CaptMike

I have Velocity Dyad rims on my Waterford Sport Touring frame, with 700x28 Schwalbe's on them now. I took the fenders off, and want to put 700x38's on them, which is the max tire allowed. This is to start gravel grinding on the great rail trails they have here in Michigan. My question is, is it pushing it to put the max tire on a rim, or is it better to get a different rim where the 38 may fall more towards the middle of the allowed tire range. I am 6'4"/250, if that is a factor. If I do go to a different rim/wheel, would the same cassette be compatible? I have E-mailed the folks at Velocity, and am waiting for a reply. Thank you.

dsbrantjr

Here is a chart of rim/tire width guidelines: https://www.sheldonbrown.com/tire-sizing.html#width In it , 38mm tires on a 19mm rim are pretty much in the middle. I run 47mm and 50mm tires on 19mm rims with no issue.
Edit: https://www.velocityusa.com/product/rims/dyad-622

JanMM

Velocity shows that 38mm is within the optimal range for dyad rims. https://www.velocityusa.com/tech/rims/
I've used a variety of 1.25", 1.35 and 1.50" tires on 559 aeroheat rims, which also show optimal for 25-38.

RubeRad

I am 6', 240lb, and on my Surly CrossCheck I have 32H Dyads with a 700x42? 45? Schwalbe Hurricane in the front, and a 700x50 Hurricane in the rear. I have no problems with the tires being 'too big' for the rims, and I let them run down to maybe 20psi before pumping them 'up' to 35-40

Cassettes should broadly be compatible, as long as you stay within the Shimano/SRAM/SunRace 8-10sp standard. Just watch out you don't get a Campy freehub (different spline pattern) or I believe 11sp cassettes need a longer freehub; 12sp definitely do.

70sSanO

In the late 80’s/early 90’s people were running 2” mtb tires on re-rolled road rims that were 14mm/15mm wide. Not on pavement, but on trails.

I still have a setup with 2.1” on 14mm wide rims. Now I don’t push that bike as hard because the tire will roll on the rim, but I’m never lost it and it is far from optimum. I would never buy a new set of wheels to run wider than optimum to ride gravel.

John

Edit added: Of course, if you are going to push a tire to it’s limit, the a better match is a better way to go.

Russ Roth

The dyad from what I understand is the old aeroheat, guessing they changed the name over confusion with the aerohead once they started offering it in 700c. Either way the aeroheat was a MTB rim that ran 26x2.0 tires, can't remember if I have 35s or 38s on my dyads but the fit is really nice with these rims. You won't go wrong.

Pop N Wood

Velocity is a bit conservative on their sizing chart. Swalbe lists a much broader range of numbers

https://www.schwalbetires.com/tech_info/tire_dimensions

I've run my Dyads with wider than 38c tires.

CaptMike

Thank you for the replies. I have a set of 700x38 Schwalbe G1 All-Arounds on the way, and will replace the 28's that are on there now. I think 40's would be pushing it with my frame clearance. Velocity did get back to me the next day, and confirmed the 38 upper limit. Richard Schwinn said they recommend 6mm of clearance from tire to frame/stays (I assume each side of the tire). 50mm is the clearance between the stays. So with the 38's, should have 6mm on each side of the tire. I have a Record Triple groupset on it, with a 10 speed 13-29. I would like to up that 29 to a bigger cog, but that is for another day. I appreciate the responses.

RubeRad

Why would frame clearance need to be as large as 6mm? If there's no rub, the frame and tire have no idea the other exists. As I mentioned above, I've got 700x50 stuffed into my CrossCheck, even though surly says the rear clearance is 700c x 42mm with or without fenders (it's barely crammed in there! I gotta deflate the tire to get the wheel out)

Clyde1820

I've used 700x42 tires on the Velocity Dyad, without issue. (Though, I don't push the cornering ability of my bike, so I can really only speak to what fits.) Never an issue.

