Dynamo belt knacked

[Rex]

G'day GB.
The SRM instructions say 90 degrees. I take it as in one direction.
Cheers

We use the same rule of thumb on industrial processing machinery. Even though accurate tensometers are supplied the old 90' in one direction is more than adequate.

[muskrat]

G'day Mike.
Thanks for your input. I had forgotten your kits are wider.
The inclusion of grease in the compartment is to reduce heat (a little) and reduce wear of the pulley's. Both mine last a lot longer now.
Cheers

[muskrat]

G'day GB.
The SRM instructions say 90 degrees. I take it as in one direction.
Cheers

We use the same rule of thumb on industrial processing machinery. Even though accurate tensometers are supplied the old 90' in one direction is more than adequate.

G'day Rex.
Same for the belt primary on the Cafe and the rear belt on the HD FXST.
Cheers

[Slymo]

Seems to me the inherent problem with fitting modern drives on old machines is that they simply aren't engineered for them. Belts need to run quite tight and that will flog out a drive designed to run slack. The bearings and general precision of the generator mounting and tensioning is far too variable for the relatively fussy tolerances required by a belt. I'm sure they can be fitted successfully but I struggle to see the point.

[groily]

Three points weighed with me in favour of belt drives, which worked for me for a dozen years and tens of thousands of miles:

First, the gearing up by about 20%, making 12v operation perfectly practicable without other changes.
Secondly, not eating the casting of the inner timing cover and creating that familiar mix of aluminium shavings and grease.
Thirdly, quieter operation.

I found the Dynamo Regulators one (now supplied by another business) tougher than the SRM one I started with - fatter belt, but also a more durable taper (in my case) on the driving pulley. Couldn't fault it - but neither of them put untoward stress on the dynamo drive end bearing as far as I could tell - I never replaced mine, anyway. Maintaining belt tension didn't seem to me to be a problem either but I checked it at intervals all the same.

Apart from costly-to-replace-regularly timing belts on cars (where chains really are preferable I reckon), I quite like belts to be honest.