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Thread: Rear tyre / sprocket change question

  1. #1
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    Default Rear tyre / sprocket change question

    I want to install an IRC TR-011 Tourist on my rear wheel on the Serow 225, but it's a big tyre and people usually change the front and rear sprocket and chain to accomodate it. However, I don't want to spend that sort of money when the chain and sprockets seem to be in pretty decent condition. Can anyone tell me (I know this is a long shot) if I can get away with changing only the front sprocket? I'm wondering if dropping a couple of teeth would give me the tyre/swingarm clearance I would need.

    Thanks in advance


    Yamaha Vino 50cc (Sold), Honda Transalp 400V (Sold), Honda CB400 Super Bol D'or (Sold), Yamaha Serow XT225WE (Sold), 2005 Beta Rev 3 (Current) 2015 Yamaha Serow XT250 (Current)

  2. #2
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    Default Rear tyre / sprocket change question

    How far back in the adjuster blocks is the rear axle currently?

  3. #3
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    2 teeth on the frnt will equal out to about 6 on the back which will make quite a big change to your gearing.
    By clearance, do you mean in the swingarm or are you talking about large tire / gear ratio

    http://www.sprocketcalculator.com/

    http://www.gearingcommander.com/

  4. #4
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    Quote Originally Posted by Markw View Post
    How far back in the adjuster blocks is the rear axle currently?
    The adjuster blocks have several notches left to go back Mark, but the chain is the main issue here. I'm wondering if I can change out just the front sprocket and keep the chain and rear sprocket. The chain isn't stretched and, at the correct tension, with a 13T front sprocket instead of 15T, I'm wondering if I would get enough clearance between the tyre and the end of the swingarm.

    wrk2ride, I would welcome the change to the gearing. A little more torque is part of the plan.


    Yamaha Vino 50cc (Sold), Honda Transalp 400V (Sold), Honda CB400 Super Bol D'or (Sold), Yamaha Serow XT225WE (Sold), 2005 Beta Rev 3 (Current) 2015 Yamaha Serow XT250 (Current)

  5. #5
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    Default Rear tyre / sprocket change question

    Yes, why not try a tooth smaller front sprocket. It will move the rear wheel back slightly back and perform better offroad.

  6. #6
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    Quote Originally Posted by Markw View Post
    Yes, why not try a tooth smaller front sprocket. It will move the rear wheel back slightly back and perform better offroad.
    And no issues with the chain length? It's currently at 120 link.


    Yamaha Vino 50cc (Sold), Honda Transalp 400V (Sold), Honda CB400 Super Bol D'or (Sold), Yamaha Serow XT225WE (Sold), 2005 Beta Rev 3 (Current) 2015 Yamaha Serow XT250 (Current)

  7. #7
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    Are you asking what the difference in radius between a 13T and 15T sprocket is?

    It must only be a few mm. How much bigger is the radius of the tyre?
    If the radius difference on the sprocket is more than the tyre radius difference, you're ok I guess.

  8. #8
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    Default Rear tyre / sprocket change question

    Dualta- you mentioned you have several notches left in the blocks to move the axle back. I'm assuming the axle is already rear of the center point of the blocks. If this is the case you won't be able to use a 122 link chain as it probably be too long. If you want to lower the gearing anyway (for better offroad performance) get a tooth smaller front sprocket (they're relatively cheap), which will allow you to move the axle back slightly. Then fit the Tourist tire and see how the clearance is. If you need to move the axle back even further you could then get a smaller rear sprocket...

  9. #9
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    I might be 100% off here but what about buying an extra link for the chain fitting it, then moving the rear axle adjuster all the back would that be enough? One link might be cheaper than a whole new chain. Just an idea from a biking noob.

  10. #10
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    Default Rear tyre / sprocket change question

    Quote Originally Posted by Adeonhisown View Post
    I might be 100% off here but what about buying an extra link for the chain fitting it, then moving the rear axle adjuster all the back would that be enough? One link might be cheaper than a whole new chain. Just an idea from a biking noob.
    Single chain links are quite unusual and not recommended because they are weaker than regular links. Typically you would add links in twos...

  11. #11
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    Default Rear tyre / sprocket change question

    Quote Originally Posted by Markw View Post
    Single chain links are quite unusual and not recommended because they are weaker than regular links. Typically you would add links in twos...
    I see. And the coment abovre says 2 links would be too long. Sorry for the noob comment.
    ;)

  12. #12
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    Default Rear tyre / sprocket change question

    Quote Originally Posted by Adeonhisown View Post
    I see. And the coment abovre says 2 links would be too long. Sorry for the noob comment.
    ;)
    That's something Dualta will need to figure out. Without knowing exactly how many more mm the axle can go back in the blocks there's no way of knowing whether two links could be added...

  13. #13
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    Quote Originally Posted by Markw View Post
    That's something Dualta will need to figure out. Without knowing exactly how many more mm the axle can go back in the blocks there's no way of knowing whether two links could be added...
    I'll go with the front sprocket and tyre at first, then, if necessary, I can get a chain and rear sprocket. Thanks for the advice Mark.


    Yamaha Vino 50cc (Sold), Honda Transalp 400V (Sold), Honda CB400 Super Bol D'or (Sold), Yamaha Serow XT225WE (Sold), 2005 Beta Rev 3 (Current) 2015 Yamaha Serow XT250 (Current)

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