1961 CB72 Project

[LOUD MOUSE]

I figured if you have a way to re profile the original wheel it shouldn't be that tough for you to use the other wheel.
Looks like you could fill a nitch for parts which are becoming more and more difficult to get. ................lm

Hah! Just when you think you understand what's going on... :-) That must have been a little awkward adjusting the cam chain on those CLs.

I've just found a needle roller bearing which would take the place of the bronze bush in the primary tensioner. 9/16 x 13/16 x 5/8"

Still around $6

So yes, it is possible to re-purpose a primary tensioner wheel as a cam chain tensioner wheel. Budget about $10 and an ½ hour to do the mods.

G

Actually a limited number of CL72 bikes did have the left side adjuster.
Who's to know how many as the 1966 parts book shows the 010 issue. . ..............lm

LM

Thanks for clearing that up. I was wondering if the early CLs had the left-hand type but you have explained why they didn't. I know that two of those early ones came from 1961 CB72 engines so the other two could be from early Dreams.

I wonder if Honda just wanted more cooling fins around the cam chain tunnel with those late ones and therefore had to make the tensioner narrower?

G

Of the 4 first issue you will see the 2 on the right are the earliest (sharp edge between bolt holes) and the 2 left have more rounded edges.
The ones with the set bolt on the right came about when the CL72 bikes came with the high pipes.
The pipes were in the way of the adjuster bolt.
I have had tensioners with 3 different wheel diameters but don't know what's up with that as the C/CB/CL engines were the only engines using this design and they all worked.
As you stated the cast cylinder assemblies came with a more narrow tensioner and I haven't figured out what's up with that either.
As you said the wheel could be damaged with a loose adjustment and also by us "pushing on the shaft and causing excessive pressure at the wheel and chain " which caused the wheel to become a sort of sprocket. ...............lm

I tipped out my box of old tensioners and was a little surprised with how many there were.



G

[G-Man]

LM

It was a good suggestion. Thankyou. I'll get a bearing and build up a cam chain tensioner with a primary tensioner wheel and see how it turns out.

G

I figured if you have a way to re profile the original wheel it shouldn't be that tough for you to use the other wheel.
Looks like you could fill a nitch for parts which are becoming more and more difficult to get. ................lm

Hah! Just when you think you understand what's going on... :-) That must have been a little awkward adjusting the cam chain on those CLs.

I've just found a needle roller bearing which would take the place of the bronze bush in the primary tensioner. 9/16 x 13/16 x 5/8"

Still around $6

So yes, it is possible to re-purpose a primary tensioner wheel as a cam chain tensioner wheel. Budget about $10 and an ½ hour to do the mods.

G

Actually a limited number of CL72 bikes did have the left side adjuster.
Who's to know how many as the 1966 parts book shows the 010 issue. . ..............lm

LM

Thanks for clearing that up. I was wondering if the early CLs had the left-hand type but you have explained why they didn't. I know that two of those early ones came from 1961 CB72 engines so the other two could be from early Dreams.

I wonder if Honda just wanted more cooling fins around the cam chain tunnel with those late ones and therefore had to make the tensioner narrower?

G

Of the 4 first issue you will see the 2 on the right are the earliest (sharp edge between bolt holes) and the 2 left have more rounded edges.
The ones with the set bolt on the right came about when the CL72 bikes came with the high pipes.
The pipes were in the way of the adjuster bolt.
I have had tensioners with 3 different wheel diameters but don't know what's up with that as the C/CB/CL engines were the only engines using this design and they all worked.
As you stated the cast cylinder assemblies came with a more narrow tensioner and I haven't figured out what's up with that either.
As you said the wheel could be damaged with a loose adjustment and also by us "pushing on the shaft and causing excessive pressure at the wheel and chain " which caused the wheel to become a sort of sprocket. ...............lm

I tipped out my box of old tensioners and was a little surprised with how many there were.



G

[LOUD MOUSE]

I find more bad ones than usable ones and you may find a market for a repair unit. .............lm

LM

It was a good suggestion. Thankyou. I'll get a bearing and build up a cam chain tensioner with a primary tensioner wheel and see how it turns out.

G

I figured if you have a way to re profile the original wheel it shouldn't be that tough for you to use the other wheel.
Looks like you could fill a nitch for parts which are becoming more and more difficult to get. ................lm

Hah! Just when you think you understand what's going on... :-) That must have been a little awkward adjusting the cam chain on those CLs.

I've just found a needle roller bearing which would take the place of the bronze bush in the primary tensioner. 9/16 x 13/16 x 5/8"

Still around $6

So yes, it is possible to re-purpose a primary tensioner wheel as a cam chain tensioner wheel. Budget about $10 and an ½ hour to do the mods.

G

Actually a limited number of CL72 bikes did have the left side adjuster.
Who's to know how many as the 1966 parts book shows the 010 issue. . ..............lm

LM

Thanks for clearing that up. I was wondering if the early CLs had the left-hand type but you have explained why they didn't. I know that two of those early ones came from 1961 CB72 engines so the other two could be from early Dreams.

I wonder if Honda just wanted more cooling fins around the cam chain tunnel with those late ones and therefore had to make the tensioner narrower?

G

Of the 4 first issue you will see the 2 on the right are the earliest (sharp edge between bolt holes) and the 2 left have more rounded edges.
The ones with the set bolt on the right came about when the CL72 bikes came with the high pipes.
The pipes were in the way of the adjuster bolt.
I have had tensioners with 3 different wheel diameters but don't know what's up with that as the C/CB/CL engines were the only engines using this design and they all worked.
As you stated the cast cylinder assemblies came with a more narrow tensioner and I haven't figured out what's up with that either.
As you said the wheel could be damaged with a loose adjustment and also by us "pushing on the shaft and causing excessive pressure at the wheel and chain " which caused the wheel to become a sort of sprocket. ...............lm

I tipped out my box of old tensioners and was a little surprised with how many there were.



G

[G-Man]

These were the shortest M7 bolts I could buy and I need to take a few mm off the end so that it clears the oil hole in the centre pin.



Also the bolt head won't quite sit flush and the head needs thinning.... Apart from that, they're perfect!!

G

[LOUD MOUSE]

With the machines you have that work will be simple. ..............lm

These were the shortest M7 bolts I could buy and I need to take a few mm off the end so that it clears the oil hole in the centre pin.



Also the bolt head won't quite sit flush and the head needs thinning.... Apart from that, they're perfect!!

G

[G-Man]

Well it's taken about ½ hr more in the workshop to do the mods to the bolt, open up a round hole in the tensioner arm and fit a new needle-roller bearing to the wheel.



I need to clean everything up properly and remove some burrs here and there but I'm quite pleased with this. For once there were no horrible snags and the wheel spins nicely on its new roller bearing.



I haven't checked the fit in the cam tunnel yet but my bolt head is thinner than the little scoop at the other end of the pin so it should be OK. Ive used a grade 8 bolt so I think that this should be stronger than the original riveted part too. I just have to decide whether to use loctite on the bolt or find a way to stake it in place.



G

[Steverino]

If you start building these I want one G Man.
Steve