sprocket sizes

Yorkie · Post by **Yorkie** » Thu Aug 25, 2011 3:18 pm

or a Tri**ph

Rob Harknett · Post by **Rob Harknett** » Thu Aug 25, 2011 3:56 pm

Or a modern 50cc scooter, now those things really rev, they have to, plie on the revs & BHP to max, thats just to pull away and up to 30

bigwol · Post by **bigwol** » Fri Aug 26, 2011 2:00 am

quote:
Or a modern 50cc scooter, now those things really rev, they have to, plie on the revs & BHP to max, thats just to pull away and up to 30

Dont knock 50cc scooters Rob, they are the entry level P2W of today, and their riders may just end up, in 40 years, the classic and vintage iron enthusiasts who keep british iron running and on the roads.
We need new blood of all ages on bikes. Just ask yourself what was the average age of people at the section meet tonight.
Oh, and thanks for the CD, will listen when i get a chance!

bigwol · Post by **bigwol** » Fri Aug 26, 2011 12:44 pm

quote:
Rob has a pertinent point about weight, these bikes were aimed at much younger riders and none of us were exactly overweight in those days.
Just look at any 1950's 60's bunch of riders and see what a lean and scraggy lot we all were.

I met Rob for the first time last night (thanks for the CD Rob)and can see why he brought up the weight issue. He's a big lad that Rob!

Rob Harknett · Post by **Rob Harknett** » Fri Aug 26, 2011 1:03 pm

Not knocking the scooters at all Dave, in fact I was one of the first to put my hand up at a committee meeting to except they are " club bikes of the marque" the AJS ones that is. An also had a hand in agreeing to add such a bike as a raffle prize last year, in the clubs raffle.
I think the average age at the section meeting last night was approx sixteeneight.
as most are recycled teenagers.

SPRIDDLER · Post by **SPRIDDLER** » Fri Aug 26, 2011 1:46 pm

Power developed by Chinese 50cc motors, (both 2 and 4 stroke), is claimed to be about 80bhp/litre versus the 42 bhp/litre from a standard 350 heavyweight and only 18% less than the 105bhp/litre from the 350cc tuned 7R .
As Rob says, the power of the 50cc engines derives principally from the higher revs; the power figures above are at roughly 7500rpm for the Chinese 2 and 4 stroke 50cc and the 7R, but at only 4250rpm for the standard H/W 350.
One other major factor is that all the Chinese 50cc scoots have belt drive Constantly Variable Transmission (CVT) which means that whatever the road speed th'engine is almost always running at the high revs where it produces its max power, unlike our plonkers which have heavy flywheels and deliver throughout the rev range, therefore choice of sprockets (gearing) has a substantial effect on the bike's flexibility.

(Just idle thoughts on a boring grey, wet and dreary 'Summer's' day )

Merlin · Post by **Merlin** » Fri Aug 26, 2011 2:04 pm

(Just idle thoughts on a boring grey, wet and dreary 'Summer's' day )
I was hoping for on of those days but SWMBO has other ideas.

SPRIDDLER · Post by **SPRIDDLER** » Fri Aug 26, 2011 6:38 pm

quote:
(Just idle thoughts on a boring grey, wet and dreary 'Summer's' day )
I was hoping for one of those days but SWMBO has other ideas.

......

itma · Post by **itma** » Fri Aug 26, 2011 7:06 pm

more wallpapering then Merlin?

Merlin · Post by **Merlin** » Fri Aug 26, 2011 7:45 pm

Sadly not itma WALKING she is obsessed with exercise.Have suggested horizontal jogging but fell on stony ground.