T5 and Cosa clutch

I’m finally gettin ready for the coming season and need to replace my clutch side oil seal. Thought I may as well do a few other bits and bobs while I’m there and have become fixated on the idea of fitting a Cosa 21 tooth Clutch.
Firstly is there any point, it’s a standard T5 motor with a Simonini, I though it might up gear it a touch and reach those revs the Simonini won’t reach.
If I do fit it, what other bits/extras will I need (and that doesn’t include a Malossi Kit!).

Oh Aye, metal oil seal or not?

Cheers Ears, Hally

The cosa clutch,means the complete clutch, easy to replace and a lot smoother, you can get a 20 tooth but I think more expensive by about a £5.
Check the T5 clutch and see if the small hole in the basket lines up with a small hole in the clutch backplate that fits to the crank(crap discription sorry!)the springs sit at a angle not straight,as this makes the clutch release better, no wheelies!
you will also need a special tool to undo the clutch nut on old clutches,like a castle nut.
As for the rear shock,indian lambretta shocks tend to be a lot more harder, so might work,probably a lot cheaper than the bitubo so woth a try!

[:O] standard t5 timeing setting marks are 16 px 125 is 18 (IT)[:shock1:]

Cheers fellas but you’ll have to excuse my ignorance. Is 20 tooth the T5 standard? And do you mean just change the clutch plates? I thought the only cosa clutch that would fit was the 21 tooth, now I understand why not to fit it, but not sure which cosa clutch parts to fit instead.

My clutch at the moment is fine, well a bit keen, and I’m sick of doing inappropriate mini-wheelies at the traffic lights. I guess what I’m needing is something a bit smoother.

Also been told that the Bajaj rear shock is a lot more solid than a Bitubo, my front end wobbles with pillion so I need something more solid as the Sebac rear shock just won’t cut it. it’s a Sprint with a T5 motor in it btw.

Cheers again


i’d go metal with the seal definately,as for the clutch gear its down to personal choice.buy one try it if you like it leave it if you dont sell it on ebay.some say they rev too hard some say theyre too lazy and wont pull.all motors have their own way of working so suck it and see

stroud valleys(midnight hour)sc est 1984

I’ll be the third, and say keep the 20 tooth! but get the cosa clutch as I have just changed mine and it’s a lot better.
The standerd T5 probably wouldn’t pull fourh with 21 as it’s bad enough against the wind as it is[:D]
but if your going to malossi it go for the 21
go with the metal seal, and JB weld it in!
and you will need a new nut and washer as there diffrent,not those skin skimming castle nuts!! ;D

I’d go for a 20 tooth clutch in a standard T5, a 21 tooth will not pull right in 4th, it’s to big of a jump. you will need a lot of power to make them work right more than a malossi on it’s own. i think you can get a 20 tooth cosa clutch ?