Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 04-18-13, 03:27 PM   #101
DubT
Senior Member
 
Join Date: Sep 2009
Location: Central Illinois
Bikes: Trek Speed Concept 9.9, 2011 Calfee Tetra Tandem
Posts: 1,046
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by sinkr8 View Post
Amen. Just because they designed a new system that will stay on the pulleys doesn't mean they addressed alignment issues specific to the frame and cranks! That's the beauty of chain drive, its very tolerant!
The CDX system is supposed to be able to absorb some misalignment.

I use the iPhone app and ours only varies a few hz as I rotate the cranks.


BTW Dilbert is not always right.
DubT is offline   Reply With Quote
Old 04-18-13, 03:51 PM   #102
DubT
Senior Member
 
Join Date: Sep 2009
Location: Central Illinois
Bikes: Trek Speed Concept 9.9, 2011 Calfee Tetra Tandem
Posts: 1,046
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by sinkr8 View Post
Hi Folks,
I'm new on the list, and have read a lot!
I'm trying to update our 2009 Cdale. Co-Motion has/had a sale to close out the Gates CDC system. I thought, "what the heck" and purchased. Now I am having some difficulties with install...of course I'm hoping someone will set me straight.
Equipment:
FSA Gossamar cranks
FSA MegaExo BB.
Cannondale dual-wedge ECC

First question: I am using the iPhone app for tension. I tested with the cranks in various positions to see what the range is and expect some differential in tension. I am getting a 15hz variation i.e 50hz in one position vs. 65 in another. That seems significant to me especially since the Gates App indicates a 5hz variation between "lightweight" and "big and powerful" for tandems.
I have repositioned the front pulley on the spider to see if it changed, it didn't have a noticeable impact.
What kind of hz ranges are others getting with this App?

Second question: Alignment. If I can rotate the cranks forward and backwards without the belt walking off, is that considered aligned? I believe I can hear the belt rubbing against the flange of the pulley but I currently have the system "aligned" such that the belt will not walk off while on the stand but have not ridden it.
I ask this question after investing a significant amount of time trying to attain alignment. I am using the ECC to attain aligment though I do have some option with shims. Once I get the alignment set I have to rotate (using a pin spanner) the ECC for tension, the ECC "walks" in the BB which throws off the alignment. If I'm lucky and get the tension acceptable (see above) and the alignment is still good, I have the challenge of tightening the ECC which again may cause the alignment to shift ever so slightly...and the belt will wander.
Am I the only one pulling my hair out? - technically not my 3rd question...
Any insight appreciated!
I just looked at the co-motion website and they are selling the CDC system for $195. I paid $245 for the CDX system directly from Gates.

Just saying!
DubT is offline   Reply With Quote
Old 04-18-13, 04:29 PM   #103
jnbrown
Senior Member
 
jnbrown's Avatar
 
Join Date: Nov 2006
Location: Encinitas, CA
Bikes:
Posts: 1,007
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Quote:
Originally Posted by uspspro View Post
I love Calfees, but that is totally lame. Imagine if you have ordered with a chain drive, they may have not discovered this. My front water bottle mounts are crooked. One day I will bring the frame back to fix it.... but still that kind of stuff should not happen.
You are not alone, my front bottle mounts are crooked too, the bottle is the angled slightly clockwise. I tried adjusting it using the slop in cage mounting holes but it didn't help much.
Also they put the mounts too high up on the downtube, had to go to a side loader cage to get the bottle in and out.
Guess I can't complain since the bike rides like a dream and for the most the construction is as good as it gets.
jnbrown is offline   Reply With Quote
Old 04-22-13, 12:51 PM   #104
sinkr8
Newbie
 
