Pro 2 bike working loose in frame

[Philatlondon]

I'm after some advice please. No matter how tight I wind everything up, my bike is starting to work loose after about 45 minutes. It's very noticeable when I've been riding out of the saddle I'm following the manual on setting up, so it's a bit frustrating. Any ideas on how to solve this? I did put some grease on the threads to make the screws turn. Could that be causing it?

 

[CXRAndy]

There is a locknut to stop the thread from unwinding. Is that tight? A quick test is to put some masking tape on a fixed point on the frame and on the adjustment bolt, mark them in line. See if the lines move. another possibility is the frame is weak and bending with use. again you could measure accurate ly between two points to see if the width get bigger

 

[Philatlondon]

Thanks. The lock nuts are tight and don't loosen off, so something else seems to be going on. Maybe it is the frame bending slightly under load. I'll try the masking tape trick.

 

[Philatlondon]

Solved. I tightened the plastic nuts even more (I'm now actually struggling to undo them to get the bike out) and that seems to have worked. Can't say I'm too impressed with the way the bike attaches compared to most other trainers.