3+ speed automatic jackshaft idea

Deleted, sorry!
 

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2-speed transmission spacing. Just like in the solidworks file with slightly tweaked bearing locations.
 

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beginner01 said:
Well it's coming together. Cutting those jackshaft plates with a jigsaw, drill, and angle grinder was a huge pita but I did it... Last time I ever do that. Next time will pay a machine shop whatever they ask to do it.

I just finished the spacings and just figuring out what direction the bearings and sprockets are pointing in relation to he plates. My final drive sprocket will be just outside of the two bearings, and the alignment for my pedal chain is off by about a quarter inch but I really don't give a damn at this point. The first gear freewheel is an ACS fat FW at 3/16" thick. If it fails I can swap it with the pedal freewheel which is a standard 1/8" and also 16t. Now it is time to straighten he bearings (they swivel in their friggin mounts!), break the chains and figure out what height and slack adjustment to set everything at. The problem with thing having too many adjustments is setting it up... Huge pita ahead!
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Next time maybe take it to a good steel supply and have them plasma cut it out. Just need a drawing and measurement,they lay it in the computer ( If they have it ) and cut. A hole lot cheaper then a machinist.

Like what you are doing. Can't waite to see how it ends up............Curt
 
Thanks Curt, that is a good suggestion.

bowljoman said:
looking good. Must be heavy. How much does it weigh?
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Yes it is heavy. The plates themselves with four bolts weigh just over a pound each. Doing some calculations, I could remove half a pound from each if I drill 48 1/2" diameter holes in them. I will get back to you on the total weight. I'm guessing around 8lbs total. Unfortunately apart from drilling the holes and completely redsigning/replacing drive parts for lighter chain, I think there is not much to be done to reduce weight. I try to focus on rotational weight more.. Have built a 48 spoke heavy duty rear wheel using a SA drum hub drilled to 72h so that I could avoid using a steel 36h rim.
 
Man, you have done some awesome work so far!
I have to second the idea that curtisfox has on having a steel supply house cut the plates for you. I once solicited quotes from a few machinist shops to have the center hole enlarged on a 44T chinagirl rear sprocket. The cheapest bid I received was $120.00.
Holy crap Batman! $120 to machine a $20 sprocket!?!
 
GearNut said:
Man, you have done some awesome work so far!
I have to second the idea that curtisfox has on having a steel supply house cut the plates for you. I once solicited quotes from a few machinist shops to have the center hole enlarged on a 44T chinagirl rear sprocket. The cheapest bid I received was $120.00.
Holy crap Batman! $120 to machine a $20 sprocket!?!
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Easy fix to do that is clamp the sprocket to a block of wood and find the center,find the right size hole saw using the wood for guide with a center mark hole saw it out. If its slightly tight get a rotary file that fits a drill and file it out,should be just as good if not better then a rag setup..................Curt
 
bowljoman said:
looking good. Must be heavy. How much does it weigh?
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19.5 lbs including all clutches, chains, bearings, sprockets, shafts and keys. Not including wheel sprocket, aluminum JS mount blocks, or pedal chain. If you remove the main clutch and final chain it's around 16lbs.

Compare to my original single speed setup with half the hardware and it's 10.3lbs including all as above for the 19.5. Guess I was way off!!!

Need to redo my exhaust and then will be breaking in my new motor on this transmission! Improvements are so much more fun to do than repairs hahaha!!
 
Thanks.

Took it on another test run today in the mountains. I had the road to myself for a little while.. it was wonderful!! BUT, then I got stuck behind a goddamn asian driver in a Toyota Prius, OF COURSE going exactly the speed limit of 30mph... which.. you guessed it.. is just 2mph under my shift speed. So here I was revving almost 5000rpm at 30mph because I couldn't go 3mph faster. :-||

Shifting should happen at 25-27mph at no more than 4500rpm. Have new sprockets coming to make this happen though my final drive sprocket will be a 9t. Little small but limited by my wheel sprocket. Looking for a suitable sprocket bigger than 44t to fit the ragjoint 9-hole *small pattern* on my hub, so I can go back to a 10t.


The bike looks pretty much the same with the 2-speed as it did with SS.
 

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Nice job on your 2 speed. I was hoping I wouldn't be the only member who fabricated one from scratch. I would be interested in a three speed but 2 seems to be adequate once the shift point is established. Great looking bike, overall design is nice and strong.
 
msrfan said:
Nice job on your 2 speed. I was hoping I wouldn't be the only member who fabricated one from scratch. I would be interested in a three speed but 2 seems to be adequate once the shift point is established. Great looking bike, overall design is nice and strong.
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Hahaha!! Thanks Dale! :)

Adapting your 2-speed to a 3-speed is easy. Your first gear has a solid mount sprocket and a freewheel, and your second gear is the same but with a MT clutch in place of the freewheel. A 3rd (middle) gear would simply have a cent clutch driving or being driven by a freewheel sprocket.

The biggest drawback to any MB transmissions that use a freewheel is the freewheeling aspect itself. Desiring engine feedback above 25mph, I just pick the top gear ratio I'm comfortable with, make sure my engine can pull it at 25mph, and set up low gear according to the engine RPM jump desired. With a 3-speed you can run a much taller top gear and provided engine torque from a 200cc engine, have shifts at low RPMs.. 4k or less. Especially if your engine can decently pull a 6.75 ratio at 2600rpm. Mine is very slow at this ratio!

My gears that are coming will give me a top gear of 7.85, shift at 4000/2500rpm at 25mph minimum (1715 JS RPM). So riding in the city in traffic I will be on/off the throttle, freewheeling and idling a lot in stop-and-go and saving gas, and then when the speed increases to 30mph will already be in the performance range of the engine at 3000rpm with full feedback.
 
Hey guys, has anyone experienced a shudder,luggitty,luggitty when starting out? I have a max torque and after the take off runs nicely...hey 01 when you had your belt mt drive going was it smooth?
 
I think it's the shoes wearing rapidly. There is a lot of fine grey dust all over the inside of the 2nd gear clutch. I'm gonna service it today and see what's up.
 
After 1 year, it looks like this:
 

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