how do you turn a 40 tooth sprocket into a 60 tooth on bsa full hubs pre60

[jimg1au]

need to have a rear sprocket in the 50-60 tooth size and ariel/bsa didnt make them that size for the full width alloy rear hub. you used to see old dirttrack and scrambles bikes with sprockets on top of the old sprockets.
jim

[Tomas]

Just buy any 50-60 tooth sprocket that has enough material on it and machine inside diameter to suit your hub and than drill bolt holes to suit your hub.
Hope it helps.

[jimg1au]

that wont work as the full width ariel/bsa hub sprocket is dished
thanks

[OverTheHill]

not sure if this helps but on my unit unit t100 metisse back in the late '60's i had a BSA wheel [not full width ariel type] & had a sprocket overlaid [over the teeth], machined to fit snug over tops of teeth then 6 or so holes large drilled that fits half the bolt in the tooth dish & half up into the overlay sprocket. Worked fine for years. Cheers.

[jimg1au]

this is a sprocket only 42 teeth

[huskibul]

not sure if this helps but on my unit unit t100 metisse back in the late '60's i had a BSA wheel [not full width ariel type] & had a sprocket overlaid [over the teeth], machined to fit snug over tops of teeth then 6 or so holes large drilled that fits half the bolt in the tooth dish & half up into the overlay sprocket. Worked fine for years. Cheers
                                                                                                                                                                                                                         Great idea OTH  ! The modern Renthal Twin-ring sprockets work on the same principle with alloy inner and steel outside/teeth   

[JAP 454]

not sure if this helps but on my unit unit t100 metisse back in the late '60's i had a BSA wheel [not full width ariel type] & had a sprocket overlaid [over the teeth], machined to fit snug over tops of teeth then 6 or so holes large drilled that fits half the bolt in the tooth dish & half up into the overlay sprocket. Worked fine for years. Cheers
                                                                                                                                                                                                                         Great idea OTH  ! The modern Renthal Twin-ring sprockets work on the same principle with alloy inner and steel outside/teeth   

And very early CT 90s, 1967/8 used the same system, before the dual range box. Did put a few together at Bennett Honda.
Foss

[bazza]

Turn down original ,sweat a 60 tooth on,weld,turn down weld if want smooth look

[mike1948]

OverTheHill's idea used to be the way to go in the past, being much easier to change gearing by simply bolting on another outside sprocket for different tracks, whereas welding is a done deal, you then need another dished inner to use.