Chain Tension

[PaulHMartinez]

Who can tell me why it needs to be so tight?
Thanks

[siai47]

The recommended 17 mm deflection at no more than 1 kg of force seems reasonable if not a little tight.  With some people reporting sprocket problems, it might be wise to go toward a tighter chain then you might be used to.  A tighter chain will ride in the bottom of the sprockets where the sprocket is the strongest, not at the top where the tooth is narrow and weak.  As long as there is some slack, you will be OK

[Shinysideup]

I always thought the tension was specified in an attempt to reduce the drive-train slop that many have complained about. Of course, I have no evidence to support my opinion. 

I've never felt comfortable with the tightness of the spec and adjusted the chain to be a little bit looser. I can't really measure it meaningfully: it just feels right. It's certainly not as outlandishly floppy as I see on a number of bikes.

At 40K miles, I just put on my 3rd chain and set of sprockets. The sprockets have shown no undue wear, and certainly no tooth failures.

Just another data point.

[siai47]

The drivetrain slop is in the weird transmission used in the Empulse.  No way of getting around it no matter how tight the chain is.  It would be interesting to take a transmission apart and see where all the slop is.  The parts book drawings don't show anything obvious but I could have missed it.  It's almost like something used in drag bikes to shift under full power by using an ignition interrupter to unload the drivetrain momentarily to allow a clutchless shift.  Can't see any use for whatever it is in the Empulse.