So, I've fitted my TDSZ2 conversion (from Woosh, great service BTW) and although the bottle cage mounts on my frame line up with two of the holes in the battery plate, the battery then wount fit on as it collides with the seat post tube. I'm a little concerned about using a rivnut supplied with the kit, in an alloy frame. That's from the point of view of corrosion (though it's unlikely to get wet) or simply of weakening the frame by drilling.

 

The bike is a specialized crosstrail pro, so as mention alloy frame.

 

I have also looked at some of the non-drill add on fittings, but they are really only designed for the weight of a bottle, not a chuffing great battery.

 

Anyone any experience or comments on this, please?

It looks a fairly sturdy bike, so weakening shouldn't be a problem.

 

A drop of lacquer or nail varnish in and around the hole should stop any corrosion problems.

I did this on my (alloy) bike and there is no sign of corrosion 3+ years later - and it **has** got wet at times.

I used this, you can get 3 slot versions.

https://www.sigmasports.com/item/Wolf-Tooth-Components/B-RAD-Mounting-Base-4-Slot/HVBP

I use the Wolftooth as well, it has cable tie slots as well which are supplied.

Thanks guys. Wolftooth device looks an option, leaves the frame unmodified, and I reckon I'd rather do it that way.