Go Back  Bike Forums > Bike Forums > Tandem Cycling
Reload this Page >

Jockey Wheel rubbing Big cog

Notices
Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

Jockey Wheel rubbing Big cog

Old 01-15-20, 01:01 AM
  #26  
72andsunny
Senior Member
Thread Starter
 
72andsunny's Avatar
 
Join Date: Mar 2005
Posts: 281
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked 2 Times in 2 Posts
Originally Posted by Carbonfiberboy View Post
Why is that? My 26 X 34 worked perfectly with the jockey wheel directly under the center of the cog. I'm using a 40T now with an extender, so I can't send a photo. But my B-screw didn't do anything to change that either. See the post right below this one.
Not sure weíre talking about the same thing. The gear is unusable because the jockey wheel is hitting the large cog. See video above somewhere. When riding in that gear, it makes the entire bike vibrate.
72andsunny is offline  
Old 01-15-20, 09:50 AM
  #27  
akexpress
Senior Member
 
Join Date: Nov 2007
Location: Anchorage, Ak
Posts: 605

Bikes: 2015 Calfee Tetra tandem,2016 Calfee Tetra Adventure Tandem, Ventana ECDM 26 mtn tandem, Ventana ECDM 29r full suspension Mtn tandem ,Ventana Fat tire tandem, Calfee Dragon Fly, Santa Cruz Carbon 5010, 907 Whiteout fat tire

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Likes: 0
Liked 4 Times in 3 Posts
15 plus years ago most tandems came with 12-28 cassettes. As we started putting on ever larger cassettes to expand gear range especially with two ring cranks this became an issue. One of the first solutions was a K edge cage at $300 plus that moved the jockey wheels down and back. This problem occurs with single mountain bikes also hence the 25$ solution from wolf tooth components in the form of the Goat link then the Road link. Put a road link on,the problem goes away
akexpress is offline  
Old 01-15-20, 10:14 AM
  #28  
Carbonfiberboy 
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Posts: 15,582

Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004

Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 2084 Post(s)
Liked 187 Times in 146 Posts
Originally Posted by 72andsunny View Post
Not sure weíre talking about the same thing. The gear is unusable because the jockey wheel is hitting the large cog. See video above somewhere. When riding in that gear, it makes the entire bike vibrate.
Ahaa. Well, that's simple then: your cassette is outside the limits of your RD. You either need a different RD or a Wolftooth or similar extender. B screw has nothing to do with it. You're outside your RD cog size limit. I've been assuming that this is a stock tandem. Apparently not.
__________________
Results matter
Carbonfiberboy is offline  
Old 01-15-20, 03:38 PM
  #29  
sch
Senior Member
 
Join Date: May 2003
Location: Mountain Brook. AL
Posts: 3,641
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 205 Post(s)
Likes: 0
Liked 14 Times in 14 Posts
Multiple options besides Wolftooth: https://www.amazon.com/s?k=rear+dera..._sb_ss_sc_2_19

FWIW before I sold my tandem which had a DA long reach 10spd RD I used a Wolftooth to cover an 11-36 10spd cassette on the bike with a 50/39/30 cw
and it shifted fine. RD was ~2007 model. I looked at the setup without the Wolftooth, fussed with the B screw and finally decided to go with the extender,
though the RD cage did just clear the cassette without the extender.

FWIW Shimano road RD have had built in extenders which is accomplished by moving the pivot point outboard of the RD
mounting point on the frame for the past 4-5 yrs. Started with DA
and moved to Ultegra with the 8000 series and 105 7000 series. The ATB RD had this years before styled as "Shadow".
sch is offline  
Old 01-18-20, 02:50 PM
  #30  
72andsunny
Senior Member
Thread Starter
 
72andsunny's Avatar
 
Join Date: Mar 2005
Posts: 281
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked 2 Times in 2 Posts
Originally Posted by Carbonfiberboy View Post
Ahaa. Well, that's simple then: your cassette is outside the limits of your RD. You either need a different RD or a Wolftooth or similar extender. B screw has nothing to do with it. You're outside your RD cog size limit. I've been assuming that this is a stock tandem. Apparently not.
Itís stock, or at least how I got it from Santana. It was new old stock when I bought it, and they did a bit of downgrading of some of the components. Santana had just moved to 10 speed, mineís a 9. I remember complaining to Bill about several shifting problemsóhe thought most of them were eliminated with the 10 speed system, but didnít think it was enough of an improvement to be worth upgrading. I suspect between the 160 mm spacing, the small frame of the bike, and the briefly used double boom tube some incompatibilities were created.
72andsunny is offline  
Old 01-18-20, 02:55 PM
  #31  
72andsunny
Senior Member
Thread Starter
 
