Final drive, front sprocket play on spline

piranha-bro2 said:
Highly unlikely the sprocket would be soft, Greg. It's the splines that seem to get hammered. No easy fix on them without a case split and some specialised engineering work.
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Yes, agreed. But re sprockets, I've been retoothing vintage/classic sprockets for years. Where a new original is unobtainable. Pull the right size/pitch sprocket off the shelf and bore it to fit the machined down original. Then weld. And harden.
But it has been surprising to me how many off the shelf replacement sprockets are soft. I expect to have to soften them prior to machining but probably 20% don't need it.
These are reputable brand aftermarket front sprockets too.
Always worth a quick and dirty hardness test before fitting a new front sprocket.
 
I was strongly advised by both Wolfgang and Red to check replace the two little needle bearings on the mainshaft inside the 5th gear output shaft. If these collapse there's all sorts of damage. Now my bike's only done 41,444km, and these two little bastards look like they've been pretty hot.
Regardless of the output shaft, I'm glad I pulled the motor just for these! It might have to be yet another job to add to the list for "regular maintenance" 🤣

IMG_2866.jpeg
 
That's one big job for 'regular maintenance' Andy!! Mine runs the bronze bushes. Probably covered 160,000km before I let an idiot ride my bike and very soon after I discovered it had a broken mainshaft at the oil hole between the bushes.

My guess is he was trying to wheelstand it or do burnouts or something foolish - he was the younger brother of a Laverda owning mate who'd hounded me forever about riding my bike. Came back with a canary (ie a yellow sticker the cops put on it for 'excessive noise')!!!

I'd love one of Red's extended shafts with the outrigger bearing.
 
piranha-bro2 said:
That's one big job for 'regular maintenance' Andy!! Mine runs the bronze bushes. Probably covered 160,000km before I let an idiot ride my bike and very soon after I discovered it had a broken mainshaft at the oil hole between the bushes.

My guess is he was trying to wheelstand it or do burnouts or something foolish - he was the younger brother of a Laverda owning mate who'd hounded me forever about riding my bike. Came back with a canary (ie a yellow sticker the cops put on it for 'excessive noise')!!!

I'd love one of Red's extended shafts with the outrigger bearing.
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Changing to a bronze bush is an option but takes a bit of engineering. I'll just keep replacing these tiny little bearings. Pulling the motor hasn't been too bad, even for an amateur, although I haven't put it all back together yet 🤣
 
In the "while you're in there" suggestions, It's not silly to crack test the mainshaft at the oil holes.

An engine reconditioner who can crack test cranks will be able to do it.
 
have converted a few RGS engines to bronze bushes in the output drive gear, had to really due to damage caused by the needle roller bearings
end of the mainshaft was badly worn, take it in to be hard chromed and ground back to size and then flick the needle roller bearings for bronze bushes
Most times need to bore out the inside of the output drive gear as well due to similar damage to the bore, just machine larger OD bushes

Needle roller bearings no good on hard chrome, point load to high and breaks up the chrome finish, not an issue with bronze bushes
 
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redax5 said:
have converted a few RGS engines to bronze bushes in the output drive gear, had to really due to damage caused by the needle roller bearings
end of the mainshaft was badly worn, take it in to be hard chromed and ground back to size and then flick the needle roller bearings for bronze bushes
Needle roller bearings no good on hard chrome, point load to high and breaks up the chrome finish, not an issue with bronze bushes
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Reminds me of the 500 camshafts.
Paul
 
Andy said:
I was strongly advised by both Wolfgang and Red to check replace the two little needle bearings on the mainshaft inside the 5th gear output shaft. If these collapse there's all sorts of damage. Now my bike's only done 41,444km, and these two little bastards look like they've been pretty hot.
Regardless of the output shaft, I'm glad I pulled the motor just for these! It might have to be yet another job to add to the list for "regular maintenance" 🤣

