cgallagh

I bought a Co-Motion Roadster end of July. It had just right at 100 miles on it and it sat in the owners house for about a year. We now have right at 790 miles on it. It has always had issues with derailer adjustment. The previous owner complained about it. It has always made noise when in the 54 12-13-14 configuration with more noise in the 54-12. It has FSA 54-42-30 chain rings with ultegra components. I took it to the LBS where the bike was originally set up and sold, twice. After the last trip, I had some trouble getting into the 30 chain ring. I have adjusted the front d so that the chain only rubs just a little. The big noises come when we are in the 54-12 and really pushing on the cranks. Then it is very noisy. I took it back to the LBS today. There is a new mechanic there who seems a lot more experienced and he is going to go through the whole thing again. We did find a couple of chipped teeth on the 54. He did some adjustments on the derailer and it only makes noise when putting pressure on the right crank.

Have any of you had a similar problem or have any idea what it may be? My first thought is that it was set up incorrectly in the first place and if so the LBS should eat the cost of making this right.

zonatandem

Sounds like you are not original owner and did not purchase it used at that LBS. If you wish to have the problem solved, expect to pay for that service.
When front der. rubs 'pushing hard' in 54T ring, that seems to indicate possible flex in BB area. Try setting up pedals 90 degrees OOP and see if it cures the flex issue.
Just thinkin out loud . . .
Pedal on TWOgether!
Rudy and Kay/zonatandem

cgallagh

"Sounds like you are not original owner and did not purchase it used at that LBS. If you wish to have the problem solved, expect to pay for that service."

You are correct. I am not the original owner. I have, however paid to have this looked at twice now. I am not trying to get out of a financial obligation but I do think the LBS should be responsible to some degree if this was an original problem, it has not been rectified, and they are the ones that set up the bike.

The LBS owner is a friend. I have spent a not to small amount of money in his store. My wife is getting ready to ride for his race team. I am not trying to place blame. What I am trying to do is figure out what the problem is and if it is something caused by me then what can I do to fix it. If it is the LBS that set the bike up wrong then they should accept some responsibility and step up. There is no animosity between me or the LBS.

We are a small community of bikers here and whatever the outcome I am sure it will be mutually acceptable. I just want the bike fixed and I thought I would throw this out there and see if any of the experienced tandem riders with more bike mechanical knowledge than me would have some idea.

We tried OOP and the stoker does not like it so there you go, but thanks for the suggestion.

Since I posted this the LBS owner called and said they broke it down all the way to the bb and did not see anything wrong. He is going to put it back together and we are going to ride it together at 2.

mrfish

Regarding whether the bike shop should help you out, I think they should. However it's the sort of thing that makes people wield their own tools as the bike shop doesn't ride the bike and will never be as focussed as you are on getting it right.

It's not the sort of problem that sounds as if it has an obvious answer. As you've suggested, the answer is to work through the possibles and eliminate them one by one.

I'd suggest starting at the front deraileur / chainset / chain and if possible eliminating these from the enquiry. Then it boils down to the deraileur chain of command or the cassette not working. Key is to check everything very thoroughly as it's probably something quite basic but subtle, like the time my riding buddy's rear deraileur shifted into a bigger cogs as the ride went on. Turned out the downtube and bottom bracket lug had separated making the path for the cable longer. It took us at least 15 minutes to spot it as we were focussed on the deraileur.

Some ideas off the top of my head, which may help.

Pre ride checks;
Is the chain roughly the right length?
Is the deraileur itself and hanger straight, and hangs vertically below the cogs when you look at it from behind, with the upper pulley in the middle of its float?
Are the deraileur pulleys set up the right way round, i.e. floating one at top?
Are both deraileurs set up with correct endpoints and b-tension?
Is the chainset / bb combination correct to give the right chainline? Are the chainrings set up with correct spacers (if needed)?
Is the chain lubed sufficiently and no bent links, 8spd quicklink or other craziness etc?
Is the deraileur cable friction free?
Measure all the spacers in the cassette - could be a 10 speeder in there, clean and reassemble. Is lockring tight enough?
Are the STI levers tight on the bars? Are all the cable end points on the frame firm?

When you ride it you could help diagnose it by:
does pulling the deraileur cable / adjusting the adjuster make the noise go away?
does it make the same noise in the middle ring, or just in the big ring?
does it make the noise just riding along, when you press the pedals, when you get out of the saddle?

Desperate measures;
Swap out each part in the drivetrain to see if it makes any difference
Measure the deraileur movements using a dial indicator and if different to the cassette spacing get your machine shop to make up a custom spacer set.

You're not going to solve it;
The tandem has really short chainstays and therefore with a triple there will always be a degree of compromise about the shifting?
The tandem flexes a lot when you go for it (both unlikely I think).

dfcas

Does this tandem have a Shimano STI shifting system with limited front derailleur trimming?

zonatandem

Shim D/A STI did create a rub and shifting problem for us. Fought it for 3,000 miles. Stoker said: 'Why don't we go back to bar-end shifters?'. We did. Problem solved.
Hey, pays to listen to the stoker . . .
Sounds like LBS is doing their best, but these little annoyances can be frustrating!

cgallagh

Thanks to all for the input. I agree it is best to be able to do your own repairs. I only started back into biking the end of last October and there was a very long period of no biking between. Technology has marched on and I have not kept up. I am trying to pick up and learn as much as I can but do rely on the shop for some of the trickier things that I have never done before. This has been a learning experience.

