thanks, I will give pulling the cord tight a try, it does make sense!

I recall my upholster saying that my cord had either gone, or was on the point of going, so he replaced it with some curtain cord, or suchlike, and pulled this tight at the rear of the seat.

Mine has the cord coming out of the front, I did a test pull  on one of them (with seat on bike), had to use pliers since it was just slipping between my fingers but it did straighten it out a bit.  I think I need to take the seat off then apply a little bit of heat with the heat gun and give them a pull...

Yes if clips are crimped down the cord may not pull or will pull really hard. 

Ok, I'll open them up a little.  Thank you!

 Hi Fellas, i have done a few seat covers and found this method makes the job easier. use the wood as a prop to compress the seat foam while you fit the cover . keeps the seat still and gives you an extra hand . good luck

Thanks Jez

You're right trailboss, I didn't glue the foam down.

I would imagine that glue is a last resort.

I still haven't gotten around to taking the seat back off so I can release some tension on the clips then I'll apply a little heat so soften things up and give a pull on the cords, the one I did pull on a bit with the seat on looks better so I think I'll be good. As for gluing down the foam, that just doesn't make sense to me and I had no problem pulling the cover over it.