Jackshaft Ebay Jackshafts?



gary55

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Nov 27, 2012
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No personal exp. with the ebay j shaft assy. . I have heard they take considerable more fitting. I do have 2 SBP j shafts. Very pleased with both. In my opinion SBP is the way to go. 1-you can contact them for help. 2-they will probably be more responsive if something is missing or wrong 3-the newer design is much better. If you spend 90 on ebay then 80 + shipping for hd free wheel you have only saved around 25, and that is not worth the headache of the crude older design.
 

Jonj57

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Jul 16, 2016
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You're right, no need to downgrade to save 20 bucks bought the HD freewheel kit from SBP and will be enjoying shifting on tuesday!
 

gary55

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Nov 27, 2012
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You're right, no need to downgrade to save 20 bucks bought the HD freewheel kit from SBP and will be enjoying shifting on tuesday!
Are you going with derailleur or internal hub?
 

Jonj57

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Jul 16, 2016
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Derailleur; not enough dough nor experience lacing wheels to do a internal. Though I'd REALLY like to and probably will eventually.
 

gary55

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Nov 27, 2012
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Derailleur; not enough dough nor experience lacing wheels to do a internal. Though I'd REALLY like to and probably will eventually.
Might as well get the use out of what you already got. The bike I j shafted already had a strumey archer 4 speed internal. I bought it used and have around 1500 motorized miles on the hub with no problems so far. I'm building another with a nuvinci 360 hub, but it's not done yet. Send us a pic when you get yours done.
 

KCvale

In memory of KCvale 1959-2019
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Apr 18, 2010
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I found a jackshaft on Fleabay for around 90 dollars and it looks like it's one of the older SBP kits that they discontinued. Any experience anyone? Also wondering if I got this and the HD freewheel (assuming compatibility) if it's just a cheaper solution to the jackshaft money issue?

http://www.ebay.com/itm/Jackshaft-Kit-For-80CC-Gas-Motorized-Bicycle-/172373083935?hash=item28223c871f:g:DEgAAOSwpLNX~sy1
Wow, blast from the past, I had to go back 6 years to find this one I did, and used on the bike of my forum pic.





More details in my forum topic about the build.
http://kcsbikes.com/topic.asp?TOPIC_ID=77

In short, a long nightmare to make it work right, and the new SBP mount, though not 'easy' itself, is vastly easier than that original but sure cool at the time, it was the first thing made to use your bikes gears with an engine and have been building shifters ever since.

The flebay kit no doubt uses the cheap freewheel bearing at that price.

The freewheel bearing is not something you want to cheap out on with a 2-stroke.
The ~$50 difference in kit price is the price difference of that one-way bearing your right pedal connects to that allows you to 'kick start' your engine.

You can get away with it on a low compression 48cc engine, but not a 66cc, especially with compression mods. I learned this the hard way, I built a 48cc shifter and the customer decided it wasn't enough power so I swapped the engine for a 66cc.

A couple dozen kick starts later it failed, and they don't fail 'friendly'...
It won't come back off so not only do you have to buy the good bearing, you need new pedals and the large outer sprocket as well.

The 'regular' freewheel bearing however holds up just dandy for a pull start, you never have to engage it to start the engine.
 

MotorBicycleRacing

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Jul 3, 2008
Messages
2,344
I found a jackshaft on Fleabay for around 90 dollars and it looks like it's one of the older SBP kits that they discontinued. Any experience anyone? Also wondering if I got this and the HD freewheel (assuming compatibility) if it's just a cheaper solution to the jackshaft money issue?

http://www.ebay.com/itm/Jackshaft-Kit-For-80CC-Gas-Motorized-Bicycle-/172373083935?hash=item28223c871f:g:DEgAAOSwpLNX~sy1
This is not an older SBP kit.
It is a not so cheap shoddy chinese knock off and a piece of junk.
Everyone who mistakingly buys these regrets it.......
 

gary55

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Nov 27, 2012
Messages
3,963
This is not an older SBP kit.
It is a not so cheap shoddy chinese knock off and a piece of junk.
Everyone who mistakingly buys these regrets it.......
This has nothing to do with this thread, but a while back you and I were bumping heads on the arrow direction on the pistons. I the last 80 or so engines I have built only around 2 had arrow pointing to intake (pin side). Well I just bought 6 engines and all had arrow pointing to pins. Now I see where your coming from. I got to go find a crow to make some pie for dinner.
 
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