Does anyone make a "stand-alone" jackshaft kit for bicycles?

VenomRS4

New Member
Nov 30, 2017
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Hello. Newb here. The bicycle I am looking to build is a folding model. The frame design requires the engine to be mounted behind the rider...thus a typical jackshaft kit that is designed to be mounted to a normal engine assembly itself may not work. I will be using the frame around the back wheel as well as the rear rack mounts to install the engine mount plate. Then I want to run the chain to a jackshaft from there. The problem is I cannot find any jackshaft kits specifically designed to be "stand-alone". They all seem to integrate the bicycle engine assembly. There is a spot on the bike where I can put the jackshaft which has 3 solid areas that I can use for mounting points...so I was hoping to use strictly the frame (not the engine like normal bike engine kits) for mounting the jackshaft. Does anyone know of any "stand-alone" jackshaft kits? Or am I fabbing up one of my own? Or altering an existing kit?

Ideas?

Thanks in Advance!!!



 
Last edited:

Tony01

Well-Known Member
Nov 28, 2012
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sf bay area
Motorizing a folder is a BAD idea. Best bet for that bike would be to go electric with a 1000-1500w hub motor.
 

MEASURE TWICE

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Jul 13, 2010
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CA
I bought the jackshaft kit AGK brand at a store front, but online there are many sellers. I chose the 5/8 with the longest length keyed shaft. Then I could cut it down if needed. What I found is that the mounts for the pillow bearings do not come where they could be bolted onto the frame. They included some metal pieces stamp cut for the bearings and they do not fit tight. I ended up shimming them with thin metal as best I could. If I ever did a custom DIY again and needed a jackshaft I would used the pillow bearing blocks. Many of these are much nicer. The can be bolted on as I have seen with most. Some even can adjust for not being exactly true angles. Some have oiling caps that you can open and lubricate. Grainger at the store front or online and Farm All I think are some names. One thing I really like to use is split collars to hold bearings in place. I only use the set screws where they will press on a key in a keyway on the jackshaft. Otherwise they mar the metal and taking apart when servicing is a nightmare. I never had a split collar ever loosen. The set screws I have had come out and use blue or green thread lock which is easier than the red. Possible to weld the folding section an gusset it too? If you do not want to weld or have someone do it, at least I'd say find a way to fasten better some way the existing folding section especially if the engine is peppy.
 
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VenomRS4

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Nov 30, 2017
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With a few parts and a lot of creativity, almost anything is possible.......make it so!
Thanks for the motivational words!


I bought the jackshaft kit AGK brand at a store front, but online there are many sellers. I chose the 5/8 with the longest length keyed shaft. Then I could cut it down if needed. What I found is that the mounts for the pillow bearings do not come where they could be bolted onto the frame. They included some metal pieces stamp cut for the bearings and they do not fit tight. I ended up shimming them with thin metal as best I could. If I ever did a custom DIY again and needed a jackshaft I would used the pillow bearing blocks. Many of these are much nicer. The can be bolted on as I have seen with most. Some even can adjust for not being exactly true angles. Some have oiling caps that you can open and lubricate. Grainger at the store front or online and Farm All I think are some names. One thing I really like to use is split collars to hold bearings in place. I only use the set screws where they will press on a key in a keyway on the jackshaft. Otherwise they mar the metal and taking apart when servicing is a nightmare. I never had a split collar ever loosen. The set screws I have had come out and use blue or green thread lock which is easier than the red. Possible to weld the folding section an gusset it too? If you do not want to weld or have someone do it, at least I'd say find a way to fasten better some way the existing folding section especially if the engine is peppy.
Interesting. I like where you are going with this. I will probably just build my kit from scratch instead of looking for an existing jackshaft kit to modify. Some pillow bearing blocks with a custom bracket that clamps to the frame in the "triangle" area of the frame seems to be a good route. I'd like to do this whole project without welding and I think it can be done. As far as securing the folding section, I think it's pretty strong. The engine is a Zenoah G2D...23cc and 2hp...not exactly a screamer. So I am confident I won't have any issued with it. I'll be lucky to see 20mph. Maybe on future projects I'll upgrade engines but I already have this so I'm just going to work with it. Thanks for the input!
 

TheSignGuy

Member
Nov 24, 2014
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seattle, wa
Motorizing a folder is a BAD idea. Best bet for that bike would be to go electric with a 1000-1500w hub motor.

Yeah I don't think he wants to ride off and get folded up passing a bump. Those bikes are pure aluminium dahon is the last steel makers as of lately.
 

Dan

Staff
Staff member
May 25, 2008
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Not for button, but Measure 2ce does some really cool stuff. Functionally in the box stuff but outa there end production. Really great at problem solving and coming up with he right compromise.

In the end, it's always about finding the compromise that works. And Xman is right! Always a way.

LoL, but refer to above. Always some sort of trade off!


Any pics yet?
They really help. Some one will go "cool, did ya think of trying this..." Or post a link to some thing.


Really cool thing about here. Mutual crazy and colabrative.