Trike gearing

[DougieT]

Hi this is my first time on the forum.
I have just completed building a trike using a Yamaha 900 Diversion, using a
Ford Mk2 Escort axle with a 3.77 Diff fitted. Unfortunately the gearing is way out. In 5th gear at 50 Mph it is at 5000 revs.
What Diff would I need to sort the problem. It has 14 inch wheels fitted with 60 series tyres.
I have been told that the Mk1 3 litre capri had a 3.09 diff which would fit the English axle, and that would pos sort the gearing. Other people say all the capris had the Atlas axle fitted.
Anyone any ideas.

[Mark]

Hi mate, try these sites:
http://pw1.netcom.com/~sgalaba/mph.htm

http://www.tirerack.com/tires/tiretech/general/size.jsp

Remember to measure total diameter of your wheel and tyre.

If you can find a 3.09 diff you'll be bloody lucky...the lowest I can get is 3.14

from:
http://www.classicconversions.co.uk/fordstandard.htm
I have a 3.36 in my Valkyrie trike, and I'm changing it to a 3.14 to reduce my revs..I may still have to put on bigger wheels, ATM I run 16" wheels with 245/45/16 tyres on I might have to go to 17" wheels yet.

[DougieT]

Hi Mark
Thanks for those site details, now to sort out the input data.
What vehicle the 3.14 and 3.36 diff fitted to.
The 3.09 for English axle seems hard to find. Better availability if you have the Atlas axle fitted.
With regards to the 17 inch wheels check tyre availability, I was looking at
some but found that the highest tyre profile available was 50 series, which probably might not make much diferance. A higher profile tyre on the wheels you have might do the same job.
The 17inch wheel with a 40 series tyre is near the same as a 14inch with 65 series tyre.
Higher profile availability for 15 inch wheels.

[Mark]

Diff fitted to my Valkyrie trike.....currently a 3.36, but changing it in a couple of weeks to a 3.14