Question for jackshaft guys?

Discussion in 'Motorized Bicycle General Discussion' started by toker_ace, Nov 22, 2009.

  1. toker_ace

    toker_ace Member

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    I am so on the fence about ordering a jackshaft from sickbikeparts.com . My questions are .... How much trouble is it to keep rear gears adjusted? Is it a constant tinkering to keep adjusted correctly. I have always had no luck with bicycle gears. Is it worth the price of two motors? LOL! Also, will it allow me to do some slow off roading? Hard to start? Will regular (wal mart) sprockets work or am I going to need to upgrade everything? See...... I got some questions. Thanks
     
  2. Sydneysider

    Sydneysider New Member

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    Hi TA, havent got a jackshaft kit yet but Im gonna get one for sure.. my friend has one on his bike and theyre well worth it I think. If you got a good quality brand set of rear gears like Shimano, you wouldnt need to adjust them that often like you would on cheap ones. As for the starting, your motor should be tuned to start pretty much right away otherwise youll be doing alot of pedaling as you kick that engine over.. Id say go for higher brand for sprockets and derailleur than the regular ones because there will be alot of shifting up and down.. cant wait till I get mine :)

    Good luck with your decision..
     
  3. Technocyclist

    Technocyclist Motorized Bicycle Senior Technologist

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    my 2 cents is that if you have the $$$, then go for it... I'm using an internal gear hub so the adjustment is very minimal. But you might have to modify the rear mount to keep the chain with a correct tension. The engine has a tendency to twist downwards to the right, so install that little angle aluminum bar, to minimize the engine movement, and chain slacking. You might need to have an extra angle aluminum bar, it can sometimes break. I have upgraded to a steel angle bar.

    Starting the engine is not that difficult.

    Your bottom bracket should be wider, about 127mm or longer.

    It will certainly allow you to do off roading, but this depends on your sprocket size, and that your spokes, rims, brakes, and tires can handle the additional torque and power.
     
  4. Sydneysider

    Sydneysider New Member

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    I agree with Techno.. go for the heavy duty double walled rims with 12 guage spokes preferably stainless steel ones as Ive done.. theyre the best wheel ever! :)
     
  5. Maxvision

    Maxvision New Member

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    I just put a shift kit on a bike for a guy that has a 3 speed Nexus hub. First gear is so low that he can take off from a dead stop without having to pedal first and he's a big guy. I drove it across a very thick matted grassy lawn and started in first without pedaling. Barely any strain on the clutch. Off roading wouldn't be a problem I'm sure.

    I'm putting a shift kit on a 7 speed derailer right now. I'll be curious to see if all those extra gears are really worth it. The 3 speed hub seemed to cover all the needs that a shift kit allows.
     
  6. MrLarkins

    MrLarkins HS Math Teacher

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    I got a kit this past summer. my chain keeps jumping off and I don't have the time currently to tinker with it. I can't seem to keep the setup from shifting angles when I ride it. I haven't ridden my bike for 5 months. I also lost a locking 'key' for a gear on one of the jackshafts and haven't figured out how to replace it. i have had moments where i wished i would have spent the money on other things...but once i get it running again, i'll probably change my mind again. i will say that sickbikeparts has awesome customer service. they've been very eager to help with all my problems...but i just haven't had the time i need lately to get it and keep it going.

    one more note, i'm a small guy and i find it VERY hard to start it with the jackshaft
     
    #6 MrLarkins, Nov 22, 2009
    Last edited: Nov 22, 2009
  7. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Once your rear gears are dialed in, then you should not have to adjust them any more than if you use your gears for pedal power only. If you have a 20 year old bike and you never have adjusted the derailleur, then probably it's time to adjust the derailleur. Pretty easy, really. No constant tinkering.

    The shift kit isn't the price of 2 motors. Slow off roading? You will need low gear ratios, but I do it all the time.

    If your engine is always hard to start, then it will remain hard to start. It's different, but if it's hard to start then something is not correct.

    Not sure what a "regular (wal mart) sprocket" is. Don't use cheap, soft stuff. Some people do use some low cost bikes. But some low cost bikes even have terrible axles.

    Hope this helps.
     
    #7 Pablo, Nov 22, 2009
    Last edited: Nov 22, 2009
  8. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Sounds like something is not aligned correctly. Our instructions need to be followed explicitly on alignment issues. The key is simply 3/16" key material, available at most any hardware store. I can relate to the time issue. I wish I had time just to ride my bike.

    As for starting, is your engine just difficult to start? Do you have a high compression head? Did you read our "how to" on starting?
     
  9. toker_ace

    toker_ace Member

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    hey sidneysider. Do you have a link to those rims?
     
  10. Sydneysider

    Sydneysider New Member

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    I think tyrslider still builds and sells these wheels, I may be wrong but see if he's around on the forum or drop him a message..
     
  11. xlite

    xlite New Member

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    I don't own one myself but have installed 2 for others and tried them out. IMO the eninge is much easier to start and also easier to get the bike going. There was no adjustment to original chain/sprocket required and both these setups are working great. I really don't think you need special wheels if you've been offroad pedalling. Unlike what many believe though it does not improve top speed compared to using a small sprocket.

    Personally this is not for me though because I go on long trips and the redundancy of two drive systems is essential. Something you sacrifice with the jackshaft. Kinda like with the clamshell hub sprocket mount kits, sounds like a neat idea at first until you need to switch bikes. There's drawbacks. As Roseanne Roseannedan says: "It's always sumpin'!".
     
  12. Goat Herder

    Goat Herder Gutter Rider

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    I don't get what the big scare is about the aluminum rims? Check some of the you tubes the down hill stunts and all the curb tricks for bunny hops etc. Thats what they swear by according to those forums and I as well! Mag wheels among stunt riders are said to be the weakest they crack! Many steel rims come with the worst axles . I would take a high end free wheel cassette hub with aluminum rims over steel any day. You won't find that on a walmart bike. Front rim and hub will usually always be fine.

    If you weigh as much as a horse jockey you can use anything. I made a a low end walmart hub work fine until the spokes broke 4000 miles. It was aluminum and ran on the Jshaft just fine. Because it was a cheap hub the axle would flex and need to be properly set for bearing end play a pain for some folks! A high end aluminum hub you set the end play on the bearings once. I even drill a hole in the center for a grease cert.

    My currant build has a jshaft Bike and I are 300 plus pounds! One any given day I will be carrying groceries etc. Because I did not mount the front part of the china right the rear gave me a little hassle but that wasn't the kits fault! I simply adapted for it. Once I ran the bugs out? Oh man I would not run things any other way this thing has really spoiled me!

    Check this link out if you doubt aluminum rims are any good! Aluminum is stiff it can flex and even move back. Steel don't flex and bends easily. Pound for pound the aluminum is better! I am sure some steel versions have better hubs I am just not interested in them.
    http://motorbicycling.com/f28/post-cool-videos-like-one-here-13006.html
     
    #12 Goat Herder, Nov 25, 2009
    Last edited: Nov 25, 2009
  13. furament

    furament New Member

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    oist i have the same qwestion found out the bike im building wont work with out it so then hers the thought i have a bike here with one of those slider self change gears aneyone do it will it work seems to me id be kool but could be bad i duuno aney thoughts?
     

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