Bafang 100mm BBSHD shimano press fit 41mm diameter 89.5mm- 92mm width to BSA/JIS adaptor.
The BBSHD motor is designed for JIS/BSA threaded bottom bracket shells. If you have a 2012 and newer bike chances are good you may have a Shimano Press Fit bottom bracket shell. Full suspension mountain bikes such as the Giant Trance and Giant Anthem models have an ideal frame for battery placement, but motor installation was not an option due to the bottom bracket and motor incompatibility. We are able to fit BBS02 and BBSHD motors in the 2011 and older Giant Trance and Giant Anthem bikes because they use a threaded BSA bottom bracket, but were unable to install mid drives into the newer models after the BB shell design change to press fit. To solve this decided to custom machine an adaptor making it possible to install a 100mm wide BBSHD 1000 watt motor into the PF41 89.5mm-92mm wide BB shell. *Not intended for use on Carbon frames where shell may be too thick for motor clearance, intended for aluminum frames only.*
Intended for BB Shells with the following:
A very common bearing we see in these shells is the SM-BB71-41. This press fit bearing cartridge is another thing you can look for to determine if your bike has the compatible shell this adaptor is designed to work with.
Seen below, is a 2012 Giant Trance X4 that will soon be receiving a BBSHD.
Its a 2 piece adaptor machined from 6061 aluminum designed to fit without needing a press and easily slides over the motor spindle shaft into the Shell's bearing races. You have the option of using Loctite 638 recommended for the adaptors gap clearance, but its completely optional. Our test results have shown it is not needed due to the way everything fits together when the M33 lock rings are tightened securely. The adaptor has been carefully designed and machined to fit a 100mm motor into a 89.5mm width PF41 shell without requiring additional spacers. This makes for a secure mechanical mount because the clamping force of the M33 lock rings compress the adaptor pieces against the non drive side shell face and the drive side bearing race wall. If shell is 92mm wide all that is needed are 2.5mm spacers on the two bolts between the fixing plate and motor body.
Non drive side.
Tighten up M33 lock rings. Done!
Plenty of threads left for second lock ring and no spacers needed. Clean and mechanically sound install. The motors on our installations have not rocked or moved at all, but if for some reason this does occur on your installation. You can easily drill, tap, and install a set screw on the non drive side adaptor seen below, but because the adaptors press up against the shell face and bearing race walls, we don't think you will ever need to do this.
Finished install with no Loctite, no set screw, and no problems. Motor is held firmly in place against the frame downtube. So if you have a bike with the shell like this Giant Trance X4 and you want to install a powerful mid drive electric assist motor, you are in luck. The wait is finally over.