MOTOTRAX VIBRATIONS

Norma Stitz · Feb 10, 2017

Jnorth said:
Honestly, I know exactly what happened. The bolt sheared due to the bogeys bottoming out on the Motolink swing arm. And when the bolt sheared, I lost the bogey on that side. I had a shorter bolt that I could slide in the end and gorilla tape in there to make it off the hill but since the bogey was gone , the track clips contacted that part of the aluminum shaft and wore a groove.

As far as the sliding bushing goes, I have no idea why it failed unless that bottoming torqued it somehow. Or when the track came off several times and forced the skid sideways it might have stressed that yoke and fatigued the shaft.

Probably the side torquing. I broke mine at standstill trying to get bike out of a trench. It's a little too fragile part. I suggest they make them with more radius to the transitions on the part, it's obviously a stress riser in that area and they snap.

PalousePoo · Feb 10, 2017

Honest question....When you mototrax owners aren't short on bolts, or have the suspension broken, does a 120 climb up on top of the snow and compete with a 120 Timbersled?

Seekins · Feb 10, 2017

PalousePoo said:
Honest question....When you mototrax owners aren't short on bolts, or have the suspension broken, does a 120 climb up on top of the snow and compete with a 120 Timbersled?

On the flats yes. In mountains with hills not in my opinion. The 2" track spins and the approach angle doesn't lend itself to climbing on top of the snow.

Jnorth · Feb 10, 2017

Seekins said:
On the flats yes. In mountains with hills not in my opinion. The 2" track spins and the approach angle doesn't lend itself to climbing on top of the snow.

My experience in 2' of powder with base was that a TS 120" outclimbs my Mototrax 137".

Norma Stitz · Feb 10, 2017

I wonder if gearing has something to do with it because I feel like my MT enduro kit is geared perfect to my bike and it climbs pretty well.

chumbilly1 · Feb 11, 2017

Honestly , I have been impressed with the 129 mototrax side by side against my yeti. I'm faster and what not, but I feel that I should be.

wwillf01 · Feb 11, 2017

Norma Stitz said:
I wonder if gearing has something to do with it because I feel like my MT enduro kit is geared perfect to my bike and it climbs pretty well.

I agree... If you set you sag appropriately... Which keeps the attack angle for from being steep I feel it trenches less.... I think it would still like a 2.5 inch track though.

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HELICO · Feb 11, 2017

wwillf01 said:
I agree... If you set you sag appropriately... Which keeps the attack angle for from being steep I feel it trenches less.... I think it would still like a 2.5 inch track though.

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Your right sag has a lot to do with it.I am lucky I have a box of springs for that shock that I have tested. Different rider and bike weights come into play. Check out the rebound in the shock it needs to be addressed too. Remember this shock was only tested in the dirt.
Check out your 3 part idler wheel axle/ aframe support. A lot of forces here . Should be a solid axle.

Jnorth · Feb 11, 2017

HELICO said:
Your right sag has a lot to do with it.I am lucky I have a box of springs for that shock that I have tested. Different rider and bike weights come into play. Check out the rebound in the shock it needs to be addressed too. Remember this shock was only tested in the dirt.
Check out your 3 part idler wheel axle/ aframe support. A lot of forces here . Should be a solid axle.

I agree, however the advise to lower your preload resulted in snapping the bolts on the idler shaft due to bottoming out on the moto link arm. If you compare the kits side by side, the mototrax has the shortest rails by far to comparable length tracks. Also, slightly higher drive bogey placement. This means longer attack section, but less track on the ground. Also, since the rails are so short the track bags out between the front of the rails and the drive bogeys due to no support.

I do think that this is a "Pick your poison " situation because the mototrax kit imo the best handling skid if it holds together and you use another manufacturer's ski.

Moto4Life · Feb 11, 2017

Typically MotoTrax kits do not vibrate very much which setup and working properly. Definitely more than a stock bike but it should not be heavily noticeable over the bikes original vibration, unless its a newer KTM, like 16 or 17 model, they seem to vibrate more than other brands.

Some Notes on Vibration.

If you notice vibration starting or getting noticeable, Stop and look at all skid bolts, nearly every time you have vibration it is because a bolt is getting loose somewhere.

You may notice a slight "Hum" when slowing down and engine braking, this is due to the track tension relaxing around the driveshaft and rubbing the plastic guard up front. If its too noisy you may want to check the track is not sloppy.

9 times out of 10 if a notice vibration develops a bolt is coming loose.

HELICO · Feb 11, 2017

Jnorth said:
I agree, however the advise to lower your preload resulted in snapping the bolts on the idler shaft due to bottoming out on the moto link arm. If you compare the kits side by side, the mototrax has the shortest rails by far to comparable length tracks. Also, slightly higher drive bogey placement. This means longer attack section, but less track on the ground. Also, since the rails are so short the track bags out between the front of the rails and the drive bogeys due to no support.

