Eliminating the driven sprocket

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,664
5
38
Duvall, WA PNW
www.sickbikeparts.com



We will be selling this set-up as a kit sometime in spring.

We are still refining it, working a few logistics issues. Sourcing the big dollar item the crankset is complete just need to settle on volume.

This is a commercial enterprise. Well OK we are a couple of clowns. He's the engineering muscle. I'm the the guy with a headache.

I'm open to your thoughts.
 

deacon

minor bike philosopher
Jan 15, 2008
8,117
3
0
north carolina
Man that is way past anything I could do myself it looks great. any idea what the cost will be on that thing.
 

spad4me

New Member
Jan 20, 2008
472
0
0
Arizona Bullhead
Does the crank freewheel, or do the pedals spin at engine speed.
How do you start it
This looks like a nice setup if the ratios on the crank are different enough.
 

Ghost0

New Member
Mar 7, 2008
764
0
0
Bellingham, WA
The crank freewheels. Starting it is just like before except you can't use your inertia from your forward momentum to start it. When you peddle with the clutch out your cranking the motor over directly. Makes it a little harder to start but not much.
 

Ghost0

New Member
Mar 7, 2008
764
0
0
Bellingham, WA
Well think of it this way. If your car was stuck in 2nd gear, how fast can you go? You can start a car off in 2nd gear but it won't accelerate very fast and then it will top out at a relatively low speed. Now if you are able to shift to 3rd, then 4th then 5th now how fast are you going? Same thing applies here.
 

paul

Well-Known Member
Dec 23, 2007
5,548
39
48
63
Kalamazoo, MI
nice job guys! i went to work today after pablo told me about it and i was like duh all day trying to figure out what you all were doing for sure and now i see. you guys are geniuses. i cannot wait till it is available. i for one definitely want to try it. ghost welcome to the forum. we are all happy to have you with us. and pablo thanks for the pictures it was making me crazy and that craz has turned into big time excitement
 

Skyliner70cc

Member
Mar 8, 2008
138
0
16
It should make the bike go faster on level ground because you'll have the ability to vary the gear ratios widely!

I want one!
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
2
38
68
pampa texas
Very very nice and looks well made. I'll bet you can get into the white knuckle range easily. Is the next step in speed on a bicycle turning your hains into stains? rotfl
Keep up the good work.
Norman
 

Skyliner70cc

Member
Mar 8, 2008
138
0
16
I'll answer your question with a question.

What is the advantage of a 21 speed mountain bike versus a 1 speed bike?

This thing would be ^&*()ing with a Nu Vinci hub.
 
Last edited:

mean

New Member
Mar 18, 2008
6
0
0
gday pablo and ghost0,
my stock happy time 48cc has a 44tooth i think? with this jackshaft set up are we getting a lot more pull up hills in the easiest gear? or is top end on the flats more where the improvement is? I suppose the range can vary a lot by choosing different chain rings and such? your marketed set up will be a standard configuration? or options available?
so looking forward to this!
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,664
5
38
Duvall, WA PNW
www.sickbikeparts.com
gday pablo and ghost0,
my stock happy time 48cc has a 44tooth i think? with this jackshaft set up are we getting a lot more pull up hills in the easiest gear? or is top end on the flats more where the improvement is? I suppose the range can vary a lot by choosing different chain rings and such? your marketed set up will be a standard configuration? or options available?
so looking forward to this!
Well if you have a multispeed bike and choose a "lower gear" than your current set up, sure you will pull up hills better by matching the power band to the situation. Same goes for top end. Our current set up (standard engine gear -supplied left driven gear-right jackshaft gear-freewheel gear) on most 5-6-7 sprocket rears, brackets the range of purchaseable bolt on sprockets.

It will be a little bit before we get it all sourced, bid, procured,etc but we are over the fundamental issues. Cost is also a factor - we want to get this thing as low as reasonable.
 

Ghost0

New Member
Mar 7, 2008
764
0
0
Bellingham, WA
Just to add to what Pablo said. If you want to get technical, the approximate ratios you will achieve will be between 2.9:1 and 5.8:1. This will be like going from a 29t rear sprocket to a 58t and everything in between.