I need to buy/build a bike to have and electric assist fitted, only hard spec is it needs to be either 31.6 or 30.9 down tube that is straight and un interrupted.

Unlike my other bikes which I seem to change every 2 years I want something to last, fortunatly it won’t be getting beaten up a couple of times a week.

Budget is £1500, not sure wether to go 26 or 29. I have both at the moment and love both, probably leaning toward 29 if I can find one in budget. Thinking SLX group set, but not fixed and possiy rockshox fork, as I find they last longer and I find them easier to service. I was thinking a steel frame. But can seem to find anything with the seat tube I need.

I’m sure the STW collective can help me.