Need help locating an extra wide one piece crank.

silverbear

silverbear

The Boy Who Never Grew Up
I'm trying to find an extra wide one piece crank to fit my Worksman NB. I need to have an extra wide crank so that I can install a pull start kit, but it needs to be a one piece so that I can use the small chain ring I have from a Worksman folding bike... fits under the engine and also allows for a chain guard. A larger chain ring won't work. Anybody know where I can find one? Thanks,
SB
 

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Thanks for the link, I had already looked at that and ordered one for the Panther/EZM build coming up next. I'll know better when it comes if I can adapt it to work with the Worksman build, too. The problem with it is that it comes with it's own keyed chain ring, so you are kind of stuck with that size, whatever it is. The smaller chain ring I have on the Worksman right now allows the pedal chain to just miss the bottom of the engine and also allow for a chain guard. A bigger chain ring will negate the chain guard and run into the motor. And there is no more room vertically for the engine to move to. So I have to use a smaller chain ring and also need a wider pedal crank. My hope is that the keyed opening in the chain ring that comes with the crank is larger than the opening on the small worksman chain ring. If so, then I plan to reshape the worksman sprocket to match the key and be able to use the smaller one. Hassles. But I can see a need for a pull start with this build, unless...
A question. IfI were to use a bit larger sprocket on the wheel would it make pedaling easier? I thought that might be an alternate solution to the pedal start problem. Just a thought.
SB
 
azbill said:
have you thought of using shorter, kiddie cranks (5" or so), and pedal extenders ?,,,
or even bending normal cranks to fit

I am only suggesting this as I have only seen wide 1piece cranks with the hexagon hole in the center :(

http://motorbicycling.com/attachmen...-ezm-powered-jaguar-mini-may-15-09-newly-bent
Click to expand...

I'll think about bending cranks as pictured. Might be a way around the problem. What are pedal extenders? Never heard of them. I'll study the problem to see if just extending the pedals would fix the problem. I'm already using short pedal arms as it is. A cheap solution is always the best in my book. I'm going to look at some of my pedal arms and see about heating and bending them. Wish I had a good vice. Thanks, Bill.
SB
 
silverbear, how much wider is the motor when you add a pull start? lemme know and i might be able to help you out with something from my box-o-cranks...
 
wow, that's a lot. the cranks i have are NOS, old Wald cranks, and they're a lot wider than the new ones that come on Huffys and Schwinns, but they're not that wide. on my bikes, they clear the motor by at least a half inch.

i do have some really short ones, though, that would go under the motor if you're interested. they'd make pedaling a little funky, but who needs to pedal, right?

i'll go take some pics of them now. hang on...
 
I just googled pedal extenders and I'm thinking it might be the simplest solution to the problem. About $20.00 isn't cheap, but if it makes the difference between pedal start and pull start it would be worth it. Now I have to find out if it is at least 1 1/4". Anybody have experiences with these things? I would use the 9/16" size.
SB
 
just saw you're question about a larger cog on the rear wheel... yes, it'll make pedaling easier and it'll also make your coaster brake work better, 'cause it gives you more leverage. i put a 20t on the rear of my 24" and almost flipped over the bars the first time i stopped. it locked right up. took me a minute to get used to it, and now it's great.

as far as pedal extenders, as far as i know, all one piece cranks are 1/2" thread for the pedals.

they only extend your pedals out further, they won't help if your cranks are hitting the engine. not sure which problem you're having. are the cranks under the motor, but with a pull start the pedal doesn't stick out far enough for your foot? if that's the case, pedal extenders would be the way to go. but if your cranks are hitting, then you need wider ones.

in any case, here's the cranks i was talking about. if you think one might work for you, they're yours, free of charge...:)
 

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Bairdco, Just went for a sweaty and unsuccessful attempt at starting the Worksman. Will troubleshoot later. I think the answer is pedal extenders since my crank arms are short and come under the engine, just barely. It is the pedals which run into the pull start case, so extending them out even an inch will do it. Thanks for your offer, however. This way I can use the same crank, chainring, keep my pedal chain guard and just screw in the extenders. Excellent. Next I'll be asking questions about installing the pull start kit since the kit runs into the manifold bolts without clearing. Always something.
SB
 
Just now ordered a set for $22.00 with shipping. Thank you guys for all of your suggestions. Now to deal with the pull start kit... a new thread is born.
SB
 
Just to let you guys know, Pyramid make a 32T sprocket that has the hexagon hole in it. Its a little smaller hexagon hole than the one that comes with the one piece wide crank, but I just clamped the two together then put the dremel to it, till the holes matched. Fits good on the crank and should make the bike easier to pedal with the extra weight, but I have yet to complete the build so I haven't tested it yet. I also am moving to a 20/22T rear sprocket on the rear right.
 
Tad Bit Tipsy said:
Just to let you guys know, Pyramid make a 32T sprocket that has the hexagon hole in it. Its a little smaller hexagon hole than the one that comes with the one piece wide crank, but I just clamped the two together then put the dremel to it, till the holes matched. Fits good on the crank and should make the bike easier to pedal with the extra weight, but I have yet to complete the build so I haven't tested it yet. I also am moving to a 20/22T rear sprocket on the rear right.
Click to expand...

That's good to know. Thanks. I may need that for the Panther build which is using the one piece crank with the keyed sprocket. What did that run you? I'm looking around in my department of dead wheels and organ donors to find a rear sprocket with more teeth.
SB
 
Silverbear,
I have the exact same problem with cranks. I want to run the Worksman 28t and need a 9" I.D. spacing on the arms. I like bill's approach the best.
 
azbill said:
have you thought of using shorter, kiddie cranks (5" or so), and pedal extenders ?,,,
or even bending normal cranks to fit

I am only suggesting this as I have only seen wide 1piece cranks with the hexagon hole in the center :(

http://motorbicycling.com/attachmen...-ezm-powered-jaguar-mini-may-15-09-newly-bent
Click to expand...

Sorry to resurrect this but I had two different kiddie cranks to try. One of them was a great length (5") but was from a smaller bottom bracket (~1.75") and the 2" bottom bracket cone nuts were too big to thread on the smaller crank so it wouldn't fit. The other was shorter than my Worksman one piece but still interfered with my lifan 98cc motor. My question is this: is there a way I use the smaller ones from a 1.75" bottom bracket on a 2" bottom bracket?

Thanks,
Keith
 
hmmm.....I'm having a hard time getting my head around the trouble.

Do you mean to say that the inner bearing race (if that's the right term) on your 5 in crank has a smaller diameter than on the more standard sized one-piece cranks?

If that's your trouble then you ought to be able to find a bearing that fits. It might take some searching. Maybe a lot.

This is nothing but memory, but I think these folks have a fair selection of bearings available. www.niagaracycles.com

FWIW, I don't think there's anything wrong at all with resurrecting an old thread. Sometimes they contain interesting stuff that we might have missed when new.
 
Venicemotorbikes has the wide one piece listed in the "shop online" section. And I might know someone with a couple small(32 tooth & under) chain rings with that hexagonal hole.
 
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