Quote:
Originally Posted by Monochron
Hhm, this could be a key part of the root cause. Any ratcheting increases stretch. Therefore a system that never ratchets would stretch much slower overtime than one that ratchets ever 50 operations or so.
|
I think I confused you on cause and effect. Ratcheting is caused by loose chain, which is a consequence of chain stretch, wear, etc. Chain-in-tube drives help alleviate some of the symptoms of poorly tensioned chain. If they're designed so that the chain is very close to the inside of the tubing, the chain physically can't ratchet without interfering with the wall of the tubing. Since ratcheting is the thing you actually care about in drives (along with efficiency and to a small degree backlash), if you solve the problem of ratcheting you don't have to worry quite as much about the problem of chain stretch causing a loss of tension over time. It's addressing the symptoms, rather than the underlying condition, but that doesn't mean it's not an effective solution.
Ratcheting certainly causes sprocket wear (and a lot of tooth wear on belts), and it's possible that it stretches chain more as well. However, I've almost always heard it described as an
effect of loose chains/belts, not visa versa.