# Don't lose a digit



## Sparticus (Dec 28, 1999)

Yesterday a mountain biking friend was telling my GF about a chain-drop experience of a 3rd party who owns an ebike.
The 3rd party was out riding his ebike recently when his chain came off.
He went to put the chain back on.
Of course we can't backpedal our ebikes because the crank freewheels in the motor, so we have to drape the chain on over the top run of the chainring, then wind the chain on the rest of the way by spinning the crank in the forward direction.
Well, evidently during the process of doing this, while the top run of chain was on the top section of the chainring, this fellow's thumb was between the chainring and chain.
He attempted the slowly turn the crank to spin the chain on, intending to move his thumb out of the way at the appropriate time.
But...
...the motor engaged.
According to our friend, the guy nearly lost his thumb.

Moral of the story:
Whenever we need to put our ebike chain on, we'd do best to turn the motor off first.
=sParty


----------



## meltingfeather (May 3, 2007)

Ugh— sucks for that guy. 
What has two thumbs and doesn’t ride an eBike?

Too soon?


----------



## Sparticus (Dec 28, 1999)

meltingfeather said:


> What has two thumbs and doesn’t ride an eBike?


You? 

Back to the ebike chain drop issue.
Mine came with a little chainguide atop the chainring.
I wondered why that chainguide was there -- I considered removing it.
But it didn't seem to be causing any problems (no chain rub) and on an ebike, who cares about weight?
So I left it on.
Now I think I understand why it's there.
=sParty


----------



## spaightlabs (Dec 3, 2011)

I think they may have an excellent products liability claim. Dewey Cheatham and Howe should be consulted immediately.


----------



## noapathy (Jun 24, 2008)

Needs a warning sticker (only half kidding). Does the manual say anything about this? I assume any point where something can get pulled into the chain would have a similar hazard.

I know for car maintenance, a lot of procedures have you disconnect the battery so it's not all that different in that sense.


----------



## .WestCoastHucker. (Jan 14, 2004)

this is why i always engage the dropped chain from the bottom and walk the bike backward a foot or so to pull the chain on over the top...


----------



## RBoardman (Dec 27, 2014)

That sounds like a procedural issue, not an ebike issue. When I’m putting a chain back on with one hand I move the derailleur forward/up/CCW to give the bottom of the chain slack, and then with the other hand put the chain back on from the bottom to the top. No need to pedal, shift through gears, or mess with the chain while it is tensioned.


----------



## wolfmw (Dec 18, 2020)

E-bike adds a layer of potential danger, but messing around with metal chains running over sharp spiky metal rings has never been safe. Learned that the hard way, only took once.

Ever experienced the fun of getting your finger sucked under the chain of a coaster brake bike? damn near lost a finger trying to get the chain back on my crappy beach cruiser - can't backpedal to release it once it's on either! (I knew better but there may have been some drinking involved in the cruisin' that night) Luckily the chain was loose enough that my finger escaped (after a full ride around to the bottom of the chainring) with some superficial punctures and bruising, but owwww.....


----------



## AKamp (Jan 26, 2004)

Happened to me with a timing chain once. Made it about half way and then the second half hurt like a mother.


----------



## Whiterabbitt (May 16, 2020)

meltingfeather said:


> Ugh— sucks for that guy.
> What has two thumbs and doesn’t ride an eBike?
> 
> Too soon?


omg, even better, what has one thumb and DOES ride an ebike?

I would totally pull that one in every bar I went to after ‘the accident’


----------

