Gearbox Sprocket Back Lash?

Hi all,
Have finished I think they call it a sympathetic restore on a 2009 T100 865 EFI, strip down brake callipers new seals,pads etc etc the list is long….have put new chain and sprockets on,……here’s my question with bike on the main stand and putting the bike in gear I can turn the rear wheel 20-25mm before engaging gear sort of back lash I suppose….the engine has only done 20,000 miles and runs really good, was going to move it on but I really like the bike and it rides really great…..or am I being paranoid!……thx advice welcomed…

 

Have you checked the cush drive rubbers in the rear wheel? When you turn the wheel does the rear sprocket turn at the same time or is that where there is some slack? Which way are you turning the wheel? Could be taking up the slack in the chain depending on which way you turn it.

 

Thx for your reply, put new cush drive rubbers in the rear wheel…have checked the movement is gear cox sprocket, have taken the gear cover off to make sure… just wondering if this bit of slack is standard…

 

I think a small amount of movement / backlash is normal but can't say when it becomes excessive.

 

Is chain adj up to spec? Is chain new?

 

Hi, yes chain is new as are both sprockets, might not have described this very well, so if I put the bike in first gear with the back wheel of the ground I can turn the back wheel 20-25mm before before the engine turning…….so I suppose what I’m asking if anybody with a Bonny or the T100 865 EFI 2009 ish with a main stand can do the same with their bike in gear and tell me if theirs is the same amount of play….i have taken the sprocket off so I can see the slack in the gearbox sprocket when in gear…..this might perfectly normal, would like it confirmed though……

 

Every chain driven bike I’ve ever owned has had the “backlash” you described, from new. If you saw a gearbox in bits you’d see it’s normal. Bike gearboxes are not like car gearboxes. Cush drive play is when the rear sprocket moves relative to the rear wheel.

 

Thx for your reply, definitely not Cush drive play that’s fine…..beginning to think this is just normal and the gearbox sprocket turning approximately 20mm when in gear is perfectly ok….so if any body with a 2009 ish Bonny/T100 can see if theirs is the same just to confirm and put my mind rest….

 

If l think on l can have a butcher's at my 2010 tomorrow

 

Much appreciated……

 

Well, as l expected, you have nothing to worry about. Put bike in gear and turned wheel backwards until it stops, then forward. There's around 30mm of lost motion. I can clearly see it isn't chain slack or cush drive play. Given the angular moment of a rear wheel against a gearbox sprocket, completely no surprise. So worry about paying your mortgage or global warming if you must, but my view is you have a totally normal bike to ride to take your mind off such things

 

....unless there's something wrong with my bike. Another sleepless night incoming

 

Ahh many thanks for that info….not normally paranoid about things but that had me wondering, still all good now…..right back to worrying about the demise of the Wide mouth tree climbing frog from the gobi desert and also the marathon running tree sloths from the sands of the Kalahari……..

 

Ahhhh say it’s not so!……back to fretting and pacing about the room!

 

Hmm, this backlash situation reminds me of one of my Hondas; in 1969 bought me a new Honda 350 scrambler after owning a Honda 150 and 305; noticed immediately that there was a backlash when going into first and then clutching out to move; definitely a bit of a hesitation; took back to dealer and got the answer - nothing wrong, thats the way it is; got used to it and clutched out a bit from a stop to suck up the play before beginning my move.

 

Thanks for your reply, kinda realise this is normal now….still had me wondering though