I've owned a Trek 3500 bike (shown below) for 2.5 years now and I like it very much.

Trek 3500

My bike has the same specs as under the link. It has the XL frame size and 26" wheels with Bontrager AT-550 36-hole rims. I've started looking into changing the Bontrager tires to slick road tires though as I've begun to ride more for exercise and not just recreational. 95% of my riding is on paved roads/trails. The problem is I have no idea what tires can work on my bike for me. I'm considering the high pressure Kenda K193 tires. Can anyone advise? I'm looking for the best tires I can get for around $35 each. Is it even possible to replace the 2" tires with 1.5" without needing to buy new rims and everything?

I'm riding ~35 miles on weekends and let's just say I'm right now a heavier guy (~300 lbs). I've ridden on the same tires almost daily since I first bought it, so I feel it's about time to change them anyway.

  • No problems doing what you're doing, seems sensible if you're riding the bike on asphalt all the time. Those Kenda tyres don't look particularly slick, though. I used to ride 26x1.25" Conti Gatorskins, might be worth checking them out
    – PeteH
    Commented Jul 8, 2014 at 20:39
  • First off, brand doesn't matter that much, until you get into puncture-resistant tires. Bontrager makes some perfectly decent road tires. It all depends on what you can find in the local store or online, since no one carries every possible model. Commented Jul 8, 2014 at 22:49
  • Re width, the tire width should be at least a little bit wider (maybe 1.2x) than the rim width, measured on the outside. Unfortunately, I cannot find specs for the Bontrager AT-550 online, so I don't know what the rim width is. Commented Jul 8, 2014 at 22:55
  • 25 dollars is pretty low for a decent tire in most markets. I'd probably look at least 10 dollars a tire higher if possible.
    – Batman
    Commented Jul 9, 2014 at 3:16
  • I'm not steadfast on the $25 mark. I'd be willing to go up to about $40 if I had to. Since I'm a beginner, I just don't want to be spending $100 per tire yet. Commented Jul 9, 2014 at 14:36

2 Answers 2


Those tires should work just fine. Any of the MTB slick tires listed on that site would work well with your bike and current rims.

You can get too small a tire on too wide a rim, but it takes a much bigger jump than from 2" to 1.5 or so. There is a very conservative sizing guide on Sheldon Brown's bike pages.

Given your weight, I would try and find the largest size slick you can. Something like the Schwable Big Apple in a 2.0" format1 supports a maxim load of 275 lbs per wheel, but it's outside your price range, or from that page the Kenda K1029 Kwick Roller Sport 26 Inch Tire (50-559).

The last number is key to understanding tire sizes. You have 559mm rims, so just about any 559 tire will work with your bike. The 50 is the nominal width of the inflated tire in mm's. ( i.e. 50mm ~ 2 inches ).

1 Schwalbe has a sizing guide too.


There is not an issue going down in size. I see nothing wrong with the tires you have selected. At 300 lbs maybe step up to a 1.75. Just going to a street type tire from the knobby is going to reduce rolling resistance and give you a nicer street ride. When you go down in size that far you should also get new tubes. Once the tubes have been stretched the problem is you may get a fold putting them in a smaller tire.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.