Road Bike, Cycling Forums banner
1 - 16 of 16 Posts

·
Registered
Joined
·
9,274 Posts
Discussion Starter · #1 ·
I was having problems with shifting so I replaced my chain which was 1/2 a link long. Then got a clickety-clack and replaced the cassette which quieted it down, but now during hard efforts I get a autoshift of 1 or 2 cogs.

My thoughts are RD adjustment (but it's fine shifting when I want it to and doesn't make noise), RD pulley replacement, or replace the shift cables?

Just venturing into doing my own wrenching so any advice would be great. KJ
 

·
Registered
Joined
·
180 Posts
KJohnson said:
I was having problems with shifting so I replaced my chain which was 1/2 a link long. Then got a clickety-clack and replaced the cassette which quieted it down, but now during hard efforts I get a autoshift of 1 or 2 cogs.

My thoughts are RD adjustment (but it's fine shifting when I want it to and doesn't make noise), RD pulley replacement, or replace the shift cables?

Just venturing into doing my own wrenching so any advice would be great. KJ
I had a similar "autoshift" issue. Turned out to be the RD. Took the guy at the shop 5 seconds to fix it. Like your experience, my bike shifted great until I started to climb out of the saddle.
 

·
No Crybabies
Joined
·
11,692 Posts
worn cassette?

KJohnson said:
I was having problems with shifting so I replaced my chain which was 1/2 a link long. Then got a clickety-clack and replaced the cassette which quieted it down, but now during hard efforts I get a autoshift of 1 or 2 cogs.

My thoughts are RD adjustment (but it's fine shifting when I want it to and doesn't make noise), RD pulley replacement, or replace the shift cables?

Just venturing into doing my own wrenching so any advice would be great. KJ
Probably a worn cassette. I've had this same thing happen several times when I replaced a chain and used an existing cassette. If your chain had stretched that much, it probably wore out some cogs. New cassette is most likely cure.

see: http://sheldonbrown.com/chains.html#wear
 

·
Endorphin Junkie
Joined
·
203 Posts
KJohnson said:
I have just replaced the chain and cassette. Chain has 50 miles, cassette 25.
Any other ideas?
If you waited until your chain was half a link too long, your chainrings are probably worn. If the teeth get hook shaped, or too thin, they won't let go of the chain nicely, and can tug on the rear der, causing skipping. If you replace your chain when it is no more than 1/8" too long, you won't have to chain the cassette and chainrings as often. The chain is usually the cheaper part.

Kathy
 

·
Registered
Joined
·
21,832 Posts
Let's be specific

Lucky said:
If you waited until your chain was half a link too long, your chainrings are probably worn. If the teeth get hook shaped, or too thin, they won't let go of the chain nicely, and can tug on the rear der, causing skipping. If you replace your chain when it is no more than 1/8" too long, you won't have to chain the cassette and chainrings as often. The chain is usually the cheaper part.
The recommendation these days is to replace the chain when it's elongated by 0.5%, which is 1/16" over an original length of 12" (24 links). If the OP's chain was elongated 1/4" (1/2 link) over its entire length, that would be just shy of 0.5%. If it was 1/4" over 24 links, then it was OUTRAGEOUSLY worn out, and the chain rings were likely damaged.

All that said, if it really is shifting 2 cogs under hard pedalling, then it's not something that can be fixed with adjustment screws. That sounds a lot more like a bent derailleur hanger, or perhaps a broken BB cable guide. Back in the day, really wimpy frames used to auto shift under hard pedalling because they could flex so much, but that seems unlikely on a modern bike.
 

·
Registered
Joined
·
9,274 Posts
Discussion Starter · #7 ·
Kerry Irons said:
The recommendation these days is to replace the chain when it's elongated by 0.5%, which is 1/16" over an original length of 12" (24 links). If the OP's chain was elongated 1/4" (1/2 link) over its entire length, that would be just shy of 0.5%. If it was 1/4" over 24 links, then it was OUTRAGEOUSLY worn out, and the chain rings were likely damaged.

All that said, if it really is shifting 2 cogs under hard pedalling, then it's not something that can be fixed with adjustment screws. That sounds a lot more like a bent derailleur hanger, or perhaps a broken BB cable guide. Back in the day, really wimpy frames used to auto shift under hard pedalling because they could flex so much, but that seems unlikely on a modern bike.
OP = Obviously Phred? :D That's probably me.

The chain was 1/2 a link long over the entire length of the chain, so hopefully my chainring is still okay. The chainring only has about 1500 miles on it at the most. I called my LBS and will drop by tomorrow to have them take a look. Hopefully it's quick, easy and cheap to fix. (does that apply to the 2 out of three rule? - you only get to pick 2 )

This does lead to another question, How often do you check your chain?
 

