Rear wheel: 17" vs. 18"

Discussion in 'Thumpers' started by zakidos, Dec 30, 2010.

  1. zakidos

    zakidos Adventurer

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    Hi folks!

    I'm planning to get a new rear wheel on my XT 660 Z Ténéré. The stock one (17 inch) has a bad bump in it and it's already quite rusty. So I'm gonna contact Thorsten from OTR and see what the costs are for a new Excel rim and Talon hub.
    But I'm still not sure if I should get the 18" or stick to the 17" one. I'm not a rally driver, just a on- and offroad traveller. Any ideas?

    Cheers, Mike
    #1
  2. rivercreep

    rivercreep Banned

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    Not a bad idea as it can open up new oppertunities for tire selection for off road use.
    If I had the cash and a reason (like your wheels bump) I'd do the same thing on my DR.:1drink
    #2
  3. BikePilot

    BikePilot Long timer

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    Definitely a lot more off road tires available in 18". Maybe more street tires in 17" (I haven't checked). I would be inclined to go with an 18 I think.
    #3
  4. DaBit

    DaBit Been here awhile

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    Many decent 50/50 tyres available in 18" rear, much better offroad tyre selection available.

    Even more road-biased and 50/50 tyres available in 17" rear, but very limited offroad selection.

    I would only go 17" if you intend to use road-tyres-with-an-allroad-look like the Conti Trail Attack for example.
    #4
  5. zakidos

    zakidos Adventurer

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    I got the TKC80 and are very happy with it. So I'll never intend to use a road-only tyre. But the one concern I have, my whole bike is gonna be higher about 2cm because of the 18 inch rim. Maybe this is a killer criteria. I'm not sure yet. And of course, stupid Swiss regulations: It would be a lot harder to get the rim registered in the vehicle documentation.

    Cheers!
    #5
  6. Fubars

    Fubars What would Scoobydo?

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    Look on ebay for a DR350S (*not* E model) rear wheel. Same hub w/cush drive. You'll have to change out the brake rotor, though.
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  7. DaBit

    DaBit Been here awhile

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    With tyre mounted it's not that much. About a centimeter at the rear axle, which translates to several millimeters at the saddle.

    That would be a good reason to stick with 17".
    #7
  8. BikePilot

    BikePilot Long timer

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    You can always alter ride height to compensate for changes in tire/wheel height. I doubt there's much difference in overall height from an 18 to a 17 as the 17 will normally have taller sidwalls. Can't help with the wacky swiss regs.
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  9. abhibeckert

    abhibeckert Long timer

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    I wonder how much it will effect your gearing? Clearly it'll make all your gears taller, but I have no idea how much.

    Personally, I'd go for the 18" and work my way through the regulations. There are loads of good dirt tyres and plenty of good road tyres for 18", but not the other way around.

    Then again, the only thing that matters is whether the tyres *you* want are available in your size. I know my favourite tyres are available in both 18" and 17", because the shop accidentally gave me a 17" one (which I only learned after 3 hours of back breaking effort to get the thing on with my inadequate tools! :cry)
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  10. zakidos

    zakidos Adventurer

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    Thank you guys for all the responses. I have to wait a couple of weeks from now to get the paperwork for the new wheel sorted out. But it looks like I'm going to go with the 18 inch rim.

    Cheers
    #10
  11. Lankbrown

    Lankbrown No Pain No Gain

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    I recon go for it. You will get a better tyre selection and it is slightly better on the bumps when using the bike off road. Only thing to be aware of is the sprocket ratio will have to be changed. For example the BMW Xchallenge runs a 18 inch rear wheel with a 15/47T combination. The F650 (same rotax motor) has a 17 inch rear wheel with a 16/47T combination.

    Cheers
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  12. zakidos

    zakidos Adventurer

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    The stock Ténéré has a 15/45T combination, I changed it to 15/48T. But with the new rim I guess I go with one tooth less in the front or take or go up to 50 tooth at the rear. Let's see ;-)
    #12
  13. JensEskildsen

    JensEskildsen Long timer

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    How much room do you have in the swingarm for the 18" ?

    I often change gearing on my bike, i dont think a 18" rim woul dhave much room to spare with a knobby, making it impossible to go a couple of tooths up and down.

    Worth to think about.
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  14. plugeye

    plugeye unforgiven

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    went from 17 to 18 on the 97 dr650.
    feels & looks better to me. narrow tire WANTS to corner
    profile looks like an xr650l now, sweet
    no fitment issues with the shinko 705, 4.10x18
    #14
  15. switch

    switch Romanian Trailbiker

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    Do be careful with an 18 incher on a bike devised for 17. It's going to be a bit more unstable if highly tilted.
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  16. zakidos

    zakidos Adventurer

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  17. LukasM

    LukasM Long timer

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    There won't be a significant difference in handling from raising the rear 1/2".

    If you need the better off road tire selection 18" makes sense, otherwise a 17" is fine. It's important that you don't go too wide on the rim if you want the best strength. 2.5" width is the norm for 650 class enduros.
    #17
  18. switch

    switch Romanian Trailbiker

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    Silly headlight. I would've kept stock one. That guy probably never rides at night.

    Also, to note is the fact that he increased suspension travel back rear. This would also imply raising the back a bit. It IS possible, although only theorethically, that an 18 incher would not fit and during suspension bottoming out you'd actually be hitting the underside of the subframe.

    Removing the stock exhaust fixes that problem. He also did that.

    All in all, get the 18 and if you'll have to, replace exhausts. That should do it. You'll also have to add subframe dirt protection plastic. Easy to source.
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  19. switch

    switch Romanian Trailbiker

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    The XT660Z is not a 650 class enduro. Honda's XR or KTM's LC4 - those are 650 class enduros. The new tenere is a 200kg beast. IMO a 3" should be taken into consideration as a minimum.
    #19
  20. The Jester

    The Jester Long timer

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    A mate replaced the 17" rear rim on his XT600 with a standard off road 18", definitely no wider than 2.50. No ill effects of any kind. Not quite the same bike but I doubt if it is any lighter. Remember that the rim you will be fitting will probably be a higher quality / stronger item than the stock, built to a price, rim.
    #20