Hyfax - What's wrong with this picture? What's the solution?

[ReX]

With you guys complaining about hyfax wear with the monoshock skid I can tell you for certain it is better for wear rate than a super tight tracked ProActive is. I suspect running the track looser on the ProActive would produce similar results (if only it didn't ratchet).

My buddy rode his Apex ER on the same trails, same miles, same speeds, etc. as my 07 RTX and we both started with new hyfax at the start of the season. His hyfax is still fine, while mine is - well - new again...

 

[Mikecam]

I feel for you Rex. Makes me think something is out to whack. Mine very very rarely ratchets and it hangs a good 3/4 inch with no weight on it. So you having to tighten the track so tight to stop the ratcheting is hurting your hyfax wear. So how do we help the ratcheting which in turn will help the hyfax wear. I have my compression cranked up to about 4 back from full to help with the bottoming out. Front shock is backed out 1/2 to 3/4 inch from stock and that was info someone PM'ed me to help with the ratcheting and it certainly did. Helped with the studderbumps also. I have almost 1700 miles and another 300 would not be a problem with current wear so 2000 miles is better then most. Ice buildup is certainly an issue. Pam certainly helps me on cold days. It still builds up at times but a few small kicks to the back snow flap takes care of most of it.

 

[ReX]

Tonight I decided to see exactly what happens when you compress and extend the suspension at the front and at the rear.

What I discovered is as the front is compressed the track tightens and as the rear is compressed the track loosens rapidly. Similarly if the front is extended the track loosens and if the rear extends the track tightens.

So when you accelerate hard and the front extends at the same time that the rear compresses the track gets very, very loose - even if you start off with the track tight. The other extreme is when you unload the skid with the limiter strap tighter than stock and the track becomes extremely tight.

I also discovered that if you're in the accelerating condition (rear compressed, front extended) that if you compress the suspension at this point the track tightens up again. So - if you happen to weigh the "wrong" amount that the rear is able to compress the max at the same time as the front is extended against the limiter strap you will be most likely to see ratcheting. Both a heavier and lighter rider will be less likely to have a ratcheting problem (heavier because the track tightens a lot, lighter because the track can tighten a little and there is less weight on the track).

Setting up my sled by lifting the front and adding my weight to the rear to simulate hard acceleration I found my 200 lbs seems to be just about the worse configuration to make the track the loosest possible if I use the high settings on the rear torsion spring (if I use the low torsion spring setting the track tightens up a little).

To get real numbers I took measurements two different ways. One per Yamaha's procedure and the other measuring the track deflection between the upper idler wheel and the rear axle (so I could see how things are when I am sitting on the sled). For this I applied 22 lbs using a fish scale and measured the gap using a 2x4 and some digital calipers. Here are pictures showing the setup (of course when I'm measuring I have the 22 lbs applied at the same time as taking a measurement):

 

[ReX]

Here are the measurements (keep in mind these were only taken once and were not double checked in any way - I was really just looking for the trend to understand what was going on):

I started off taking measurements per the Yamaha procedure:

I adjusted the track for 30mm (1.2 inches) of deflection measured at the center of the track region that contacts the ground with 22 lbs applied (adjusted exactly to Yamaha's spec) with everything at the original factory settings.

I then tightened the limiter strap all the way and measured the deflection. The track had now tightened to 26.6mm of deflection with 22 lbs (overtightened).

I then stuck a 2x4 at the front of the suspension to compress just the front of the skid. The track tension had now tighted to 21mm (0.8 inches) with 22 lbs applied. It was basically like a guitar string - incredibly tight. It would tighten more if I added some weight to it.

I then loosened the limiter back to stock, stuck the 2x4 at the rear of the suspension and put some weight on the rear bumper and it loosened off to 48mm (2 inches) with 22 lbs - very loose (actually probably where most of you prefer to run your tracks). Adding any more weight and the track starts to tighten back up again (coupling blocks close and it starts to compress the front).

I know from riding the sled that it pretty much doesn't ratchet with it this tight so it seems 48mm with 22 lbs is the magic number with standard introvert drivers and my fully clipped 9837 1" track.

Basically this shows that just when you need the track the tightest (accelerating) the track becomes the loosest. Some of the newest multi-shock suspensions incorporate a mechanism that moves the upper idler wheels rearwards and upwards as the rear compresses in order to keep the track tight under acceleration. The ProActive in the Phazer has this for example. Not having this isn't necessarily a problem - as long as the track stays tight enough not to ratchet...

Things that will keep the track tension more consistent (reduce the ratcheting) are:
- reduce the weight transfer
- reduce the preload on the front shock
- allow the suspension to compress more overall (run less preload in the springs or have a heavier rider)
- tightening the limiter might help too - but since you adjust the track off the ground you will actually be adjusting it looser to start with. One thing that also concerns me with a tight limiter is as the skid unloads over rises the track becomes super tight. I don't know for sure but this might cause temporary heating at the rail curve.

