Velocity Dyads and 50mm Tires

[John Rinker]

Good morning,

Just wondering if anyone else has had an issue with Velocity Dyad rims splitting on the sidewalls while running fatter tires. I have been running some Schwalbe Marathon Mondials (28x2.0) and muy rear rim recently split. I am told by Velocity (who has been very helpful, indeed) that the tires are too big for these rims. 

I love the tires and the rims, but perhaps I need an alternative to the Dyad to run these tires. Any recommendations?

Cheers,

John

[Adam Leibow]

Sorry to hear your rim broke! Cliffhangers are great and can easily handle a 50mm tire. 

[Garth]

I think Velocity's conservative rating are more to do with minimizing/discouraging legal/warranty claims. A rim such as a Dyad ought to handle a 50mm tire. The wheel build itself has to be taken into account though, as well as air pressure. 

For other rims...

DT TK540 is spec'd as being suitable for 23-60mm tires.

Alex DM24 for even bigger. I'll have these for my Susie.

Sun Rhyno Lite. I have one wheel with these.

Mavic's A319 and A719, spec'd @47mm though some European retailers note 50mm works also. I have the A719 with Big Ben's on my Bombadil and will be trying some Vittoria Terrene 2.1's. Many riders report riding them up to 2.35's.

Cliffhangers

[Peter White]

I'm a Velocity distributor. But their recommended tire sizes make no sense to me.

The problem with fat tires isn't that they're fat. It's that the tire manufacturers give pressure ratings that only take into account the tire's ability to stay on the rim, rather than a tire pressure that actually delivers a good ride, and doesn't put excessive force on the sidewall of the rim. For example, Schwalbe says that if the rider weighs 240 lbs, a 50mm wide tire should be inflated to 70psi. This is absurd. At the same pressure (psi) the larger the tire, the more force is applied to the rim's sidewalls. It's POUNDS PER SQUARE INCH, and when you increase the square inches of the tire's surface area, you increase the load on the sidewalls of the rim. So it's no wonder that we see rims failing due to cracks in the sidewalls, and cracks under the rim strips.

Peter White

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Peter White

[Bill Schairer]

I did a week loaded on the GDMBR last summer with the DT TK540 on the rear and 50mm Mondials. I had no issues and wheel didn’t need any truing afterwards. As I recall it was an easy build and the rim has a very nice breaking surface.

Bill S

[John Rinker]

Peter,

Thank you for your insight on this. I weigh about 180lbs and run my Marathons at around 25 psi and 32 psi front a rear respectively (a little more depending what I'm carrying). I don't know if these lower pressures are a culprit, but it doesn't seem so according to what you've said. Velocity has been great about offering to replace the rim with a more suitable one (Cliffhanger). 

On my mountain bikes, I've run Mavic 719s forever with 2.25 tires. These rims seem to have a similar width as the Dyads, and I've never split a rim with fat tires. I got a set of wheels that are almost 20 years old and they still ride true after being beat to hell and back on my hardtail. 

Cheers,

John

On Monday, June 22, 2020 at 4:01:11 PM UTC-7, Peter White wrote:

I'm a Velocity distributor. But their recommended tire sizes make no sense to me.

The problem with fat tires isn't that they're fat. It's that the tire manufacturers give pressure ratings that only take into account the tire's ability to stay on the rim, rather than a tire pressure that actually delivers a good ride, and doesn't put excessive force on the sidewall of the rim. For example, Schwalbe says that if the rider weighs 240 lbs, a 50mm wide tire should be inflated to 70psi. This is absurd. At the same pressure (psi) the larger the tire, the more force is applied to the rim's sidewalls. It's POUNDS PER SQUARE INCH, and when you increase the square inches of the tire's surface area, you increase the load on the sidewalls of the rim. So it's no wonder that we see rims failing due to cracks in the sidewalls, and cracks under the rim strips.

