Gates Carbon Drive timing belt eating bottom brackets?
07-26-21, 06:02 PM
#26
Junior Member
Sram bb
Yes, come to find out my BB or reversed. The stokers is common and the captains is opposite. The SRAM BB that I need is discontinued. My bike mechanic suggest flipping the eccentric over 180 degrees and then the SRAM BB’s will be the same. Can that be done? Are eccentric BB reversible?
Thanks in advance!
Dave
Thanks in advance!
Dave
07-26-21, 09:07 PM
#27
Full Member
After all the comments and trying with the belt tension looser, I believe that in addition to having excessive runout, I have been running the belt way too tight which is likely my problem (I never could get a consistent tone out of the belt strumming method). To set the looser tension I choose the limit to be just a bit tighter than the belt being able to climb out of the center track when slowly turning the crank and pushing the belt sideways just ahead of where the belt met the ring. If the belt climbed out of the center track and started to ride on top of the ring, I backed off and adjusted the eccentric just a bit tighter. Riding it over the weekend it performed well, but I still need to replace the BB (or bearings) as these are ruined. I believe the belt tension measures in the low 30lb range and the difference due to runout is fairly small.
I'd be curious of how others determine "loose" as "loose enough" or "too loose".
I'd be curious of how others determine "loose" as "loose enough" or "too loose".
07-27-21, 05:18 AM
#28
Full Member
Thread Starter
Yes, come to find out my BB or reversed. The stokers is common and the captains is opposite. The SRAM BB that I need is discontinued. My bike mechanic suggest flipping the eccentric over 180 degrees and then the SRAM BB’s will be the same. Can that be done? Are eccentric BB reversible?
Thanks in advance!
Dave
Thanks in advance!
Dave
05-09-23, 09:50 AM
#29
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Excellent analysis. Appreciate the comments and your thoroughness. Are you sure the click click is coming from from your bottom bracket. I occasionally get a ticking noise which is caused by the belt. Spray my belt with silicon eliminates the sound.
05-09-23, 03:07 PM
#30
Newbie
I also used the method discussed by Sheldon Brown (https://www.sheldonbrown.com/synchain.html) to minimise differences in tension from rotational position.
05-10-23, 08:47 AM
#31
Full Member
Thread Starter
if the measured runout moves into the acceptable range, terrific. If not try rotating a ring one bolt position at a time until you achieve success.
05-10-23, 11:08 AM
#32
Newbie
I agree this should be tried first. I my case it didn’t work which is why I went down the rabbit hole I did. It should not have to be this way but unfortunately it is in far to many instances.
if the measured runout moves into the acceptable range, terrific. If not try rotating a ring one bolt position at a time until you achieve success.
if the measured runout moves into the acceptable range, terrific. If not try rotating a ring one bolt position at a time until you achieve success.
06-21-23, 02:58 AM
#33
Newbie
Indeed!
I recently removed the stokers chainset to change chainrings. When I refitted the Gates timing belt it would slowly creep of the rear cog untill it rubbed the frame. I removed it and refitted it the other way round, and all was good. Are Gates belt directional?
I recently removed the stokers chainset to change chainrings. When I refitted the Gates timing belt it would slowly creep of the rear cog untill it rubbed the frame. I removed it and refitted it the other way round, and all was good. Are Gates belt directional?
08-20-23, 03:40 PM
#34
Newbie
The stoker bottom bracket develops this incredibly annoying click at a given orientation of the crank set. It will only do this when all 4 of our feet are on the pedals. With any combination of 3 or less feet on the pedals, no click, 4 feet, click. I replace either the entire bottom bracket or just the bearings and the click disappears.... for a few hundred miles, then - click click click.
08-21-23, 01:47 AM
#35
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Well, Philly, if it’s any comfort for you, in the past 12 or so years we have ridden over 30,000 miles with the original Gates belt on our Macchiato with no problems with belt or BBS.
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08-21-23, 05:40 AM
#36
Full Member
Thread Starter
I believe my issues are due to poor manufacturing of the crank(s). I’ve stated before that this shouldn’t be the case, especially at the price points of these products, however, the evidence is abundant that the bicycle industry is doing a poor job insuring an acceptable level of quality. It could do better.
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08-21-23, 05:42 AM
#37
Ferengii
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AND we’re now over 45,000 miles on our original Gates belts on our Equator with no problems with belt or BBS.
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08-21-23, 10:17 AM
#38
just another gosling
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After all the comments and trying with the belt tension looser, I believe that in addition to having excessive runout, I have been running the belt way too tight which is likely my problem (I never could get a consistent tone out of the belt strumming method). To set the looser tension I choose the limit to be just a bit tighter than the belt being able to climb out of the center track when slowly turning the crank and pushing the belt sideways just ahead of where the belt met the ring. If the belt climbed out of the center track and started to ride on top of the ring, I backed off and adjusted the eccentric just a bit tighter. Riding it over the weekend it performed well, but I still need to replace the BB (or bearings) as these are ruined. I believe the belt tension measures in the low 30lb range and the difference due to runout is fairly small.
I'd be curious of how others determine "loose" as "loose enough" or "too loose".
I'd be curious of how others determine "loose" as "loose enough" or "too loose".
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