1. kev the builder

    kev the builder Loyal Comrade

    as youve found the longer shock forces the rear end up and tightens the chain,when you sit on it the suspension goes down and the chain goes slacker those rubber guards for over the swing arm are to stop this but only if the chain rubs when theres no rider,the other spring loaded tensioners are fitted under the swing arm to take up the slack on long suspension travel bikes,unfortunatly the chinese bikes tend to be copies of other manufacturers bikes but not particulary well made or designed more like throw away toys as youve found out
  2. turbofiat124

    turbofiat124 Premium Member Forum Donor

    Nothing to report on the Trabbi. Just been driving it! It was a balmy 92F/33C today to finish off the end of April....

    Well more Chinese mini ATV hi jinks!

    So the other day my daughter and I are having a bit of fun riding around the field, giving this poor thing absolute hell when I accidentally hit this auger used to drill post holes that goes on my father's tractor. I had dodged this thing many times but it's kind of hard to spot because it's entangled with weeds and I was going in a different direction when I hit it. The sound of the chain guard hitting it didn't sound that good but I thought no damage had occurred. Boy was I wrong.

    We make it up the hill a few hundred yards then as I am in my front yard, I hit the "brake" then all of a sudden the rear wheel comes flying off! Luckily we were not going fast so nobody got hurt.

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    Well at least the bearing didn't break! Notice the stack of flat washers underneath the adjustment thingies. I used this same method on my Chinese pit bike when I'm out of chain adjustment! And my Yugo's clutch cable!

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    Note the burr in the section. This appears to be a pin!

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    So here is the problem . I cannot find an axle with 24 mm splines on it in the length I need. So far all I've been able to find are ones with 28 mm. The axles with 24 mm splines are too short. Maybe those size axles no longer exist.

    Could those Chinese "craftsmen" have decided to make a design change at some point and upgrade to a 28 mm axle? Since they can't seem to make their products any shittier, they decided to use a larger OD axle and actually make something stronger?

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    Upon further investigation, it appears the axle is not machined from a solid rod but rather three pieces pressed together. The center section and the outer splined sections appear to be drilled through the center and pressed together using two 6 mm pins to hold them in place. So the pin is what broke. So based on that I think I can weld the center and sprocket end sections together and it should be stronger than the original design.

    I ground down each end to a 45 degree angle so I can weld as much metal to both ends as possible. Luckily there are two interlocking "burrs" on each end that should help make it easier to true the axle back to where it was. I just got to carefully prop it up and hold it together with magnets and check the straightness as I go along with tack welding it before putting the final weld on.

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    Last ditch effort so save this bike: Order a new housing section with 28 mm ID bearings, axle, sprocket and brake rotor. All axles seem to use 16 mm ends for the wheel hubs.

    OK the Polaris Xplorer 300:

    So I'm I wrapping up all the neglected maintenance on this bike. The gear oil looked like water after I drained it out. Must have been automatic transmission fluid or a sever case of viscosity breakdown! Greased the zerk fittings.

    The worst thing was the brakes. This thing did not seem to have the best brakes but I did not know they were that bad.

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    Some idiot had ran the pads down to nothing. One of the backing pads on the outer pads was paper thin and the other one was gone!

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    But here is the bad thing. The "fingers" on the calipers were worn to the point the calipers had to be replaced from where the fingers were rubbing against the brake rotor. For some odd reason the thickness of the rotors are still in spec. I guess aluminum wears better than the friction material used on brake pads.

    Backing plate on outer pad is gone except for the ends that slides over the pins!

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    A set of new calipers are around $230. Some Chinese aftermarket calipers are $120 (but look totally different than OEM). So I found some used ones on Ebay for $50. So I took them apart, and gave them a good cleaning and bead blasted them and will lubricant the seals with my equivalent of Castrol's Rubber grease and put them back together.

    Now to the brake caliper on the drive. Unlike allot of ATVs that use a drum brake on the axle, Polaris ATVs uses a caliper mounted to the drive sprocket on the transmission. Kind of clever. However once again the pads were worn down but luckily the backing plates were still there so no damage occurred to the caliper. After installing new pads I discovered the rotor was not centered and there was no clearance for the inner brake pad so the caliper would not slide over the rotor with both pads installed.

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    Someone on the Polaris forum suggested that the rotor may be on backwards. I pulled the sprocket and chain off and was about to remove the clip that holds the rotor on when I discovered it floats in and out. A slight tug toward me centered it. It was also cocked sideways a bit.

    My guess is where someone had ran the pads down to nothing pushed the rotor inwards and had it in a bind.

    I'm assuming because the rear caliper is bolted to the frame and can't move, something has to move so the rotor "floats" on the shaft. Where on the front calipers, the rotors are fixed to the hubs so the calipers "float" .

    No photos but last on the agenda. I had my ATV wheels sandblasted by my neighbor up the street and repainted them today.

    Hopefully I'll be able to hit the trails soon!
    Last edited: Apr 29, 2017

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