Now to tell the rest of the story so far. The LBS stripped it down to the bottom bracket, inspected and put it back together. We went down to the shop and test rode the bike. They had eliminated most of the rubbing issue but not completely. LBS owner jumped on the stoker seat and I showed him exactly what was happening. We then readjusted by small increments, both the H and L stops and repositioned the front D. After about 5 small adjustments and rerides the rubbing went away. We then had problems getting into the 30t. More adjustments and more riding and it looked like all was right with the world. I asked him what I owed him. He had seen RR looking at jerseys and said if she bought one he would call it good. She picked a nice PI sleeveless yellow one on clearance sale, picked up a pair of arm warmers for winter and we called it good.

I was frustrated when I posted originally and I did not mean to give the impression the LBS was not going to make it right. We were originally going for a self supported century this morning and five miles into the ride, while running downhill at about 30mph, we got a visit from the instant flat fairy. I managed to get it stopped without falling but the sidewalls on my gator skins were chewed up. While changing the flat, RR found a huge cut in the rear tire that went all the way to the liner. Had to buy two new tires so we got some Armadillos. The chain was really making noise on the downhill sprint so we figured the century ride was not going to happen so we decided to make it a maint. day.

We then took the bike on a 30 mile hammer fest that included a three mile steep climb that includes a section that climbs 250 feet in .6 miles. There was a moment when we had some trouble getting into the 30t but it straightened itself out. There was no rubbing as we flew down the flats at 30+. For now all is right with the world.

I will save this thread for ideas if it starts to act up again and continue to learn bike mechanical skills.

stokessd

I've had nothing but shifting problems with my Ultegra STI shifters on our cannondale. I put in a new front derailler cable and that helped a lot. I used the thickest stainless one I cold find (on bikeman). The longer cable is an issue, I'm convinced. This winter, I'm tossing the crappy Shimano shifters and Going either with bar ends or with Campy brifters and a travel agent.

I put osme of the blame on the Truvative cranks as well, which don't have perfect chainring spacing and wobble a bit.

People may tell you that the shifter cable don't stretch (I'm not talkng about initial break in stretch, I'm talking about lengthening with increased tension), but they do a little, and with such a long cable run, it will effect things. For me, it's rubbing in the gears you talk about.



Sheldon

mrfish

Agree those Shimano STIs can be problematic to set up, but if you get them set up right they do work very nicely and are then trouble free. I think the issue compared with Campag is that with Shimano it either works or doesn't, whereas with Campag you can set it up so that it's nearly perfect and get away with it 99.9% of the time. On tandems its normally easier to get right than on single bikes as the chainstays are longer meaning the angle of the chain is smaller.

To get it right I follow the following procedure.
1) Set the height and angle of the front deraileur so that you can just get a small coin in between the big ring and the outer cage, i.e. 2mm. At that point the deraileur outer cage should be parallel with the big chainring.
2) Set the end stops of the deraileur so that the mech just shaves the chain in 52x12 and 30x32 or whatever your largest and smallest gears are.
3) Set the cable tension so that the shifter clicks as you shift up to the big ring; normally this will mean there's a tiny bit of slack in the cable on the small ring.
4) Check it all works; you may need to fine tune the adjustments, but remember if you change (1) you also need to reset (2) and (3). Key is to diagnose what's rubbing and think through what you should change to eliminate it. You should also check that after a shift is completed, the deraileur cage should no longer touch the chain. If it does, it will likely overshift at some point.
5) Once it works ensure all fixings are firm and then ONLY CHANGE THE CABLE TENSION while out on a ride.

Occasionally the thing still won't work and drops the chain regularly. If after many hours trying it still doesn't work a deda dog fang can be useful to catch the chain on downshifts or you can try slightly bend the lower half of the front deraileur cage to give more clearance. This was the only solution to get clean shifting on my old road bike.

joe@vwvortex

You mentioned that you had a few chipped teeth on the 54 ring - is the ring "true" and not warped or bent? Shimano front shifters are a ***** to set up correctly - especially the triples. I'd also check the front derailleur cage to make sure it isn't bent. Also - make sure the rear derailleur hanger isn't bent either. How old is the chain? One of the reasons - there are many - that I don't like Shimano STI on triples is the lack of trim adjustment - Campy levels are far superior in this regard. No fuss to set up correctly at all.

