Bicycle Mechanics - Upshift problem: Cable tension has been fiddled around to death. Other solution?

Would adding a chain link help my upshifting problem on my Campy Veloce rear derailleur?

I've had 4 different mechanics dick around with the cable tension and the thing still autoshifts.

I may have some frame flexing causing the upshifting coz I have a big frame (61 cm steel) and I'm a 195 lbs. rider according to one LBS owner. Is this b.s.? :rolleyes:

Did any one of those mechanics check to see if the derailleur hanger was bent out of alignment?

there are several situations that may cause your problems:
Rear derailleur is loose, not bolted until the end or either of the threads are damage.
Fixer pointed out the rear derailleur or the rear derailleur may be bent.
Did you check if the chain is twisted some where?
and most of the time, you are not able to tune your gears because you have a not at your rear derailleur that a nut where the cable housing seats. You need to screw all the way down that nut where the cable housing seats and the gear cable passes trough, before you tune your gears.

If you know how to assemble the rear derailleur this time it will not fail

Did any one of those mechanics check to see if the derailleur hanger was bent out of alignment?

Yes. The hanger was straight. :(

You've eliminated about everything beyond a defective derailleur and/or shifter. Go to Sheldon Brown's site. He has a short article on autoshifting that may help.

Yes. The hanger was straight. :(

So how did they check it? Eyeballing doesn't always work. For a persistant problem like yours you need to unbolt the rear derailleur and use a gauge to check it. Even it it proves to be OK at least you will have definitively ruled out derailleur hanger alignment as the source of your problem.

Did you pull out the shift cable inner wire and inspect all of it including right up at the shifter? Did you inspect the cable housings? Did anyone replace a cable recently?

Wear in the shifer ratchet and cause autoshifting. Repair options include: 1) replace worn parts; 2) upgrade to friction shifting. (Sorry, couldn't resist. :) )

How about if I move up to a medium cage Centaur (Campy says a medium cage can accomodate a 13-29)? :)

I may have some frame flexing causing the upshifting coz I have a big frame (61 cm steel) and I'm a 195 lbs. rider according to one LBS owner. Is this b.s.? :rolleyes:

yeah, this is probably b.s. i'm 220 on a 62cm steel, no autoshifting probs. however, perhaps u have a bad flexy steel frame? or something else more mundane...

sd

Flexing frame that causes shifts should also only occur under high load, like out of the saddle pushing big gears up a hill. This is when the frame flexes the most. If it shifts when you're cruising along with no load, then it's definitely not frame-flex.

Cable-friction can cause what you're experiencing. The cable slowly slips into the proper position long after you've moved the lever and the derailleur shifts. This is usually evidenced by the disparity in downshifts vs. upshifts. Downshifts into the larger cogs move precisely and centers the chain properly. However, upshifts into smaller cogs are lazy and slow and tends to rub the chain on previous big cog a little. Adjusting the cable-tension CANNOT fix this because it affects both upshifts AND downshifts simultaneously.

Then again, the friction could be in the levers themselves due to wear & tear or gummed up innards. Hose it off with WD40 to clean it out and see if shifting improves.

Flexing frame that causes shifts should also only occur under high load, like out of the saddle pushing big gears up a hill. This is when the frame flexes the most. If it shifts when you're cruising along with no load, then it's definitely not frame-flex.

Cable-friction can cause what you're experiencing. The cable slowly slips into the proper position long after you've moved the lever and the derailleur shifts. This is usually evidenced by the disparity in downshifts vs. upshifts. Downshifts into the larger cogs move precisely and centers the chain properly. However, upshifts into smaller cogs are lazy and slow and tends to rub the chain on previous big cog a little. Adjusting the cable-tension CANNOT fix this because it affects both upshifts AND downshifts simultaneously.

Then again, the friction could be in the levers themselves due to wear & tear or gummed up innards. Hose it off with WD40 to clean it out and see if shifting improves.


the friction could be in the levers themselves due to wear & tear or gummed up innards. Hose it off with WD40 to clean it out and see if shifting improves.

How do you do this? Peel back the hood covers and give it a blast of Winn-Dixie? Where exactly do you spray? :)

Flexing frame that causes shifts should also only occur under high load, like out of the saddle pushing big gears up a hill. This is when the frame flexes the most. If it shifts when you're cruising along with no load, then it's definitely not frame-flex.

Cable-friction can cause what you're experiencing. The cable slowly slips into the proper position long after you've moved the lever and the derailleur shifts. This is usually evidenced by the disparity in downshifts vs. upshifts. Downshifts into the larger cogs move precisely and centers the chain properly. However, upshifts into smaller cogs are lazy and slow and tends to rub the chain on previous big cog a little. Adjusting the cable-tension CANNOT fix this because it affects both upshifts AND downshifts simultaneously.

Then again, the friction could be in the levers themselves due to wear & tear or gummed up innards. Hose it off with WD40 to clean it out and see if shifting improves.


