136" extension track tension issues

[gibb73]

Hey all,

Been a long time watcher...never a poster so please bare with me....sorry for the long post!

I decided to stretch my 07 fx to a 136" this summer with the 7.5" tracks USA extensions (yam-100) http://www.tracksusa.com/All-Yamaha...6&browse=-47269&shopBy=-13183&catalogId=-3708

The fit of the extensions was great...took a bit of massaging at the rail joint to get a tight fit, but worked out great. Here's the issue I'm having: my track tensioners are loosened all the way (axel is touching the front of the axle slot) but my track is still too tight. I had a heck of a time just getting the skid in (which used to go in like butter when it was a 121").

My way of thinking is this; 136" - 121" = 15" total length difference. 15"/2 (as the track has an "upper" plane and a "lower" plane to split the total length of the track) would make a 7.5" total length on the rail needed for the extension. The tracks USA extensions are advertised as 7.5" but measure at 8.25".....which I think is too long. I haven't changed any components in the skid other than adding the 4th wheel.

I've been in touch with tracks USA ...which had great customer response time btw....but they said they've never had issues with them and have sold hundreds. Their suggestion is to elongate the axle hole and weld on longer threaded rod to the adjusters. The issue I see with that is right now the adjuster nut (that is all the way backed off already) is about 1/4" away from the track windows. If i move the track in more, the nut is gonna hit for sure.

Anyone ever had issues like this before?

 

[Mooseman]

When we stretched out my son's 121" to 144", we had the same issue. It was a new take-off track. I think it has since stretched a bit but still not where it should be. I think it's just the way it's designed.

 

[Gone Blue]

X2. I stretched my 09' to 144" with Tracks USA tipped up extensions and also had the same thing. I was concerned that I could not drive the adjuster nuts did not on adjusters far enough to engage the nylon insert in the nut. So I put some blue locktite on the threads and have been running it that way ever since. New new track did stretch some but not alot. I am running extra wheels in my skid and they are Excel oversize along with low snow wheels up front so that may be part of what is going on with my skid. G.B.

 

[Gone Blue]

BTW - If you haven't already, you should post some pictures of your sled. The black rails and tunnel look sweet. G.B.

 

[gibb73]

thanks guys.....kinda glad to hear I'm not the only one! How is your track tension? Mine seems really tight....way tighter than I used to run it. I'm not too concerned with the adjusting nuts not engaging the nylon....I would be comfortable putting locktite on them and running it....but I want my track looser.

Anyone know if the mtx drivers are smaller diameter than the fx drivers? I'm thinking if I run smaller drivers, change the gearing to get it as close as I can to stock, that might loosen things up? Kinda brutal I should have to do this though. Should be a straight forward mod.

I'll post some picks once she's back together....my garage looks like a bomb went off right now.

 

[cannondale27]

I would make a adjuster that pushes instead of pulls and mount it to outside of rail.

 

[Mooseman]

Once the axle nut is tightened after adjusting, the adjuster becomes irrelevant.

 

[cannondale27]

I know but look how close it is. Those rear adjusters were always a bad idea anyway.

 

[Handy]

Here is a suggestion. Move the bracket that the adjuster goes through forward by 1/2" to 1" by drilling new mounting holes, then grind the slot longer to the front. Cut off the back of the extension if it rubs on the track.

 

[Voda2000]

I did the same conversion (136") last winter and had the same issue.

I attributed a lot of it to the way the track came rolled up. There was a wave in it that I couldn't get out and it doesn't take a lot to make it tight.

I was able to get the axel in with the help of a pry bar. After running it for last winter it was fine and loosened up.

Mooseman is right, the adjesters don't really do anything once the axel is tightened up, just lock tight the nuts.

 

[Voda2000]

Here is a suggestion. Move the bracket that the adjuster goes through forward by 1/2" to 1" by drilling new mounting holes, then grind the slot longer to the front. Cut off the back of the extension if it rubs on the track.

If you have to go this route I would just grind the slot but not move the adjester. You would be better off just making a longer adjusters. Drilling extra holes weakens things. You only need maybe a 1/4" extra clearance but as I said above it can be done without modifying anything.

Also you asked about the MTX drivers and you are right they would also work because the are smaller.

 

[gibb73]

Since I'm running a used take off track, I'm sure it won't stretch. I think I'm going to pick up a bolt on adjuster (like the pic ) and put it on the outside like cannondale suggested....i'll probably have to trim the back of the rail extension too. So much for a bolt on extension!

Thanks guys!

 

[Voda2000]

Is it a freeride track?

 

[gibb73]

No....it's an 1.25" ripsaw takeoff from a ski don't that I cut down

 

[steiner]

Looks like if you elongate the holes on the ext and use longer bolts for the adjusters the track may contact the back of the ext.

The best way would be to move the ext forward on the rail. Its more work seeing that the old axle slot would need to be longer and the hyfax extender would need to be cut back.
It also looks like the hyfax is a little on the long side