zonatandem

"Some trouble getting into the 30" . . . On a tandem, especially when hill climbing (gee, that's why we have a 30!), anticipate your shifting a bit more; shift into the 30 'before' it's actually really needed. Also, must let up a bit on the pedal pressure when shifting while under extreme power pedaling power.
We always spin the wheels to give a quick 'visual check' of tires and trueness of wheels before going on a tandem toot.
Just some of our observations though the years . . .
Sounds like you've got a 'real keeper' in your LBS!
Pedal on TWOgeyther!
Rudy and Kay/zonatandem

lmzimmer

We had similar problems with a 9 speed Santana. Despite frequent checks and adjustments the front Der was frequently cranky about shifting into the large and sometimes small ring. In our case it was solved when we replaced the front shifter cable/ housing. Our LBS told us there had been a bad lot several years ago. It might be worth discussing with your
LBS.

lmzimmer

Also to note in addition to above with our shifting problems on our santana- We could never duplicate this problem on a workstand- it would shift flawlessly over and over but issues were apparent when riding.

zonatandem

Imzimmer:
Agree the tandem can work 'perfect' on workstand. But then add the weight of 2 bodies to the bike on the road, and it needs a bit more fine tuning!
Minor things like cablehousing, fraying cable, bent der., worn teeth on chainrings/cassette, etc all can cause these annoyances.
Pedal on TWOgether!
Rudy and Kay/zonatandem

stokessd

Yup, I've got an interesting issue right now. with my wife and I the chain jumps on the middle chainring when under high load (like jumping across an intersection after the light first turns green). The chain literally lifts off the ring causing us to flail a tooth or two until it recatches (still on the middle ring).

I've measured chain stretch and the chain looks just like new. The chainring doesn't look worn at all, but the chain still jumps.

I can't reproduce it with just my peddling force, it's got to be both of us.

I'm going to buy a new chainring and see if that helps.

Sheldon

Jinker

Sheldon: That sounds a lot like it's frame flex causing the issue. Either the alignment of the BB/chainrings and derailleur is changing, or the flex is causing the length of the cable run to the derailleur to change and having it help shift the chain to a different ring.

Another possibility is that you've got some bad chainline issues, which are exacerbated by frame flex.

Is it climbing to a bigger ring, or shifting down to the small ring from the middle ring when you're accelerating? Are you in your biggest cog at the back when you're starting?

stokessd

It doesn't appear to be changing gears. It's jumping on the middle ring like the teeth are badly worn and it's slipping. If we really make it slip badly, we can have it fall into the smaller chainring. But with just slightly too much pressure it stays right on the middle ring and jumps teeth. The problem is that I can't clearly see the problem from the captain's spot and have been schooling my wife on what to look for. This cannondale frame is a brick, and the chainline measures like it's in the ballpark. So I doubt that it's frame flex. I also had the front derailler trimmed so the cage was centered nicely about the chain.

The chain measures fine like it isn't stretched. The teeth on the crank look fine. I'm buying a new middle ring in hopes that it goes away.

I was also in the middle of my 9-speed cassette when starting as well. It doesn't happen in a similar gear on the big ring either.


Sheldon

Old Hammer Boy

It could also be a free hub needing service/replacement, or a rear D/R out of adjustment. I find it hard to imagine a chain "spinning" around on a chainring, jumping off, and then back on. Is your stoker actually able to see this occuring?

stokessd

Yes, and the last time I watched it too as best I could. I thought for sure that it was my freehub (DT hugi) and I was all set to return from the ride and tear it down. We are able to replicate it in the middle chainring and the middle of the rear cassette. The cranks are Truvativ (which are pretty crappy), and the cassette is a 9 speed ultegra (12-25). The chain is a shimano 9 speed unit with about 500 miles on it. I just replaced the timing chain with one just like it about 150 miles ago and the measure the same.

The frustrating thing is that I can't make it do it with just my power alone, so I can't go out and watch closely. My wife's feet and legs are typically in the way.

There is what feels like a freewheel slipping a ratchet location, but the distance is one chainring tooth, or a multiple of them. When it happens I see the chain jump on the middle chainring. I was thinking it was inertia from the freeing up then catching if it was the freehub. But the fact that we can't make it do it in the big chainring (with a bigger cog in the back for the same gear) is pointing to the something other than the freehub.

I've been riding and a bike mechanic since the early 80's and this has me stumped. IF the chainring teeth were shot, I'd be a lot less confused, but they look good.

Sheldon

Old Hammer Boy

You sound like you have a good understanding of your driveline. I also have a Cannondale with the same group set, a 2005 RT. I still think it may be your R/D or the free hub. But, I guess anything is possible. You might also check your chain length and your "B" adjustment, just in case she's jumping between rear cogs. On mine, the "B" was way too "open." After dialing it in, it shifts much better.

I agree, these SDI set-ups can be frustrating, especially on a tandem. I can't believe the difference between my 1/2 bike and our tandem, both with Ultegra shifters.

zonatandem

Re-check the whole chain, each link, and see if there is a stiff/bent link.

ftsoft

I suppose you have the XTR rear? My Speedster was really a mess when I brought it home from LBS, but a couple of tuneup sittings and it was good. I have some noise in the 39/11, but that's it. You should be able to make it nearly perfect. The noise in the 54/12 is a little worrisome ( chipped teeth won't hurt anything) because it could be from rubbing on the chain stays. I'm surprised that you have trouble getting into the 30 (most of the time the problem is shifting off the 30). Could be cable tension issues.

Frank