Co-Mo Wheel overhaul
#1
Full Member
Thread Starter
Co-Mo Wheel overhaul
Greetings again, I believe that the bearings on the rear wheel of our 2011 Primera are in need of replacement. The hubs are Co-Motion branded without any other markings. I found on the Co-Mo website and in a Co-Mo spec sheet from 2013 that the Primera uses the "Co-Mo A-10 Tandem Hub". Searching the web and this forum did not yield any information.
I started to disassemble the hub and removed the free-hub body and the axle appears to require disassembly as it has machined edges for a 10mm wrench. I tried to loosen the axle but it would not budge. I tried the gentle persuasion with an piece of wood and a mallet to no avail. If it does unscrew, it might be bound up with thread lock.
The bearing in the hub body was visible after removing the free-hub and is a standard off the shelf item so once I understand how to dig into this thing I should be able to service myself.
Has anyone tackled one of these or is this hub an OEM re-brand off of some other brand that you can point me to? Any hints out how to remove the axle and if I need an special bearing press, etc?
The free hub body has a rubber seal (not visible in the picture) over the bearing(s) that has 2 small holes that I suspect may conceal a snap ring? Anyone know?
I decided to reach out here before tossing the towel and calling Co-Mo.
I started to disassemble the hub and removed the free-hub body and the axle appears to require disassembly as it has machined edges for a 10mm wrench. I tried to loosen the axle but it would not budge. I tried the gentle persuasion with an piece of wood and a mallet to no avail. If it does unscrew, it might be bound up with thread lock.
The bearing in the hub body was visible after removing the free-hub and is a standard off the shelf item so once I understand how to dig into this thing I should be able to service myself.
Has anyone tackled one of these or is this hub an OEM re-brand off of some other brand that you can point me to? Any hints out how to remove the axle and if I need an special bearing press, etc?
The free hub body has a rubber seal (not visible in the picture) over the bearing(s) that has 2 small holes that I suspect may conceal a snap ring? Anyone know?
I decided to reach out here before tossing the towel and calling Co-Mo.
Last edited by Alcanbrad; 07-29-18 at 06:51 PM.
#2
pan y agua
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Call Co-Motion They've been helpful to me in the past with repair issues
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#3
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#4
Nigel
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Is there still a sleeve outboard of the bearing that can be pulled off?
What does the other side look like?
What does the other side look like?
#5
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I have seen some SRAM hubs that need to be disassembled from the non-drive side. Did you try that?
#6
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Thread Starter
There is a sleeve On the axle that sits between the hub bearing and the freehub bearing. It is visible in the first picture. The other side looks just like the freehub side. As visible in the second picture there is that would traditionally be called a cone in olde tyme parlance. This piece is fixed to the axle and with a fair amount of force with a cone wrench on the "cone" side and a wrench on the flat machined surface of the axle, no move-y (unless it is reversed thread)
#7
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I wonder if this is the same hub that Velocity uses for their Tandem Wheelsets they sell? Velocity Wheels - Hand Made in USA
It looks like it is probably different.
It looks like it is probably different.
#8
Nigel
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My best GUESS, is that the bearings are pressed into the hub. To get them out, push (using a arbor press, and properly supporting the hub) out from the DS towards the NDS. The NDS bearing and axle will then be separate from the hub. Next press the DS bearing out. Because it is only possible to push against the inner race of the bearings for removal, the removal process ruins the bearings. Heating the hub up may reduce the forces (aluminum expands faster than steel).
I do not suggest attempting to do this without the proper tools. A press that can do this with an assembled wheel is big and expensive.
If you are a bit on the wild side (I am), you could make a press from a 3 jaw puller (for example: https://www.amazon.com/ABN-3-Jaw-Gea...70_&dpSrc=srch) A two jaw pull might work, but three will be more stable. Plus a steel plate to hold the hub. The puller would engage the plate and push the axle thru the plate.
Once the axle-NDS bearing assembly is out, you can figure out how to take it apart.
Installing new bearings - press only on the outer races of the bearings, or they will be ruined.
I am surprised the bearings need replacement, if the hubs aren't pressure washed or submerged for a long period, the bearing should last 100,000 miles of riding with no issues.
