kahuamp

I currently have the 700c x 38 tires on my DS 8.2.

I find them bit skinny for my liking(my former bikes were all mtb'ish , and was thinking to install wider tires as a future project. The DS has quite a bit of clearance, and I was wondering how wide I could go as not to decrease its efficiency on the road too much.

Another reason I want a bit wider tires is that my commute also involves riding through some fields, and it gets nasty when it rains, which is often.

How big(wide) did you fit on yours and what changes have you noticed ?

hokiefyd 

My dad has a 2014ish 8.4 DS, so I suppose it has the same (or nearly the same) frame as yours. His also came with 700x38 tires, and he has run as large as 29x2.1 WTB Nanos on it. They JUST BARELY cleared the rear chain stays (as in, he had to air them down to keep them from rubbing), and he has the stock 38mm tires back on it. But the 2.1s (which I think are nominally 54mm wide) did just barely fit.

I would think you should be able to fit a 700x47 or 700x45 with enough of a safety margin. Maybe even a 700x50, given the profile. The WTB Nano has a pretty round profile, which helps. Of course, a tire with a blocky tread pattern or one with tall side lugs would have less clearance than one with a rounder or smoother profile.

andrei_r

One forum member had 2.1 Kenda small block eights on his DS.

kahuamp

wow, that big huh? I remember having 2.0 on my 26' mtb and I liked them. I could be happy with even less.

Forgot to add rims are bontrager AT-750 alloy rims:

23mm outer, 17.5mm inner width)

What would 38mm translate into -unit.decimal- size? Stupid question maybe, but still learning the basics

hokiefyd 

He has the same rims on his, and I have the same rims on my 2015 Trek Verve -- the AT-750s. Decent rim, but a little thin for going super wide (but it does keep the tire width down).

A 38mm labeled tire would be the decimal equivalent of 1.5" (25.4mm to an inch). Your Bontrager 38mm tires may actually inflate and measure slightly less than 38mm/1.5", which is not uncommon. The Bontrager 700x35 tires on my Verve (again, same rims as you have) are about 33mm wide and only 30mm tall (from the top of the rim to the top of the tire). This is where that tire profile thing comes into play...the Bontrager H5 tires have a pretty squared/flat profile at the top, and they're wider than they are tall.

Narrower wheels tend to keep tire widths narrower than wider wheels do. This is pretty intuitive -- the rim itself holds the tire beads closer together, which keeps the tire's casing squeezed a little tighter. If the rim is wider, to a point, the beads are then further apart and the casing is allowed to widen.

travbikeman

I had remembered reading this conversation several times on the DS thread. So I checked to see if the pictures are still there, they are: If you are interested go to the Official Trek DS Owners Thread and go to pages 35, 36 and 41 to see images of the DS with mountain bike tires.