Yes, but as seen below it was an index shifting drive train that had
some kind of failure first (when "indexing got finicky"). Switching to
friction left that underlying problem in place.
Reviewing the bidding, if indeed the cassette and chain and cables and
housings are new, I'm wondering if switching to a different cassette was
tried, and I'm wondering if the cable is correctly attached to the
derailleur. There are several possible ways to route the shift cable
back there, and "alternate routings" are used to alter the cable pull.
Quoting from Sheldon's site:
Alternate Cable Routings
Two alternate cable routings for Shimano derailers adapt them for use
with nonstandard shifters or cassettes.
Shimano originally publicized an alternate cable routing which placed
the cable slightly closer to the pivot, making the derailer move
slightly/farther/for each click. This adaptation makes newer Shimano
derailers work witholder Dura-Ace
<http://www.sheldonbrown.com/dura-ace.html>shifters, but it is also
useful when you want to use a 9-speed cassette with 10 speed shifters,
or 8-speed cassette with 9-speed shifters, or a 7-speed cluster with
8-speed shifters. You may need to fine-tune the amount the cable
deviates from the standard position, so the derailer sweep matches the
sprocket spacing.
cable routing to increase derailer travel
The other alternate cable routing, suggested by Brian Jenks, proprietor
of Hubbub Cycles,/decreases/the derailer travel for each click. This
makes some Shimano derailers and shifters compatible with Campagnolo
cassettes. It is also useful when you want to use a 10-speed cassette
with 9-speed shifters, or 9-speed cassette with 8-speed shifters, or an
8-speed cassette with 7-speed shifters. You will then lose the use of
one sprocket, unless you are using a shortened cassette such as an8 of 9
on 7, or 9 of 10 on 7 <http://www.sheldonbrown.com/k7.html#897>. Note
the two tabbed washers in the drawing below -- one to change the cable
routing, and the other to secure the cable. Again, you may need to
fine-tune the cable position.
cable routing to increase derailer travel
Unlike the Dura-Ace modification, the Hubbub modification is
nonstandard, and not all of the ratio changes are accurate. Chris Juden
of the Cyclist Touring Club (U.K.) has posteda Web page listing usable
combinations
<http://www.ctc.org.uk/DesktopDefault.aspx?TabID=3946>.Pulley-type
adapters from JTek Engineering
<http://jtekengineering.com/shiftmate.htm>offer a more precise alternative.
Also, some cassettes (the 9-speed 12-27s I make my 13-30s out of) have
several loose sprockets and spacers in addition to the ones on spiders.
Is there a chance there might be a problem with that, so that the
cassette isn't consistently spaced? Incorrect torque was also mentioned.
As for ghost shifting when running with friction: it's common, thanks to
Hyperglide design. You don't get much in the way of audible or tactile
feedback when you're not spot on in adjustment, and the chain is quite
happy running on two sprockets at once. Load the drive train up and BAM
you get a hard shift to - in my case - the smaller sprocket. Call it a
design issue or user error; it's not necessarily in any way related to
the underlying problem, in my experience anyway.
It's also possible that what the LBS said was checked might not have
been checked competently. We're only assuming that. I've had friends
complain about how newly serviced bikes were working to the point they
said they'd just "brought the bike in for a tune-down" because it
shifted worse afterwards than before the work was done.
On 07/06/2015 02:09 PM, NickBull wrote:
So this is now a friction-shifting drivetrain, right? In that case,
it doesn't seem like the spacing on the cassette should even matter.
All that should matter is that once you've shifted into a given cog,
the derailleur stays still and doesn't ghost-shift you out of the
cog. The main things that I can think of that could cause ghost
shifting: 1) cracked frame, 2) friction between the cable and the BB,
3) cassette wobbling, and 4) play in the derailleur/cog. My
suggestion: zip-tie a piece of derailleur cable housing under the
bottom bracket and run the cable through it. If the ghost-shifting
stops then you know that friction was causing it. That worked for me
with my Rambouillet. You can easily feel for "3" or "4" and rule it
out. I've had bad shifting because of "1" a couple of times so it's
not impossible.
FWIW, I tried the silver-shifter 9-speed friction shifting for about a
year before giving up and going back to indexed shifting. Main
problem: In the winter when your ears are covered in a couple of
layers of fabric, you can't hear when you are not-quite in gear. So
then you get to a hill, stand up, and BANG it shifts into the next cog
down. Used to be with older 5-speed freewheels and accompanying
chains that you could feel when it wasn't quite in gear. But with
modern narrow chains, they are too flexible to let you feel when you
are in and out of gear.
On Thursday, July 2, 2015 at 10:59:32 PM UTC-4, Tim wrote:
I'm so frustrated with my drive train. I had Shimano 9 speed bar
ends with a front triple. They worked great in index mode. The
indexing got finicky so I switched to friction. It worked well for
a bit then the "ghost shifting" started. I switched to Silver bar
ends. They feel great but I just can't get them dialed in. I've
worked on it it, I took it to my LBS and they tuned it up, but it
still doesn't shift right. I had them check for a bent derailer
hanger and they said it wasn't. When I shift to the two or three
lowest (biggest) cogs, it will not stay on that cog. The problem
is worse when I am going from higher to lower gear. If I mess with
the shifter it will finally stay in gear, but it's really
frustrating, especially when riding lots of rollers. I can't
descend a roller and then hit the gear I need for the climb. It
always skips out. If I do slight adjustments to the cable tension
the best I can do is move the problem from the lowest end of the
gears to the middle part. It's driving me crazy! By the way, all
of the parts, chain rings, cassette, and chain, are new (they were
all bought at the same time and now have around 1500-1700km on
them. Any ideas? Please!?!?
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