Does anyone know if theres a rule of thumb re chain slack? Should it be the same as a motorbike? Ive got a Mid engine BEC and need to put a new chain on as its way way too slack. I could always use shims to tighten it up but for peace of mind id rather get a new one

Its for track use only so not many quick take offs

Cheers

N1

I think the class R boys run them a bit tighter than a bike as there is no rear swing arm to take into a ccount so dont need as much slack

I have quite a short chain run on the Furore & run the chain with virtually no slack at it's tightest point. I think "at it's tightest point" is the fairly critical bit, particularly with short chain runs as you will have on a mid engined setup. No matter how accurate your diff, bearings & front & rear sprockets are there will always be a slackest point & a tightest point in the chain run & it's important to set tension at the tightest point, if you set at the slack point then it will be too tight at times.

I find that a brand new chain, set if anything a fraction overtight, will have a significant amount of play by the time it's done 100 miles or so, but once set after this initial bedding in I rarely need to adjust again possibly for 1000 miles plus.

I run mine pretty tight although it's important to check that's at the tightest spot as Russ suggests. Its different to a bike as there's no relative movement between the two sprockets.

It was pointed out to me that where a chain is used to drive machinery the chain is usually very tight. The argument that this overstresses the bearings seems spurious when you consider the forces applied when you dump the clutch at 8k rpm in first gear!