Above 700x40, I'd prefer the Velocity CliffHanger rims, myself.

If doing the 38mm tires, I can't see that you'd have any issues whatsoever. Great rim.

CaptMike

RubeRad, he had mentioned mud/rock/etc. Sounded reasonable to me. 40's sound enticing, don't know if I would notice much difference between those, and the 38's. Would there be any issues going with the CliffHanger, or other slightly larger rim, such as hub/drivetrain? Thanks.

RubeRad

Mud makes sense for wanting a little clearance. I live and ride in SoCal, so that's never an issue for me and I didn't think about that.

I don't see any potential issues with CliffHanger, don't know anything about it though. Just know, a slightly wider rim will allow the profile of the inflated tire to also widen a little bit. It makes sense, if you think about what an inflated tire would do if you had some kind of crazy experimental rim that you could widen/narrow while the inflated tire is still on it.

JanMM

There were problems with aeroheat rims used with larger tires. More than a few sidewall failures, as I recall reading about several years ago. Not sure if those were rims made in Oz or in USA. Velocity started warning against use of larger tires on aeroheats at some point. I have used a set of Velocity wheels with aeroheat rims(559 & 406) on a bike for a decade with no problems. Nothing larger than a 1.5” tire on either wheel.

Russ Roth

Maybe people don't like reinflating tires regularly just to take a wheel out? besides mud as mentioned the ability to keep riding with a busted spoke. If you've got as little clearance as you claim one wayward stick could mean carrying the back end of the bike as you walk to wherever. 6mm clearance might mean you have to slightly adjust the wheel in the dropouts to stop frame rub but with still 32h you'll probably just keep riding till you can get around to replacing the spoke.

40 vs 38 isn't going to be radically noticeable. Biggest issue with changing rims is spoke length. I'd guess if your frame has 50mm of clearance between the stays you should have zero trouble going a couple mm bigger on the rim width. They will make the tires slightly rounder but not much.

I'm going to guess from when 1.95-2.1 started being replaced with 2.25, 2.35,2.4
As we can see with newer rims wider to a point makes a difference in how the tire fits. My first pair were Aussie made and bought in 98 when the stock WTB velociraptors on a lot of bikes were 1.95. All the older rims would have been a hazard once sizes started slipping up.

RubeRad

lol I've got 32h, I broke a spoke on the rear wheel, tried to ride with the spoke dangling and somehow it got inserted into a link of the chain! After forcing it out, I hand-bent it around some neighbors. When I got home I removed the spoke (including deflating/reflating the tire, and removing/replacing the cassette), tweaked the neighboring spokes to get it true enough, and have been meaning to get to the bike shop to buy a replacement spoke ever since.

That was like 2 weeks/10 commutes ago.

I hope to get around to going to the lbs and buying a spoke tomorrow

CaptMike

At the risk of asking a dumb question, are slightly rounder tires a good or bad thing?? Thanks.

70sSanO

While I'm not a follower of Jan Heine, this is an interesting article...

https://www.renehersecycles.com/myth...eed-wide-rims/

John

CaptMike

Thank you for the link, John. I just finished installing these 700x38 Schwalbe Allrounds. Getting ready to go out and opscheck them on a little gravel, and mostly road. Going to try 50/60psi. They max out at 75. They fit perfectly, 5mm each side at the chainstays, 6 at the seat stays. I appreciate all your input.

Clyde1820

CaptMike , that's a really great-looking bike. Tasteful contrasting colors, great Waterford frame. Beautiful.

70sSanO

Yes, it certainly is a beautiful Waterford.

John

cyccommute 

Don’t pay too much attention to all the charts that you’ll find on tire sizes. They are far too conservative. I have 559mm Aeroheats on several mountain bikes which are the old version of the Dyad. I run 55 to 58 mm tires on them without issues. I’ve been doing this for years...if not decades. 38mm tires aren’t even pushing the envelope on tire size.