Join Date: Apr 2013
Location: Seattle
Bikes:
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by sinkr8 View Post
Thanks Turbo,
That is what I needed to hear.
On a couple occasions I did manage to get it aligned perfectly such that it was not rubbing on either flange at which time it was very quiet and smooth! Alas, the alignment was not quite right and it would walk off the stokers pulley. On this CDale there is only about 2mm clearance between the stoker pulley and the chain stay so it really cannot walk off but is can rub if misaligned. My back pedaling comment was driven off of what i read on the Co-Motion FAQ's page and another comment I read which indicated a perfect alignment would allow both forward and back rotation but maybe that is pie in the sky...
As an additional comment on the tension challenge, I find it amazing the either the belt or the pulleys cannot be manufactured (economically?) to a higher tolerance such that the variation is minimized.
I will get things aligned and tensioned and give a report back.
Thanks again.
I managed to get the belt alignment pretty darn close. Back pedaling a bit will still cause the belt to wander off of the stoker pulley to the point it will rub on the chainstay. The ECC protrudes from the BB on the drive side about 1-2mm. I may get a spacer and make it right but its working for now. I was able to attain a reasonably consistent tension but still quite a bit of variability in my opinion!

Yesterday we managed a 25 mile ride with a lot of stop and go as well as a solid hill. All I can say is that it worked flawlessly and is amazingly quiet!
sinkr8 is offline   Reply With Quote
Old 04-22-13, 01:37 PM   #105
Turbotandem
Senior Member
 
Turbotandem's Avatar
 
Join Date: Nov 2011
Location: Boulder, CO
Bikes: Paketa V2r di2, C-Dale MT 3000, Teesdale, 1963 Huffy Daisey
Posts: 213
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Quote:
Originally Posted by sinkr8 View Post
I managed to get the belt alignment pretty darn close. Back pedaling a bit will still cause the belt to wander off of the stoker pulley to the point it will rub on the chainstay. The ECC protrudes from the BB on the drive side about 1-2mm. I may get a spacer and make it right but its working for now. I was able to attain a reasonably consistent tension but still quite a bit of variability in my opinion!

Yesterday we managed a 25 mile ride with a lot of stop and go as well as a solid hill. All I can say is that it worked flawlessly and is amazingly quiet!
We had a tape dot on the chain stay right at that point where the belt might rub when we back pedaled. With CDX no longer needed.
As metioned above in the string, a dry film silicone spray from an auto parts shop is used for belts in cars. Great for the cardon drive belt. For the CDC especially it was nice to spray it from above the teeth and a little from side such that it coated the side face of the belt that rides against the flange of the CDC, as well as on the teeth. Spray liberally, a couple rotations of the belt. Don't skimp on it, it wears off in a month or so from abrasion and/or rain. That removed any residual squeek.
Turbotandem is offline   Reply With Quote
Old 05-11-13, 04:34 PM   #106
Bent In El Paso
Senior Member
 
Bent In El Paso's Avatar
 
Join Date: Nov 2009
Location: El Paso, TX
Bikes: Co-Motion Speedster Co-Pilot
Posts: 187
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
As others adopt the new Gates Center Track belt drive I am sure some will run into the issue of the Garmin cadence magnet interfering with belt. The center track belt is positioned in a more outboard position then the older CDC belt drive system. I have found a nice solution to this problem. I apologize for the poor photo quality. The batteries for the camera were dead, so I took these with my phone.

I ordered 1/2" X 1/4" X 1/8" rare earth magnets. I had to order 10 but they were less than $10 for the bunch.



Here is the image of a single magnet...



The magnet was then placed on the inside of the stokers left crank on the end of the pedal spindle...



As you can see here, there is good clearance between the belt and the magnet...



It is recommended to go with the ring-shaped magnet vs. a disc-shaped magnet. These babies are really strong and the ring allows you to use a small screwdriver to remove it from the spindle. The disc could lead to damage of the cranks while trying to get a tool behind the magnet for removal.

The magnet is strong enough that the Garmin cadence sensor picks it up easily even though there is considerably more clearance than with the original magnet.

I hope this is helpful for others who may run into this same problem in the future.
Attached Images
File Type: jpg 51GSTBruE+L._SL500_AA300_.jpg (15.7 KB, 5 views)
File Type: jpg photo 1.jpg (31.3 KB, 6 views)
File Type: jpg photo 3.jpg (36.9 KB, 14 views)
File Type: jpg photo 2.JPG (87.7 KB, 12 views)
Bent In El Paso is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 10:54 AM.