Full marks Glen, if you can make a vin 'box work as well as a norton/amc, as they say here, you have "rung the bell" Respect, Roy.
Quaife/Surtees overshifting
- Thread starter Monkeypants
- Start date
Thanks Roy, but honestly I think it is the design of the Quaife that makes for the slick shifting, rather than my efforts.
Of interest, while looking for info on the overshifting problem, I found an MPH article written by John Lumley in 1969. In the article John discusses the idea of a new Vincent 5 speed gear cluster to be made by his friend Ken Quaife. The description of the kit is almost identical to the one we can purchase today, however the estimate of cost is a little lower at just 100 GBP!
John mentions that some of the experienced Vincent people of the day have expressed concern that the narrow gears of the five spl not be strong enough for the job, however Ken Quaife responds that with modern gear geometry the Quaife 5 speed for the Vincent is "good for 180 Brake Horsepower"
At the time of the article, the design work is complete and all that is needed to get production underwsy is a minimum order of 25 gearts by a group or individual. Aparently
Of interest, while looking for info on the overshifting problem, I found an MPH article written by John Lumley in 1969. In the article John discusses the idea of a new Vincent 5 speed gear cluster to be made by his friend Ken Quaife. The description of the kit is almost identical to the one we can purchase today, however the estimate of cost is a little lower at just 100 GBP!
John mentions that some of the experienced Vincent people of the day have expressed concern that the narrow gears of the five spl not be strong enough for the job, however Ken Quaife responds that with modern gear geometry the Quaife 5 speed for the Vincent is "good for 180 Brake Horsepower"
At the time of the article, the design work is complete and all that is needed to get production underwsy is a minimum order of 25 gearts by a group or individual. Aparently
Apparently that did not occur until much later, perhaps sometime in the 1980s when John Surtees plunked down enough cash to get the first 25 gearkits built.
Also, until about 2008, the fourth gear in the five speed was at a 1.075 ratio, great for a road racer running at 6,000 rpm but not all that effective for a heavily laden road bike pulling up a hill at around 3,000 rpm and needing more oomph. After 2008 the fourth gear ratio was lowered to 1.15 to give a greater advantage when dropping down one gear. This made the gear spacing between 3rd,4 th, and 5 th more even.
Also, until about 2008, the fourth gear in the five speed was at a 1.075 ratio, great for a road racer running at 6,000 rpm but not all that effective for a heavily laden road bike pulling up a hill at around 3,000 rpm and needing more oomph. After 2008 the fourth gear ratio was lowered to 1.15 to give a greater advantage when dropping down one gear. This made the gear spacing between 3rd,4 th, and 5 th more even.
I think Surtees or Quaife recognized that the vast majority of the gearkits go into 1000cc roadbikes. For racers or overbored solo roadbikes they still offer the 2.07 to one high geared first, same ratio as Black Lightnings and early Shadows. The other first gear option is 2.46, which I have. With 150 mph overall gearing the 2.46 first feels about right for a road bike that will get used in heavy traffic on occasion.
For a standard 1,000 cc bike that gets loaded two up plus touring luggage, it seems that, once again, Phil had it about right with the 2.6 Rapide and late Shadow ratio. He also picked a really great third gear ratio that gives a standard bike good pull from about sixty mph all the way to 100 mph.
Glen
For a standard 1,000 cc bike that gets loaded two up plus touring luggage, it seems that, once again, Phil had it about right with the 2.6 Rapide and late Shadow ratio. He also picked a really great third gear ratio that gives a standard bike good pull from about sixty mph all the way to 100 mph.
Glen