Topic: 5 speed CR ratios

[Rod]

Bill, TG and other interested parties: finally got the ratios for the CR cluster in my Tony Dunnell/Dave Dixon IOM 500. Does anyone recognize these ratios, I don't know if they are Yoshi, HRC or other, any ideas?

40/21   1.905
33/24   1.375   27.8%
31/26   1.192   13.3%
29/27   1.074    9.89%
28/30   0.933   13.1%

Overall reduction 51%

[bwaller]

The Yosh CR 5sp that Kayaker pulled out of his bike uses two different gears.

38/21  1.809
33/24  1.375  24%
31/26  1.192  13.3
29/28  1.035  13.2
28/30  0.9333 9.8

Total overall reduction 48.4%

[Rod]

Thanks Bill - I think given their age (late 70's) they must be Honda Racing then as I'm not aware of anyone else doing aftermarket at that time. From a riding perspective, the spacing of the yoshi ratios seem to make more sense to me - i.e. the shortest drop being 4th to 5th.

[bwaller]

It's tough to know where Yoshimura would have had their work done, but I agree it wouldn't seem there were too many options for getting gearbox parts made then?? To have a 21T mainshaft would make you think it came from the same place. Someone chose a couple different ratios with yours and makes one wonder if was better suited for a specific track.

By the way I'm Brent but I've been called worse! 

[Rod]

It's tough to know where Yoshimura would have had their work done, but I agree it wouldn't seem there were too many options for getting gearbox parts made then?? To have a 21T mainshaft would make you think it came from the same place. Someone chose a couple different ratios with yours and makes one wonder if was better suited for a specific track.

By the way I'm Brent but I've been called worse! 

Sorry Brent! - this tranny was in a race engine bought from Dixons in the late 70's with the specific purpose of going into an F2 IOM special built by Tony Dunnel (no slouch round the island himself by the way). Bill Smith had previously ridden one of Dixons 500's to TT success, and Dixon was very much plugged into Honda racing and with Pops - winning a production TT was a big scalp for Honda in those days. Do you think it is possible that they may have given Smith a special set of ratios for the island?

[bwaller]

Who knows? What advantage does it offer over the Yosh set-up? In & out of 4th often might explain keeping 3&4 closer??

Wouldn't think that would suit the Island though?

I'm no bloody help at all!   

[Sam Green Racing]

Phone him Rod, he might remember. 01244 323845.

http://www.billsmithmotors.co.uk/content/pages/about_us/heritage.htm

Sam.

[simon#42]

his memory isn't so good these days , but its possible there were records kept

just a thought but could quaife have made gears at that time ? 

[Sam Green Racing]

I did only say might Simon, he's quite bad on his legs as well but gets in the shop from time to time. Steve Murray might be the one to ask, his long term memory is brilliant, his short term on the other hand is a little to be desired.
The gearbox could also have been a Schafleitner, a very popular box in that era.

Sam.

[lordmoonpie]

I'd heard that Bill was permanently in a wheelchair these days. Bit of a hard deal for someone with fixed false elbows too!

[Sam Green Racing]

Perhaps the reason his Yamaha R1 was slower over the Aintree quarter mile than my RS175. 

Sam.

[simon#42]

I'd heard that Bill was permanently in a wheelchair these days. Bit of a hard deal for someone with fixed false elbows too!

hope thats not true . it would be a real shame . i havnt seen him since keith heckles birthday party last feb and he was walking then .
was he riding at aintree this year sam?