seen on this is from Sheldon Brown.

https://www.sheldonbrown.com/tire-sizing.html

"If your tire is too narrow for the rim, there's an increased risk of tire/rim damage from road hazards.

If its too wide for the rim, there's an increase risk of sidewall wear from brake shoes, and a greater risk of loss of control in the event of a sudden flat."

A little lower on the page he provides a "what fits what" chart, and states: "Note: This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem"

I'm running Conti Speed Ride 42s on Atlas rims no problem.

[Mark Anderson]

A wider-than-recomended tire is unlikely to blow off an undamaged rim due directly to the weight of the bike.  That's not really how clinchers work.

An important part of the upper limit on width from Velocity's perspective is that very wide tires run at high pressures can lead to rim failure, likely in the form of cracked webs and/or sidewalls.  If you are pumping up those 50 mm tires to 90 psi, then you're probably out of spec. for the Atlas rim.  You'd also be nuts to do so for any number of other reasons.  If you're using sane pressures for your weight (what, 25-35 psi? Less? I haven't weighed that little since I was ten...), 50s on Atlas and 45s on the A23 are probably fine structurally.  Just ride in the rain enough and you'll wear out the brake tracks before fatigue failure wrecks the rim anyway.

One reason to use a wider rim on your prospective AHH is that (many) caliper brake quick releases just open the brake a certain amount relative to the operational setting.  Thus, the wider the rim, the wider the inflated tire that can pass through the opened brakes.

-- 

Mark Anderson in Chicago

[Ash]

All,  much appreciate your comments.  I learned a bunch of interesting details!  Thank you.

I'm considering Dyad.  But I've also been told that the A23 OC makes for a stronger rim.  I have to call Rich sometime.

The Quill rim has a staggeringly wider range (25mm - 47mm), but that's way more money than I'm likely to invest.

[John McBurney]

The velocity nobs rim is really good. Not pretty but sturdy, functional wide and NO BS. 

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[Nick Payne]

I've run both Schwalbe G-One 650b x 30 and Switchback Hill 650b x 48 tyres on DT Swiss XM401 27.5 rims, which have a 22.5mm internal width and according to DT Swiss are suitable for tyres up to 2.5" wide. To me, the handling has seemed fine with both sizes of tyre. I use the narrower tyres for Auxax events on sealed roads the the wider for rides combining both sealed and unsealed roads.

Nick