Triumphrat

Mecchanica · 09-25-2006

Oh, and the fifth cog isn't an overdrive. The top gear in both the four speed and the five speed is the same ratio....1 : 1. The first gear in the five speed is a little lower than the first gear in the four speed standard box, and you can then up the engine sprocket to 20T and have a slightly higher first and a nicely higher fifth, although many five speeds already have the 20T.

KADUTZ · 09-25-2006

you are correct big fish in April 71 a five speed gearbox by rod quaife were made optional and a Quaife 5-Speed sticker was put on the trans cover of equipped bikes. (as per Dave Gaylin in Triumph Motorcycle Restoration Guide Bonnieville &TR6 1956-1983)
The parts list is on the last page of the 1971 parts manual
However in Triumph Motorcycles in America it is stated
while the 5 speed was advertised as an option it didn't arrive until spring '72 on the 650 models.
a road test of the '72 T120RV, done by Cycle World in 6/72,is reprinted in the Brooklands Book Triumph Bonneville Gold Portfolio 1959-1983.
if I remember the early 5-speeds were recalled due to some failure
also Triumph service bulletin (Twin) 18/71 dtd 12/6/71
deals is titled Five-Speed Gearbox Overhaul Instructions)

other than the 80's Honda dual range gearbox what motorcycle ever had an overdrive?

[ This message was edited by: KADUTZ on 2006-09-26 04:10 ]

Mecchanica · 09-26-2006

None that I know of, outside of some aftermarket HD gearsets, but a lot of people think the Triumph fifth is on TOP of the four speeds, an overdrive. Just to clear that up. Don't install a five speed if you are looking for a taller top gear.
The Quaife is a considerably different gearbox from the Triumph box. The 1971 factory manual lists the Triumph box as an option and uses Triumph numbers for the parts, which were made by Triumph, near as I can tell. I have never seen a Quaife come out of a stock 71.
Speaking of fish, a buddy just brought me a big hunk of ahi for tomorrow's din-din. That's yellowfin tuna. Good stuff, so fresh, it's almost twitching. I had a little today as poke (po-kay)...raw cubes of fish in a soy, sesame, and wasabi dipping sauce, topped with chopped green onion and red pepper flakes. I traded a bag of Norton Commando footpeg rubbers for it. Fair deal. The fish was fresh, the rubbers have been in the bin for a couple of years.