Adjusted my chain today to the factory specs (Haynes manual). Slack was at 1 3/4" (44.45mm). Following the specified procedures, brought the slack to 1" (25.4mm). Spun the wheel and all was good. Sat on the bike and slack all but disappeared, .5" (12.7mm). Is this normal? Thanks
Some bikes should be adjusted on centre stand but measured on side stand. Does that help, not sure about your make and model.
Here’s your issue. The chain and swingarm have different axes (pivot points). Chain adjustment aims to optimise tension without being so tight as to impede suspension movement and damage bearings, chain etc. The relationship of swingarm axis and gearbox sprocket axis varies between different designs and consequently the methods of adjustment with suspension loaded/unloaded.
So just to follow on from Callumity's excellent post, the consequence of what he stated is that the chain tension (without adjustment) is slackest on the centre stand, then slightly more taught on the side stand and finally tightest. Most modern bike mfrs advise setting/adjusting the chain tension on the side stand. Is this how you did yours? What you wrote sort of implies you adjusted the chain with the bike on the centre stand, if that is the case and you set it at 25mm ON THE CENTRE STAND, that is incorrect and makes the chain tension too tight when the bike is in operation. IF you've done it on the centre stand it really needs to be done again, but this time on the side stand.
The bike in question is a 2019 Bonnie T100., and yes, the bike was on the side stand. To me it was just too tight when sitting on it. Since asking the question, went back to the garage and, using my motorcycle jack, raised the lift just high enough to cause the bike to sit straight up/down, with the weight still on the wheels. I readjusted the chain (having to slack it a little), now with me on the bike, there is a little over 9/16" inch slack, and at rest (side stand) the slack still falls within factory spec. Not nearly as tight as before. Thanks for the replies gentlemen