Hi all, I'm having trouble making up my mind about tire size.

I've fixed up my old Giant Option hybrid for commuting and have so far been very pleased with the comfort/ease of use. However, I think I'd like to switch out the tires, which are currently 700x38, in order to increase speed a little. I like the comfort and stability of the wider tires (as compared to th 23s on my road bike), however. I'm thinking of dropping down to 700x35 or 700x32.

Here are some questions I have:

Is it even worth it to think about switching out 38s for 35s?
Can 32s handle the occasional side-jaunt down a short patch of dirt road?
How do 32s handle gravel?

Any input you can offer will be greatly appreciated.

Cheers.

Changing tire size only really has an effect if you change it by a large amount,say by going from 38's to 28's. Tread pattern,air pressure,and tire weight will have more of an effect on handling than a couple mm's of width.

What tires are you running now?

Keep in mind, that the brand/model of tire has as much to do with rolling resistance as width. For example, you might not see a difference between a slow 32 and a fast 38.

I've been all over the map with tire sizes on my various bikes. The fixed-gear has 23's, another fixed-gear has 25's, and my cross bike(s) have been between 28's and 35's. I recently retired the 28 Specialized Nimbus tires, which I liked, and installed some Schwalbe Marathon Supreme's in 35c. I've put maybe 500 miles on them now and am still on the fence as to which one works better for me.

The 28's felt faster, but I don't think they really were. The 35's ride completely different. With them, I don't have to worry about road seams or debris at all, I just ride right over it - plus the overall grip is outstanding.

My next set of tires for this bike will likely be the Marathon Supreme in a 30c. This size didn't exist when I made my initial purchase.

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As far as the gravel question... I'd say that depends on the size of the gravel, and your overall comfort/skill level on the bike. I wouldn't think twice about heading down a gravel path with the 28's I had (as long as they weren't huge rocks). Anything larger than that should be fine.

I ride Continental Top Touring 2000 700x37 tires on my commuter. I actually think they roll pretty fast when I run them at their maximum pressure (75psi). I also run them at 50psi or so when I want more comfort on really chunky stuff.

Sure you can ride the occasional trail or dirt road on skinnier tires, but the best thing about the wider tires like the 700x37 or 38 is the wide range of pressures you can run. The Panaracer Pasela 700x37 takes up to 90psi, but you can also run it at 40psi or so without fear of a pinch flat. Then again if you ride on roads 95% of the time, you don't need such a wide tire.

Sean

I have a set of marathon plus in 700x28 and I can say they feel very different from P2Rs and other tyres. I don't feel that fast on them, but they feel plush, have good rolling resistance and certainly lives up to it's popularity.

From my experience, going over gravel in anything less than 28 is no problem as long as you don't go too fast or too slow, even on slicks.

Unless you're changing to a lighter, more supple tire. I wouldn't think so.

I do it all the time on 700x32c Vittoria Randonneur Pros that actually measure 29mm when mounted on my Mavic Open Pros.

If they're true to size, they're OK for most gravel if it's not too coarse or deep.



Changes in tire size will make noticeable changes in handling. I swapped the stock, never ridden, 28c tires for some 37c's on my brand new Jamis Aurora tourer/commuter for the winter. I had to install KoolStop Thinlines to fit them between the brakes. With such big tires, the bike had a tendency towards hyperstability. It just doesn't respond quick enough to ride easily with no hands. However, if I do any loaded touring this year that's the sort of handling I want so I'll keep them around and may put them back on for next winter.

This year I put the original tires back on while screwing around last month. With the bottom bracket lowered by almost a centimeter, the bike handled much quicker although I didn't try riding with no hands through the foothills surrounding my house. The same thing happens when I put 700x25c Michelin Krylion Carbons on the Soma Double Cross cyclocross/commuter. I then tried the 700x32c Randonneur Pros that were pulled off when cross season started. I liked this last set of tires best even though they probably weren't the fastest.

For this reason, I'd hesitate to jump from 38c all the way down to 28c. Every geometry will have a corresponding tire size that will handle closest to your liking. Maybe go for some faster 35's or 32's if you're fairly certain the bike still will handle well. I think I'll be trying some 700x30c Marathon Racers, which supposely measure about the same as the 32c Randonneur Pros, on the Soma for the summer.

I put 32s on my Cypress and they work really well. However, my route has 8 miles of really rough gravel. Without that I might be better off with 28s. I'm sticking with 32s.

Thanks for your input, everyone.

I don't want to trade in the "all-terrain" and comfort part of the bike, but it sounds like I could get away with the right 32s. I'll shop around and see what I can come up with.

I just rode some singletrack on 32 Panaracer Urban Maxes this morning. They weren't ideal, but worked well enough!

32 is my all around tire size, but I'll go back to 25s when I'm sure it won't snow again for the year.

i have changed from maxxis detonator 26x1.5 to panaracer tserv 26x1,25 with great satisfaction.

they actually feel more like a 28 than a 32 and i have gained a few km/h with this set... i think... actually... well it seems at least...

... ok, more than anything it's all in your mind... if you think they'll make you go faster, you gonna go faster...

ride on