What can I do to stop the BBSO1 dropping the chain on some gears?

flik9999

Finding my (electric) wheels
Dec 11, 2016
156
4
18
27
london
#1
Hey so I have the BBSO1 installed on a bike that has an 8 speed cassette 11-32 (11,13,15,18,21,25,28, 32). However the chain occasionally drops mostly when in the climbing gears (28,32). What do I need to install to stop this happening.

I have already tried putting a front derailer back on that is locked into position but that didnt work. Can I install a narrow-wide chainring as it is or would I need to buy an adapter first and would this work or is there more that I need to do to stop the chain dropping off the chainring.

I found this chain holder will this work? https://www.evanscycles.com/hoy-pin...nlASQN0SbOwfN-cfBU754Xp_WfqvMpLBoCga8QAvD_BwE
 
Last edited:
Jan 26, 2015
6,950
139
113
The European Union
#2
It drops to the inside I presume? My GSM does that too when i change gears on really bumpy terrain. The problem is less serious for me because I have a double chainwheel so the chain drops from the big ring onto the small one and I often don't notice until I change up again on the flat.

The chain guide you show is a good option.
 
Feb 26, 2010
3,322
107
113
Tyne and Wear
#3
I'm running an 8 speed that had exactly the same issues as yourself. The cure for me was to fit an offset chainring to improve the chainline. Originally used an Alcedo Italia 42T and now a Bling Ring 42T.

I also refitted the front derailleur and locked it as you have done, plus shortened the chain by a few links to allow good chain tension across all 8 gears.

Haven't had a single chain drop, where as before I was dropping constantly in the first two lowest gears.
 

Gagsinio

Finding my (electric) wheels
May 9, 2015
42
2
8
44
#4
I have a BBSHD, which originally threw the chain off and would only let me use the middle cog and smallest on a 9 speed cassette. Changed the cassette and chain, now can use every gear, have a gear sensor, which turns the motor off momentarily (bit like a clutch), makes gear changes much better, no crunch.
 
Oct 20, 2017
208
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28
t'North
#5
flikk9999 what is your chainline like - it sounds like the chainset is on a BB that is too long. What quality / speed chain are you running?
 
Oct 29, 2015
318
34
43
Porthmadog
www.ukbusas.org
#6
We run 104BCD adaptors, NW chainrings (using 10sp), clutched derailleur and a chain guide and have never had a chain drop on any of our bikes (we run red and black trails), even on the 72mm BBs with a non-mechanically-sympathetic chainline.
 

Gagsinio

Finding my (electric) wheels
May 9, 2015
42
2
8
44
#7
New chain is a Wipperman connex 808 and rear cassette is a Shimano CS-HG41, works how it should now.
 

whiteturbo

Finding my (electric) wheels
Jul 22, 2016
127
5
18
69
Bristol UK
#8
Simple! get a Lekkie Bling Ring, first its a narrow wide ring so the chain sits nice and deep, second it moves your chain line inboard.Since fitting the Bling Ring i have had zero chain drops.Expensive(£75) but worth every penny.
 
Feb 26, 2010
3,322
107
113
Tyne and Wear
#9
Simple! get a Lekkie Bling Ring, first its a narrow wide ring so the chain sits nice and deep, second it moves your chain line inboard.Since fitting the Bling Ring i have had zero chain drops.Expensive(£75) but worth every penny.
Definitely. Quite surprised that Bafang didn't start churning out something similar as standard with the kits.
 
Jan 26, 2015
6,950
139
113
The European Union
#10
Definitely. Quite surprised that Bafang didn't start churning out something similar as standard with the kits.
Lack of imagination... Or penny pinching.

Better still they could have delivered the motor with a spider that would allow mounting of one or two standard chainwheels. A spider designed to provide a standard chainline...
 

whiteturbo

Finding my (electric) wheels
Jul 22, 2016
127
5
18
69
Bristol UK
#11
@anotherkiwi best idea yet, a spider with a 9mm offset would be good, surprised no one makes one , would make a fortune selling at about a tenner so you could fit any narrow wide chainring because that Bling Ring is way overpriced.
 

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