These dual suspension bikes always are a little tricky to convert. Problems being the bottom bracket size and also the limited room for battery in the triangle. This customer was very pleased with the outcome even though the battery couldn’t fit in the triangle and had to be mounted on the top tube. Apparently still handles extremely well.
The standard distance across a bottom bracket is 68 – 73mm. Most mid-drive kits are manufactured to work with this distance. Dual suspension bikes are often different and have a distance of around 90mm. It’s possible to get specific Bafang kits for this but the alternative is to get an adaptor kit that extends the difference. The one picture below is such a kit, from Lekkie, that was designed to both extend this distance and work with the larger diameter press-fit bottom bracket originially on the bike.
Chain line and teeth number can also be a problem once you mount a mid-drive kit on certain bikes. The angle becomes a little extreme when using the lower gears and can result in the chain coming off. This is somewhat negated but using a Lekkie bling ring, that has the narrow/wide tooth pattern. In addition, we regularly lock the derailleur from being able to engage in the lowest gear. When you have so much extra power it’s really not not needed anyway. You often have to work to the limits of the bike frame size. With a motor you often increase the number of teeth on the front chain ring as you’ll typically be travelling at higher speed but you can hit limits with the ring bumping on the chain stay. It’s possible to space the motor across a little as well if you are looking for an extra mm or two.
Unfortunately, there was no room to mount the battery within the frame of this bike as the customer was after the larger capacity battery for greater range. The best option left to us was to mount on the top tube. To achieve this we tapped 3 x holes with riv-nuts into the top tube and purchase some battery mounts. A satisfactory results and proved stable.