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Old 05-04-14, 07:27 PM   #1
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Gates Drive Frequency Measurement

Sorry if I missed it, but I was wondering if anyone has used the Gates app. for iphone, ipad to achieve the proper tension on there CDX Centertrack system. I can't reach the specified Hz recommended, yet if seems tight enough.
Thanks very much
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Old 05-05-14, 12:13 AM   #2
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I haven't had any problems getting to the recommended frequency. Is your problem caused by not having enough range of adjustment in the eccentric? If so, are you sure that your frame's dimensions are within spec'? Otherwise, what seems to be the cause?

Many people on this forum have written about running the belt with lower tension than recommended, with very few problems reported. Also, it's important whether you're using the newer CenterTrack system (which has symmetrical rings) or the older CDC system (which has a guide on the outer edge of the rings).
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Old 05-05-14, 06:10 AM   #3
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I was able to reach proper frequency, but the belt seemed way too tight for my liking. I ordered the Gates measurement tool and while I was waiting for that to arrive, I adjusted the belt to where I thought it should be. According to the tool, my adjustement by feel was right on and we have had no problems with the belt at this tension.
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Old 05-05-14, 09:17 AM   #4
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We have never had a problem running the CenterTrack/CDX belt on a crossover or same-side drive at a lower tension than the Gates spec. I just set it by ear and feel. I saved a 83Hz tone to my computer and play it back occasionally to "calibrate" my ear.

Reasons to run lower tension?

1. A high tension timing chain or belt will cause unnecessary wear on the bottom brackets & bearings.

2. While the belts are robust enough to be used in mtn biking, it is still possible to break the carbon strands in the belt if you ever get anything caught in the belt & timing ring. Chances are better to not damage the belt if there is some wiggle room in its tension max. So far we have had one case where a small rock somehow kicked up onto the belt and made a horrible crunching sound as it met the ring, and another with our SSD setup where the drive chain overshifted the big ring and got caught in the belt/ring. We are still riding our original belt, with a spare remaining unused.

Last edited by twocicle; 05-05-14 at 09:20 AM.
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Old 06-06-14, 09:08 AM   #5
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I haven't used the app, but used the Gates measurement tool at first. Now, though, I have found that if I set it by feel it is usually close or nearly spot on with the measurement tool. Like the previous posters, I don't like it too tight and have had no problems so far (two years on.)

I would like to correct a previous post regarding the earlier belt system. It does not have a guide on the rings (at least ours doesn't) and you need to keep it aligned to track straight.
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Old 06-06-14, 09:18 AM   #6
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CDC system has a flange on the outer edge to keep the belt from flying off.
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Old 06-07-14, 02:13 PM   #7
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Hi Bad1 - thank you for the correction. You are right and I am maybe half-right. There is a flange on the outside of both front and rear rings, but the insides of the rings have no flange, so the belt could track off to the inside if not aligned although ours never has.
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