BikeBuilder43
Member
I want a really low gear for takeoff and a really high gear for top speed
Is there a way to make a 2 speed without having to buy the jackshaft kit?
- Thread starter BikeBuilder43
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FurryOnTheInside
In Memoriam
A shaftless shifter, eh?
I have not seen anyone crack it just yet but I'm still optimistic.
I think the biggest challenge is keeping the bump start.
The actual difference in ratios might not be really big as that is a lot of slack chain to deal with.
I have not seen anyone crack it just yet but I'm still optimistic.
I think the biggest challenge is keeping the bump start.
The actual difference in ratios might not be really big as that is a lot of slack chain to deal with.
Timbone
Well-Known Member
If you do a Google search you can find a design for a two speed dog clutch. It's doable. But another thing that can go wrong!
Frankenstein
Deceased - Frankenstein 1991 - 2018
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Can an internally geared hub be used in reverse if you lock up the freewheeling mechanism? That would evade the need for dealing with slack, retains bump start minus the ability to pedal.
Well since you left the question vague enough, yes you can easily make it 2 speed without buying a kit, you just make it instead. Every part is reproducible in some way in regard to function, the hardest part is making a good enough bracket but 3 good steel plates and some welding skills would do it, just make sure you line everything up perfect.
Duel engines with 2 sprockets and a second set of bars stacked above the original might get it done, you'll use more fuel so upgrade your tank.
Well since you left the question vague enough, yes you can easily make it 2 speed without buying a kit, you just make it instead. Every part is reproducible in some way in regard to function, the hardest part is making a good enough bracket but 3 good steel plates and some welding skills would do it, just make sure you line everything up perfect.
Duel engines with 2 sprockets and a second set of bars stacked above the original might get it done, you'll use more fuel so upgrade your tank.
BikeBuilder43
Member
What about mounting a spring loaded tensioner to eliminate slack on the top chain when bump starting? Mount it where the tensioner goes on out kits but do top chain instead.
FurryOnTheInside
In Memoriam
How about just bump start in low gear where there is no/little slack, since you need to be in low gear to take off anyway and you also don't need to be pedalling the bike as fast to start the engine when it's in low.
FurryOnTheInside
In Memoriam
I'm certain that it would be very bad to have a pulley whatsit of any kind on the upper run of chain if it actually affects the chain while power is being put through it.
I think, however, that it could be beneficial to have some kind of slack catching wheel or rail just to prevent the chain dropping too low in the event that there actually is slack there; but it shouldn't touch the chain under normal circumstances, and there really shouldn't ever be any slack in the upper run of chain if you can help it.
Another safety feature in case of some slack appearing is to fill the gap inside the clutch actuator cover / drive sprocket cover where so many people have had the chain get piled up and wedged in solid (usually when they have broken the chain or had it come off their rear sprocket). I have filled mine with epoxy resin so the chain can never lift off the drive sprocket and here's no corners or pockets where a broken chain is likely to become stuck.
I think, however, that it could be beneficial to have some kind of slack catching wheel or rail just to prevent the chain dropping too low in the event that there actually is slack there; but it shouldn't touch the chain under normal circumstances, and there really shouldn't ever be any slack in the upper run of chain if you can help it.
Another safety feature in case of some slack appearing is to fill the gap inside the clutch actuator cover / drive sprocket cover where so many people have had the chain get piled up and wedged in solid (usually when they have broken the chain or had it come off their rear sprocket). I have filled mine with epoxy resin so the chain can never lift off the drive sprocket and here's no corners or pockets where a broken chain is likely to become stuck.
Steve Best
Well-Known Member
I played with a jackshaft and gearing last summer.
Added 10 lbs to the bike and yet more lube points, chain tensions and adjustments to look after.
Grease on my pants, 3 chains, no more easy bump starts.
I found that by making the engine more versatile I didn't really need the gears.
I'm really after simplicity, not re-inventing a motorcycle.
Improve your head design, widen the ports in the cylinder head, improve you jetting, stay modest in your sprocketing (44t-56t) and you CAN have a single speed bike that will pull away from a stop, crawl up any hill, and still do 35mph.
Added 10 lbs to the bike and yet more lube points, chain tensions and adjustments to look after.
Grease on my pants, 3 chains, no more easy bump starts.
I found that by making the engine more versatile I didn't really need the gears.
I'm really after simplicity, not re-inventing a motorcycle.
Improve your head design, widen the ports in the cylinder head, improve you jetting, stay modest in your sprocketing (44t-56t) and you CAN have a single speed bike that will pull away from a stop, crawl up any hill, and still do 35mph.
BikeBuilder43
Member
I am trying to get into the upper 50mph club. That's why I want a low gear. I have built bikes that pulled hard as hell all the way to 35mph with a 44tooth sprocket. Port matched intake and exhaust, ngk plug, grinded a notch in the intake side of the piston skirt, thrust racing muffler. The problem is I felt very limited because I could reach top speed so easily.
FurryOnTheInside
In Memoriam
Hey no need to justify your reasons for wanting to do build something new and/or bikey. It's all fun playing with bike bits, whether it turns out to be a dead end or a step forward in motored bike technology or just a fun experiment.
I have my reasons for wanting a two speed shaftless shifter but the main thing is to see if I can.
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