Peter White

On Mon, Jun 22, 2020 at 1:50 PM John Rinker <jwri...@gmail.com> wrote:

Good morning,

Just wondering if anyone else has had an issue with Velocity Dyad rims splitting on the sidewalls while running fatter tires. I have been running some Schwalbe Marathon Mondials (28x2.0) and muy rear rim recently split. I am told by Velocity (who has been very helpful, indeed) that the tires are too big for these rims. 

I love the tires and the rims, but perhaps I need an alternative to the Dyad to run these tires. Any recommendations?

Cheers,

John

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Peter White

[John Rinker]

Thanks Garth for that fine list of recommendations. I always had very good luck with Mavic 719s. Can't find them is silver anymore.

Cheers,

John

[John Rinker]

Thanks Adam. The fine people at Velocity have offered to replace the Dyads with Cliffhangers, so this may be the route I go.

Cheers,

John

[Andrew Letton]

Could it be that your Dyads were simply worn thin from the brake pads? 

I run 50-57mm tires on Dyads on my Bombadil with no problems...admittedly at low pressure; less than 35psi.

cheers,

Andrew

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[Chris L]

Wow.   I weigh 385 and I pump any 50+ mm tire to 45 psi and consider that higher than I really need.   

I've been riding Dyads and have had 50+ mm tires on them probably 95% of the time.  I don't do huge miles but the wheels are about 7-8 years old.  Zero problems with the rims or wheels.  

On Monday, June 22, 2020 at 6:01:11 PM UTC-5, Peter White wrote:

 For example, Schwalbe says that if the rider weighs 240 lbs, a 50mm wide tire should be inflated to 70psi. This is absurd. 

Peter White

[Nick Payne]

On Tuesday, 23 June 2020 at 9:01:11 am UTC+10 peter...@gmail.com wrote:

 

At the same pressure (psi) the larger the tire, the more force is applied to the rim's sidewalls.

Yes, for a given pressure, stress in the walls of a cylindrical pressure vessel (of which a tyre is a good approximation) is proportional to the diameter of the vessel. So a 50mm tyre at any pressure will put about twice as much stress on the walls of the rim as a 25mm tyre at the same pressure. Conversely, a 50mm tyre at, say, 35psi, and a 25mm tyre at 70psi will put approximately equal stresses on the rim wall.

On the bike I have that takes that sort of tyhre size, with 55mm tyres I run the front at 25pis and the rear at 35psi (H Plus Son Todestrieb rims).

Nick

[Michael Morrissey]

I have Dyads with 50mm Big Bens on my Appaloosa. I've had no problems for the 4+ years I've had them. I think I've had such good luck because I am religious about keeping them pumped up. I have a digital air compressor (the blue one with the gauge from EPAuto on Amazon) and a Silca stainless presto adaptor on it. It's way better than any bike pump and way more precise. I usually go to 36.5 PSI! I agree with Peter W - 70 PSI is way too much.

Good luck! 

m

[Justin Kennedy (Brooklyn, NY)]

Not entirely related, but I was running 50mm tires on a set of Velocity NoBS rims and kept getting weird flats where the tube looked like it had been slashed 3-4". No punctures and not your typical snakebite pinch flat pattern. I couldn't figure it out but Velocity said the tires were too wide for that rim. (Max they recommend is 45mm which is like a fifth of an inch smaller.) I switched to 45's and no problems. I dunno.... ¯\_(ツ)_/¯  Never figured it out but there was something going on with running too big tires on those rims. 

On Monday, June 22, 2020 at 1:50:22 PM UTC-4, John Rinker wrote:

[Ginz]

For the longest time, the average mtb rim was 18mm.  People ran 2.1" knobbies.  Nowadays it sounds like you need a 23mm rim to run a 2" commuter tire.  Are things changing?  Were they always wrong?  I dunno!

I have one set of wide-ish rims -- Rhyno Lites.  They have Big Apple 2.35" tires on them.  I don't notice much of a difference.  Oh well!

I thought about running 2.5" tires but wondered what incredibly wide rims I'd need to do it!

