Bafang Mid-Drive Installation

[simon.r]

I hope this helps. Its a convenient place to be despite what it looks in the pic.
The 38t chainring will mess your chainline. The smallest chainring that has a decent offset is 42t. However, it is possible to fit a suitable spacer on the inner side of the freehub and take out one of the smallest sprockets of the cassette. In this way you will bring the biggest sprocket one position out and loose one gear.

I’ve not received it yet, but it looks to me as if this set up will give a very similar chainline to the Bafang supplied chainring:

https://www.ebay.co.uk/itm/352870426326

I’ll let you know when it arrives.

 

[Bonefish Blues]

No, I understand that, but at the moment I simply don't have the time - I'm doing stupid hours sorting out the CJRS for a company and I'm just knackered by way of icing on the cake!

It also fails my 'can I be *rsed?' test, if I'm being frank!

 

[simon.r]

14 - Battery base plate re-fitted. New hole drilled and existing slot extended slightly, so it *just* fits. Spacers added so it’s parallel with the downtube.

 

[Bonefish Blues]

14 - Battery base plate re-fitted. New hole drilled and existing slot extended slightly, so it *just* fits. Spacers added so it’s parallel with the downtube.

View attachment 514427

View attachment 514428

Drilling holes? That's engineering

 

[simon.r]

Drilling holes? That's engineering

Only in plastic and aluminium though!

This level of ‘project’ is just about right for me. A few minor difficulties to overcome, but nothing too taxing for someone with limited practical engineering experience!

 

[simon.r]

15 - Realise that new position of battery base plate is no good as the battery just touches the motor, making it difficult to seat properly Take battery base plate to bits and discover slot that can be used to put a bolt through. Reposition battery base plate.

Cross fingers that it’s 3rd time lucky

 

[CXRAndy]

15 - Realise that new position of battery base plate is no good as the battery just touches the motor, making it difficult to seat properly Take battery base plate to bits and discover slot that can be used to put a bolt through. Reposition battery base plate.

View attachment 514460

View attachment 514461

Cross fingers that it’s 3rd time lucky

I drilled and added two more riv-nuts to make the battery mount as secure as possible. They weigh a fair bit. I too had to carefully place the holder to clear chain ring and allow removal of battery

 

[Ananda]

I used rubber grommets between the base plate and the frame. I also drilled the holes on the aluminum plate where the screws go through quite a bit larger, to allow some vibration absorption. It works well (so far!).

 

[simon.r]

16 - Tidy up the wiring.

 

[simon.r]

17 - Ride to the supermarket, load a trolley full of shopping onto bike and marvel at how easy it is to cycle home

 

[simon.r]

18 - As is the way with these things a few miles under the wheels and you start to think ‘what if...’. This is, I think, the finished article.

Changes:

Battery changed for rack mounted. Looks neater and the bike feels more normal with the battery in this position.

44t chainring. I underestimated the motor assistance and don’t need anything smaller.

Smaller display fitted.

Gear change sensor fitted, which cuts out power when changing gear. This has made the ride significantly less jerky.

Wiring tidied. I can live with the wiring bundle around the headtube as I always have a large black bag fitted to the bike (as shown in previous photos) which obscures it to some extent.