72andsunny's Avatar
 
Join Date: Mar 2005
Posts: 281
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked 2 Times in 2 Posts
Originally Posted by 100bikes View Post
Agreed that derailleur spring determines the float of the derailleur with both pulleys in the same vertical plane as the (largest, in this case) cog.
I still contend that the dropout alignment matters. With the large gear range tandems sometimes have, this would be an important factor.

The small chainring and large rear cog combination is in the middle of the range of tensions that rear derailleur needs to
handle(small front chainring/ small rear cog being the the most difficult for the derailleur to handle - carrying a lot of the
chain wrap/weight as well). The shifting may not be affected through the ability of jockey pulleys to float around a bit.

The photo shows that there is a clearly a misalignment. A tandem with a forged dropout such as this should/would definitely
have the hanger in alignment to accept the B screw to hit dead center from the factory/builder.


Check the most outward edge of the derailleur for any indication of damage;
and
Check the hanger for paint buckle

From the posted photo, it is difficult to determine any /all issues.

Two photos that would help the group diagnose the issue:
One from behind the bicycle , showing the rear derailleur with the chain on largest cog in rear and smallest ring in front, to show alignment;
Photo showing the face of the derailleur from the side having stated that it is all original, except the cassette.
sorry, been meaning to shoot some photos, but havenít been near the bike when I was thinking about it. The bike is on an angle, which is sort of making the derailleur look like itís not directly under the big cog. It is.


72andsunny is offline  
Old 01-18-20, 02:57 PM
  #32  
72andsunny
Senior Member
Thread Starter
 
72andsunny's Avatar
 
Join Date: Mar 2005
Posts: 281
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked 2 Times in 2 Posts
Note: Iíve order the roadlink a week ago. It just takes a long time for things to get here. Iíll post an update when it arrives.
72andsunny is offline  
Old 01-18-20, 08:16 PM
  #33  
Carbonfiberboy 
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Posts: 15,582

Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004

Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 2084 Post(s)
Liked 187 Times in 146 Posts
Originally Posted by 72andsunny View Post
Itís stock, or at least how I got it from Santana. It was new old stock when I bought it, and they did a bit of downgrading of some of the components. Santana had just moved to 10 speed, mineís a 9. I remember complaining to Bill about several shifting problemsóhe thought most of them were eliminated with the 10 speed system, but didnít think it was enough of an improvement to be worth upgrading. I suspect between the 160 mm spacing, the small frame of the bike, and the briefly used double boom tube some incompatibilities were created.
I tried to count the teeth on the cog in question in your photo. I think I got 34. Is it 34T? The RD you have should work perfectly with a 34T cog. Everyone else's does. If that's a 34, my assumption was wrong, and they should work perfectly together. Your shifter is evidently moving the RD correctly.

Chain length/tension: I always set my chain length to big-big plus 1 link. Try to go big-big and see if your chain length is about that. Some folks go big-big + 2 links, also fine. I don't see how that could affect your problem, but it's something else to check. It's so weird that this problem in only with the granny.

Looking at your video, it looks like you have at least 1 stiff chain link which is causing the RD to jump when it comes through. You could try putting on a new 9-speed Ultegra chain set to length as above.

I hear a lot of chain noise in your video, maybe just because the pickup is so close to the RD, but still . . . Could the FD cage be touching the chain?
__________________
Results matter
Carbonfiberboy is offline  
Old 01-21-20, 11:26 PM
  #34  
72andsunny
Senior Member
Thread Starter
 
72andsunny's Avatar
 
Join Date: Mar 2005
Posts: 281
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked 2 Times in 2 Posts
Roadlink received. It was pretty much a 5 minute install and my skipping is gone.


The noise in the background is the disc brake running the Metal pads. The adjustment options for it are either accept a little rubbing or accept not being able to stop. Someday Iíll remove it and put the V brake back on.

Iím sure there was a more elegant fix, but the options for mechanics with better tandem skills are limited.

72andsunny is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.