MAK

I've had a few tire questions on the forum but I think I've arrived at the exact questions that will solve my problem. I promise no more tire questions of this nature in the future.

I have a 520 that's about 11 or 12 years old but in great shape. With a few tweaks it's set up perfectly for me and I love it. When I got it used, I replaced the cheap Forte tires (I think 35mm) with Continental Top Contact II 37mm tires. They fit but I didn't realize that the clearance with the fenders (raised as high as they go) would be a problem. Pebbles in the treads scrape and mud just jams everything up horribly.

I'm looking at new tires and I'm considering either the same Continentals in a 32mm (they don't make a 35mm) or Schwalbe Marathon Green Guards in a 37mm, 35mm or 32mm. I understand that Marathon Supremes are extra high due to their thick flat protection so they are probably out. I'm trying to get the diameter of the mounted tires so I can compare the diameters with the tires I have.

My request...If you have Schwalbe 37mm, 35mm or 32mm tires mounted on your bike, could you please measure from the ground to the top of the tire and let me know what you come up with. If I could get an extra 1/2 inch or so clearance, I think I'll be fine. Yes, I know that the rim width matters, but I'm ball parking it here.

A second question...Most of my riding with the 520 is self contained on some pavement and some hard dirt, crushed stone and occasional mud. Think Erie Canal, C&O Canal, GAP, rail trail type riding in sunshine and rain. No off the grid adventure riding. In your experience, can a 32mm tire handle dirt and mud comfortably?

Thanks for any assistance.

robow

Though the differences might not be great, the same tire can exhibit different widths and heights depending on the individual rim installed on because of varying rim widths.

FBinNY 

I can't answer the specific question about those tire diameters. But just to clarify that the rim diameters will always be the same, though I suspect that you meant rim width.

For rough estimate purposes, deduct the full change in tire width from the overall radius.

As for the tow paths, I may be the wrong guy since I've ridden much worse on my road bike with 25mm tubulars. The only issue will be mud, where narrow tires cut in and wide tires float above, but how wide they have to be to do this is anybodies guess. The slightest change in water content, makes more difference than 10mm of tire.

One suggestion is look for tires with minimal tread. These won't trap and carry small stones to jam against the mudguards. They also spin easier even when the guards are fully packed with zero clearance.

Folks tend to over think small differences, make a judgement call, roll the dice, pick a tire and enjoy your trip. What you learn may influence future choices.

MAK

You're right. Rim width not diameter. I fixed it.

Thank you.

pdlamb

IME, a 32 can handle reasonable gravel and mud. Reasonable is perhaps a quarter inch of mud slurry with something fairly firm below that. If you're riding through the muddy analog of quicksand, you'll need bigger tires, and maybe a large snake to pull yourself out. ("Say, 'grab the rope!'")


Gravel's not bad up to 1/4", and with a bit of care 1/2" it possible. I know of one rail-trail with 2" ballast gravel surface that needs tractor tires or horse hooves.


FWIW, I can feel the difference between 37 and 32, but there's not much difference to my tush between 35 and 32 tires.

Doug64

My 32 mm Schwalbe Marathon (plain old Marathon) are close to 30 mm from edge of rim to top of tread. It is mounted on a Velocity Dyad rim.

We have toured a wide variety of surfaces using this tire, and have not had any issues. On one tour part of our route was over 400 miles of unsurfaced roads and trails. IMO the 32 mm is a good compromise between weight, traction, rolling resistance, durability, and cost.



My wife could have ridden through the puddle, but she is short and she didn't know how deep it was. Also, her mechanic voted against it

jefnvk

I have 1-1/4" tires on most of my bikes, effectively a 32mm. They are ridden extensively on clay and limestone rail trails without any sort of issue, and handle mud adequately. Bit too narrow for sand, IMO, but if faced with it occasionally they can suffice. Some of the things they've gone through for me without concern:






The last was a bit dodgy, and probably as rough as I'd want to take them on any sort of regular basis.

Doug64

Sorry, I did not read the request thoroughly. The distance is 27 5/16" for Marathon 32 mm.

BigAura

dirt = yes

mud = no

Jbarcs

Three of us rode the GAP/C&O last May during straight 18 days of rain. All of us rode Marathon Plus 32s. Mud was unbelievable on the C&O. Tires were not an issue. Waterproof shoes and socks would have helped.