1. The most important thing about buying a new bike is to make sure it fits. The only way you'll know if the bike is right for you is to size up the bike and make sure that the bike's geometry matches your body's geometry. Ask questions and do some research.
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2. If possible, try to find a shop that will let you demo the bike on real dirt. Five minutes in a parking lot won't cut it. You wouldn't buy a car without a real world test drive, and a bike should be no different.
3. Don't belive the hype. Just because your favorite rider or best friend rides a certain bike, that doesn't mean that's the best one for you. Have an open mind and be realistic about your needs and ability.
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  1. #1
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    Newb question...

    This might be a very stupid question but...

    I just got a Trek 4300 from Craigslist. Everything about it is great and I got a pretty decent deal on it.

    However, I just realized that it only has 7 sprockets in the back. Being a 24 speed, I thought it was supposed to have 8 in the back. Also, whenever I go into gear 2-1, the chain rubs the front derailer, and when I go into 2-8 the chain falls off. Did I get scammed? If so, how much would it cost to add the missing sprocket?

  2. #2
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    It's possible that the seller swapped out the rear wheel and sprocket assembly from a different (21 spd) bike for the original from the 4300.

    Personally, I'd look up the specs on the bike at: BikePedia

    And make sure that it actually has all of the correct components that specific year's 4300 is supposed to have and that the bike hasn't been downgraded in other ways as well.
    ~ 2011 GT Avalanche 2.0
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  3. #3
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    Get it tuned up or get reading about how to adjust derailleurs. Sounds like you need some adjustments and it is possible the rear derailleur may have been knocked out of alignment.
    Don't you hate it when a sentence doesn't end the way you think it octopus?

  4. #4
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    Quote Originally Posted by zebrahum View Post
    Get it tuned up or get reading about how to adjust derailleurs. Sounds like you need some adjustments and it is possible the rear derailleur may have been knocked out of alignment.
    If the OP is correct in his counting and the bike in question only has seven rear sprockets then re-aligning the derailleur isn't going to compensate for a missing gear on a bike which is supposed to have eight sprockets on the rear hub.
    ~ 2011 GT Avalanche 2.0
    ~ 1993 Diamondback Topanga
    ~ 2012 Diamondback Overdrive Expert

  5. #5
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    Quote Originally Posted by Luclin999 View Post
    If the OP is correct in his counting and the bike in question only has seven rear sprockets then re-aligning the derailleur isn't going to compensate for a missing gear on a bike which is supposed to have eight sprockets on the rear hub.
    7 speed shifters and 8 speed shifters use the same cog to cog spacing, you just have to adjust the high and low limits properly. Yeah the OP might have some issues, but it can be made to work as it sits.
    Don't you hate it when a sentence doesn't end the way you think it octopus?

  6. #6
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    Quote Originally Posted by zebrahum View Post
    7 speed shifters and 8 speed shifters use the same cog to cog spacing, you just have to adjust the high and low limits properly. Yeah the OP might have some issues, but it can be made to work as it sits.
    Which doesn't address the OP's concerns of having been "scammed" in that his "24 spd" bike is only capable of "21 spds" now.

    He might be able "to make it work" but he's not getting 24 speeds from a seven sprocket hub no matter how he adjusts it.

    Bottom line, the hub is missing a sprocket either due to it having been removed or from having had the rear wheel assembly swapped for one from another bike. Either way, IMO the fact that the seller didn't disclose this is shady enough to warrant going over the bike completely to make sure that no other components were swapped out or downgraded as well.
    ~ 2011 GT Avalanche 2.0
    ~ 1993 Diamondback Topanga
    ~ 2012 Diamondback Overdrive Expert

  7. #7
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    Shimano HG 70 for $15 bucks

    I cant say for certain the OP was scammed without seeing the ad. However there is an easy fix for 15 bucks.

  8. #8
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    Thanks for the help guys. I went over all the parts and everything else is stock EXCEPT the back tire was replaced with an Innova 26x1.95 and the sprocket is a Mega Drive. I'm not too irate, even after replacing the cassette the bike still only ran me $300.

    The guy did throw in a free Cateye Enduro 2 odometer and Trek bottle holder too though.

  9. #9
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    Cog to Cog spacing is the same however the cassette width is different. It looks like the 4300 has always had a 8 spd cassette. So if it only has 7 cogs on the rear it seems likely that the wheel has been replaced and may even be just a freewheel not a cassette at all.

  10. #10
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    Quote Originally Posted by Matfam View Post
    Cog to Cog spacing is the same however the cassette width is different. It looks like the 4300 has always had a 8 spd cassette. So if it only has 7 cogs on the rear it seems likely that the wheel has been replaced and may even be just a freewheel not a cassette at all.
    If it was replaced, it was replaced with a Trek bike wheel, because the rim is still the same as my front one; a Matrix 550. Also, the Mega Drive back sprockets are the exact same as the ones on my little brother's Trek 820.

    Ultimately I don't really feel like buying another cassette if I can simply adjust my derailer to go from speeds 2-8 like someone mentioned. I really never use the 1-1/2-1/3-1 gears anyways.

  11. #11
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    Quote Originally Posted by mk.utlra View Post
    Thanks for the help guys. I went over all the parts and everything else is stock EXCEPT the back tire was replaced with an Innova 26x1.95 and the sprocket is a Mega Drive. I'm not too irate, even after replacing the cassette the bike still only ran me $300.

    The guy did throw in a free Cateye Enduro 2 odometer and Trek bottle holder too though.
    So long as the rest of the parts weren't downgraded and you are still happy with the deal then have fun and enjoy the bike.

    ~ 2011 GT Avalanche 2.0
    ~ 1993 Diamondback Topanga
    ~ 2012 Diamondback Overdrive Expert

  12. #12
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    Quote Originally Posted by Luclin999 View Post
    Which doesn't address the OP's concerns of having been "scammed" in that his "24 spd" bike is only capable of "21 spds" now.
    I know, there isn't much I can do in regards to the seller providing a product that differs from what was expected. Just trying to provide an interim solution.
    Don't you hate it when a sentence doesn't end the way you think it octopus?

  13. #13
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    yeah i wouldn't think that you were scammed, as much as you didn't know what to look for. bikes break, parts get replaced, sometimes an upgrade, sometimes not so much. you can fix it pretty easily/cheaply, and if the rest of the bike's ok, ride it. definitely read up on tuning, and make sure the gears are all tuned correctly and everything works as it should. if not, go down the list and fix it one by one. bikes require maintenance, parts wear out, etc.

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