Sick Bike Parts New 21T Jackshaft Sprocket

[FurryOnTheInside]

It would seem logical that the oscillations from the poor quality engine drive sprocket are transferred through the whole bicycle frame and therefore the jackshaft too, especially if not running the S.B.P. LHS tensioner where the spring would help somewhat in reducing the looseness at the loose side of the engine drive sprocket. So it could be that it appears as though there is eccentricity in the RHS jackshaft sprocket even if there isn't.

 

[Ghost0]

The keyway won't really cause oscillation unless the bore is so big that tightening the set screw on the key will throw it out of round which doesn't sound like the case if it was tight to get on. Only if the teeth are out of round will it oscillate. It would have to be out 20 or 30 thousandths of an inch to tell and that is a lot. I am not saying it isn't possible, all sorts of anomalies can occur when machining and heat treating. If you are confident it is out of round send me a PM or email me and we can replace it just to be sure. We are very careful to put out a good product so when something isn't right we want to address it right away.

 

[FurryOnTheInside]

There is no question that the engine output sprockets are dreadfully out of round. Pablo and I just made the decision tonight to pursue a high quality round engine output sprocket made in the USA. We will let you guys know when it is available.

SICK!

 

[Fabian]

Let me put it this way: Do you guys think there will be a big demand for a good 10T output sprocket?

Most definitely yes; more so if it's a spiffy looking anodised sprocket with multi colour options. The same goes for the 17T and new 21T jackshaft sprockets i.e. lots of pretty colour options.

 

[Fabian]

I don't know how much it'll bug me if the chain goes loose then snaps tight 1000 times per minute or how severe the loose-tight-loose-tight action will be. I'm sure Fabian will elaborate on that though.

I can say from my personal experience that a noticable amount of medium frequency vibration disappears when the left hand side chain tensioner is fitted; eliminating the chain whipping about from the acentric 10T sprocket.

 

[Fabian]

yes i want one now

my last two sprockets have been dreadful

the out of roundness causes an oscillation which runs through the drivetrain and rear suspension

I agree. all of my 10T sprockets have been horribly out-of-round, and i mean horribly out of round.
The installation of the SickBikeParts left hand side chain tensioner noticeably reduces vibration.

Scroll forward to 1 minute on the video to see the poor machining tolerances of the 10T Chinese output shaft sprocket:

 

[Fabian]

I have never had a problem with SickBikeParts jackshaft sprockets.

 

[battery]

I cant say thgat thats what it is. but it does only happen with the 10T further investigation needed. and yes there will be a demand for anything gears and sprockets! as for all kind of coulors I disagree black or silver would be nice. I have a black engine, if my shift kit could have came in a powder coated black it would have been a plus.

 

[Fabian]

If you have a brand new chain installed, give it time to wear in, because brand new chains have tight spots (or better put, slight dimensional differences), even though that sounds like an impossibility.

 

[Fabian]

I have a black engine, if my shift kit could have came in a powder coated black it would have been a plus.

What if you had a "red" engine? Wouldn't it look so much better if the shift kit (with chain tensioners) had "red" anosidsed sprockets...