Originally, when I fitted my BBS02 kit to the bike, I stupidly thought that I could do away with the front derailleur cage. Unfortunately, with the original Bafang chainring, the chain would jump off on very bumpy ground, causing loss of drive.
Even after fitting a customized 42T chainring, the issue was still there, but not as bad, as the chainline was greatly improved.
I learnt to live with it until last week, when I thought I'd do something about it. Putting a chain back on with the bike covered in mud isn't much fun
I really wasn't keen on fitting another derailleur, as I had cut the last one off to keep the integrity of the chain.
That would mean I would have to break the chain to fit one.
As luck would have it, I found a front derailleur on eBay that has a screw fixing to open the cage. Result, I didn't have to break the chain to fit the derailleur
SHIMANO STX Bottom Pull 31.8mm Bike FRONT GEAR MECH/DERAILLEUR (FD-MC31)
It was only a tenner, so no great loss if it didn't fit or work.
One worry was that it wouldn't have enough lateral adjustment, to allow the cage to contain the chain without fouling.
Luckily, once fitted, the stop screw allowed it to be positioned far enough out to do its job without touching the chain.
Note: There might not be enough lateral adjustment for stock Bafang chainrings. My custom 42T is offset about 5mm towards the seatpost, and the stop screw was very nearly at the limit to allow the cage clearance.
After a test on some very rough ground, I can confirm that it works perfectly.
So folks, a lesson learnt, not to be so hasty when fitting kits. Take your time and explore all the options
Even after fitting a customized 42T chainring, the issue was still there, but not as bad, as the chainline was greatly improved.
I learnt to live with it until last week, when I thought I'd do something about it. Putting a chain back on with the bike covered in mud isn't much fun
I really wasn't keen on fitting another derailleur, as I had cut the last one off to keep the integrity of the chain.
That would mean I would have to break the chain to fit one.
As luck would have it, I found a front derailleur on eBay that has a screw fixing to open the cage. Result, I didn't have to break the chain to fit the derailleur
SHIMANO STX Bottom Pull 31.8mm Bike FRONT GEAR MECH/DERAILLEUR (FD-MC31)
It was only a tenner, so no great loss if it didn't fit or work.
One worry was that it wouldn't have enough lateral adjustment, to allow the cage to contain the chain without fouling.
Luckily, once fitted, the stop screw allowed it to be positioned far enough out to do its job without touching the chain.
Note: There might not be enough lateral adjustment for stock Bafang chainrings. My custom 42T is offset about 5mm towards the seatpost, and the stop screw was very nearly at the limit to allow the cage clearance.
After a test on some very rough ground, I can confirm that it works perfectly.
So folks, a lesson learnt, not to be so hasty when fitting kits. Take your time and explore all the options
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