Is there an ideal sprocket center to center distance?

[sikbrik]

Planning on going from an 81 tooth to 96 or 97 tooth sprocket (bigger tires.) With the 10t clutch gear, do I have to worry about tooth engagement if I just move the engine forward without lengthening the chain?

Previously, going from 81 to 84 tooth required a decent move of the engine... concerned that going really big might mean there's almost a full tooth less engagement on the clutch side, where about 4.5 teeth are currently engaged. Is it a valid concern or am I okay as long as the engine can move far enough without interference?

Chain pitch is 219, if it matters, and it's a tiny 60cc 2 stroke with a 90lb kid.

Thanks for any tips!

 

[itsid]

there is indeed!

the problem is the fewer teeth are engaged on one end, the more those few teeth will wear
(and with that the small sprocket)..
once the sprocket is worn down a considerable amount, it itself eats away the chain, the worn chain then chews on the larger sprocket.

And a full teeth less engagement on a 10T sprocket means relatively precisely 10% shorter lifespan.

But I don't think you're already in the ballpark where you should worry about that too much.
Just keep an eye on the clutch sprocket occasionally and replace it once it starts to wear down.
(which you should do anyways, even with a 8:1 ratio.)

Also you could re-engage that tooth you lost by adding an idler sprocket (with a chain tensioner) and a few links to the chain without moving the engine around.

the 100cc kart I have has a 10:1 setup more or less (89:9)
anyways it's in the same ballpark than what you are planning
even the intermediate ratio currently installed (85:9 [9.44:1 ratio]) isn't far off;
especially because of my tiny 9T engine sprocket [no clutch.. it's direct drive]
my front sprocket doesn't engage with more than 4 teeth either...

So no, with 10:1 or less I wouldn't be too concerned about the setup,
again keeping an eye on the small sprocket and having a spare handy just in case

'sid

PS yes, 219 chain of course