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Discussion Starter #1
After a struggle to fit a16t sprocket I realised the rear is a 42t. The chain was too short to pull it off the original 17t front. After much wrestling and swearing we managed to pull the chain off the rear sprocket.
Now I have a substential ratio change. I belive 17t front 37t rear are standard?
What riding symptoms am I about to experience?

Your experiences will be much appreciated.
 

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Discussion Starter #2
Riding symptoms wonderful. Not as snachy off the peg and 60kph in town in 3rd gear fine. Not hunting. Pulls nicely in top gear from 100kph. At this stage will not change to a progressive throttle tube.
 

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After a struggle to fit a16t sprocket I realised the rear is a 42t. The chain was too short to pull it off the original 17t front. After much wrestling and swearing we managed to pull the chain off the rear sprocket.
Now I have a substential ratio change. I belive 17t front 37t rear are standard?
What riding symptoms am I about to experience?

Your experiences will be much appreciated.
Did you try turning the chain adjuster blocks around? Would give you more room to work.
 

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Discussion Starter #4
Adjusters were already reversed to accomodate 42 tooth sprocket. Had to take axle out and skew wheel before enough slack allowed chain to peel off the rear sprocket. Previous owner may have cut and rivetted chain with both sprockets in position. The 16 tooth sprocket made the reversable procedure easier. Little pin which stops the clutch pack rod from rotating fell out. It sits behind the sprocket guard mounting plate in a black plastic bush. Not having noticed it drop out I reassembled the lot. Only to have to do it all again after discovering this pin on the garage floor. Lucky! May done damage to bike and or myself.
 

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Discussion Starter #6
Thank you Spottydawg for this sprocket combination chart. With 16t front and 42t rear, there is a significant torque increase over stock combination. I cannot get my head around how this seems to have virtually eliminated slow speed snaching? Is it that the engine revs sligtly higher?
 

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Is it that the engine revs sligtly higher?
No engine revs stay the same it’s just the change in ratio your using. 17T 42T = 2.47. Just means the main drive shaft has to turn 2.47 times for 1 full turn of the rear wheel.
Standard ratio is 17T 38T = 2.24 hence the jerking, less turn of the driveshaft up front for full circumference of the rear.
I’m running 16T 38T less snatchy than standard but tops out at about 126mph.
I also purchased the dampened front 16T sprocket as it has a rubber mould which in turn helps the plastic chain adjuster last that bit longer.

With the ratio your running you must be struggling to keep that front end down :D
 

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Discussion Starter #8
Bike revs about 400rpm more at 110 kph. So it sounds busyer.in gears just need to change up sooner.. Careful twist of throttle required. But reduced snatchines particularly in second and third gear,
 
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