Front SBP chainring wear

What condition is your chain in? Sometimes if a link is getting rusty it doesn't bend far enough, that can also cause jumping.

First I would recommend running the chain a little tighter than you think you should. This is typically the most common reason for chains jumping along with alignment but you said you checked that. Next I would check that the rest of the set up is tight. If something is coming loose it could cause the engine to twist under load. I would also carefully examine each tooth on the chainring. It is possible that when it jumped the first time it may have slightly bent a tooth on the chainring causing it to continue to jump. Just some suggestions.

timboellner said:

I don't quite know how many miles I have on my HD shift kit from SBP.
but I think the front chain ring and the 10 tooth sprocket are starting to wear. (500 miles or so )...

How many miles have you guys put on the shift kit and have you needed to replace sprockets?
How bout the bearings?...

Click to expand...

Hey Tim, tho I suspect ya figured out the problem I figured I'd answer yer other questions jus' ta give you an idea about wear rates

I've dang close to 4000 miles on my Rollfast build w/a shiftkit & the bearings are showing no signs of undue wear whatsoever. I did gently pry off the dust covers & pack them with a quality marine grade bearing grease when I first built the bike... and then proceded to abuse & neglect them heh

Two of the sprockets do have fewer miles on them, I switched out frm a 10t to 9t & 44t to 48t chainring while dialing in the gearing to suit my 3sp, the hills around here & my crazy heavy vintage bike... I did that at around 1000 miles or so.

The only problems I've had would be breaking the lil aluminum L bracket used on the gen2 SBP kit to attach & stiffen the back plate to the right side plate, I replaced it w/a steel one and that fixed it right up (moot point w/the newest shiftkit ofc) and bustin' a coupla chains.... which is my fault & nufin' to do with the kit as not only were they cheapo chains, I mighta been abusing my bike a bit at the time


edit;
erp... I forgot about the freewheel bearing I swapped the HD bearing out for the standard one about 1500+ miles ago. I had a bit of a "pulsing" issue in the powertrain somewhere & I was trying to track it down (it's also what broke that lil L bracket) - turns out it was the press fit on my right-side pedal crank (replaced) & not the bearings which are in fine shape (also repacked w/marine grade grease when new)... I'm still runnin' the cheap freewheel bearing just ta see how long it'll put up w/me