I do not suggest attempting to do this without the proper tools. A press that can do this with an assembled wheel is big and expensive.
If you are a bit on the wild side (I am), you could make a press from a 3 jaw puller (for example: https://www.amazon.com/ABN-3-Jaw-Gea...70_&dpSrc=srch) A two jaw pull might work, but three will be more stable. Plus a steel plate to hold the hub. The puller would engage the plate and push the axle thru the plate.
Once the axle-NDS bearing assembly is out, you can figure out how to take it apart.
Installing new bearings - press only on the outer races of the bearings, or they will be ruined.
I am surprised the bearings need replacement, if the hubs aren't pressure washed or submerged for a long period, the bearing should last 100,000 miles of riding with no issues.
#9
Full Member
Thread Starter
I wonder if this is the same hub that Velocity uses for their Tandem Wheelsets they sell? Velocity Wheels - Hand Made in USA
It looks like it is probably different.
It looks like it is probably different.
My best GUESS, is that the bearings are pressed into the hub. To get them out, push (using a arbor press, and properly supporting the hub) out from the DS towards the NDS. The NDS bearing and axle will then be separate from the hub. Next press the DS bearing out. Because it is only possible to push against the inner race of the bearings for removal, the removal process ruins the bearings. Heating the hub up may reduce the forces (aluminum expands faster than steel).
I do not suggest attempting to do this without the proper tools. A press that can do this with an assembled wheel is big and expensive.
If you are a bit on the wild side (I am), you could make a press from a 3 jaw puller (for example: https://www.amazon.com/ABN-3-Jaw-Gea...70_&dpSrc=srch) A two jaw pull might work, but three will be more stable. Plus a steel plate to hold the hub. The puller would engage the plate and push the axle thru the plate.
Once the axle-NDS bearing assembly is out, you can figure out how to take it apart.
Installing new bearings - press only on the outer races of the bearings, or they will be ruined.
I am surprised the bearings need replacement, if the hubs aren't pressure washed or submerged for a long period, the bearing should last 100,000 miles of riding with no issues.
I do not suggest attempting to do this without the proper tools. A press that can do this with an assembled wheel is big and expensive.
If you are a bit on the wild side (I am), you could make a press from a 3 jaw puller (for example: https://www.amazon.com/ABN-3-Jaw-Gea...70_&dpSrc=srch) A two jaw pull might work, but three will be more stable. Plus a steel plate to hold the hub. The puller would engage the plate and push the axle thru the plate.
Once the axle-NDS bearing assembly is out, you can figure out how to take it apart.
Installing new bearings - press only on the outer races of the bearings, or they will be ruined.
I am surprised the bearings need replacement, if the hubs aren't pressure washed or submerged for a long period, the bearing should last 100,000 miles of riding with no issues.
This is a used wheel and I don't know it's history. My wife reports noise behavior consistent with worn bearings and going through the litany of determining if it is the brakes or freehub, etc, eliminates every cause other than wheel speed.
I won't tackle replacing the bearings unless I am confident I know how to remove and press back in. If I don't feel confident, then the stoker will have to learn to live with some noise.
So, unless someone has service manuals for Velocity (or Chosen) hubs, I'll reach out to Co-Motion and see what they have.
Thanks all.
#10
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Looks very similar to the Velocity/Chosen tandem hub we have. I've had it apart - removed the freehub - but have not done anything with the bearings. They seem fine after 7+ years/9,000 miles.
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Last edited by JanMM; 08-02-18 at 05:02 PM.
#11
Senior Member
Co-Motion sometimes used rebranded DT Swiss hubs on some of their wheels. You could search for schematics for a DT 340 or 540 hub and see if they match up.
#12
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Regardless of the hub brand, you will need a generic bearing puller tool set and press to service the hub fully. This hub appears to use radial sealed cartridge bearings. They handle radial loads very well. But side loads can cause issues, as can overtightening the bearing adjustment. In general, cartridge bearings should have some side-to-side play (felt at the tire), whereas cup and cone bearings, and radial contact bearings (used in Chris King) should not. There are exceptions to this rule. Mavic wheels usually had side play, whereas White Industries hubs do not. Depends on the brand and the way the hub is assembled. You probably need to pull and replace all the cartridge bearings in the hub. Pulling the seals, flushing and regreasing very well may not resolve the problem. Once a cartridge bearing goes bad, overhauling will not restore it. Enduro Bearings in Oakland supplies bearings for many manufacturers, distributers and retailers in the bike industry. Find an LBS who can order them. If you don't want to perform the repair, then find a shop that can.
