Chain line for bbshd on Felt dd7 fatbike

M

Monkeypowah

1 W

Joined

Nov 22, 2017

Messages

50

• Feb 8, 2021

• #1

I made a quick vid showing the chain line issue when not using a dished chainring.

The chain stays on perfectly but, if you push the bike backwards it will drop down the rear sprocket, resulting in horrendous takeoff grinding and banging.

https://youtu.be/kZynL4z2_ws

 

M

Monkeypowah

1 W

Joined

Nov 22, 2017

Messages

50

• Apr 8, 2021

• #2

The chain popped off the fatbike and got so jammed between the chainring and the motor that I had to undo the screws to give me space to get it out.
Is this a common occurance?

You can see the issue half way through this short vid.

https://youtu.be/aVOmlBNz5v4

 

spinningmagnets

Moderator

Staff member

Joined

Dec 21, 2007

Messages

12,954

Location

Ft Riley, NE Kansas

• Apr 8, 2021

• #3

You need a chain guide. Mountain bikers take big jumps and the chain bounces a lot. There are many choices and models available....

 

geosped

100 W

Joined

Mar 18, 2015

Messages

258

• Apr 8, 2021

• #4

You probably have a different issues but I used to have the chain pop off all the time until I realized that my sweat pants were getting caught up in the chain. Once I realized this i would either pull the sweat above my knee, use shorts, or stuff the bottom of my pant into my sock. Haven't jumped a chain since.

I have a BBSHD with a lekkie 42t chainring.

 

C

COAR

100 W

Joined

Feb 11, 2021

Messages

171

Location

Colorado

• Apr 9, 2021

• #5

spinningmagnets said:

You need a chain guide. Mountain bikers take big jumps and the chain bounces a lot. There are many choices and models available....

Click to expand...

the majority of new mountain bikes sold don't include a chain guide. they're largely unnecessary IME with the advent of modern clutch derailleurs.

first step I'd take is to ensure the derailleur is properly set up.

 

pwd

10 kW

Joined

Oct 11, 2011

Messages

799

Location

Ontario, Canada

• Apr 9, 2021

• #6

As COAR has pointed out, if you bike has a derailleur clutch make sure it is engaged. Some of them can be adjusted as well. I've mistakenly taken off for a ride a few times without re-enabling the clutch which caused chain issues.

 

P

pomah

10 W

Joined

Jan 2, 2016

Messages

83

Location

Gothenburg, Sweden

• Apr 9, 2021

• #7

You are using a 36T lekkie the chain line is probably still "bad", so you need to fix using a chain guard, I use one similar to this on my BBS02 with a 104 adapter and 38t ring

https://www.bike24.com/p2146800.html