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  1. #1
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    2005 Trek Fuel 70 Drivetrain Upgrade

    I wanted to find out if anyone had any experience upgrading the drivetrain on their Fuel 70. The bike came stock with an 8spd drivetrain and a Shimano Alivio derailleur on the front. I would like to upgrade to an XT on the front and possibly upgrade the shifters as well depending on cost. I'd like some advice on what model of the XT derailleur and shifters I need to avoid any conflicts. It appears that most of the new derailleurs are built for 9spd drivetrains and I don't want to have to upgrade the entire drivetrain at this point in time. Also if I just swap out the front derailleur will the stock (Alivio) shifters still work?

    TIA

  2. #2
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    I don't believe you would have a conflict swapping out the front derailleur and still using the existing shifter. The Alivio is a POS, but before you heave it into the scrap pile, you may want to check to see if it is adjusted properly. Mine came from the factory with too much tension on the cable, to the point that the H Limit screw was useless for making adjustments. The only problem is that to adjust the cable tension, you have to remove the rear wheel as there is not enough clearance to loosen up the cable tension nut with any of the tools I own, so to make a proper adjustment is a real pain.

    As far as the rear, I'd leave it at 8 speeds (I mean, do you really need one more speed?). I would however, replace the SRAM cassette with a Shimano 8 speed cassette. The gaps between the three largest cogs are very big on the SRAM (more than 4 teeth) and this is made up by smaller gaps on the smaller cogs, which you don't use a whole lot of. The Shimano cassette has a much more even spread of gears across the whole 11-32 spectrum.

    I

  3. #3
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    Follow-Up Question

    Saxman - Thank you for the insight, I definately want to stay with an 8 speed cassette and I always thought the SRAM cassette looked a little "funny". Do you know if the hyperglide model line of cassettes would have any conflicts with the stock components on the Fuel 70? In terms of the front derailleur, it seems like their are a multitude of different models of the XT. I measured the bottom tube to determine what size clamp I needed and I believe I need to get a 34.9mm - do you know if this is correct? Currently the bike has a top swing derailleur. If you have any advice on the the best specific model to get I would appreciate any advice their. Thank You!

  4. #4
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    Possibly some helpful tips in this thread - http://forums.mtbr.com/trek/03-fuel-notes-tips-266.html#post1630
    Quote Originally Posted by rockytd
    Saxman - Thank you for the insight, I definately want to stay with an 8 speed cassette and I always thought the SRAM cassette looked a little "funny". Do you know if the hyperglide model line of cassettes would have any conflicts with the stock components on the Fuel 70? In terms of the front derailleur, it seems like their are a multitude of different models of the XT. I measured the bottom tube to determine what size clamp I needed and I believe I need to get a 34.9mm - do you know if this is correct? Currently the bike has a top swing derailleur. If you have any advice on the the best specific model to get I would appreciate any advice their. Thank You!

  5. #5
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    Quote Originally Posted by rockytd
    Saxman - Thank you for the insight, I definately want to stay with an 8 speed cassette and I always thought the SRAM cassette looked a little "funny". Do you know if the hyperglide model line of cassettes would have any conflicts with the stock components on the Fuel 70? In terms of the front derailleur, it seems like their are a multitude of different models of the XT. I measured the bottom tube to determine what size clamp I needed and I believe I need to get a 34.9mm - do you know if this is correct? Currently the bike has a top swing derailleur. If you have any advice on the the best specific model to get I would appreciate any advice their. Thank You!
    I don't think you should have a problem with the cassettes. While the gear ratios may differ the lateral spacing stays the same. I have an old Klein Pulse Comp that has two sets of wheels. One set has the SRAM 8-speed cassette, the other set has a Shimano 8-speed cassette. I do not have to adjust the derailleur at all when I switch between wheels. I would probably stick to a top swing derailleur as similar to the existing one to keep the adjustment issues to a minimum. Mind you, I haven't done these mods myself to my Fuel 70, but I've definitely considered them and I know the bike pretty well mechanically.

  6. #6
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    Quote Originally Posted by SaxMan
    I would probably stick to a top swing derailleur as similar to the existing one to keep the adjustment issues to a minimum.
    I just got back in from trying to adjust my front derailleur. Man, what a pain in the butt that was! No matter what I did, I just couldn't get it perfect, and each time to make an adjustment, you have to take the rear wheel off. I got it pretty close, though. The only gear that grinds on derailleur is the big chainring / smallest cog combination. Every other combination works.

    Considering the top-swing Shimano XTs are only $33 at Nashbar, I'm seriously considering giving the Alivio the heavio into the trash bin. If you can't swing the $33, the Deore LX's are only $19, which is better than the Alivio as well. Either way, it seems like small change to replace a seriously under-spec'd part on the Fuel 70.

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    Quote Originally Posted by SaxMan
    I just got back in from trying to adjust my front derailleur. Man, what a pain in the butt that was! No matter what I did, I just couldn't get it perfect, and each time to make an adjustment, you have to take the rear wheel off. I got it pretty close, though. The only gear that grinds on derailleur is the big chainring / smallest cog combination. Every other combination works.

    Considering the top-swing Shimano XTs are only $33 at Nashbar, I'm seriously considering giving the Alivio the heavio into the trash bin. If you can't swing the $33, the Deore LX's are only $19, which is better than the Alivio as well. Either way, it seems like small change to replace a seriously under-spec'd part on the Fuel 70.
    I'm running an LX on my 90, works fantastic - don't quite grasp the "having to remove the wheel to adjust cable" issue......I have no problem loosening and tightening cable length adjustment bolt with the rear wheel in place. Perhaps you need a better selection of tools ?? Perhaps a pic would help me understand better, it you have a digicam. XT would be great...LX works just fine. Can't go wrong with either...

  8. #8
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    Quote Originally Posted by Fuelish
    I'm running an LX on my 90, works fantastic - don't quite grasp the "having to remove the wheel to adjust cable" issue......I have no problem loosening and tightening cable length adjustment bolt with the rear wheel in place. Perhaps you need a better selection of tools ?? Perhaps a pic would help me understand better, it you have a digicam. XT would be great...LX works just fine. Can't go wrong with either...
    It's the way the Alivio is set up, possibly in combination with the 15.5" frame. The bolt is askew enough that you can't get a hex tool (or a Craftsman hex socket) in there without bumping the tire.. It is just weird...I've never had that problem with any other bike. When I rode today, I was happy with the way the front derailleur works. I'll probably live with it for the rest of the season, but during my winter overhaul, I'm definitely going to upgrade to XTs in the front & rear and replace the SRAM cassette with a Shimano one. I'm also considering ditching the Axel Comp for another fork (the Manitou Skareb is the one that most prominently comes to mind) and getting some lighter wheels.

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