I hope your experience with the bike is entirely good.

(The title of 'assertiveness training' maybe gives a flavour of 'hard bargaining' - I've always found bike shops to be entirely reasonable and happy with straightforward communication along the lines of "I'm very interested in this machine, but I've never seen one, and I'll need to be certain that it fits me before I buy it"...."Fine, let's get one in so you can see it and we can get it to suit you - and if it doesn't, it's a good bike and someone else will want it while we find the one that's best for you")

Sounds to me like that's the spirit of the present dealing??

I hope it turns out to be perfect for you.