Help With Bottom Bracket.

[i have no seat]

Hi.

I am riding a toxsin 1 frame and i needed a bottom bracket for it. So i brought a tryall and it broke within 3 weeks, so i got a new one replaced broke again in about 4 weeks. So i got this fsa one everyone was telling me to get. But when i got it i put it in and the drive side went in nice and smooth and when i come to put the other side on it only goes in a certain amount. I rang the bike shop air valley cycles i think. And they said it will be fine as long as its tight. But it kept coming loose. Also there were these 2 spacers to put on the drive side, So i put them on but its still the same. I rang them again and they said its definitely the right size. Also i had the same bottom bracket in my coustellier and it was exactly the same. Also when i go out on ride some people have said is it meant to be like that. And some said it should be.

So could someone please tell me what it should be. And could i saw the left cup down to size so it fits right.

If this is not meant to be like this i was thinking of getting the new echo one.

So please advise me in the right direction.

Thanks.

[Lawnmowerman]

is it the non drive side that wont go in?

Put the non drive side in half way first then put the drive in all the way then tighten the non drive side up all the way

[i have no seat]

is it the non drive side that wont go in?

Put the non drive side in half way first then put the drive in all the way then tighten the non drive side up all the way

I have. Ive tried everything. So i know just ride with a non drive side sticking out. But if it is the wrong size im going to be unhappy with air valley cycles as they told me 3 times is the right size.