 

[ReX]

Measurements taken at the back of the sled (between upper idler and rear axle with 22 lbs applied):

These were all taken with the limiter and weight transfer in the stock position:

Sled raised up in the air: 12.1 mm
Sled on the ground (it loosens because the rear of the skid compresses more than the front as the weight comes down): 19.9 mm
Me sitting on the sled: 17.6 mm
Me on the sled with the springs on the low position: 16.9 mm
A 2x4 under the back of the sled and the front slightly raised with me on it: 24.6 mm

Again the same thing. Accelerating/weight transfer makes the track the loosest.

 

[ReX]

I think I've just figured this out.

The ratcheting got worse after I installed the heavy duty springs on Friday. This is because, even though the springs have less preload (lower sled height unloaded), they are stiffer and don't sink as much with me on the sled when accelerating.

Looking at the numbers, the higher the sled while accelerating, the looser the track. Basically it needs to compress down at the back to tighten the track back up. With the stiffer springs the compression reduced which provided looser track tension when accelerating hard. I then tightened the track to the point where the ratcheting stopped, but this meant while cruising the track was very tight (possibly even a hair tighter than Yamaha's spec) and that lead to the hyfax problem.

I wanted this sled to ride higher (like a monoshock rides) so I can soften the shock and keep a compliant ride without bottoming. Yamaha made their RTX "heavy duty springs" so they actually lower the sled and it seems there is good reason for this.

 

[ReX]

I thought I'd bring this one back.

To my surprise after another 700 miles my hyfax is shot again (not quite worn through yet) and the area where it is worn the most is right at the curve again. This time the track has been run much looser so it can't be blamed on track tension being too tight.

I did install cheap aftermarket hyfax instead of Yamaha hyfax so I don't know if this contributed to the rapid wear. Trail conditions have been fairly good also, except for some of the recent colder days/nights that made for hard trails.

Also, this time the hyfax wear is much more even, but still the worst area is the curve (last time the rest of the hyfax was very good, but it was completely shot at the curve).

What now?

I'm not sure what to do. I don't like the idea of running extra very small idler wheels because I'm sure high speeds will lead to lots of maintenance.

What about ski mounted ice scratchers that I can pull down just when the trails get too hard packed?

The other option I was thinking about is to go with larger OD Skidoo idler wheels. I don't really think this will fix the problem though. The wear rate didn't seem to slow down as it wore (if the wheel was helping I would have expected it to).

Anyone else gone through this with an 07 RTX, 06/07 Nytro, or 05 Vector? What did you do to keep your hyfax from wearing out fast?

 

[snowbeast]

Rex i dont understand why you of all people are having racheting problems or melting hyfax,you are running the antirachet drivers,what is going on with them,i had them on my mono and could let the track hang 3" and no rachet problem,or hyfax problem.

 

[Mikecam]

Something is wrong. I replaced my Hyfax at 1700 miles and up front in the bend they are still like new. My wear was in the back. After added the studs at 500 miles my wear really got better. I can'
t for the life of me figure what could be causing your extreme wear.

 

[ReX]

Rex i dont understand why you of all people are having racheting problems or melting hyfax,you are running the antirachet drivers,what is going on with them,i had them on my mono and could let the track hang 3" and no rachet problem,or hyfax problem.

There is no ratcheting problem anymore. I can let the track run as loose as I want and it never ratchets with the antirachet drivers installed.

The ratcheting problem was with the stock drivers.

I can't understand this at all either. I'm riding with guys with Apex ER's with monoshock skids in the same conditions, same speeds, etc. and their hyfax is wearing, but at about 1/2 the rate or better than mine is wearing. I'm also more carefull than most to keep the hyfax cool (dipping into snow, dragging feet if conditions are marginal, etc.).

One thing I wonder about is they are all running stock Ripsaw tracks, clipped every third window. I'm running a Predator and its fully clipped. The other possibility is the ProActive CK is just worse for both hyfax wear and track ratcheting (there are a lot of other guys complaining about ratcheting with them so I do believe they are worse than the monoshock for ratcheting).

I was getting 6000+ miles out of my hyfax on my monoshock skid and a Ripsaw clipped every third so I'm very surprized to find this problem with a 1" fully clipped Predator and a ProActive skid.

 

[ReX]

Something is wrong. I replaced my Hyfax at 1700 miles and up front in the bend they are still like new. My wear was in the back. After added the studs at 500 miles my wear really got better. I can'
t for the life of me figure what could be causing your extreme wear.

If I remember correctly you are running with the preload on your front skid shock backed off a little. I'm running mine stock still, but I did just make some changes that will unload the front of the skid a fair bit. Hopefully this will slow the wear down.

