Tandem Cycling - Gates Belt Drive Upgrade?

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View Full Version : Gates Belt Drive Upgrade?


Tandem Tom
04-05-12, 06:06 AM
My wife and I have a Co-Motion Speedster. I see that some folks have the Gates on their tandem. What advantage is there to this upgrade?
Thanks!


NoTrail
04-05-12, 07:23 AM
It's quieter, lighter, and requires no grease.

DubT
04-05-12, 07:28 AM
The new CDX version is coming and is supposed to be available this winter. When it is available I am going to upgrade.

Wayne


twocicle
04-05-12, 08:39 AM
The belt is impossible to break if installed correctly (ie: snug enough to not slip nubs). Possibly on the downside, I suspect it is a little harder on the BB bearings due to the much higher amount of timing belt tightness needed, though nobody appears to have reported this occurring.

A big plus to the current system is that pricing is finally somewhat reasonable. ie: $50/per timing ring, $50-75/belt, but supply is a bit slow and scarce. I wouldn't be surprised if the new CDX version hits the $400-500 again for the first year or so.

NoTrail
04-05-12, 08:53 AM
I actually have the Gates CDX CenterTrack on my commuter bike and I love it. And the belt tension required for the CDX CenterTrack is much less than for the standard CDX, so you shouldn't have any fears about the BB.

waynesulak
04-05-12, 09:05 AM
I suggest searching this forum for prior discussions regarding the Gates Belt drive. There are comments both pro and con. Keep in mind though that the cost of the drive has gone down dramatically

DubT
04-05-12, 09:11 AM
I actually have the Gates CDX CenterTrack on my commuter bike and I love it. And the belt tension required for the CDX CenterTrack is much less than for the standard CDX, so you shouldn't have any fears about the BB.

Are you at liberty to share the cost of the CDX system on your single?

Bent In El Paso
04-05-12, 09:17 AM
We have the Gates drive on our Speedster. We went through a learning curve getting it set up right. First the bike shop that assembled the bike put the rear sprocket on backwards. That led to a lot of belt noise and wear. They also did not put the bottom bracket spacers on correctly that led to the belt not tracking correctly. With a belt, it is important that the pulleys be perfectly aligned front to back.

Since we have a coupled bike, the belt has to be tensioned whenever the bike is assembled. On our bike if the belt is not tensioned properly, it will not stay centered on the pulleys. I first started adjusting the belt using the method of pressing on the belt and measuring the amount of movement. That was not accurate enough in our case. I then bought a belt tension tool which helped a lot, but was still somewhat subjective. Now I am using the Iphone app from Gates where you pluck the belt like a guitar string and measure the frequency. This has proven the be the most accurate method to adjust the belt. At the right tension, the belt tracks the center of both pulleys flawlessly.

It is important to note that the belt tension varies as you turn the cranks due to the pulleys not being perfectly round. I pluck the belt as I slowly turn the cranks to find the tightest position (highest frequency). I then adjust the belt tightness at that point.

As stated before, when working properly the belt is clean, quiet, and light. We love it.

NoTrail
04-05-12, 09:26 AM
Are you at liberty to share the cost of the CDX system on your single?

Bought the bike as a whole so I don't have the price on just those parts. Sorry.

twocicle
04-05-12, 10:44 AM
We have the Gates drive on our Speedster. We went through a learning curve getting it set up right. First the bike shop that assembled the bike put the rear sprocket on backwards. That led to a lot of belt noise and wear. They also did not put the bottom bracket spacers on correctly that led to the belt not tracking correctly. With a belt, it is important that the pulleys be perfectly aligned front to back.

Since we have a coupled bike, the belt has to be tensioned whenever the bike is assembled. On our bike if the belt is not tensioned properly, it will not stay centered on the pulleys. I first started adjusting the belt using the method of pressing on the belt and measuring the amount of movement. That was not accurate enough in our case. I then bought a belt tension tool which helped a lot, but was still somewhat subjective. Now I am using the Iphone app from Gates where you pluck the belt like a guitar string and measure the frequency. This has proven the be the most accurate method to adjust the belt. At the right tension, the belt tracks the center of both pulleys flawlessly.

It is important to note that the belt tension varies as you turn the cranks due to the pulleys not being perfectly round. I pluck the belt as I slowly turn the cranks to find the tightest position (highest frequency). I then adjust the belt tightness at that point.

As stated before, when working properly the belt is clean, quiet, and light. We love it.

Maybe we can learn the tune. Which note pitch is the correct tension?
Or do we want no stinking pitches?

Bent In El Paso
04-05-12, 11:27 AM
Maybe we can learn the tune. Which note pitch is the correct tension?
Or do we want no stinking pitches?

LOL

What works for me is 78 Hz. +/-

twocicle
04-05-12, 11:52 AM
LOL

What works for me is 78 Hz. +/-

Play it at (Netscape/Mozilla only): http://onlinetonegenerator.com/


Closest to: D#/Eb http://www.seventhstring.com/tuningfork/tuningfork.html

merlinextraligh
04-05-12, 12:11 PM
What year is your Speedster? Co-Motion recommends against retrofitting the Gates system (apparently due to alignment issues with the BB's)

Our experience was mixed, and is well documented in various threads here.

Personally, we're waiting for the center drive system, and have the timing chain back on our Robusta.

Sprout97
04-06-12, 02:11 PM
What year is your Speedster? Co-Motion recommends against retrofitting the Gates system (apparently due to alignment issues with the BB's)

When I contacted Co-Motion last summer, they gave me the impression that the change over on our '04 Speedster probably wasn't a good idea. Anyway, here's the link from their website: http://www.co-motion.com/index.php/information/faqs/the_gates_carbon_drive_timing_belt_system .

Ritterview
04-07-12, 12:04 AM
The biggest advantage is cleanliness, and this mainly not while riding, but in handling the tandem.

I have two tandems, one with a Gates, and one with a chain. The sync chain on a tandem is very long and prominent, and handling a tandem is awkward enough anyway that it is a threat to get grease all over anything it gets near. As a result, a tandem with a sync chain is a low grade menace, like a wet dog at a wedding reception.

A tandem with a belt is a different animal. You don't mind getting and keeping it close. Into the car? Into the house? The hotel room? No problem.

With riding, I am not sure there is much difference. The weight advantage is overstated, it isn't that much (I calculated it on some post about 2 years ago, 100-200 grams IIRC). There may or may not be an efficiency loss, but no one seems to say there is an efficiency gain. Its quiet, but I wasn't aware a sync chain made noise.

Another thing about it is that it gets noticed right off. So, it starts a lot of (repetitive) conversations.