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  1. #1
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    Suntour XC Expert conversion to SS

    I've put it off long enough, but I think it's time to retire my 93 rigid Rockhopper from the trail riding I've been enjoying on it for the past 17 yrs. The plan is to get a full suspension rig for more comfortable and faster riding, but I want to do something with the Rockhopper.

    I'd like to convert it to a SS, but on the cheap, as the current bike budget would be towards getting the most bike I can for the money I've budgeted. Here's the plan along with some questions on whether this is possible.

    - Remove the middle and inner chainring and leave the 42t outer chainring.

    - It's got an 8 speed cassette, but I'm not sure if it's one piece or invdividual cogs. Ideally, I'd like to take off all the cogs except for one and use spacers to achieve the ideal chain alignment. Does anyone know if this is possible and if there are spacers available for an old 8 spd Suntour hub?

    - shorten chain and either use a half link or chain tensioner if I can't find a "magic gear ratio".

    Am I missing anything and/or is this a tougher and more expensive conversion than I'm anticipating because of the Suntour drivetrain?

    Thanks for any help and guidance anyone can offer!

  2. #2
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    is it flat where you will be riding the SS because a 42 chainring might be a bit much unless you are a hammer. most keep the middle ring (32-34) up front and anything from a 16-20 rear cog. cogs can be had for $3-$40 ... you can just remove the cassette and use spacers from and old cassette or use 1.25" pvc to make custom spacers. and yes you may or may not need a tensioner ... kits can be had cheap that have the cog and spacers sets you will need. if you dont use a half link you will need to decide if you want the tensioner to push up or pull down on the chain
    I used to ride to Win ... Now I ride to Grin

    While my guitar gently weeps, my bike sits there mocking me

  3. #3
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    Quote Originally Posted by Zoke2
    is it flat where you will be riding the SS because a 42 chainring might be a bit much unless you are a hammer. most keep the middle ring (32-34) up front and anything from a 16-20 rear cog. cogs can be had for $3-$40 ... you can just remove the cassette and use spacers from and old cassette or use 1.25" pvc to make custom spacers. and yes you may or may not need a tensioner ... kits can be had cheap that have the cog and spacers sets you will need. if you dont use a half link you will need to decide if you want the tensioner to push up or pull down on the chain
    Thanks for the input. I'm wondering if the hub off the old Suntour is compatible with any cogs available now. I read somewhere that Suntour switched their groupsets to be compatible with Shimano, but that wasn't until 1995. I would have never even thought of the pvc for spacers, so definitely thanks for that idea.

    I'm in the San Francisco Bay Area and there are definitely hills galor. I'm wondering if I'd want some hill gearing or whether this bike would be more of a tame trail/around town bike after I get a new rig. That's something I still have to decide.

  4. #4
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    Zoke2 is absolutely right with his suggestion of keeping the 32 or 34 tooth chainring. There have been numerous posts about the ideal gear ratio which is dependent on the terrain you ride, tire size, personal preference to spin or not, and meat that will be pedaling.

    I have used an old rear derailleur for years as a chain tensioner with much success. I am sure the derailleur could be modified to save weight... But I am lazy. For spacers, I filed off or ground off the rivets that held a couple old cassettes together and then stole the spacers from that. These can be had in scrap bins at university bike shops or I have also just asked my LBS for scrap cassettes to dissect.

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