I do think that this is a "Pick your poison " situation because the mototrax kit imo the best handling skid if it holds together and you use another manufacturer's ski.

So setting rider sag on this mono shock system could cause breakage?

Jnorth · Feb 12, 2017

HELICO said:
So setting rider sag on this mono shock system could cause breakage?

I loosened my preload in an attempt to get it to climb at least as good as a 120" TS. This is what some on this forum found helpful for deep snow.

But, if you look at what makes contact when you bottom out you can see that there are no bump stops. It's just the motolink arms slamming into the upper bogey assembly. And yes. It causes breakage!

I will admit that I adjusted the preload softer than I normally would for my weight (190lbs) however there should be a proper bump stop on anything with active suspension imo.

Norma Stitz · Feb 12, 2017

Jnorth said:
I loosened my preload in an attempt to get it to climb at least as good as a 120" TS. This is what some on this forum found helpful for deep snow.

But, if you look at what makes contact when you bottom out you can see that there are no bump stops. It's just the motolink arms slamming into the upper bogey assembly. And yes. It causes breakage!

I will admit that I adjusted the preload softer than I normally would for my weight (190lbs) however there should be a proper bump stop on anything with active suspension imo.

We'll hurry up and design one so I can copy it

Moto4Life · Feb 13, 2017

Jnorth said:
I loosened my preload in an attempt to get it to climb at least as good as a 120" TS. This is what some on this forum found helpful for deep snow.

But, if you look at what makes contact when you bottom out you can see that there are no bump stops. It's just the motolink arms slamming into the upper bogey assembly. And yes. It causes breakage!

I will admit that I adjusted the preload softer than I normally would for my weight (190lbs) however there should be a proper bump stop on anything with active suspension imo.

We are looking into the upper idler wheels a bit more. We typically see them breaking on pretty hard repetitive hits but not always. Technically the shock is supposed to bottem internally before the wheels can ever hit the swingarm but this is not always the case. That's why no physical stop was built in. We have so far successfully tested using a 10mm deeper bolt for the upper idlers, it rest more in the meat of the idler spacer and therefor is stronger. A bit more testing is needed though.

dooman92 · Feb 13, 2017

Moto4Life said:
We are looking into the upper idler wheels a bit more. We typically see them breaking on pretty hard repetitive hits but not always. Technically the shock is supposed to bottem internally before the wheels can ever hit the swingarm but this is not always the case. That's why no physical stop was built in. We have so far successfully tested using a 10mm deeper bolt for the upper idlers, it rest more in the meat of the idler spacer and therefor is stronger. A bit more testing is needed though.

It does not take hard repetitive hits to break the upper idler shaft. I am the lightest, oldest and least aggressive rider in our group. I can ride for days and neither the ski nor track leaves the snow unless it is a really bumpy trail. I broke the upper idler shaft. An energy absorbing physical stop is necessary. If the arms/sides of the moto link were a couple inches wider the wheels would fit inside the arms without making contact. Then a bump stop on the arm that made contact with the shaft near the tunnel might survive. Current design has the moto arm hitting the wheel (inboard too far increasing leverage) then flexing and breaking the shaft. If the bump stop was outboard near the tunnel reducing leverage, the right energy absorbing design/material would survive. An additional benefit of the motolink arms/sides being further apart would be reduced leverage of the current narrow moto link acting as a lever when encountering side forces like leaning/turning that are transmitted to the main shaft and bushing that holds the motolink parallel to the tunnel sides. More width to the motolink would result in a more stable motolink that transferred less force to the plastic bushings on the main shaft.

Jnorth · Feb 13, 2017

Moto4Life said:
We are looking into the upper idler wheels a bit more. We typically see them breaking on pretty hard repetitive hits but not always. Technically the shock is supposed to bottem internally before the wheels can ever hit the swingarm but this is not always the case. That's why no physical stop was built in. We have so far successfully tested using a 10mm deeper bolt for the upper idlers, it rest more in the meat of the idler spacer and therefor is stronger. A bit more testing is needed though.

Awesome. Thanks for the response! Sounds like you are on your way to a solution.

snowrydr · Feb 13, 2017

As someone that has suffered an idler shaft bolt breakage, I'm happy to see that MotoTrax is working on a fix. I'm far from an aggressive rider. I think the kit has a lot of potential when things are sorted out.

007 · Feb 14, 2017

Has anyone had this trouble with the MX kit with the upgraded shock?

snowrydr · Feb 14, 2017

007 said:
Has anyone had this trouble with the MX kit with the upgraded shock?

I have a MX 129 and had this problem. I did reduce the preload a little and it happened. Now that it's repaired I actually increased the preload somewhat from the stock setting.

KTMDirtFace · Feb 14, 2017

What does changing the pre-load have to do with anything? that just sets the static ride height. Doesn't make it any stiffer or less prone to blowing through the travel. Maybe im not understanding the problem.

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