Seizing nose wheel- but only with a brand new chain

[SteveSr]

I noticed a notch on one nose tooth as well. I would think Husqvarna 435, Husqvarna logo on chain, 33 number on drive link, would mean this is the SP33G chain which is NK .325. (0.050 gauge) Not sure about a dedicated NK bar with 5 rivets though. All my NK .325 bars have 10 tooth noses which I think the ones in post 4 look like. My Oregon Pro lite bars in both 0.050 and 0.058 are 12 tooth noses.

Thanks for noticing! The OP never responded to my request for gauge information.

Would running NK chain on a regular bar cause this? I think not because the drive links should be the same thickness which should space out the tie straps so as not to wear out the side of the nose sprocket. I would think that it wouldn't cut very well due to the wider bar and narrow cutters.

 

[cookies]

Thanks for noticing! The OP never responded to my request for gauge information.

Would running NK chain on a regular bar cause this? I think not because the drive links should be the same thickness which should space out the tie straps so as not to wear out the side of the nose sprocket. I would think that it wouldn't cut very well due to the wider bar and narrow cutters.

if you run 3/8 lp chain on a regular 3/8 bar or rim it will cause these issues, im not sure how one could put .325 on a 3/8 setup and not notice the crazy jumping/tooth skipping chain

 

[Franny K]

...

Would running NK chain on a regular bar cause this? I think not because the drive links should be the same thickness which should space out the tie straps so as not to wear out the side of the nose sprocket. I would think that it wouldn't cut very well due to the wider bar and narrow cutters.

A laminated non NK bar is about 0.020 thicker than a NK one. Generally I think the replaceable nose solid bars are wider still than that. Hard nose ones really vary a lot.

It looks to me like the pictures in post 4 have necked down drive links and thicker at the rivets. The Oregon NK chain is this way, the Stihl NK chain is like the 3/8lp stuff with drive links same top to bottom. For guys that sharpen all the way back until the cutters break off new NK chain on standard 0.050 bar should not be any problem. Oregon uses tie straps out of the 0.043" stock for their NK chain and the regular stuff like 20LPX is around 0.052" or there abouts. So eventually it could kind of wear towards the inside and leave a ridge where it comes off the nose sprocket. Likely have seen this sort of wear somewhere.

 

[JonnyK28]

Thanks for noticing! The OP never responded to my request for gauge information.

Would running NK chain on a regular bar cause this? I think not because the drive links should be the same thickness which should space out the tie straps so as not to wear out the side of the nose sprocket. I would think that it wouldn't cut very well due to the wider bar and narrow cutters.

Yes I did respond with the gauge info. It is an SP33g chain, and both bars are husqvarna that have been supplied with new saws with that chain.

 

[JonnyK28]

Your old chain and bar have worn together over time so they work. Take a new chain the drive links are not worn down, so are longer and wider. The picture of the two chains show the new one's drive links showing some wear from the sprocket and bar.

As you are cutting at first there is tight clearances and seems to work but while cutting heat is generated and you loose that acceptable clearances and get seizure. After letting the bar cool I wonder if you would be able to spine it around

I would take a good look at the bar and possible just replace it along with a new sprocket and chain. Sort of starting over with new. Sometimes stuff just wears out, nose bearings become defective with wear, etc. Take it as maintenance fees and move forward.

Just a opinion....

Thankyou, I am of the same opinion, the wear in the old chain and bar just happen to be complimentary and work together, whereas the new chain is not worn. New bar is on order!

Well spotted on the two different bars- there are two, they are both Husqvarna originals supplied for the same chain (one older than the other hence changes) but we were having exactly the same problem regardless of which bar we were using (we switched bars to see if it was a bar problem, the new chain seizes on both bars, the old chain runs fine on both bars)!!

 

[JonnyK28]

Thanks for noticing! The OP never responded to my request for gauge information.

Would running NK chain on a regular bar cause this? I think not because the drive links should be the same thickness which should space out the tie straps so as not to wear out the side of the nose sprocket. I would think that it wouldn't cut very well due to the wider bar and narrow cutters.

Thanks everyone. Just to confirm:
- It has never run the wrong chain on the bar- same chain since the bar was new. Gauge is 1.3mm for bar and chain (050, Husq SP33G)
- We have never had to oil the nose sprocket on any of our saws before (we tried on this one, but even using brake cleaner and then putting oil/grease in the bar end hole, it would seize up the same)
- Everything works fine with the old chain, with all else equal to when the new chain seizes it
- Happens in all types of wood (lots of ash and oak recently)
- Every time it seized we cleared out the gallery and nose sprocket completely of debris, oiled and refitted chain
- I do believe it is because the nose sprocket isnt getting enough oil delivered via the gallery, and debris was getting into the nose sprocket and jamming it but the question is why only with the new chain??!

Thanks again, I think we might try a new bar with the new chain and see what happens!

 

[buzz sawyer]

Thankyou, I am of the same opinion, the wear in the old chain and bar just happen to be complimentary and work together, whereas the new chain is not worn. New bar is on order!

Well spotted on the two different bars- there are two, they are both Husqvarna originals supplied for the same chain (one older than the other hence changes) but we were having exactly the same problem regardless of which bar we were using (we switched bars to see if it was a bar problem, the new chain seizes on both bars, the old chain runs fine on both bars)!!

I agree. My final thought - the older bar slots are allowing more debris build up. The old chains leave it alone while the new chain cleans it out and deposits it into the nose.