Reverse hooked gearbox sprocket

Thanks Andy and respect your undoubted knowledge. Yes I'm sure the power loss is there, especially on a cold chain but I wonder how much? On the gear change aspect I'd never have considered that and certainly can't say I've ever noticed any difference. Mind you I've just pulled a cheap double row from my rear drum with the balls losing their chrome plate (flakes in the cleaning fluid). It was rough/notchy as bugge*y but naturally not noticeable spinning the wheel. Buying a decent quality this time.
I'd certainly be tempted to try an IWIS but that needs a new rear drum as well and I'm on a retirement budget at the moment!
BTW I did measure the chain and fully stretched with a 10lb weight on it I have less than 1/16" in 20 links. Certainly when wrapped around the sprocket/drum there is very little 'lift' off the teeth. 'O' ring has to be good for something if not efficiency and sprocket care! Cheers.

The width of the teeth and the lb-ft's of torque over time by throttle or engine drag determine the life of the teeth, as well as their temper surface quality and correct tension of course. O-ring chains new will hardly bend links when held out straight for gravity to act, so definitely sucks off some power to heat chain, but not really noticed if not trying to race around to compare with standard looser chain links. Even well worn O-rings are still a good drag. So to me, O= Obsolete and I will never buy another O ring only X-rings or just good plain chain. The best down and dirty chain wear measure is how far out of valleys the chain can be lifted when its close to correct tension, but a really worn chain can not be tensioned enough to prevent links riding on the weak teeth tips. How ever far ya can pull links out of valley that's where the chain loads are being applied to teeth. Most modern cycles tend to change front sprocket along with chain to extend the new chain's life.

On my SV650 520 X-ring conversion I fitted one tooth smaller front sprocket and alloy one tooth larger rear, as per Suzuki SV-VStrom forums suggestion to get a bit more acceleration but over 10K miles use in couple of seasons the front steel teeth began to fan over and the rear alloy teeth become nubbins with chain slip on throttle - so returned to stock set up ratio with 525 X-ring and steel rear teeth for the long haul maintenance cost - especially after exploring how corner crippled moderns are compared to my Ms Peel. Stock SV650 can run rings around a floppy eared un-tammed isolastic Commando, so my sense of a Commando being an old man's quaint fun bike or an elite racer's life/death skill tester terror.

Going smaller on the front sprocket is a really bad idea as it will induce the polyginal effect.

Not going into details so google it.

I dont care what the "experts" say unless you are riding daily in all weather O or X ring does not
make good sense. Also without dismantling the chain and micing the pins it is impossible to
accuarately measure wear as the O rings hold the chain tight. Taking your O ring to the end of
the adjustment will result in failure as it could be up to 6 times over the permisable wear limit.
Some modern bikes now have a little sticker about halfway along the adjustment with an arrow
saying "change chain".

As with any engineered product it is the base material that important, ask your chain supplier
what the base steel is on your chain purchase and watch him go blank.

Sleep well

ANDY