View attachment 90544
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Not only are the bearings prone to wear and distress, but the shaft and sleeve gear as well. The stock #630 chains are totally unforgiving and will bend/break/wear these components in next to no time if tensioned too tightly. Also check the thrust washer that retains these bearings within the sleeve. Early washers had no scallops and could starve the needles of lube. They later recieved 3 big scallops on the ID to allow more oil to pass. Simple enough to mod the washer with a Dremel and stone.

piet
 
sfcpiet said:
Not only are the bearings prone to wear and distress, but the shaft and sleeve gear as well. The stock #630 chains are totally unforgiving and will bend/break/wear these components in next to no time if tensioned too tightly. Also check the thrust washer that retains these bearings within the sleeve. Early washers had no scallops and could starve the needles of lube. They later recieved 3 big scallops on the ID to allow more oil to pass. Simple enough to mod the washer with a Dremel and stone.

piet
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More nuggets 👍
Do you mean the thin washer indicated in the photo? And can you elaborate on the scallops, would they be something like my practice washer, with the scallops towards the spline?


IMG_2868.jpeg
 
Andy said:
More nuggets 👍
Do you mean the thin washer indicated in the photo? And can you elaborate on the scallops, would they be something like my practice washer, with the scallops towards the spline?


View attachment 90558
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Yes, that's the one. As it is, it rather effectively seals the bearings from lube. Remove 3 or 4 large scallops from the ID, more than those on your practice washer, but not so much that they catch on the shaft splines. You want as much oil in there as possible, but at the same time need to retain the needle bearing axially. This oil will also lube the clutch pushrods, also often a constant source of trouble. It is generally recognised that the bearing lube is supplied via the cross drillings, from the inside out. Good luck getting any oil at all into the hollow mainshaft from the clutch end... it's the other way 'round.

I'll go through my stash tomorrow, I should have a scalloped washer to photograph.

piet
 
so finally finished our new Output/final drive gear shafts to run with a 180 rear tyre today though we do have a prototype already in the Mule
on the right we have 4 x custom made Output shafts that move the front Sprocket out by roughly 12mm, and supported by an Outrigger bearing in the Sprocket cover, note the extended sprocket spline

Middle row is our original Output shafts that we made for a 160 rear tyre with sprocket in standard position but supported by an Outrigger bearing
Needed the Outrigger bearing as we kept breaking Mainshafts, never broken one since we did the Outrigger

On the left we have a standard Laverda Output shaft

3 output shaft versions

here is the back side of our billet covers for the 180 tyre version showing the Outrigger bearing in place

outrigger

and the front side showing how we gained 12mm, note the difference in the depth of the cavity between the 180 version on the left and the standard cover on the right

outer cover difference
 
Red, its a real testiment to your skill and devotion that you concieve and build these parts and make them available for those who need them..and they they always look so damn good to boot. Fortunately they more usable for all us old guys than a 25 year old horney girfriend.
 
Why the factory didn't adopt a similar upgrade I'll never know. They built the primary drive side with outrigger needle rollers but completely ignored the output shaft through two decades and countless models.
 
piranha-bro2 said:
Why the factory didn't adopt a similar upgrade I'll never know. They built the primary drive side with outrigger needle rollers but completely ignored the output shaft through two decades and countless models.
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There’s an Italian saying, translated to Australian it goes: She’ll be right mate, turn off the factory lights and let’s go to the pub.
 
piranha-bro2 said:
Why the factory didn't adopt a similar upgrade I'll never know. They built the primary drive side with outrigger needle rollers but completely ignored the output shaft through two decades and countless models.
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It was perfectly adequate at the time! For normal use with regular maintenance, it still is.

Although not entirely necessary due to the different design, an out-rigger set up was adopted for the exit shaft on the liquid-cooled 750s.

piet
 
sfcpiet said:
It was perfectly adequate at the time! For normal use with regular maintenance, it still is.

Although not entirely necessary due to the different design, an out-rigger set up was adopted for the exit shaft on the liquid-cooled 750s.

piet
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.. and the air cooled 668cc engines too.

Marnix
 
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