I searched the list history and Caroline Golum has traditionally been
riding a 2009 era Betty Foy. It was their only bike and a daily rider, so
we may be talking about a Betty Foy (and a 105 Rear Derailleur) with
upwards of 50,000 miles on it.
Bill Lindsay
El Cerrito, CA
On Friday, June 9,
Caroline
You could quickly check if your chain length (# of links) is correct by
using this formula:
# links = 2 * {(2*ChainStay Length (inches)) + 1/4*(# ChainRing Teeth + #
Largest Cog) + 1}
You can measure the chainstay length or if your frame is a RBW, look it up
in the geo charts.
The reason I suggest the chain hanger is that on one of my 1x bikes,
recently, the chain suddenly started not wanting to stay on the chainring
(VO chainring on SunXCD cranks - low miles on both). I got to looking at it
and the chain appeared to be twisted where it got to the chainring. Further
I agree with the other folks here, if it’s popping off the chainring, is it
popping off inside or outside? Was the bike originally a 1x or did you do a
conversion? If you converted it, did you reuse an old double/triple crank?
Did you put the ring on the inside or outside of the spider? Did you
Part of this issue too, FWIW, is my ongoing frustration with hitting
specific gears with a friction shifter. If the chain slack is the culprit
or the derailleur hanger then it takes care of two problems and I don't
hate that!
On Thursday, June 8, 2023 at 3:45:43 PM UTC-4 John Hawrylak,
Caroline
Might want to consider installing a N-Gear Jump Stop or similar chain stop
device on the seat tube to prevent the chain from coming off. Sounds like
when you shift, you develop a wave in the chain which takes it off the ring
John Hawrylak
Woodstown NJ
On Thursday, June 8, 2023 at
So the "chain keeps coming off the crank" . where ? (inner ring or
outer or both ?) When ? (any particular cogs or all of them, terrains,
bumps, etc ? )
What bike frame and how long are chainstays ? Which crank and ring ?
Without knowing that offhand, myfirst thoughts are also the
If the chain is coming off the crank, my experience is (1) you need a
narrow-wide chainring -- if you don't have one, you need to get one. (2)
the rear derailleur might not have a clutch. (3) you might have excessive
chain length. Too much chain and your 1x setup will be prone to derailling.
