Apologies if this has been done before – I did search but non the wiser.

I have chanced upon a nice FSA SL-K Exo chainset to replace the dead iron my GF has on her Trek Lush.

Being a Trek it has the proprietary BB ALM92 (B3105). So, a BB 92 then.

I’ve look at various websites and still not sure if there is a spacer I can obtain that will allow me to to fit said chainset.

I have some BB90 spacers – is it easier to refit with a BB90 ?

Thanks in advance.