Jackshaft Sick Bike Parts jackshaft issue

[wolframore]

Update, with the shaft welded and machined to tight slip fit, the customer reports the shaft is working at this time. Again, we shouldn’t have to “fix a kit to make it work correctly.
May need to play with the output sprocket size (out of the jackshaft) for a tighter fit, currently it’s off by about 1/4link and would like to reduce the reliance on the tensioners which hop off as the pedaling puts tension on one part of the chain while engine puts tension on the other part of the chain. Tensioners which are derailer type hop off the chain and chain comes off the sprocket. We are experimenting with roller type tensioner pulley but haven’t found suitable replacement at this time (limited room and 5mm screws).

 

[s jack ahaft]

Shouldnt have to fix a new kit to make it work. Our shaft measured 0.620 which was 0.005 under. Not even close to correct, in fact you can slide it on a new shaft and actually rock it side to side. Can’t believe these guys did absolutely nothing to make right and keep shipping this crap. It’s not a cheap kit. We needed some extras and it was about $200 for the kit which would be fine if there were no issues. All I’ve seen are issues. I will never again recommend this kit.

This jackshaft is the biggest piece of s*** I've ever experienced in my life

No, both parts shrink and go together. They would kinda stay the same if you heat one and freeze the other. When they warm up, they expand and are tight together. "IF" it worked that way, you'd never want to heat your bearing.

Frozen crankshaft and speedy sleeve slip right together and once they warm up, never come apart.

Nothing shrinks together your product is absolute garbage and you're just ripping people off

 

[s jack ahaft]

You couldn't give me an excuse to explain any of this to me I'm a graduated automotive student with 3 aa degrees in automotive technology. And your product is nothing but frustrating and crap

 

[Pablo]

Your product totally sucks I don't care what excuse you have it's absolutely garbage I don't recommend it to anyone if anyone wants to tear their hair out by this product from sick bike parts otherwise it's total garbage total garbage total garbage total garbage

Please provide some details on your problem and we will be glad to help you. Email us your order #. Have you contacted us?

What EXACT problem are you having?

 

[Pablo]

FTR the shafts are precision ground and to a much tighter tolerance than other/earlier shafts.

 

[Pablo]

You couldn't give me an excuse to explain any of this to me I'm a graduated automotive student with 3 aa degrees in automotive technology. And your product is nothing but frustrating and crap

Doesn't matter how many degrees a person has, a little common sense and politeness goes a long way.

Whomever you are, we gave you a week to contact us or at least reply to us. We heard ZERO.

Can we assume you are just making this up as an attack? Has happened before. Not saying you are lying but perhaps you are confused.

Another guess is you bought one of the extremely crappy knock off copies of our product, because yes, there is no way that fake copy will work.

Anyway, we welcome a response. Thanks!

 

[Chainlube]

Doesn't matter how many degrees a person has, a little common sense and politeness goes a long way.

Whomever you are, we gave you a week to contact us or at least reply to us. We heard ZERO.

Can we assume you are just making this up as an attack? Has happened before. Not saying you are lying but perhaps you are confused.

Another guess is you bought one of the extremely crappy knock off copies of our product, because yes, there is no way that fake copy will work.

Anyway, we welcome a response. Thanks!

He probably never even tried one, he couldn't wrap his little 3aa head around the idea of a left side chain driving the right side gears.

 

[Herebyaccident]

I agree with Frog.

When you think about heat expansion and cold contraction, it makes sense.

A shaft shrinks in diameter when cooled, anything with a hole in, the hole gets bigger when cooled. So frog is wrong.

 

[Nirve]

I had the exact same issue as the thread starter.
This is how my shaft looked after 1700 miles.


I can also confirm the problem with the two different shaft sizes. They’re bought more than a year apart from SBP’s:

old



New




I am not that bothered. I got 1700 miles out of one shaft, which is OK with me.
Looks like the new shaft fits way better and will most like not cause any problems.

It’s still the best jackshaft kit out there

 

[Nickt919]

A dab of this.... Locktite 660
Made specifically for this type application instead of thread lock or JB epoxy...spun bearing/worn shaft

If the bearing/shaft tolerance is a little loose new then some with first install and the problem probably wouldn't happen.

https://www.grainger.com/product/2TRL2?gucid=N:N:FPL:Free:GGL:CSM-1946:tew63h3:20501231

Filling Gap Size up to 0.020 In
Temp up to 300F
+/- 3,000 psi shear

A little heat to remove it