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  1. #1
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    Belt drive - is it lighter?

    I'm in the process of modifying a bike to take a belt drive.

    Here's photos of the weight of the components that came off it, and those that are going on it.

    Belt drive will be over 200 grammes lighter.

    And just think, 109 less moving parts
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    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  2. #2
    aka baycat
    Reputation: Ryan G.'s Avatar
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    how are you modifying it? and which bike?

    cool to see this project. more pics please!

  3. #3
    Schipperkes are cool.
    Reputation: banks's Avatar
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    Hella YES!

    Do you have a frame that will accept the front cog width, belt tension & angle adjustment and belt installation?
    Quote Originally Posted by mikesee
    Better suited to non-aggressive 125# gals named Russell.

  4. #4
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    I really like the beltdrive, and I'm pretty impressed with how its worked. Gets alot of looks and questions asked about it. Its super quiet, too. I think this is the route I'm going to go with my SS road/cross bike as well.
    Livin' the dream.

  5. #5
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    I haven't completed the work on my mountainbike yet, but here's how I did it to my general purpose offroad bike.

    1st photo is the pattern I made up for a locating plate. Has to be solid because the frame is going to be cut.
    2nd photo is the locating plate. Sorry it looks crude - this is a hand tools job
    3rd photo is the frame drilled and cut. I drilled the frame before cutting it to ensure the holes were properly located.
    4th photo shows how the frame sprung when cut. I expected this.
    5th photo shows the minimum clearance at the front cog on the chainstay. I have room to space this out about 1-2 mm.

    Further photos in next post.
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    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  6. #6
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    And here's the finished job - a belt drive On-One Pompino. This is the 120mm OLD model and it usually runs either a track wheel or this Sturmey-Archer 3 speed hub. (It's going to get the S-A S3X when it comes out )

    1st photo shows the plate bolted in position.
    2nd photo shows the completed bike bike. I hope I won't be pilloried for showing a bike with gears here, it was just that I can't get a freewheel sprocket. (Edit: just realised, even if it has a 3 speed hub, this bike has less moving parts than my singlespeed )

    Parts needed:
    Belt drive bits - in this case 55 tooth front, 24 tooth back, and 118 tooth belt.
    Flat bit of steel. I will be making a new plate out of stainless steel - this one is cut of an old fence post
    3 bolts with unthreaded portion long enough to go through holes.
    3 nuts
    Tools - hacksaw, drill, file and a dose of incurable optimism.

    Difficulties likely to crop up:

    1. There is a limited range of sprocket sizes and belts, so desired gear combinations can be hard to get. It would be good if sprocket sizes coincided with current bicyle sprocket sizes. Belts come in 113T 118T 122T 125T and you can't simply remove a link to get the right size.

    2. The front belt sprocket is much wider than a normal chain ring. I usually run a 48 tooth chainring, but the belt sprocket is a 55 and is a larger diameter than my 48 tooth chainring. I have had to go from a 113mm ISIS BB to a 118 and only just have clearance. I can space it out a wee bit further which will help.

    3. The rear sprocket in this case has no lateral adjustment so fit is critical. The sprocket is wide, so you need to have enough clearance right at the edge of the dropout.

    I calculated everything very carefully before I did this. My belt length is a 118 - I have ordered a 113 to pull it in a bit. (The axle is better located than it looks in the photo, but I don't like my brake position on the rims)

    The axle position also means there is no room for a tensioner (tugnut). I got sufficient tension by sticking a hammer handle between the the tyre and the frame and levering the wheel back carefully while tightening the axle nuts. I will fit the tensioners when I get the shorter belt.

    It's done about 50-60 miles so far with a few steep hills to try and make the belt jump, but no problems so far.

    What does it feel like? Smoooth, and silent.
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    Last edited by Velobike; 05-13-2009 at 02:40 AM.
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  7. #7
    Drinking the Slick_Juice
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    oh no your all the way at the end of your dropouts!!!!! Someone needs a bigger cog!!
    "If women don't find handsome , they should at least find you handy."-Red Green

  8. #8
    aka baycat
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    cool. where did you orders the parts from? gates directly or another supplier.

  9. #9
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    Quote Originally Posted by nuck_chorris
    oh no your all the way at the end of your dropouts!!!!! Someone needs a bigger cog!!
    Not ideal looking, I know, but the axle is actually fully engaged in the dropout. There is no room to fit a larger front cog, and fitting a larger rear would mean the gearing would be too low. I've ordered a shorter belt instead, but there is a waiting list.

    Quote Originally Posted by baycat
    cool. where did you orders the parts from? gates directly or another supplier.
    I get the parts from http://www.g-boxx.com/e-carbondrive.html Make sure you know exactly what you want before ordering. These parts are expensive!

    Make sure your chainstay width of the rear fork is narrow enough not to interfere with the larger diameter front belt ring.
    Also check that the rear dropout has no protrusions on the inboard side, because your rear cog will have to be right at the edge of your cassette to line up with the front sprocket and it is much larger than the 13 tooth cog that usually lives there. The diameters of the cogs are given on the website.
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  10. #10
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    just take a link out of that belt and you'll be able to position the rear wheel more fwd in the dropouts.

    [ashton kutcher voice] burrn. BURN. [/ashton kutcher voice]

  11. #11
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    Quote Originally Posted by frorider
    just take a link out of that belt and you'll be able to position the rear wheel more fwd in the dropouts...
    Just as soon as I can find a tube of extreme tensile strength super duper glue
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

  12. #12
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    I like innovations like these

  13. #13
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    If we could just get a belt drive freewheel from WI, all would be perfect
    As little bike as possible, as silent as possible.
    Latitude: 5736' Highlands, Scotland

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