Tandem Cycling - Da Vinci Front Derailleur Problem

We got our da Vinci Joint Venture about three weeks ago and love it, but it has developed a problem with the front derailleur. We are unable to shift into fourth gear on the chain ring. It worked the first few days, but now it only shifts into fourth about one out of 15 tries. And I have to use an incredible amount of pressure on the lever to get it to shift. It has been in the shop twice to get it fixed, but the mechanics seemed to be stumped. Does anyone else have any experience like this with a da Vinci using Campagnolo Chorus Ergo Carbon shifters and Custom Compact front derailleur? How did you solve the problem? We purchased this version of the da Vinci so we would have four gears on the front chain ring to use and I am dissapointed that we are having this trouble. Any clues would be appreciated. Thanks.

If you haven't called and spoken to Todd Shusterman or Brian Jenks at daVinci regarding your shifting issue you should do so tomorrow. They are located in Colorado which is on Mountain Time.

US & Canada Toll Free (800) 873-3214
Local & International Phone (303) 936-1241

Other contact info can be found at the following URL, but it's really best to call and speak to your builder on the phone when a problem needs to be addressed:

http://www.davincitandems.com/dvinf.html

My wife and I also have a newly purchased daVinci. I did need to go back to the shop for a cable tension adjustment on the FD, but shifting seems to work fine now. I haven't completely mastered the non-indexed touch required and sometimes I skip over the 18 tooth chainring and drop directly to the 12, but I'm getting better. Haven't had a problem getting up the the "big" chainring and we don't use this too much yet, but as I recall it helps to have a bit of a spin going. Sounds like if you've been back to the shop that this problem occurs even when on a stand. Would definitely call back to Colorado.

New bikes/tandems usually need to have minor adjustments to cables in the first 500 miles of usage; usually referred to as 'cable stretch.'
Just our experience.
Pedal on TWOgether!
Rudy and Kay/zonatandem

I agree with Tandem Geek call Todd, I am sure he will be more than willing to help. I suggest that after talking to Todd, you ask that he call your shop.

One other thing to look at with your shifters is the hoods. I had a similar problem with my single bike (campy). The hoods on Campy Brifters will occasionally get in the way of the shift levers. You need to just adjust the positioning of hoods. My shop showed me how to fix the hoods right after I got the bike and had a similair problem. After a short while, I never had to re-adjust the hoods. I also have Joint venture and have not had any problems so I am sure it is just a small idiosyncrasy. Good luck and I am sure with all of the smart experienced folks on the forum you will be fixed and up and running this time next week.

+1. We've put about 300 miles on our daVinci and I had to turn the cable adjuster about 1/2 turn yesterday to take out some slack (wasn't getting into the big chainring). Works like a charm now. It's just a bit hard to diagnose on the fly without help from your stoker; you don't want to spend a lot of time looking between your legs.

New bikes/tandems usually need to have minor adjustments to cables in the first 500 miles of usage; usually referred to as 'cable stretch.'


The thing that bugs me is this statement from the original post:



And I have to use an incredible amount of pressure on the lever to get it to shift.


A simple adjustment of the stop on the derailleur or the tension on the cable should have not been a problem for the LBS, and neither problem would have increased the required force on the lever. Unless the poster is just talking about exerting pressure on the lever against the derailleur stop.

Do all upshifts require excessive pressure on the lever, or just when you're trying to get into that top gear and it's not going? If you shift down to the low chainring (slack cable), can you move the derailleur freely by hand? (It still requires some force because you're pushing against a spring.) If everything moves freely (no problem with a stuck FD, cable, or lever), it sounds like a simple matter of backing out the outer stop on the FD. If that's all it is, why is the LBS stumped, and what did they try?

I sent a private message to the OP to find out if his problem has been resolved, but received no answer. The only problem I've had with the daVinci FD is that it's almost too easy to shift (only a 6 tooth difference between chainrings) and I have had my 24-to-18 shift turn into a 24-to-12 shift. The non-indexed Campy FD shifter is taking a bit to get used to, but I do prefer to the Shimano brifters. My wife is starting to tell me when I need to do a trim (which is a good thing!)

