Unchain my bike... or so I thought...
Hans Renold is credited with inventing roller chain in 1880... but
here we are 127 years later and bikes are still laboring under a
steely... heavy... clanky... messy... chain... Mercy me chains are a
pain... belts spell relief... and so my belt drive conversion starts
with an engineering drawing...
Gates Poly Chain comes in 3 belt sizes... 14mm pitch is what HD
employs on their cruisers... 8mm is what I used on the VF500
Belt-0-Ceptor... 11mm is the little known in between belt but only
comes in lengths of 155T and 172T... I need 166T to make it work on
Mr.RC45...
I started with a Buell 11mm pitch sprockets and belt... a 30T up
front and 70T out back... they were machined them to fit Mr.RC45...
so far so good
Buell's steel 30T 11mm spocket installed on the RC45 primary shaft...
Buell's aluminum 72T 11mm sprocket installed on the RC45 axle...
Ideally I needed 628mm between centers as evident with Mr.RC45's 17T
43T 110 links of chain prove to show...
But when I added the Buell 30T 72T 155T setup it measured 561mm
between centers... 67mm too short...
Next I ordered a 172 tooth belt from BMW but with the Buell sprockets
the BMW belt was 664mm between centers... 36mm too long...
Maybe if I machine my own 76T sprocket so I started with a 20lb block
of 7075 T6 Aluminum...
After the teeth were cut by RCD Engineering the block was down to 10
lbs at this stage...
After milling the spokes using only hand eye coordination it was down
to 1 lb 13 oz...
Now with the Buell 30T sprocket 172T BMW belt and 76T home made
sprocket the distance between centers was 651mm... 23mm too long...
because of the single sided swing arm I limited to 20mm adjustment so
I knew it would be close... how close??? less than 3mm or .118
thousands of an inch separates success from failure...
I have failed to unchain Mr.RC45... not that I didn't come close... I
came within 3mm of enjoying a light weight... maintenance free...
snatch free... lubeless belt drive system... it all came down to
finding the right number of teeth in a 11mm pitch belt... and so with
only 2 bikes in the world that employ the 11mm pitch belt (2003 Buell
and the 2007 BMW 800) I have to wait for a 3rd bike to employ the
little known 11mm pitch Poly Chain Belt...
So in conclusion after $1000 dollars in parts and a custom 7075 T6
aluminum sprocket consuming over 30 days worth of machining... I have
NO joy to report... in fact I'm devastated and sad... not to mention
Gates Rubber wants $65K for the mold of a custom 166T 11mm pitch
belt...
Mock up
Hans Renold is credited with inventing roller chain in 1880... but
here we are 127 years later and bikes are still laboring under a
steely... heavy... clanky... messy... chain... Mercy me chains are a
pain... belts spell relief... and so my belt drive conversion starts
with an engineering drawing...
Gates Poly Chain comes in 3 belt sizes... 14mm pitch is what HD
employs on their cruisers... 8mm is what I used on the VF500
Belt-0-Ceptor... 11mm is the little known in between belt but only
comes in lengths of 155T and 172T... I need 166T to make it work on
Mr.RC45...
I started with a Buell 11mm pitch sprockets and belt... a 30T up
front and 70T out back... they were machined them to fit Mr.RC45...
so far so good
Buell's steel 30T 11mm spocket installed on the RC45 primary shaft...
Buell's aluminum 72T 11mm sprocket installed on the RC45 axle...
Ideally I needed 628mm between centers as evident with Mr.RC45's 17T
43T 110 links of chain prove to show...
But when I added the Buell 30T 72T 155T setup it measured 561mm
between centers... 67mm too short...
Next I ordered a 172 tooth belt from BMW but with the Buell sprockets
the BMW belt was 664mm between centers... 36mm too long...
Maybe if I machine my own 76T sprocket so I started with a 20lb block
of 7075 T6 Aluminum...
After the teeth were cut by RCD Engineering the block was down to 10
lbs at this stage...
After milling the spokes using only hand eye coordination it was down
to 1 lb 13 oz...
Now with the Buell 30T sprocket 172T BMW belt and 76T home made
sprocket the distance between centers was 651mm... 23mm too long...
because of the single sided swing arm I limited to 20mm adjustment so
I knew it would be close... how close??? less than 3mm or .118
thousands of an inch separates success from failure...
I have failed to unchain Mr.RC45... not that I didn't come close... I
came within 3mm of enjoying a light weight... maintenance free...
snatch free... lubeless belt drive system... it all came down to
finding the right number of teeth in a 11mm pitch belt... and so with
only 2 bikes in the world that employ the 11mm pitch belt (2003 Buell
and the 2007 BMW 800) I have to wait for a 3rd bike to employ the
little known 11mm pitch Poly Chain Belt...
So in conclusion after $1000 dollars in parts and a custom 7075 T6
aluminum sprocket consuming over 30 days worth of machining... I have
NO joy to report... in fact I'm devastated and sad... not to mention
Gates Rubber wants $65K for the mold of a custom 166T 11mm pitch
belt...
Mock up