Quote:
Originally Posted by Alex.q
Do you mean a cam that pushes the chain down, or do you mean a cam that rotates to push the axle brackets farther out? Assuming you meant the second thing, then I was wondering why that keeps it tight. Couln't the force just cause the cam to rotate an pull the brackets together as you described before? (I'm not saying it doesn't work, just that I don't understand why it does)
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I meant the second. The forces that are pulling the chain are linear, if your chain tensioner is also linearly tensioned then 100% of the forces on the chain will be pulling on those bolts. However, a cam uses some sort of asymetrical piece on a pivot (like a bolt) as the cam turns around the bolt the radius changes relative to a point. This means that the forces required to loosen that chain must be applyed at almost a 90degree angle to the linear forces from the chain. This means only a fraction of the forces on the chain are actually doing work to turn the cam back out. If you use a bolt as a pivot for your cam then you can tighten it with a lock nut to couneract the fractional amount of force trying to turn the cam out.
We did this last year using seemless chain with great results. Ofcourse if you were really worried about the cam comming loose you could always have another cam to keep the tenision on the first cam.
Nice start on the drivetrain. I'll say that I know that C channel seems like it will work, however there is a reason that teams who use WCD's use box tubing as opposed to C channel. Generally when muliple very good teams do the same thing multible years in a row it is because it works really well. In this case you would probably do well to join the crowd. A phrase that is repeated often on my team: "The best indicator of if a design is good is if the team who used it uses it again next year."
Good luck, Bryan