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Air box plastics


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My 2018 RR 300 seems to have a problem...I crash a lot.

I ride in the big mountains of BC, Canada.  Our trials trails are steep and unforgiving.  But even so, I've just broken my third upper air box in 18 months. First, little cracks appear around the bolt holes of the white plastic section of the air box near the 2 lower screws of the gas tank. Over the next few months, these cracks propagate outwards toward the edge of the plastic.  Once they reach the edge,  it's just a matter of time. 

Are other owners seeing similar cracking and failure around these bolt holes? Anyone trying adding a metal support around these holes to beef them up? Share your Frankenstein fixes please. 

I love my TRS and plan to continue to support the brand. However hoping to avoid shelling out to buy another upper air box. 




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It looks like the bolts are over tightening on the plastic , could you try a slightly longer bolt, so you still get the purchase on the nut, but not the pressure on the plastic?

Failing that, what about, plastic welding a strip of aluminium, running under the plastic to give support and strength to the plastic! almost like a foundation strip or base strip.

Edited by jonboy883
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It's a bit late now but I've always drilled a hole 2/3 mm, or bigger depending on the crack, at the end of a split in plastics, be it mudguards or polycarbonate windows.

It's usually stopped the progressing split dead in it's tracks. 






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A hot stapler can be used to piece it back together or to strengthen a cracked one. In my limited experience from patching up Beta mudguards it'll cope with some flexing better than a plastic weld alone but a crash will just rip them out.

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