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  1. #1
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    Tire replacement ?'s

    I have this bike: http://www.epinions.com/bike-Bicycle..._Parkway__1999

    It's time to think about replacing the tires and tubes. Currently using the original 700 x 40c tires.

    I'm about 235lbs and ride it on paved trails, somewhat rough streets and occasionally packed limestone trails. I tend to ride fast, pumping hard in higher gears and take curves at full speed.

    Any suggestions for replacement tires? Can I go to a narrower tire without changing the diameter?

    Also I'm in Ohio and although I try to avoid it, we get rained on from time to time. Puddles on the trails and streets and temperatures that are all over the place.

    Thanks..KW
    Last edited by carguy07; 02-07-09 at 04:17 PM.

  2. #2
    Senior Member DieselDan's Avatar
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    Don't go any narrower then 28mm wide.
    Bikes use brakes to stop.

    If your bike has breaks, don't ride it.

  3. #3
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    Is the diameter the same for a 700 x 40c and a 700 x 28c?

  4. #4
    WillFam-Clovis,CA
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    Quote Originally Posted by carguy07 View Post
    Is the diameter the same for a 700 x 40c and a 700 x 28c?
    The diameter is close to the same (700c), the width is of course very different (40 vs 28). If you look in cycle computer manuals, it shows a "slight" increase in diameter as the width increases.

    Brian

  5. #5
    Senior Member DieselDan's Avatar
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    Quote Originally Posted by carguy07 View Post
    Is the diameter the same for a 700 x 40c and a 700 x 28c?
    The inner diameter of both tires must be the same, 622 mm. The 700 mm designation is an approximate measurement at the tread. Should I go over ERTO sizing, or refer you to www.sheldonbrown.com ?
    Bikes use brakes to stop.

    If your bike has breaks, don't ride it.

  6. #6
    Senior Member Wavy's Avatar
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    Does the shop you bought it from, or your LBS carry 40mm tires and tubes? Go there first.

    This week Uncle Al discusses tire selection for road bikes, which your isn't; but in the interest of education... http://roadbikerider.com/
    Width Matters Too

    Where is it written that: "All roadies shall ride 700x23 tires"?

    We're on frames of carbon, steel, aluminum, titanium and mixes of these materials, which tells me that we all beg to differ. Then why is it that 23-mm-wide tires have become the unchallenged norm? We should choose tire width based on body weight and several other factors, not just by going with the industry flow.

    It's rare to find a new road bike fitted with anything but 23s. We ride this size by default and some of us suffer the consequences. If you buy into my advice to lower tire inflation to 85-100 psi, then you probably realize that you, at 165 lbs. (75 kg), and your 215-lb. (98-kg) pal can't ride the same size tires at the same pressures. Big Dude will pinch-flat at 90 psi when the going gets rough.

    So while you're flying with a smile over cracks and crevasses, Big Dude is fixing another snake bite and sticking pins in his Uncle Al doll. I think I'm feeling a jab in the ribs right now.

    The solution is simple: Increase tire width if you're heavier so you can enjoy the comfort and handling benefits of lower pressure.

    Some tire manufacturers understand the need. They offer their premium models in sizes from 700x20 to 28. Continental, for example, makes the venerable Grand Prix in 20, 22, 23, 24, 25 and 28 mm. Michelin's Pro 2 Race comes in 20, 23 and 25 mm. But too many companies make their top-shelf tires no wider than 23.

    The belief is that wider tires increase rolling resistance. It simply isn't true. Testing shows that fatter rubber rules when it comes to lowering drag. One recent example was published by Bicycle Quarterly magazine in "The Performance of Tires" (Vol. 5, No. 1, Autumn 2006).

    Let me suggest an approach to greater riding enjoyment and less side-of-the-road voodoo:

    • If you weigh 170 lbs. (78 kg) or less, use 23-mm-wide tires. (I can't recommend 20 mm, but if you're really light and want to use them, knock yourself out.)
    • 170-180 lbs. (82 kg), use 24 (Conti makes 'em) or 25 mm.
    • 180-210 lbs. (96 kg), use 25 or go to 28 mm if you ride on crappy roads.
    • Over 210 lbs., use 28-mm tires. Your big power will cancel the bit of extra weight.

    If you follow these size guidelines, you can safely inflate only to 85-90 psi front and 95-100 psi rear and enjoy a quicker and more comfortable ride.

    Note 1: Not all modern frames have clearance at the fork crown and/or behind the bottom bracket shell for 28-mm tires. Take your bike to the LBS and kindly ask them to slip in wheels with those size tires. If they fit, buy your tires there. It's only right.

    Note 2: Yes, there are tires wider than 28 mm, but then you're getting into weight issues as well as clearance issues. Still, widths of 30, 32, or 35 mm may be great for commuting and general bombing around on unpaved roads and goat tracks.

    Note 3: Stop sticking pins in your Uncle Al replica voodoo doll. I didn't make this stuff up. Well, not all of it. Smooth riding!
    “Next time you're in your car, at 80 Kilometers per hour, strip down to your underwear and jump out. That's what it's like to crash in a professional bike race.” - Jonathan Vaughters

  7. #7
    Senior Member jaxgtr's Avatar
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    Really going to based on the width of the rim. More than likely about 22mm to 24mm to hold a 700-40 tire. I would stay with a 32 or higher, but, a 28 might fit. Take the wheel by the LBS if unsure, but measure between the inside of the rim wall or might say on the rim. 622-22 or something like that.
    Brian | 2013 Cannondale SuperSix 5 | 2014 Trek CrossRip Comp | 2003 Trek 7300
    Quote Originally Posted by AEO View Post
    you should learn to embrace change, and mock it's failings every step of the way.

  8. #8
    DRF aka Thrifty Bill wrk101's Avatar
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    I like having a couple of different width tires, and make a swap to change the personality, depending on the road/surface condition. For instance, I ride anything from narrow slicks (for street) to Kenda Kross (for crush and run/gravel). Change the tires yourself, and it only take a couple of minutes).

  9. #9
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    Thanks for the advice. I'm narrowing down my tire choices and leaning toward these: http://www.amazon.com/exec/obidos/tg...outThisProduct
    I'm trying to figure out if I should get 32mm or 35mm. I can't afford to get both and try them. I would assume that the wider the tire the smoother the ride, but other than that what would I feel between the 2? Does one tire corner better than the other? Steer quicker? I have some runs that go over 40mph down hill and have this fear of a "skinny" tire not holding the road at the bottom of the hill flying around a curve. Any advice would be appreciated. Thanks!

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