Cable-friction can cause what you're experiencing. The cable slowly slips into the proper position long after you've moved the lever and the derailleur shifts. This is usually evidenced by the disparity in downshifts vs. upshifts. Downshifts into the larger cogs move precisely and centers the chain properly. However, upshifts into smaller cogs are lazy and slow and tends to rub the chain on previous big cog a little.
Damn bro, that is exactly what happens! Downshifting is smooth and accurate but the other way is exactly as you described; it drags a bit. Are cheaper Campy shifters like Veloce known for doing this? My bike is only 6 months old ...

I had this problem with a new bike a few years back. The cable housing was slightly split or otherwise deformed in some fashion near the derailleur end and it rather than the cable moved on shifting and then downshifted. The shop looked at it about 3 times before they finally found the problem.

Maybe next time you'll know to buy Shimano

Maybe next time you'll know to buy Shimano

Seriously, are Campy's problematic? I like the way the up/downshifters are separated.
I don't like the dual paddle thingy that Shimano has. :p

Start with replacing the cable or cleaning the cable. That's the most likely problem and it's cheap. Start with the most common things first. Then go from there. Don't try two things at once. First test the cable carefully.

I like the way the up/downshifters are separated.
I don't like the dual paddle thingy that Shimano has. :p

Vice-versa.

Vice-versa.

Hmm..I guess what I meant to say is I don't like the fact that the up/downshifters are right next to each other on the Shimano 105 and up.

The Campy (or Sora) seems safer. The thumb upshifts and the fingers downshift. :o

The last time I had an "unsolvable" shifting problem I had both a bent cog and a bent derailleur cage. The hanger was fine, but I did switch it out to check.

Al

Would adding a chain link help my upshifting problem on my Campy Veloce rear derailleur?

I've had 4 different mechanics dick around with the cable tension and the thing still autoshifts.

I may have some frame flexing causing the upshifting coz I have a big frame (61 cm steel) and I'm a 195 lbs. rider according to one LBS owner. Is this b.s.? :rolleyes:

I have seen this problem caused by the rear wheel being slightly biased (canted?) either left or right. It's not that uncommon on the older steel bikes with the semi-horizontal drop outs. Since your bike is steel, this issue came to mind. Personnaly I had the issue come up with my older steel framed bike the semi horizontal drop outs. I'm not sure if a bike with the almost verticle drop outs could experience the problem. Anyway , my problem went away when I checked the rear wheel alignment and reset it. In fact, I intentionally induced a very slight right side bias to the rear wheel. This action has appeared to improve the large chainring relationship to the chain line back to the cassette.

Damn bro, that is exactly what happens! Downshifting is smooth and accurate but the other way is exactly as you described; it drags a bit. Are cheaper Campy shifters like Veloce known for doing this? My bike is only 6 months old ...

Cable friction problems are usually solved by replacing the cables AND cable housings. Lubing the cables may be a temporary fix and a good diagnostic test.

Al

Yeah, check the cables first, shifters are usually OK. Check the cable-guide under the BB, usually picks up crud from the road. I prefer the nylon guides which works well with a bare cable. Then check the rear section of housing and cable. A teflon-lined housing works well. The tool you use to cut that housing makes a big difference in performance. A set of wire-cutter pliers won't give as clean of a cut as dedicated cable-housing cutters. Filing the ends so that they're even and perpendicular to the housing is important. As is using a small precision screwdriver to expand the inner teflon/nylon liner so that it's not folding in on itself.

Then, the ferrule at the end that goes into the stable-stops makes a difference. Some have rubber seals that cause some drag, I like the ones without the seal. Make sure the ferrule is the right kind to fit into the shape of the cable-stop best.

I like to make my own cable-lube using a mix of 90% light lithium-grease, 5% synthetic Mobile-1 15-50w motor oil and 5% graphite powder. The graphite ensures that even if the grease dries up over time, there's still some smooth lubrication available.

While you have the cable off, pull the derailleur in and out by hand and make sure that the action is smooth. I've seen some derailleurs that have been damaged in crashes with bent pivot-pins. They look fine from the outside, but have extra friction in the mechanism.

Cable friction problems are usually solved by replacing the cables AND cable housings. Lubing the cables may be a temporary fix and a good diagnostic test.

Al


Lubing the cables

At what points do you do this?

At what points do you do this?

Take a good look at how the cable attaches to the rear derailleur. Release the cable from the derailleur and loosen the short curved cable housing found at the rear derailleur, slide it up the cable exposing the part of the cable that runs through the housing. Do not pull the cable through this housing. Lube with your favorite silicone or teflon lube (not oil base). I use silicone door lock grease. At the shifter end expose the end of the cable, push and pull the cable through the shifter exposing enough to lube, again, do not pull the cable through the short curved housing. lube the cable. Re-install the short housing, pull the free end of the cable while flipping the small shift lever (knob) making sure that the shifter is in the smallest cog position. With all slack out of the cable re-attach the cable to the rear derailleur and adjust cable tension as needed. If shifting improves it will probably be a temporary fix and means that the cables and housings will need replacing. Both Campagnolo and Shimano recommend lubricating cables when new.
Also flush out the shifter with WD-40. Do not try to lube the cable with WD-40.

Al