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-   -   I need a front triple derailleur (https://www.bikeforums.net/showthread.php?t=1223051)

RichinSC1 02-04-21 08:28 AM

I need a front triple derailleur
 
I bought a shimano tourney triple for a 7 speed but the inside of the deralleur hits the middle ring when I shift to the big ring. I even tried to mount it higher than the 2mm clearance recommendation but the throw is not far enough to reach all 3 rings. When I look online for trouble shooting I see many reviews that indicate many people have the same issue. So I am bagging the Tourney and going with different shimano model. What do you suggest? I am not trying to brake the bank. Thanks,

OneIsAllYouNeed 02-04-21 08:43 AM


Originally Posted by RichinSC1 (Post 21909214)
I bought a shimano tourney triple for a 7 speed but the inside of the deralleur hits the middle ring when I shift to the big ring. I even tried to mount it higher than the 2mm clearance recommendation but the throw is not far enough to reach all 3 rings. When I look online for trouble shooting I see many reviews that indicate many people have the same issue. So I am bagging the Tourney and going with different shimano model. What do you suggest? I am not trying to brake the bank. Thanks,

Most triple front derailleurs are made for a specific combination of chainring sizes. Your best bet is to search for one whose spec sheet lists your exact chainring sizes. You'll find an assortment from Shimano, Campagnolo, SRAM, and Microshift. If possible try to match the shifter brand and approximate year to the derailleur, but don't get hung up on it.

Joint Venture 02-04-21 12:10 PM

Are you still running the original 52/48/28 “half-step plus granny” ring sizes that were stock on a 1990 Burly Duet? The original drivetrain was 3x6 Suntour with bar-end shifters. If not, what’s you’re drivetrain set up? Most triple FD’s made any time recently need a 10 or 12t difference between middle and outer rings.

RichinSC1 02-04-21 12:14 PM

Yes using original rings on front and upgraded to brifters

bwebel 02-04-21 05:34 PM


Originally Posted by RichinSC1 (Post 21909558)
Yes using original rings on front and upgraded to brifters

What brifters are you using? Unless they are older Campy, you are likely going to have to match the brifters and the front derailleur. The cable pull needs to match or it will not index well.

RichinSC1 02-04-21 05:59 PM

Microshift

Joint Venture 02-04-21 07:30 PM


Originally Posted by RichinSC1 (Post 21909558)
Yes using original rings on front and upgraded to brifters

Try changing the middle ring down to 39-42t from the 48t half-step setup.

Ross200 02-04-21 09:17 PM

A lack of "throw" might indicate an incompatibility between the brifters and the FD. Are your new brifters dropper or flat bar? Current Tourney offerings seem to be flat bar only. Front chainline for many of the Tourney models is listed as 50 mm What is your current chainline? If you have enough "throw", you can often raise the derailleur quite a bit over 2 mm and still have acceptable shifting if the "throw' is adequate.

The inner cage hitting the middle chainring on upshift is a function of newer shaped inner cages and non-spec chainring sizes. Shimano 5503/6503 front derailleurs have a more forgiving shape that shifts well over a wider range of chainring differences, even half step, with brifters. CX50/70 might also work, depending again on your chainline.

RichinSC1 02-05-21 12:05 PM


Originally Posted by Joint Venture (Post 21910182)
Try changing the middle ring down to 39-42t from the 48t half-step setup.

Great suggestion! I took off the middle ring (48t) and replaced it with one of my rings (40t) from the timing chain just to see if it worked and it does, no more rub while trying to go to the big ring.
Still not quite enough throw, its very close. I'm still tinkering with it.
Now I need to order another 40t for the timing chain.

jim_pridx 02-05-21 12:25 PM

I don't mean to be stating the obvious, for you've probably looked at this already, but a lack of travel in the FD might also mean that there isn't enough tension in the derailleur cable. I've neglected to check this more times than I care to admit, but sometimes a little tug to tighten the cable a little further will solve the problem.

RichinSC1 02-05-21 12:28 PM


Originally Posted by jim_pridx (Post 21911172)
I don't mean to be stating the obvious, for you've probably looked at this already, but a lack of travel in the FD might also mean that there isn't enough tension in the derailleur cable. I've neglected to check this more times than I care to admit, but sometimes a little tug to tighten the cable a little further will solve the problem.

Yes I have inspected that already, thanks
And I have unscrewed both the high and low limit screws.

act0fgod 02-05-21 12:42 PM


Originally Posted by Ross200 (Post 21910354)
Front chainline for many of the Tourney models is listed as 50 mm What is your current chainline? If you have enough "throw", you can often raise the derailleur quite a bit over 2 mm and still have acceptable shifting if the "throw' is adequate.

The inner cage hitting the middle chainring on upshift is a function of newer shaped inner cages and non-spec chainring sizes. Shimano 5503/6503 front derailleurs have a more forgiving shape that shifts well over a wider range of chainring differences, even half step, with brifters. CX50/70 might also work, depending again on your chainline.

Chainline is something I don't quite understand but feel like creates a number of problems for tandems because we want wide gear ranges.

As I understand it chainline basically refers to the distance from the center of the bike to the center of the chain. What sort of chainline is required and how the front chainline should relate to the rear chainline isn't something I understand and think trial and error is the solution, but don't really know.

For example on one of our tandems we are using SRAM Etap. Up front we have a 50-36 in the rear we are using 9-34 cassette. When in the 50 up front and the 9 in the rear the chain skips when we really push hard and wants to jump up to the next bigger gear. I figure this is a chainline issue, but not really sure.

RichinSC1 02-05-21 01:45 PM

[QUOTE=Ross200;21910354]A lack of "throw" might indicate an incompatibility between the brifters and the FD. Are your new brifters dropper or flat bar? Current Tourney offerings seem to be flat bar only. Front chainline for many of the Tourney models is listed as 50 mm What is your current chainline? If you have enough "throw",

My chainline is 50mm when measure center of tube to center of middle ring.
Measuring center of tube to center of big ring is 58mm

Ross200 02-05-21 02:35 PM

After switching the ring(s) and backing off the limit screws, does the FD have enough range to get all three rings if you disconnect the cable?

RichinSC1 02-05-21 03:45 PM


Originally Posted by Ross200 (Post 21911433)
After switching the ring(s) and backing off the limit screws, does the FD have enough range to get all three rings if you disconnect the cable?

After fine tuning it now works as advertised! The key was switching to 40t middle ring.

Thanks all who helped.

Chris_W 02-07-21 04:28 PM

Road triple FDs are designed for a chainline of 45mm to the middle ring, so I'm surprised it's working with 50mm, which is more MTB spacing. Unfortuntely, MTB FDs don't work with road shifters. Tandem-specific extended FD clamp-on mounts exist to solve this problem.


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