Husqvarna SM Rim 3/8P

[el33t]

I’m not sure if you know ? . But stihl does/did sell a kit , it was for a ms261 it was a 3/8 lopro 16”chain bar & sprocket. Here’s a link
Ms261 kit link.
View attachment 461425

Yes, I knew about it. Some time ago this kit was withdrawn from the market unfortunately.

 

[Wonkydonkey]

I don't think it's a good idea either, of course.
On the other hand, comparing this situation with using a .404 sprocket with a 3/8 standard chain is not accurate, because here you are dealing with different pitches.
3/8 standard and 3/8 mini are the same pitch. What is different is the chassis.

But …… I think it is a good comparison, due to the size difference of the drive links.

Both are a sloppy fit in the rim sprocket. Anyway Thankyou for pointing out it’s the chassis that’s the difference

 

[Tor R]

In my mind it was mostly a combo for 242, a slim setup.
But, I think I can get it with 325" TsuMura 087ZK2, 088ZK2 bar that is for Echo mount. A little dremel + JB weld.

 

[Bill G]

I can do a pictorial comparison of all the small spline rims later.

 

[Wilhelm]

I have a large spline Archer (RatioParts) rim that was sold to me as full size 3/8" - but it doesn't fit more than two DL's properly.

Oddly enough, it fits 3/8" LP all the way around nice and snug.

I have posted pictures of it on here somewhere.

 

[el33t]

I found the post. @Wilhelm


It looks like this rim of theirs with the 3/8-7 marking is the LP version.
Not surprisingly, the full 3/8 doesn't fit it - due to its larger diameter.
As I wrote in their catalog there is only one version of the 3/8 rim for small spline drums. It has the designation RSM-375-7 and in the application guide they have no problem recommending it for all 3/8 chains (standard and LP).



They also have a chart where this rim is supposed to match the 18720 Oregon rim. This Oregon rim is obviously designed for 3/8 standard chains - Oregon does not have a dedicated rim for 3/8 LP.

The picture of the “Panther” 3/8 Lo Pro Sm rim from chainsawbars.co.uk (I linked) doesn't have the LP (or similar) designation either, and it's only 3/8-7. It wouldn't surprise me if the Archer and Panther rims came from the same source (in China).

This is another example that various documents must be approached with great caution. There is a lot of misleading information in the documents/websites of Stihl, Husqvarna, Oregon, so bad information in the catalog of a company like PMD is even less surprising.

Link to their guide:

https://www.pmdinternational.com.au/catalogues/archer/application-guides/ARCHERsprockets.pdf

Post in thread 'Looking for 3/8”LP 7pin small spline rim sprocket'

Jul 8, 2018

This may be considered a stupid suggestion but I'll out it anyway.

Maybe try sourcing an Archer 3/8" sprocket featuring a small spline.

I once ordered a Dolmar/Oregon 3/8" 7 tooth standard spline sprocket and received an Archer one.
A brand new 3/8" wouldn't seat into it so I tried my 3/8" LowProfile and it fit perfectly.

I'm not saying that all Archer sprockets are "faulty" by default, but maybe You get lucky and receive a "faulty" one that will fit Your needs perfectly.
Maybe someone here carries Archer and is willing to check chain fitment for You!

My one encounter with an Archer...

• Wilhelm

• 

 

[el33t]

But …… I think it is a good comparison, due to the size difference of the drive links.

The practical difference is that if you have an incompatibility of rim and chain pitches, you will notice it right away and are unlikely to force them to cooperate.

In the case of a 3/8 LP chain, you will put it on a (real) 3/8 standard rim without much problem. And, as in your example, after some time the user may encounter an unpleasant surprise in the form of a broken chain. I am almost certain that in the case of milling it can happen after more than 10 minutes.

 

[chipper1]

I’m not sure if you know ? . But stihl does/did sell a kit , it was for a ms261 it was a 3/8 lopro 16”chain bar & sprocket. Here’s a link
Ms261 kit link.
View attachment 461425

20% more "cutting power" lol.

 

[chipper1]

There is a lot of misleading information in the documents/websites of Stihl, Husqvarna, Oregon, so bad information in the catalog of a company like PMD is even less surprising.

This.

 

[el33t]

20% more "cutting power" lol.

It's funny, but I think it's more of a translation problem. The German original uses the word Schnittleistung, which can be translated as cutting performance, which sounds more reasonable assuming that the kit is used, according to their recommendation, for cutting soft wood (pinewood).
The fact that they sold this kit is proof that the safety margin of the chains is quite large, even considering this recommendation about pinewood.

For the record, despite the fact that they theoretically stopped selling this kit, there is no problem converting saws like the MS260/261 to 3/8 Picco, as there is a rim available all the time. The part number is 0000 642 1240. The problem with using it on other manufacturers' saws is that it fits their "mini" spline drums.