Unusual Oregon bar

[jonsereds 621]

I picked up a fresh non running Jonsereds 49sp a few days ago and with it came an unusual bar. It's an Oregon sprocket nose which does not look to have done a lot.(like the saw). The strange (to me ) bit is that the sprocket in the nose is deliberately offset upwards....or downwards if you turn bar over, giving the first impression that it is complete toast. This appears to be as from factory. The numbers on the bar are :-7735 2058 0317TS. It obviously has a purpose.....but what? Plunge cutting perhaps, or carving? As I have a chain that will fit I shall use it as it is......when I have rectified the points problem, and fresh seals etc. I would be interested to hear what it's true purpose is. Any ideas? It looks as though it would be a simple matter to replace the removable riveted on roller nose with a conventional one.

 

[computeruser]

Probably a banana bar, an early attempt at a low-kickback bar nose. Can only be run one side up since it is asymmetrical. It was a neat idea that disappeared in time because it was not a particularly good idea.

 

[RedneckChainsawRepair]

Banana nose bar maybe your seeing. Dont flip that one.

 

[computeruser]

But I think the regular 3-rivet noses can be swapped on and then you’d have a regular bar again. Assuming you can find an old 3-rivet nose.

 

[Czed]

Common on the homelite 330 360s

 

[RED-85-Z51]

I hated those things, they seemed to eat the tip fast

Sent from my LM-G820 using Tapatalk

 

[Philbert]

Banana Bars! They had limited ap-peal!

Philbert

 

[OM617YOTA]

Meant for a homeowner who buys bar oil by the quart and will never put enough use on their saw to have to clean the air filter, much less flip the bar. The slightly smaller kickback zone means that out of 100,000 saws sold, two less people will wind up in the ER because of it. I guess that's a win.

 

[Philbert]

Meant for a homeowner who buys bar oil by the quart and will never put enough use on their saw to have to clean the air filter, much less flip the bar. The slightly smaller kickback zone means that out of 100,000 saws sold, two less people will wind up in the ER because of it. I guess that's a win.

Actually, they were quite an innovative, and creative approach, IMO: better than the 'tip guards', which get in the way of a lot of cutting:


The banana bars led to the development of low kickback bars, which have a uniform reduced radius at the tip, and can be flipped over to balance wear. Large radius bar tips were largely (sorry) to reduce friction, especially before roller nose and sprocket nose bars became dominant. Some guys still prefer the large radius bars for bore / plunge cutting. The small diameter tips are better for limbing, etc, where they can slip in between branches easier.

Philbert

 

[OM617YOTA]

No "I guess" about it then, that was definitely a win.

 

[jonsereds 621]

Yes, that's just what it is. I'd never seen or heard of this before. I reckon I'll just stick with the conventional setup. A fresh 3 rivet nose will likely cost more here than the saw did.

 

[Philbert]

Someone might want it for a collection or conversation piece. Or, you could run it.

Philbert

 

[ray benson]

Bars were around in the late 1970's/ early 1980's. An occasional user bar , reduced kickback