Primary Belt Drive Pros and Cons?

Status
Not open for further replies.
Interesting. First I've heard of that term.

Is there anything you don't know, Les? :wink:

Debby
 
debby said:
Is there anything you don't know, Les?
Click to expand...

Well...I can't answer to your question, Debbie, so I obviously don't know everything. :wink:
 
How fast would Many belt ratio with 21T sprocket calculate at 6000 on standard tire OD?
 
Hortons Norton said:
Yea thanks Les, I learned something today!!!!
Click to expand...

actually didn't bill first talk about hunting ratio (oK didn't explain it - but common knowledge, at least i thought) :shock:
 
I know about the hunting tooth ratios on gears but I thought it only applied to chains if the number of chain rollers was divisible by the sprocket teeth. The sprocket to sprocket ratio didn't matter. Jim
 
comnoz said:
I know about the hunting tooth ratios on gears but I thought it only applied to chains if the number of chain rollers was divisible by the sprocket teeth. The sprocket to sprocket ratio didn't matter. Jim
Click to expand...

I learned the hard way that it does matter for sprockets and chains, did the standard 15t to 14 t CS sprocket change on my Ducati and it yielded a truly horrible combination (though the swap works fine on most Ducs with other rear sprockets)....14/42 w/ a 102 link chain....had noise, vibration, and rapid wear. Did some research, discovered hunting ratios, and went to 15/44 104 links and all is well. This site shows chain rotations for repeat same tooth/same link contact for up to three combinations at the bottom, interesting stuff...the current ratio I use is actually much better than stock and waaay better than my first try
http://www.gearingcommander.com/
 
So I clicked help under same tooth same link and it confirmed what I just said. Jim
 
comnoz said:
So I clicked help under same tooth same link and it confirmed what I just said. Jim
Click to expand...

umm, no that is not what it says at all, the site discusses why 11/21 is much better that 10/20 for example...maybe reread it??
this shows the numbers for the combinations I tried on my bike 15/42/102, 14/42/102, and 15/44/104
the chain length and sprocket ratios BOTH make a difference

Primary Belt Drive Pros and Cons?
 
ludwig said:
There is more to sprockets and chains than the nr of teeth .
A chain drive sprocket isn't round but forms a polygon .
This makes that the rollers do not make a circular movement , but are hammered up and down .
It is called the polygon effect .
The forces involved are considerable and eat HP, especially on smaller sprockets , like less than 19 teeth .

http://www.kettentechnik-roeder.de/en/technology/theory
Click to expand...

nice!
 
comnoz said:
Cons with the RGM drive are the clutch drum usually needs to have 20 or 30 thousanths removed from the outboard end of the splines so there is enough room between the circlip and the splines to allow the diaphram spring to go slightly concave and apply correct pressure to the pressure plate. If you make the clutch stack thicker so the diaphram spring does not need to go concave you will be rewarded with a heavier than necessary clutch pull and more clutch drag.

Sometimes with the RGM front pulley the center will be a little too large and the backside of the pully will contact the crank seal and destroy it. I have had to exchange pulleys or use shim stock under the pully to keep it from going on too far from time to time. Jim
Click to expand...

Jim, a friend of mine is working on a Mk2 850 with a belt drive, clutch is slipping.
There are only 4 copper plated friction plates
The belt drive probably was fitted quite some years ago.
Belt teeth profile is of a Synchroflex AT10, colour is red (do not know if it was this way when new), belt width is 30mm.
Distance from bottom of clutch drum (from the riveted disc) to start of diaphragm spring groove is almost 28,5 mm.
For a standard drum, this is about 32 mm.
Could this be a Hayward belt?
And is this the RGM marketed belt you refer to above?
Thanks, Bennie.
 
slimslowslider said:
comnoz said:
Cons with the RGM drive are the clutch drum usually needs to have 20 or 30 thousanths removed from the outboard end of the splines so there is enough room between the circlip and the splines to allow the diaphram spring to go slightly concave and apply correct pressure to the pressure plate. If you make the clutch stack thicker so the diaphram spring does not need to go concave you will be rewarded with a heavier than necessary clutch pull and more clutch drag.

And is this the RGM marketed belt you refer to above?
Thanks, Bennie.
Click to expand...
Click to expand...


Yes, That sounds like the RGM belt drive.
With only four bronze plates it is likely to slip some.
You would also want to make sure the diaphragm spring can go concave enough to compress the plates. Usually the area where the diaphragm spring is located needs to be widened a bit to allow the diaphragm to flex. Jim
 
Thanks Jim.
What do you reckon, is there any chance to get an extra friction plate and steel plate of any kind in there?
I assume for now the pressure plate is the standard 850 one.
 
slimslowslider said:
Thanks Jim.
What do you reckon, is there any chance to get an extra friction plate and steel plate of any kind in there?
I assume for now the pressure plate is the standard 850 one.
Click to expand...

I run 5 plates in my clutch. The pressure pate will need to be machined thinner to get the diaphragm correct -slightly concave at rest. jim
 
I ended up using Steve Maney's belt drives in both bikes, put an extra steel plate in the road bike to get the stack height correct, and it is plug and play other than that and I like the slightly taller gearing , which knocks off about 450 rpm at 70mph compared with standard gearing.No change to gearbox sprocket to achieve this.
I tried the extra plate in the race bike and it wouldn't allow me to get the circlip back in outside the diaphragm, so now realise I have a thicker pressure plate compared to the road bike.
This caused me a bit of clutch slip over 6000 rpm (increased HP as well)which would come back to me after feathering the throttle, by then you lose speed and position on the track, didnt help that some grease had spun out of the 'sealed' bearing i repacked and contaminated my first plate in the basket!
Still need a thinner pressure plate though as diaphragm sits just slightly convex at rest an really needs to be concave and full pressure on the pressure plate as Jim states in the above thread.
Regards Mike
 
Polyginal is the most destructive thing for chain drives and yes 19 tooth
is about minmum but 17 and 18 will work. This was the reason that 630
chains wore badly as most front sprockets were around 13-14 tooth so
they would fit in the space.

Roller battering is common on high speed drives thats why I like the Merc
duplex.......big pins and NO rollers.

Andy
 
Status
Not open for further replies.

Similar threads

DougBoost
Help identifing this belt drive kit? And should I just go back to stock triplex chain?
2 3
Replies
49
Views
2,535
74 Lloydy
74 Lloydy
jms
Atlas Belt Drive
Replies
7
Views
449
jms
jms
Dellis
Heavy Vibration Issue
2 3 4 5 6
Replies
109
Views
6,073
Schwany
Schwany
Jerry Doe
Belt drive on A10
Replies
10
Views
869
Matchless
Matchless
ashman
Seems a lot on here have different ways of doing thing on their Norton's
2
Replies
25
Views
1,694
sammysnail
sammysnail
Back
Top