Yamaha Synch pro has crank creak

[Charliefox]

My 600 mile Giant E+3 is giving a light knock every pedal crank rotation. I had it before but tightened up the chainring bolts and checked the crank bolts and it seemed to disappear. But now I notice distinct play in the 'bottom bracket' or it's Yamaha engine equivalent! Hard to imagine why it would wear here so quickly or is it the high torque motor. It hasn't been mentioned before has it. I will pass the bike shop soon and have a word. Any one had a similar experience? Would taking off the LH rear side plate and taking a peek be OK?

 

[soundwave]

you cant open the motor if it has warranty left but if there is any play in the cranks it could be the bearings.

 

[Charliefox]

Took it to the bike shop last Thursday. All motor bolts, cranks and pedals were properly tight. I held the bike and the mechanic moved the rear of the back wheel sideways left and right. It creaked! Rear axle bolt was fine. Mechanic, perhaps remembering that noise from other bikes, loosened the maestro low level suspension bolts and put fresh thread lock on ends before retorquing them. Wheel creak gone away! A run in nearby forest, and the bike gave only the odd noise, when going over rought stuff. It was suggested that I should take out and grease those suspension bolts before sliding them back in if the creak comes back. I have never had that problem with the same Giant Trance suspension bolts on a 2009 non electric bike I have but too be fair it is 11 kg lighter!
Soundwave! That is a great video of replacing Yamaha bearings for when the warranty runs out. Is it 1 or 2 years? Anyone know?

 

[soundwave]

i got grease on most bolts and thread lock as bits tend to fall off if i dont even lost the rear sus main pivot bolt once fkn £30 for a new one

even the bolts that hold the brake leavers on even come loose with no thread lock pmsl

 

[argoose]

The sync drive has about 1mm side float on the cranks. Plus it can knock when starting to pedal as the drive pawls engage.
Remove the chain and rotate cranks slowly, they should be silky smooth.
Make sure you hold the crank arm, otherwise rough pedal bearings will give you heart failure