Bearing Blocks/Chain Tensioning

[Billfred]

Originally Posted by ollien

My team has never used chain before, and I'm doing some last minute research to ensure we will be able to this season.

I was looking into calculating the C-C distance, and found this calculator. How do I use this correctly? The example I was looking at was if I had a #25 chain, a 36t sprocket and a 12t sprocket, and I wanted to run chain over a 10" distance. According to this, I would need 104.36 links. Clearly, this is physically impossible. Should I just play with the number of links up top until I get a number close enough to 10"?

Secondly, my team doesn't have a mill. Therefore, we figured the best way to use chain would be to utilize Versablocks. Of course, I can measure the distance I need to put the sprocket centers from each other using a tape measure, but I won't get a super high level of accuracy. How do I determine that my versablocks are sufficiently spaced, such that my chain is tensioned?

Originally Posted by J_B_Wood

Don't worry too much about getting the exact center-to-center distance correct. The chain will stretch over time anyways, so you will need active tensioning (what I mean is something you can adjust from event to event) regardless of how well you get it the first time. Here's one solution to that: https://www.mcmaster.com/#chain-tensioners/=15qqcpa

4901 made it through two regionals, SCRIW, and demos with dead-spaced #25 chain, no tensioners in use. There were teething problems, but we got it together once we started using links without clips and pins and instead used a DarkSoul tool to assemble the chains. So: sometimes, you can get away with not using them.

And yes, we did fiddle with the distance until we had an integer number of links. It's better if you aim for an even integer number of links. Miles better. Half links are the devil.