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  1. #1
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    Questions on converting to 1x8

    Im pretty new to trail riding but im loving it and havent regreted spending a penny on my bike. I rarely ever leave my middle ring so ive been pondering converting to a 1x8 (or maybe 1x10??) but i dont know much about it. I normally stick to my 3 biggest cogs while im on the trails so im thinking a 30 or 32 tooth ring might be a better bet as i think that will make it a bit easier to climb while keeping any top end i might want. My main question is what do i need to convert to a 1xN? Do i need to buy a whole new crank set? If so what should i look for and what is the typical price range? Id really like to try and shave some weight off but i dont know how much weight i would be looking at loosing and if its even worth it. Ive tried to do a bit of reading but i seem to lack the basic knowledge about cranks to really know what im even reading it seems. Any help is greatly appreciated as are links to more information

    Here is my current drivetrain
    Shifters: Shimano Altus, 8 speed
    Front derailleur: Shimano Altus
    Rear derailleur: Shimano Acera M360
    Crank: Shimano TX M171, 42/34/24
    Cassette: Shimano HG31 11-34, 8 speed

  2. #2
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    I'm pretty sure you can just Single speed front conversion kit try pricepoint.com. As for shaviong weight the frist to go would be the tube change to ether sl tubes or go tubless. After that you are going to be into changing the drivetrain and wheels for upgranded and lighter parts but you aren't going to XTR,XX, or X0. You will get the most weight by changing wheel SL trail set.

    As for the going to 10 speed rear I dont think your freewheel hub will work with it but you should be able to go to a 9 speed as they work on the same size free wheel hubs.

  3. #3
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    Super simple. I went 1x8 and it works great.

    Keep the same crankset. Remove the drive side crank arm and then remove the big and small ring.

    Re-install the crank arm and replace the big ring with a bashguard (if you want). Remove derailleur and shifter. Install an N-Gear Jump Stop (chain keeper or similar ~ $10).

    Works very well and looks nice. Total cost is $10-$20 for the jump stop and whatever you want to spend on the bash guard.
    Contact information: http://about.me/marpilli

  4. #4
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    Quote Originally Posted by shadow7874 View Post
    Im pretty new to trail riding but im loving it and havent regreted spending a penny on my bike. I rarely ever leave my middle ring so ive been pondering converting to a 1x8 (or maybe 1x10??) but i dont know much about it. I normally stick to my 3 biggest cogs while im on the trails so im thinking a 30 or 32 tooth ring might be a better bet as i think that will make it a bit easier to climb while keeping any top end i might want. My main question is what do i need to convert to a 1xN? Do i need to buy a whole new crank set? If so what should i look for and what is the typical price range? Id really like to try and shave some weight off but i dont know how much weight i would be looking at loosing and if its even worth it. Ive tried to do a bit of reading but i seem to lack the basic knowledge about cranks to really know what im even reading it seems. Any help is greatly appreciated as are links to more information

    Here is my current drivetrain
    Shifters: Shimano Altus, 8 speed
    Front derailleur: Shimano Altus
    Rear derailleur: Shimano Acera M360
    Crank: Shimano TX M171, 42/34/24
    Cassette: Shimano HG31 11-34, 8 speed
    To go 1x8 you will need a new crankset. The M171 chain rings are permanently attached to the crank, i.e. you won't be able to remove the small and big rings without ruining the crank. Since you intend to run gears in the back you will need a system to keep the chain on the middle ring. Rear derailleurs do bounce on rough terrain. This will cause the chain to drop either to the inside or the outside at times, not a good thing. A single speed specific ring can help, but usually does not totally eliminate the problem. A bash guard and chain tensioner/chain guide is the most common solution. There are also inner guards that replace the small ring that can be used in conjunction with a outer bash guard that will work as well. But you WILL need a way to keep the chain on that single chainring!

    As for going 10 speed in the rear, you will need a new cassette, derailleur, shifter, and chain. It would also be wise to go with a 10 speed chainring up front as well. Your hub will work just fine, 8, 9, and 10 speed cassettes will fit on the same hub. The width of the cassette is the same for all three, the cog spacing is just closer together on the 9 and 10 speed.

    For cranks, if you want to stick with Shimano, anything from the FC-M340 Acera cranks on up have replaceable chainrings. Removable/replaceable chainrings are critical for any 1x or 2x conversion.

    About the only weight you'll save going 1x is the front derailleur, shifter and cable. You'll end up breaking even in dropping the small and big chainrings as you'll be replacing them with a chain retention set up of some kind. You would be able to drop a tinny bit more by shortening the chain. Without the big ring your chain wouldn't need to be as long, but it's not going to be a life altering amount.

    For the front chain ring, if you are doing okay with the 34T middle ring now, I'd say drop to a 32T and see how it goes. Dropping to a 30T would definitely make it a bit easier to climb, but you loose quite a bit of top end as well.

    Anyway, you can go 1x8 fairly inexpensively. If you search the forums here you'll find quite a few threads on how to go about it.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  5. #5
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    Quote Originally Posted by Squash View Post
    To go 1x8 you will need a new crankset. The M171 chain rings are permanently attached to the crank, i.e. you won't be able to remove the small and big rings without ruining the crank.
    Good catch! That's what I get for not looking it up (even when the OP was nice enough to post up the model number).
    Contact information: http://about.me/marpilli

  6. #6
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    Need advice...I just rescued a 1988 Trek 7000 from the landfill...the bike is in great shape...I replaced the tires and tubes , grips,pads, seat, cables and tuned it up . I took it out for a spin and the inner chain ring bent...the original components seem crappy...any suggestions on crank, brakes, gearing, would like 1x8....

  7. #7
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    Thanks for the help. One last question, does anyone happen to know where i can find the weight of the m171 crank? google just directed me to a bunch of bikes that used it.

    Since my crank wont work and i do decide to go 1x8 what options do a have for a lower price range? And should i just buy a 3 ring crank and then bash guard and chain stay or should i look for a single speed crank?

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