Gear coating

E

eabergman

Full member
There's some pitting on many of the gears in my 1971 SF, probably due to the bike sitting for lengthy periods in a damp garage near a river. I just bought a gearset from a later SF (1974) on eBay which looks like it will serve nicely, but it does have miles on it, as witnessed by the hooked countershaft sprocket that came with it. I am wondering if it would be worth the trouble to apply some sort of coating to the gear teeth while I have it on the bench.

Eric
 
eabergman said:
There's some pitting on many of the gears in my 1971 SF, probably due to the bike sitting for lengthy periods in a damp garage near a river. I just bought a gearset from a later SF (1974) on eBay which looks like it will serve nicely, but it does have miles on it, as witnessed by the hooked countershaft sprocket that came with it. I am wondering if it would be worth the trouble to apply some sort of coating to the gear teeth while I have it on the bench.

Eric
Click to expand...
Oil?

Paul
 
Yeah, he does some sort of black coating on just about everything inside the motor (yeah, Red?).

I wouldn't have any concerns about your SF2 gearbox - I've worn many a countershaft sprocket and the gearbox is still totally fine. They last pretty much forever. I did break the mainshaft where it fits inside the 5th gear output bronze bush - not uncommon and worth checking that bush for wear and maybe the others using bronze bushes. The gears themselves should be fine.
 
we use anti-friction coatings on all gears, shafts, shift drum, primary chain sprockets, camshaft sprockets, piston skirts and anything else that rubs/meshes together inside our race engines
Started doing it on tough street engines as well as is an easy power gain for not much money

On the camshafts in the race engines we have the journals chromed
 
Pitting is completely normal in hi-mileage gearboxes. Especially layshaft 4th and 5th gears are affected, they do a lot of work!

No coating on earth will repair pitting, if uneasy with the wear, replace the cog. Lots of NOS sitting on various shelves worldwide.

I'd pay far more attention to shaft/bush wear. The works tolerances are very generous and gearboxes are mostly neglected when rebuild time comes along. "She'll be right" is not the correct attitude when inspecting a gearbox, a siezing/exploding 'box is no fun! But neither are too-closely fitted shafts and bushes, many have fallen to that bait.

Besides, a nicely wirring, barely audible gearbox is a nice change to the general clatter that is so very common.

piet
 
Thanks for all the thoughtful replies. After consulting another expert who is kind enough to respond to my e-mails (a well-known Norton engine builder and tuner) I decided to forego any magical coatings, just touch up rough edges here and there, check bushings and bearings carefully, and get on with it.
 
eabergman said:
Thanks for all the thoughtful replies. After consulting another expert who is kind enough to respond to my e-mails (a well-known Norton engine builder and tuner) I decided to forego any magical coatings, just touch up rough edges here and there, check bushings and bearings carefully, and get on with it.
Click to expand...
Told you Eric. ;)
 
Yes you did, Paul, and I always take note of your opinions! I'm even in the process of getting rid of my triples and sticking to twins and singles.
 
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