Ginz

[Mark Roland]

I just bought a pair of Rhyno Lite XL rims (slightly wider than the non-xl?) for my Susie, planning to run fairly knobby 2.6" tires, don't anticipate any problems. I currently have Steilacoom tires on narrow vintage racing rims, no problem. 2.3" Thunderburts on Atlas, no problem. 2.1" Powerblocks on super skinny 26" vintage road rims, no problem. Etc. As pointed out, when running appropriately proportionate pressures, you are unlikely to have problems except at the most extreme ends. Despite what Velocity says.

[Garth]

Yes Mark, slightly wider, 29.2/23.5 outer/inner I believe ..... and they are available in anodized silver, black, gold, red, blue , purple and green !  Colors !!!  I can picture a set of gold rimmed wheels for my orange Susie with black cranks. Even though I have some Alex DM24's on the way, yeah so what ! 

https://bassettbmx.com/products/sun-rhyno-lite-rim-29?variant=8587489509423

[aeroperf]

Interesting.

I run a set of Velocity Dyads that I built up with Deore hubs.  For the last 3 years I’ve run Continental Speed Ride 42mm tires at 70 psi with zero problems.
I have lately knocked the pressure back to 55 psi for ride quality, but I have never given a thought to the rims failing for any reason.
Of course, 42s aren’t really “fatter tires”.

[Mark Roland]

Garth, it was you pointing out the bmx Rhyno colors in another thread that got me to order a set from Albes a few weeks ago. However, you forgot about...white! I will be lacing up white Rhyno Lite XL rims to a set of vintage gold Deore LX hubs from my parts box, spoke nipple colors TBD, for my L Susie! So I have you to thank...or blame;^) If I can figure out the bb situation, my cranks will be a nice '80s magenta. Going with VO clunker bars for now (I have a nice pair of Choco-moose in the wings--thanks Joe).  Still debating on whether to get the pink crash pad.  Hopefully it won't clash with my raspberry Brooks. Yikes. Fun!

[Garth]

   Oh man gold Deore hubs with white rims ? You gotta post a photo when they're done !  We can never have too many wheels !! They're much easier to make room for than whole bikes.  We can both thank the good 'ol world of BMX for tempting us all as it doesn't suffer from upgrade-itis like road and mtb stuff.

If anyone is interested in old-school brakes for any of their bikes in many colors check these out .... of interest to me is the Dia-Compe 988 cantilever brakes in colors. Colorful headset spcers if you need them too !

https://porkchopbmx.com/brakes/brake-calipers-and-sets/

https://porkchopbmx.com/old-school-bmx-parts/headsets-and-spacers/

For MKS users they have pedal end caps and the wrenches for them. They have colorful VP-747 Bear trap pedals if you're looking for them.

https://porkchopbmx.com/old-school-bmx-parts/pedals/

Colorful presta valve caps !

https://porkchopbmx.com/old-school-bmx-parts/valve-caps/

Decals .... as a kid we used to covet getting STP oil stickers for Earl's Service Station... back when there was such a thing. He's check your fluids while he filled your gas tank. In side the postage stamp sized shop was a returnable bottle pop machine and a accordion-door chest freezer with ice cream sandwiches.

Porckchop has some nice looking ones ! Kool-Stop, Tange, Suzue, True Temper and MKS stickers ... who knew ? The Porkchop "Hot Wheels" and Red-White-Blue style stickers look kinda cool.

https://porkchopbmx.com/old-school-bmx-parts/decals-stickers/

The Made in Japan page has some hard to find Dia-Compe among other parts.

https://porkchopbmx.com/made-in-japan/

Too much to list ! It's like stepping into a cool old-world bike shop like Kraynick's in Pittsburgh where I have gotten a number of vintage SunTour shifters and brakes, among other parts !

[kim young]

Omg Mark. Your bike!!! Incredible

Garth-I have felt like such a victim of the upgrade-itis curve (Thank you for that word)

and which never seems to level out for me. 

So the hillibike/bmx possibilities are a dream.

Thank you for the linx!

From kim in az 

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