BTW, you never specified what the problem with the hub was. What symptoms are the hubs/wheels exhibiting that indicate they have a problem? It's very important to describe the symptoms instead of trying to diagnose the problem. Only with symptoms can someone with the proper knowledge diagnose the problem and suggest possible solutions.
Edit: sorry, I missed your reply that described the problem a little bit. A grinding sound or vibration feeling is probably bearing-related. But it could also not have anything to do with the rear wheel. When does it happen? Coasting? Only while pedaling? Only while pedaling hard? Could be the quick release. Could be the wheel not secure in the dropouts. Or if the frame has a replaceable derialleur hanger, it could be that. Or the rotor or caliper rubbing? Chainring bolts? Bottom bracket(s) and/or eccentric? I've seen someone go over an entire bike's drivetrain chasing a creak only to find out it was the pedal!
I'll add that I've serviced several hubs like this over the years that develop roughness in the bearings. Dirt and other contamination cause the bearings to become rough and the axle to creak under pedaling loads. You might resolve the issue simply by servicing the freehub body, pawls and axle, spacer(s) and locknut(s) without having to pull the bearings. Sometimes fresh grease eliminates creaks and groans created by the high forces produced by a tandem.
Good luck.
Last edited by LV2TNDM; 08-14-18 at 11:31 PM.
#13
Senior Member
Those are most certainly not DT 340 or 540 hubs. These DT hub models utilize a star ratcheting mechanism in the freehub body. The hub shown uses pawls, so it is not these DT models. Plus, the hub shell shape is wrong for DT, unless they have some lower-spec models that I'm unaware of (which may indeed be the case).
What it does kinda look like is my Hadley hub ratchets from my Santana OEM hubs. Hadley co-branded for a number of builders (like GT), I believe, so that's a definite possibility. Also similar to an older White Industries hub I have.
#14
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Yes, I believe that this is the same hub. Searching for service drawings yielded nothing but a forum thread suggested that Velocity sources their hubs from Chosen Co. LTD. Searching for Chosen revealed a Taiwanese company that OEM's all kinds of hubs to wheel builders. I could not find any service docs or drawings for Chosen hubs either, however looking at pictures of the replacement free-hubs it appears to be the same split pawl design.
I have had, and several friends had had sealed bearings wear out early. I think the leading contributor is the stresses experienced from hitting objects in the road. I think the bearings are designed to run smoothly for a very long time but when you introduce shock impacts in the plane of rotation, the races and/or bearings get damaged.
This is a used wheel and I don't know it's history. My wife reports noise behavior consistent with worn bearings and going through the litany of determining if it is the brakes or freehub, etc, eliminates every cause other than wheel speed.
I won't tackle replacing the bearings unless I am confident I know how to remove and press back in. If I don't feel confident, then the stoker will have to learn to live with some noise.
So, unless someone has service manuals for Velocity (or Chosen) hubs, I'll reach out to Co-Motion and see what they have.
Thanks all.
I have had, and several friends had had sealed bearings wear out early. I think the leading contributor is the stresses experienced from hitting objects in the road. I think the bearings are designed to run smoothly for a very long time but when you introduce shock impacts in the plane of rotation, the races and/or bearings get damaged.
This is a used wheel and I don't know it's history. My wife reports noise behavior consistent with worn bearings and going through the litany of determining if it is the brakes or freehub, etc, eliminates every cause other than wheel speed.
I won't tackle replacing the bearings unless I am confident I know how to remove and press back in. If I don't feel confident, then the stoker will have to learn to live with some noise.
So, unless someone has service manuals for Velocity (or Chosen) hubs, I'll reach out to Co-Motion and see what they have.
Thanks all.
#15
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Thread Starter
Sorry, I have not had a chance to reach out to them yet. I was planning to do so after our summer travels are behind us, stay tuned.