Hi Goat Herder,
Yeah that front end looks impressive. So far so good on the Jack Shaft, I cleaned up the hex lock screw on the sprocket and used some locktite to secure it, it's been holding up good for the last 8-9 miles.
The SBP Jack Shaft rules !!!
- Thread starter Goat Herder
- Start date
Yeah that front end looks impressive. So far so good on the Jack Shaft, I cleaned up the hex lock screw on the sprocket and used some locktite to secure it, it's been holding up good for the last 8-9 miles.
Glad you are having a great time with your JS on your ride.
I seem to recall that I had mentioned this on the forum over a year ago about the usage of jack shafts as well. We had been using these little wonders of power transfer units for over 10 years on our builds. Never had a problem with them on any type of ride either.
It is good to see your pictures and your inovations to improve your ride.
Very clean setup, keep up the great work.
Maximo
I seem to recall that I had mentioned this on the forum over a year ago about the usage of jack shafts as well. We had been using these little wonders of power transfer units for over 10 years on our builds. Never had a problem with them on any type of ride either.
It is good to see your pictures and your inovations to improve your ride.
Very clean setup, keep up the great work.
Maximo
Well as we all like to tinker with our bikes. I just could not leave it alone. I engineered me a tensioner on the jack shaft, its been on for about two weeks now. I like it and wanted to share picts. Now I put about 300 miles on the jack shaft stock and had absolutely no problems. I just enjoy tricking stuff out its what got me in this hobby lol. I was ready to put a half link in when I kept thinking about the stuff I had laying around. Well you know how it goes!!!! So here some picts of my mod it wasn't easy , but it was do able I like it. I used a steel version of a v brake arm and welded a rear dérailleur sprocket on it. Now keep in mind the j shaft is totally do able as stock it is a great design and I love it so far!
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Now the reasoning behind the brace at the top clamp is that any flexing might play havoc with the tensioner. It is really pretty easy to get that side apart to service the clutch actuator as well. Just looks hard but not too bad.Heres some post of a seat I planted myself on for the last 5000 miles or so. It has trunk storage and is pretty comfy.The seat is a Bontrager I bought it locally. The nylons made a decent air filter.
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Found it this was a cool seat is still is hope this helps someone. Storage is like cool!!! Bontrager Satellite Elite Saddle with Storage - Atlanta Bike Shop, Orbea, Lynskey, Storck, Rocky Mountain
Tensioner # two this one was fun! I managed a way! one pict shows the clearance trick for it to work. When starting the bike the tensioner side gets tight something has to give there. I now have two automatic chain tighteners. Ya probly wondering theres tons of room in the cover everything clears flawlessly! Theres a hundred miles on this one no glitches works lovy.
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Thanx you made the pict look better! Would love to see your mod did you make one?
I just bought the jack shaft and just waiting for it to get here. with an ordinary 7 gear casset what kind of speed/mpg can you get? I was getting 30 mph and 180mpg with the 44tooth sprocket. Then my throttle started to stick and one of the rear mount bolts snapped, i went 36 mph for a while after that. not sure why i went faster. i did notice that the vibrations made the top of the carberator unscrew. is there a way to improve a muffler without welding? after a few rides the baffle and stuff shot out of my muffler. it was crumpled up like a soda can. i fixed it and stuck it back in. While the baffles and stuff were out it went a few mph faster but it was deafeningly loud.
I was trying to see you pic so I photoshopped it.
I didn't make a mod, but have thought about it. In fact the front engine bracket that I made is extended out even with the sides of the motor and has a bolt hole for just that kind of thing or a chain guard, side lights, etc.
I did build my own chain tensioner like SBP sells, I only did it cause I saw the need after not ordering it when I bought the kit. I'm cheap and had the parts, so I built. You can ask the guys they will tell you that I thought up a "deluxe" kit with the tensioner included.
I didn't make a mod, but have thought about it. In fact the front engine bracket that I made is extended out even with the sides of the motor and has a bolt hole for just that kind of thing or a chain guard, side lights, etc.
I did build my own chain tensioner like SBP sells, I only did it cause I saw the need after not ordering it when I bought the kit. I'm cheap and had the parts, so I built. You can ask the guys they will tell you that I thought up a "deluxe" kit with the tensioner included.
A) This is probably the most common question we get. "How fast can I go?". You will go as fast as your little motor can power you and you can stand to bear on a bicycle. IOW - your engine power is the limiting factor. If you want top end power, work the engine over. Plenty of posts on that. Matching ports, increasing compression ratio, selecting the plug, tuning the carb, etc. To be honest we did not design the shifter kit for pure top speed improvement - of course many people report faster top speeds, but the winner in using gears is getting to that top speed WAY faster, by keeping the engine in the max power band and matching that power band to the conditions - we even have an 11T sprocket for the jackshaft if your engine can put the power out.
B) As for exhaust, the stock exhaust is a power limiter. With a two stroke, you really need an expansion chamber to make full power. Naturally the exhaust port needs to match the exhaust manifold and the exhaust gasket. These things are fairly easy work, made even easier with our expansion chamber kit.
I ordered the deluxe kit when I got my j shaft never saw a chain tensioner thingy please elaborate because that sounds pretty awesome? I only shared my picts because this is the greatest place to learn about MB on earth right now. I elaborate because I learned and we all have learned here. I know its a bit of a duty to Put back into society lol Last thanx SBP for when I emailed my picts for giving me permission to post!!!!
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Goat herder - you clearly saw the chain tensioner, because it's installed on your bike in this picture:
http://motorbicycling.com/attachments/f15/7767d1240553742-sbp-jack-shaft-rules-p1010014.jpg
I was going to ask why you didn't tension your chain the easy way?
I want to be clear about a couple things. All this welding and and extra items are not necessary nor required, and while it was cool to ask, no one needs to ask us for permission to post pictures of their own installation. Thanks.
I would expect cleaner looking work than my shod Job... Oh I see what you meant. I used it unfortunately I overtightened something the clamps. I have round ridges on the seat tube that seams to hold everything only in one place.
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Between the SBP JackShaft and that expansion chamber, I am glad I have a speedo. When the engine purrs I think I'm going maybe 18 and look and see 30, and silly me I want to put in a 11 tooth sprocket.
