You have 3 posts and all are negative. I have owned a Explorer for a year on a KTM 530 and have never had 1 problem. I have jumped it and thrashed it, up and down hills and through the woods. Again never any problems. What problems are you having anyways? Your not one of those guys that when his fingernail breaks he goes crying to Momma, are you.
I think it depends greatly on the bike that the kit is being put on. Depending on the configuration of the bike, the kit can be designed very well or very poorly. The design for my Yamaha was very poor. I saw the design for an Aprilla, and I don't think the front end on that one would have any problems. I personally broke two sets of forks. I sold my kit and lost my a$$ on it, but I didn't want to mess with it anymore. If I go with a snowbike again, I'll get a 2moto. I would be tempted to get a snow hawk, but after the abysmal customer service I encountered by AD Boivin trying to get my bike going again after each catastrophic failure I won't be giving them any more of my money. They have since upgraded their front end design for the explorer kit (after I proved they needed to and sent all you guys to their front door demanding a fix) so the future kits might not be so problematic. However, from and engineer's standpoint, I still don't like the kit for the following reasons:
The chain does not align with the counter shaft sprocket. I think mine was about 7mm off. They say it will work fine, but it accelerates chain and sprocket wear, and loads the counter shaft axially which is a load it is not designed for.
The rear suspension sucks. If you have the kit in the middle position, you get about a whopping three inches of travel before the links going up to the foot pegs smash into the top of the track housing. I made brackets for my kit to eliminate this and get some more travel, but it was still VERY limited. It would bottom out over whoops in the snowmobile trail. To be fair, I recently found out I lost all the nitrogen from my shock so that may have had something to do with it bottoming so easily last winter. That still doesn't change the travel though.
The brake design is absolutely terrible. If you look at the brake caliper on any dirt bike, you will notice that the pads but up against caliper mount, and transfer the braking force through the mount to the swing arm. This allows the caliper to freely float back and forth to compensate for the pads opening/closing and for any warping or misalignment of the rotor. AD Bovin's design, because it spins backwards, puts all the breaking force trough the pad retaining pin into the caliper, which then is transmitted trough the caliper guide pins and then into the caliper mount. The retaining pin was never designed to take the full braking load of the bike. They are designed to be able to hold the bike from rolling back down a hill, or stopping it when it is rolling back down a hill, but you never generate the braking force in reverse on a dirt bike that you do going forward. Also, in with a dirt bike most of the braking is done by the front brake (hence a larger rotor, often dual piston calipers etc). Now with the explorer kit, the rear brake is handling ALL the braking force of the bike, and in reverse of the direction the direction that the brake is supposed to work. New pins would probably work fine for a while, but they are going to wear a lot faster than they would in the dirt with wheels. As that pin wears and gets thinner (I noticed definite wear on my pin after only running the kit about 10 times) it's going to get weaker. If the operator isn't big on preventative maintenance, then one day that pin is going to fail and someone's riding home with no brakes. Having load applied to the caliper guide pins is also bad as this will wear them out too. The bores (on my caliper anyway) that the guide pins go into are just aluminum, not steel, so they are going to wear if they are greased or not. Grease will slow it down, but not stop the process.
I don't trust studs in the track. The track is supposed to be able be studded with the screw-in type studs. Pretty much every review on those types of studs is that they eventually rip the hell out of the track. I tried to ask AD Boivin if regular studs could be used and the best I can understand the indirect answer that I got was no, regular studs can't be used in the track. I found last winter that on the snowmobile trails I need studs. Kold Kutters in the lugs aren't going to cut it either. The track needs some penetration to get down in the base of the trail or to grab in ice. I ate it hard once because I was power sliding around a corner at about 30 mph and the track broke loose, then grabbed and flipped the bike around before I came to a stop with the end of the bars stuffed in my stomach (dang that hurt!). I've had a few other times cornering where the track was unpredictable because when the bike leans over far enough the side rail for the track digs into the snow. Also, ice screws like Kold Kutters don't like road crossings, so carbide is needed. The track lugs aren't that rigid, so accelerating or braking are going to be bending the lugs over. This does two bad things. First, if the lug is bending over, the stud isn't sticking down into the snow/ice, it's just dragging along it. Second, when the lug flexes, the stud is going to start ripping out of the lug. Usually the tip of the stud will start tearing the rubber internally until it rip out to the surface. It may take a while, but eventually the stud will come out, or you'll loose a chunk of lug, or both. Regular studs I think would be the way to go, but they would have to be put in the edges of the track where the clearance slots are in the nose of the track. I don't know the internal construction of the track to know if it would hold up, but AD Boivin said not to do it. Regular studs would also add a lot of weight on an already taxing system. My 400 had a hard enough time running the kit at it was.
There were also a couple other small things I found when assembling the kit that were signs of low quality. One example being that one of the aluminum plates on the side of the wear block that is between the chain running over the main sprocket and the chain running back up to the engine. There is a chamfered hole where a flat head cap screw goes through, and the chamfer was on the wrong side of the plate. Also, I'm not supposed to have to modify my bike, but I had to cut one of the tabs off that holds my chain guard to even be able to get the kit installed.
All said and told, I learn a lot and lost a lot of money in the process. I'm done with explorer kits, and because of the piss poor customer service I got from my distributor (Mike Comisac) and AD Boivin I'm also done with the company. When I buy another snow machine, I'll be taking my money somewhere else.
Hopefully the crap I've gone though will do one of three things:
a) Make AD Boivin design a quality product that will last AND SUPPORT IT
b) Educate people to decide if they want to avoid the potential problems of buying an explorer kit
c) a and b
P.S. If there are bad typos, sorry, I ran out of time to proof read this whole thing.
