Motor questions...
 

How offen should springs be changed?
What is a good dyno?

Now for the fun one....
How much longer until brushless take over and all this equipment for brush motors is not needed... :ha:

Anyone???

the brushes are what wear out, not neccisarily the springs. sure, if the spring is broken, replace it! ive used a motor for years with the same spring set.

hope it helped!

over time, the spring will loose is tension due to heat and normal motor usage. I have never used a spring dyno...a sonic fiddlestick is all i think is necessary...you mainly want both springs to have the same tension.
For changing springs...its up to you. They are cheap, so replacing them is cake