martianone

what is the widest tire that fits a Trek 520 without fenders ?
i know 37-622 will work,
has anyone run 42-622 or wider ?
Thanks,
martianone

Michel Gagnon

I have fenders on mine, and mine dates back from year 2000, but here is my take on this:

- Front wheel: 37-622 is a tight fit. A slick tire will fit, but for a knobby, it depends how high the tire actually is (some 37-622 are wider and especially higher than others). But with about 2-3 mm clearance below the fork, the thing is likely to jam quickly in the mud. And BTW, 37-622 doesn't fit under a fender.

– Rear wheel: again it depends on the tires, but 42-622 fits under a fender. In my case, the tightest clearance I have is under the rear rack. Even there a 42-622 should fit, but maybe with only a few millimetres of space.

martianone

MG:
merci beaucoup.

professorkev

So why is it people would go wide on this bike? the 520 is typically for touring , and if you go wider don't you lose speed and energy trying to get going on the bike? I can't picture the width your talking about, still trying to figure out some things.

gowfermike

I have the 2008 Trek 520. It has 700X32 tires. The only reason for a wider tire I know of is for a softer ride. When riding all day comfort is as important as speed.

martianone

Dear PK:
why wider tires ?
because i like them.
i live in a rural area with rough gravel/dirt/sand/washboard roads, the wider tire is more comfortable and secure in these conditions. Schwalbe marathons are a good balance of traction and rolling easy, 32 mm marathons can run at 95 psi, while 37 and 42 mm marathons run at 85; not much resistance loss to the lower tire pressure. the wider marathons have a slightly shorter, but wider contact patch; a shorter contact usually has slightly lower rolling resistance. yes, my wider tires might loose a little speed, especially in stop and go traffic as they are heavier. toured thru syracuse last july, primarily along bike route 5, in the city, probably 32 mm tires would have been fine. on the trail east of the city were a number of mucky sections, my wider tires coasted thru nicely, saw plenty of evidence in which narrower tires bogged down, passed a couple bikes with their wheels sunk below the rims in mud
and the cyclist struggling to keep going.
wide or narrow ? a preference based upon conditions and experience.

brianmcg123

Professor,

Yes the 520 is for touring, not racing.

Speed is of little importance, but since you were asking, you will be able to go a lot faster carrying 50lbs of stuff using 35mm tires instead of 23mm tires when you factor in all of the flats you will be getting with the 23s.

Plus you are only talking about at most a 1-2 mph difference, and that is only if you are on completely smooth roads. Most people don't ride on completely smooth roads.

Michel Gagnon

My preferred touring setup is with 28-30 mm wide tires in front and 30-32 mm wide tires behind. Note that I'm talking about real, measured width... and that I have about 29,5 mm wide with my current 700x32 Continental Top Touring 2000. The above setup is fine for commuting and even for touring on good roads, but when I was touring with my daughter on a trailercycle, I much preferred having a 700x37 on the rear wheel. Why? Comfort mostly, and pinch flat avoidance, as I had about 150-200 lb on the rear wheel.

Now having a bike that accepts fatter tires has a few advantages. For instance, the LHT runs 700x40-42 (from memory) with fenders on both wheels. This allows one:
- to use wider tires for comfortable and safer rides on gravel roads;
- to install knobbies (typically available only in sizes wider than 700x35) for off-road touring;
- to install knobbies or studded tires for winter rides or touring.

All this broadens the uses of the bikes. One might suggest that off-road touring is best done on a mountain bike, but what if one rides cross country and the ride includes the Top of the World highway (through Dawson City) or the Trans-Labrador highway? Isn't it nice to have a bike suitable for those stretches and the paved ones alike?

And if/when one tours on asphalt, it's quite possible to install narrower tires. The rims used on the LHT are perfectly suitable for 700x28-30 tires. Not exactly racing tires, but much better for commuting, touring or randonneuring.

Jack Kessler

One reason for putting wider tires on a touring bike is that one wants to ride on dirt roads without buying a whole new bicycle.

UKFan4Sure

Comfort by being able to run lower pressures. Smoooooth, baby!

cb400bill

This thread is 13 years old.

hfbill

I've tried tires ranging from 42 to 32mm on my 520. I settled on 38mm because of the poor condition of so many of the roads I ride on here in upstate NY. If you ride more on level, smoother surfaces, 35mm would be fine, but I found I was getting too many snakebite flats with them. The 38s don't seem to have that problem for me. The 42mm tires were overkill as they just felt heavy and had too much rolling resistance. However If you really need a tire that wide for off road etc, you probably should be looking at a different bike. Just my $.02

KC8QVO

Correct. It makes me wonder why we are replying to comments from 13 years ago as if there is advice to offer back to that time period?

On the plus side - it shows people are searching and looking for information.

Jack - I share the same sentiments. I rode about 3500 miles on the Illinois & Michigan Canal Trail in IL over about 3 years (mostly gravel trail). At the time I went from the 38mm stock tires to 42mm tires. I wish I could have gone to 50 but no way to make them fit (700c disk trucker, not a trek 520 but the same concept holds true). My disk trucker is currently my main bike, and certainly the heavy duty hauler. However, I want to add an ECR (Surly also) to the stable so I can get up to a 3"+ wide tire. With that frame set and a couple of wheel sets it would be possible to span a lot of tire width options (disk brakes so no worry on rim caliper/pad spacing).