I thought I would share my modification of the tension wheel with the community.
I was unhappy with the tension wheel bracket supplied with my zbox 50cc engine kit. My chain had quite a lot of slack in it and this seemed to increase the force applied to the tension wheel bracket when I started and stopped. The result was it kept moving out of alignment and dropping the chain between the spokes and rear sprocket - not a good thing as the rear wheel locks!
I fixed it with a new bracket, as pictured, that was secured top and bottom.
The bracket is flat bar aluminium, cost me about A$8.
At the top it secures to the same thread as the rear rack.
At the bottom I had to make the same shape as the existing bracket. Easiest way to do this was get a block of wood, drill a large diameter hole in it, then cut the wood in half, through the hole, to make a stamp. Then place the flat bar and a bit of solid bar (I used a handle from my socket set) in your stamp and hammer the **** out of it to forge the curved shape.
The slot to adjust the pulley height was made with a round file.
The aluminium is soft, so when I first tightened the nut on the tension wheel, the flat sides of it's shank just gouged through the aluminium. To fix that, I removed the bolt, and with a grinder made two flat sides on the round head, so that I could hold it with a spanner on its end. Then I was able to tighten it up.
I also had to twist and bend the bar slightly to have the wheel running in the same plane as the rear sprocket.
Now I ride and free roll without crapping my myself with the thought of the chain dropping into the gap again and seizing up the rear wheel! And it's fractionally lighter as well!
I was unhappy with the tension wheel bracket supplied with my zbox 50cc engine kit. My chain had quite a lot of slack in it and this seemed to increase the force applied to the tension wheel bracket when I started and stopped. The result was it kept moving out of alignment and dropping the chain between the spokes and rear sprocket - not a good thing as the rear wheel locks!
I fixed it with a new bracket, as pictured, that was secured top and bottom.
The bracket is flat bar aluminium, cost me about A$8.
At the top it secures to the same thread as the rear rack.
At the bottom I had to make the same shape as the existing bracket. Easiest way to do this was get a block of wood, drill a large diameter hole in it, then cut the wood in half, through the hole, to make a stamp. Then place the flat bar and a bit of solid bar (I used a handle from my socket set) in your stamp and hammer the **** out of it to forge the curved shape.
The slot to adjust the pulley height was made with a round file.
The aluminium is soft, so when I first tightened the nut on the tension wheel, the flat sides of it's shank just gouged through the aluminium. To fix that, I removed the bolt, and with a grinder made two flat sides on the round head, so that I could hold it with a spanner on its end. Then I was able to tighten it up.
I also had to twist and bend the bar slightly to have the wheel running in the same plane as the rear sprocket.
Now I ride and free roll without crapping my myself with the thought of the chain dropping into the gap again and seizing up the rear wheel! And it's fractionally lighter as well!
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