Tried brifters (Dura Ace) for 3,000 miles. Switched to the tried and true D/A 9 speed barcons. No issues.
There is a slight learning curve to everything. I think 3,000 miles was a good try . . .
Just our experience . . . yours may differ.
Pedal on TWOgether!
Rudy and Kay/zonatandem

I appreciate all the feedback. The da Vinci is back in the shop and it is being worked on now. My wife and I rode it and one of the mechanics followed us on his bike to observe what was failing. He now believes it is a problem with the shifter. I think Mike Frank may be closest to diagnosing the problem if the mechanic is right. I will update you all when the problem is solved. I am confident the mechanics at Continental Bike Shop with nail it. (By the way, the mechanic has placed a call into da Vinci to see if they can cast some light on the problem.)

I just hope I have the da Vinci back before we go TOMRV next week, otherwise, we will have to do it again on our Burley Samba. This will be OK, but we were looking forward to the range of gears on the da Vinci to face the hills on TOMRV.

Sorry, but I never got your private email to me. It is still a problem, but as I post below, the da Vinci is back in the shop and being worked on. Thanks.

A simple adjustment of the stop on the derailleur or the tension on the cable should have not been a problem for the LBS, and neither problem would have increased the required force on the lever. Unless the poster is just talking about exerting pressure on the lever against the derailleur stop.

Do all upshifts require excessive pressure on the lever, or just when you're trying to get into that top gear and it's not going? If you shift down to the low chainring (slack cable), can you move the derailleur freely by hand? (It still requires some force because you're pushing against a spring.) If everything moves freely (no problem with a stuck FD, cable, or lever), it sounds like a simple matter of backing out the outer stop on the FD. If that's all it is, why is the LBS stumped, and what did they try?

The mechanic, as well as I, tried adjusting the cable and the derailleur stop to no avail. Not all upshifts require excessive pressure, just going into fourth. And yes, the derailleur can be moved by hand into fourth. Backing out the outer stop has been tried. As I point out in another reply, the mechanic now thinks it is an issue with the shifter.

I should add that we found if you go down hill at about 36 miles an hour it will shift into fourth with some effort!!! Of course, waiting for a down hill to shift into fourth could be inconvenient.

You might try also posting in the bicycle mechanics forum since the audience will be extremely wide. If you can move the FD by hand and cause a shift I can't imagine how tightening the cable wouldn't produce a fix. If the shifter has pulled all the cable it can pull then you should loosen up the in-line adjusters and take all the slack out at the derailleur end of things. I would think this would result in the FD being positioned correctly over the 4th chainring. At that point should the cable stretch a bit more only a small tweak on the adjusters should do the job. It sounds like you can move the FD by hand to the right position, but can't hold it there with cable tension?

Much ado about nothing. Some times it takes a different set of eyes to spot the problem. Another mechanic at Continental Bike Shop took a quick look at our da Vinci and spotted the problem immediately. The cable connected to the front derailleur was not properly attached. It was looped over the nut holding it in place making the cable just short enough that it would not pop into fourth gear. Once this was fixed, in a minute or two, the problem was solved. We took the tandem on a long bike ride over a lot of hills and it worked great!

Now my wife and I have two great tandems to use. A Burley Samba for unpaved trails and our da Vinci Joint Venture for roads.

I agree with Tandem Geek call Todd, I am sure he will be more than willing to help. I suggest that after talking to Todd, you ask that he call your shop.

One other thing to look at with your shifters is the hoods. I had a similar problem with my single bike (campy). The hoods on Campy Brifters will occasionally get in the way of the shift levers. You need to just adjust the positioning of hoods. My shop showed me how to fix the hoods right after I got the bike and had a similair problem. After a short while, I never had to re-adjust the hoods. I also have Joint venture and have not had any problems so I am sure it is just a small idiosyncrasy. Good luck and I am sure with all of the smart experienced folks on the forum you will be fixed and up and running this time next week.

You know, I had this problem quite a lot on my older campy levers(circa 2001) but the newer 10 spd levers haven't exhibited this problem. Not sure why, but I even trimmed the covers on the old ones.

Frank

Great news! Had to be something simple 'cause the FDs are very simple.