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Unread 12-09-2015, 19:04
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Re: Bearings vs Bearing Blocks

Quote:
Originally Posted by asid61 View Post
I was actually asking how one would measure tension. Specifically, if the chain is ratcheting but it properly tensioned, does that mean that the shafts of the sprockets are bending, or just that the chain is stretching to the point where it becomes undertensioned, or something else? Or is "tensioned" for one team different from another?
You can measure tension either by the displacement under a known deflection force, or the frequency of the "twang". If you apply a known force F at the mid-point of a span of chain of length l, and it deflects by a distance h, the tension in the chain can be figured out with a force diagram. My quick scratches tell me that if h<<l *, the tension T can be calculated as:
  • T = F l / 4h

As I indicated above, at a minimum, the stationary tension in the chain should be more than half the tension differential needed to turn the sprockets at peak load; otherwise the back side will go completely slack under load.

* - and if it isn't, the chain is definitely too loose!
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