Comet Top End Speed

[vibrac]

I must admit to a henious crime two links and a spring link are wired to my biggest sprocket thats what I used when we went to 3 sisters at wigan. (it was named because of 3 slag heaps that used to be there) buy another chain just for that go cart circuit? I dont think so. we shall not return to that place again.

 

[johncrispin]

I agree with the remarks about the overall gearing, and the bike being a happy revver and the liberating effect of say the 50t rear, but I went the other way. Depends a lot on the type of riding you do. Here in Devon there are some steep hills and many VMCC runs are a bit like a road trial in places. The wide gap between 2nd and third is a bit of a constraint IMHO so I went the other way and fitted a 46t, I wanted a 47 but could not find one (they used to be available as far as I know). On steeper gradients the bike on the higher gearing I can stomp past other similar capacity bikes revving hard in second, rather than slogging the motor (although willing) on the lower gearing in third. When compelled to use a motorway. I do not like trying to do 70 I find the noise too much and the bike although quite capable of it is working quite hard, so I tend to stick to about 60-5. Fast A roads I find its nicer with the slightly taller gearing. The old saying that a Comet is 80mph and 80 mpg seems about right.
I would suspect your carb/ setting. I replaced the monobloc on my bike with a refurbed original type 29 and this imparted much more flexibility with book jetting, the motor seemed just that bit more at ease with itself. I would check if you are getting full advance also. I have always thought that the Comet needed just another couple of BHP really but for an old bike it is very comfortable, fabulous handling, and just look at the contemporary British Iron and it compares pretty well. all the best J

 

[Bill Thomas]

I agree with Vibrac, Two spring links are fine, You never know you might want to change back again !! 17 years of racing, Twin and Comet, I did it all the time, Because of fast and slow tracks. On the Comet, On the road I have tried 45, 46, 48, and 50, But I have come back to 48 !! The Factory knew best !! Good Luck, Bill.

 

[Howard]

I must admit to a henious crime two links and a spring link are wired to my biggest sprocket thats what I used when we went to 3 sisters at wigan. (it was named because of 3 slag heaps that used to be there) buy another chain just for that go cart circuit? I dont think so. we shall not return to that place again.

Thanks for that (thanks button?), I wondered where it got the name. Like you, biggest sprocket and chain with a couple of extra links, and I still only used second and third!!
H

 

[redbloke1956]

I agree with Vibrac, Two spring links are fine, You never know you might want to change back again !! 17 years of racing, Twin and Comet, I did it all the time, Because of fast and slow tracks. On the Comet, On the road I have tried 45, 46, 48, and 50, But I have come back to 48 !! The Factory knew best !! Good Luck, Bill.

Hi Bill, was that with a stock Comet? Thanks for the info.

Kevin

 

[vibrac]

I looked on images for that picture of a fifties TT winner crossing the line with the chain cascading off his rear sprocket.
I think that picture more than anything started the 'no spring link' rule. But I must admit I have never riveted up a chain for club racing- if I did a TT machine or classic endurance perhaps I would

 

[Bill Thomas]

Hello Kevin, Nothing of mine is ever Stock !! But the power is not always good, The Comet now has a rear cylinder head with a 34mm flat slide carb, Don't think it's giving out much power ! Getting old now and not needing the speed like I used to, Me and the bike ! She did 99.8mph at the end of a flying 1/4 in road trim But I had nicked the front head and 36mm delorto carb off the Special, It did that on standard gearing. Have fun, Bill.

 

[nkt267]

The Comet now has a rear cylinder head with a 34mm flat slide carb, Don't think it's giving out much power

Someone,a long time ago when the dinosaurs roamed the earth, I was told that a Comet was supposed to go better with a rear head that a front one.He ran with a 229 mounted sideways and the correct float chamber to go with it..John

 

[Bill Thomas]

That may have been, But with me I just wanted to make it go, Had to get to the 500 Rally, The Engine/Gearbox had been sitting in my front room so I had to throw a bike together quick. Got a bit of car exhaust with a bend in it to make an inlet manifold without altering the petrol tank, As long as it did 70mph that was fine with me. Cheers Bill.

 

[cinquecento]

Hello Bill - what was the spec' for the 'special' head mentioned?