I didn't change the hyfax for the second time yet. I went out to change them last night, but after measuring decided to run them some more as is and see. Right now at the curve of the rail they are worn down to 12mm (wear limit is 10.5mm and new is ~18.5mm). At the back they are now about 13mm (I normally consider 13mm "lots of life left").

Last time they still had over 15mm left at the back when they wore right through (8.75mm is where they wear through) at the curve so it did improve a lot by loosening the track.

Our snow conditions aren't great, but when I see my buddies hyfax wear rate so much better than mine I know it should be better.

One last thing I should mention. When my hyfax wore through I needed new ones quick so I bought some off a friend. These are cheap aftermarket hyfax that I'm running now (cheapest hyfax available is all he had). The first pair were stock Yamaha hyfax. I really have no idea, but its possible that if I was running Yamaha hyfax that my wear rate would be as good or better than my buddies with thier monoshock skids (they are running Yamaha OEM hyfax).

Does anyone know if the cheap stuff wears faster? I've always run Yamaha hyfax in the past.

 

[ReX]

An update and it looks like the problem is solved (although not exactly the way I wanted to do it...).

Today I put another 300 miles or so on. At first the hyfax was running too hot as usual. The hyfax and skid was basically running with no snow accumulation at all and I could feel the hyfax dragging a little every now and then. Basically it was on the verge of overheating.

The trails were hard packed, but the rock hard base left by the groomers of a few days ago had been broken up a fair bit by all of the studded sleds running on it. Lubrication should have been decent.

As an experiment I decided to bend the snowflap down a little. Right away I noticed a big improvement and there was no more dragging sensation.

Halfway through my trip I was trying to get to my cottage and I came to the end of a closed trail (annoying - now there's no way to get there...). While trying to turn around on the narrow trail I ended up backing up on the snowflap (studs caught it) and this bent the snowflap mount down quite a bit more.

After this the hyfax ran perfectly cool for the rest of the day - so much so that snow was building up on the slide rails and the sides of the hyfax when riding on the exact same trails that had left them bare just a little earlier. Temperatures hadn't changed either so the snowflap was definitely the only change.

Looks like I'll be leaving the snowflap pointing much more downwards instead of the stock almost 45° angle it used to sit at.

 

[RTX DUDE]

wear

I had hyfax problems too!! I think it was mightyattack that posted about the 135mm wheels. I machined the mounts down so the bearing fit nicely with 135mm Poo wheels and slp wear pads. 1200 miles later and very little wear. Before that I had 4 sets in about 600 miles. I run my track loose, came from Cat where loose is fast. It's the every third window clipped and 1 1/4 track with the weight of our sleds that cause the wear. Very little snow for lube is my guess. But this little mod that cost me $80.00 saved me a ton of work on replacing slides. On my Cat, I had 3500 miles and never replaced them. But the cat track was fully clipped with 1 inch track and 460 pounds. Quality is heavier. LOL I think some of you guys get better wear because of moisture content in the snow you ride? less hardpack? slower speeds? I run alot of lake effect and high speeds, so the mod was needed or I could have bought slides by the case. LOL hope this helps you.

 

[ReX]

I can now say that my hyfax wear is 100% resolved. Over the past two days I put on well over 1000 km, much of this in very low snow conditions (including refrozen solid ice trails), and my hyfax still has almost 12mm of thickness.

I tried it with the snowflap back up on one railway bed and immediately the hyfax started to heat up, drag and smell. Bending it down and they ran cool again.

There must be just enough ice chips thrown up by the studs/track that with the snowflap down the chips hit it and get blown around the tunnel and skid, keeping things cool.

I also noticed with the flap down that the radiator fan doesn't run as much. With it up, the fan was running most of the time (and had been most of the season), but with it down it only came on in the absolute worst conditions.

I don't know why others aren't having the same issue, but most likely my situation was due to a combination of things including the 1" track that I'm running (I suspect the Ripsaw gets more snow caught in the tips of the lugs and throws it in the tunnel more), the taller ride height (I'm running with only 3" of sag at the rear bumper which you can't get with stock springs), and the local snow conditions (most of my riding was in very cold temperatures with only a couple of inches of base).

The other puzzle is why my 1" track was ratcheting so badly that I either needed the track tighter than spec or needed to install anti-ratchet drivers when many others with the stock Ripsaw aren't having ratcheting problems.

We're planning a longer saddlebag trip for next week so we'll see how my hyfax hold up for that. I'll probably install new hyfax before we leave since they are very close to the wear limit.

 

[Mikecam]

Great news. Only thing I'm not sure of is why the 06's with there flap (straight down) also has problems with the hyfax wear. I do know that next time out I'll bend the flap down and see what happens. Thanks Rex.