·
Registered
Joined
·
9 Posts
I check the chain length every month. I clean and lube it 100-150 miles. Last chain lasted 6540 miles. On the same cassette. It's an 8 speed. And no the cassette didn't need changing this time.

Good maintenance makes things last longer.
 

·
Banned
Joined
·
2,767 Posts
gmcastil said:
You won't be getting 6,000 miles out of 10-speed chains, regardless of how well you take care of them or what manner of wonder-lube that you use.
Ah, an absolute statement that is absolutely wrong. 5000+ miles on a Campy C10 chain, here. When I took it off, it was still plenty serviceable. I only changed it to put on a lighter chain.

Can you please walk us through the empirical data that says a 10 spd chain won't last 6000 miles?:rolleyes:
 

·
Registered
Joined
·
2,009 Posts
I agree on the previous comment on flexing of the frames which probably isn't an issue to date. Next maybe the crank nut is loose or the crank bearings are bad, latter is unlikely, and the crank is moving. Last, maybe little too much slack in the cable, tighten up the adjustment nut at the derailleur but this may be a long shot because if the this is loose, you would have automatic shifting and skipping some gears also under normal pedaling.
 

·
Registered
Joined
·
9,274 Posts
Discussion Starter · #12 ·
Took the bike into the shop (ProPeloton) on Saturday. After looking and fiddling with it for a few minutes the diagnosis was a worn out DA shifter. He said the spring mechanism and another part inside the shiter that keeps both levers from moving when the little lever his pressed was probably worn out. Can't really service the shimano shifters so replacement will be the course of action.

Options are at this point.
1) Just replace the 9spd shifter with another 9spd DA Shifter
2) Replace the 9 speed with 10 sepped Shifter, chain and cassette. Said I could use the same wheel. Also said the 10 speed Shimano chains are only lasting 1500 miles or so.
3) Convert to Campy - serviceable, but expensive
4) Convert to SRAM - said it was a nice setup and the shifting was pretty cool after a short adjustment period.

I'm leaning towards just replacing the shifter(s) and sticking with the same setup. I got 9 years out of the last set. The Tech said that was pretty good for the DA. If I properly maintained the cables and other stuff I could probably get more out of it. It would be fun to play with the new SRAM stuff, but hey, in 9 years when I'm replacing this latest, think of all the new stuff they will have. Some of it might even be better!
 

·
Registered
Joined
·
5,358 Posts
KJohnson said:
Took the bike into the shop (ProPeloton) on Saturday. After looking and fiddling with it for a few minutes the diagnosis was a worn out DA shifter. He said the spring mechanism and another part inside the shiter that keeps both levers from moving when the little lever his pressed was probably worn out. Can't really service the shimano shifters so replacement will be the course of action.
That doesn't make sense to me, unless he's saying that the detents for some gear positons wear so that the shifter does not hold the derailleur in the correct position.

Does the skipping happen in all gears or some gears? Only when you stand, or when seated?
 

·
Registered
Joined
·
1,876 Posts
Replacing the shift cables and cable housings could possibly make a big improvement in the overall shifting performance. Hosing out the shifters with WD40 and cleaning the cable guides may also help. Excess friction in the cable housings can cause sluggish and erratic shifting. But a two cog auto-shift seems pretty severe and sounds more like a bent derailleur or derailleur hanger. Just some thoughts.

Al
 

·
Registered
Joined
·
9,274 Posts
Discussion Starter · #15 ·
ericm979 said:
That doesn't make sense to me, unless he's saying that the detents for some gear positons wear so that the shifter does not hold the derailleur in the correct position.

Does the skipping happen in all gears or some gears? Only when you stand, or when seated?
The auto shifting happens when I'm out of the saddle with a hard effort from a standing start. It only happens towards the smaller cogs of the cluster, or in the

He said the shifter isn't releasing as much cable as it should when shifting. I could feel the difference in a few of the shifts when holding the cable coming out of the shifter. A few definintley didn't move as far as the rest. The standing effort pulls on the cable and it 'completes' the shift. I went for a ride yesterday and it consistently shifts poorly when getting down to the smaller cogs.
 

·
No Crybabies
Joined
·
11,692 Posts
experience

alienator said:
Ah, an absolute statement that is absolutely wrong. 5000+ miles on a Campy C10 chain, here. When I took it off, it was still plenty serviceable. I only changed it to put on a lighter chain.

Can you please walk us through the empirical data that says a 10 spd chain won't last 6000 miles?:rolleyes:
I've had several Campy 10 speed chains destroy cassettes in less than 2000 miles. Anecdotal, but I think it's not all that rare. I would never suggest keeping one 6,000 miles, unless you ride very easily and don't care about destroying cassettes. If you don't care about that, I suppose they can wear together and then be replaced together.
 
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top