Difference in 17-17 and 21-18 tire combo.

Discussion in 'Thumpers' started by dazler, Apr 18, 2013.

  1. dazler

    dazler Been here awhile

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    FL
    Hi im new to this so bear with me.
    Im looking to buy a bike and it seem that most adventurers use the 21-18 knobbies.
    why not use the 17-17 knobbies, more area equal better traction or im missing something.
    I really dont know how much time I be spending off-road but I do have plenty of sand,dirt,rock - south texas desert here.


    I might end up buying a set of warp 9 wheels but not completely sure if to get a bike with 17 or the 21/19 and then buy the other wheel set.
    #1
  2. kubiak

    kubiak Long timer

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    the bigger diameter wheels go over rocks and holes better than smaller ones that may drop into instead of going over them. if you are doing easy trail riding the 17s are ok for that. the 17s are better for fast road use since they turn in easier and quicker than bigger wheels. tire selection is easier for bigger wheels if you are looking for offroad type and for smaller 17 inch wheels, street tires selection is better.
    #2
  3. OKlr

    OKlr 25mph gate inpector

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    a good compramise is the 19/17 combo. although you will be more limited on tire choises. I like my 21/17 but wish i had tubeless rims.
    #3
  4. Kommando

    Kommando Long timer

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    The narrower 21" front tires also slice through loose terrain better, like a pizza cutter or an iceskate. Wider 17s up front tend to wash out in loose terrain and not hold a line as well.

    A 17" knob in the rear can work fine, but the selection of aggressive and inexpensive rubber is often better for an 18" wheel, at least in the US.

    The larger rims are also often easier to change tires on. The 17" rims with tubes can be a bit more difficult if you don't have good tools and technique. I barely even need 2 levers to change some 21" tires. The rear 17 on my DR requires 3 levers, a valvestem-fishing tool, and a BeadBuddy. I haven't tried the zip-tie method yet though.
    #4
  5. markk53

    markk53 jack of all trades...

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    ++++++++++ absolutely +++++++++++

    The 19 front is fine if mainly dirt/gravel roads, but the 21 is best off road. Seems some people like having fat front tires or lower the bike a bit (1"?) with the 19. They may work a bit better in the sand/desert riding, but even then most desert bikes now run 21s. There is also the fact that some riders just like the look of the 19 front. Personally I like the look of 17s, but like the way the 21 works on rough trails and all.

    17s are mainly street oriented, but with a set of good tires like the Avon Distanzias, they can do well on dirt/gravel and more groomed trails without busting your butt.
    #5