Bottom Bracket confusion - Seized bearing
#1
Senior Member
Thread Starter
Bottom Bracket confusion - Seized bearing
So, bottom bracket bearing seized (I neglected its routine maintenance this year) and now I need a new one.
The bike is a Trek Fuel EX 5 29 2014. On the side of the frame is "BB-ALM92 Φ19". It is an FSA Gamma Drive crankset.
I was able to tap out the faulty bearing using a long bolt. I am trying to buy a new bearing but cannot seem to find what I need.
A LBS (one I have never been to) said they can't replace the bearing, they have to replace the whole thing? Why, I already have the bearing out, just press in the new one.
Obviously, I will replace both bearings, if I can find them.
In my Googling, I read that the FSA Gamma Drive is trash, and never to get one. TBH, I have never had any problems with it. I service it once a year (the whole bike, like take everything apart service) and never had problems. The thread OP said they went with a completely different crankset and BB. I would like to avoid this cause I don't have much money and would honestly see it as a pointless upgrade because what I have is perfectly okay.
Where can I find just the bearings for this? I don't need anything else, no cones, no tubes, just bearings....
Or, what are my options?
Thanks
The bike is a Trek Fuel EX 5 29 2014. On the side of the frame is "BB-ALM92 Φ19". It is an FSA Gamma Drive crankset.
I was able to tap out the faulty bearing using a long bolt. I am trying to buy a new bearing but cannot seem to find what I need.
A LBS (one I have never been to) said they can't replace the bearing, they have to replace the whole thing? Why, I already have the bearing out, just press in the new one.
Obviously, I will replace both bearings, if I can find them.
In my Googling, I read that the FSA Gamma Drive is trash, and never to get one. TBH, I have never had any problems with it. I service it once a year (the whole bike, like take everything apart service) and never had problems. The thread OP said they went with a completely different crankset and BB. I would like to avoid this cause I don't have much money and would honestly see it as a pointless upgrade because what I have is perfectly okay.
Where can I find just the bearings for this? I don't need anything else, no cones, no tubes, just bearings....
Or, what are my options?
Thanks
#2
Really Old Senior Member
A pic would be nice.
Measure the OD, ID and "thickness".
Likely Metric and a standard size if you were to search for whatever type bearing you have.
IF you look close, I'd expect a part# ON the bearing itself.
Measure the OD, ID and "thickness".
Likely Metric and a standard size if you were to search for whatever type bearing you have.
IF you look close, I'd expect a part# ON the bearing itself.
#3
Senior Member
So, bottom bracket bearing seized (I neglected its routine maintenance this year) and now I need a new one.
The bike is a Trek Fuel EX 5 29 2014. On the side of the frame is "BB-ALM92 Φ19". It is an FSA Gamma Drive crankset.
I was able to tap out the faulty bearing using a long bolt. I am trying to buy a new bearing but cannot seem to find what I need.
A LBS (one I have never been to) said they can't replace the bearing, they have to replace the whole thing? Why, I already have the bearing out, just press in the new one.
Obviously, I will replace both bearings, if I can find them.
In my Googling, I read that the FSA Gamma Drive is trash, and never to get one. TBH, I have never had any problems with it. I service it once a year (the whole bike, like take everything apart service) and never had problems. The thread OP said they went with a completely different crankset and BB. I would like to avoid this cause I don't have much money and would honestly see it as a pointless upgrade because what I have is perfectly okay.
Where can I find just the bearings for this? I don't need anything else, no cones, no tubes, just bearings....
Or, what are my options?
Thanks
The bike is a Trek Fuel EX 5 29 2014. On the side of the frame is "BB-ALM92 Φ19". It is an FSA Gamma Drive crankset.
I was able to tap out the faulty bearing using a long bolt. I am trying to buy a new bearing but cannot seem to find what I need.
A LBS (one I have never been to) said they can't replace the bearing, they have to replace the whole thing? Why, I already have the bearing out, just press in the new one.
Obviously, I will replace both bearings, if I can find them.
In my Googling, I read that the FSA Gamma Drive is trash, and never to get one. TBH, I have never had any problems with it. I service it once a year (the whole bike, like take everything apart service) and never had problems. The thread OP said they went with a completely different crankset and BB. I would like to avoid this cause I don't have much money and would honestly see it as a pointless upgrade because what I have is perfectly okay.
Where can I find just the bearings for this? I don't need anything else, no cones, no tubes, just bearings....
Or, what are my options?
Thanks
You might also consider just replacing the whole unit as the LBS suggests since your BB comes with bearing preinstalled in cups that are pressed in to the shell as a unit.
#4
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The Gamma Drive cranksets use an uncommon 19mm spindle. Cartridge bottom brackets like that are not intended to have just the bearings replaced. The whole bottom bracket should be replaced. They cost about $35.
#5
Senior Member
Thread Starter
I think you need bearings like the ones here...https://wheelsmfg.com/enduro-24-x-37...d-bearing.html. 24mm ID for 24mm spindle on your crankset; 37mm OD; and 7mm thick.Are there any markings on the bearing seals? If not, do as Bill Kapaun advises.
You might also consider just replacing the whole unit as the LBS suggests since your BB comes with bearing preinstalled in cups that are pressed in to the shell as a unit.
You might also consider just replacing the whole unit as the LBS suggests since your BB comes with bearing preinstalled in cups that are pressed in to the shell as a unit.
Inner: 19mm
Outer: 32m
Thickness: 7mm
Here is the picture of the bearing, there is stuff on it, hopefully I can find them.
#6
Senior Member
Thread Starter
I have no idea how the heck the rest of it comes out then.. It would be about 70 bucks for everything if they cost $35. They quoted me $30 for installation and removal. I'll give them a call tomorrow (the one I like to go to, not the one I called today) and see if they can set me up. Guys there are absolutely incredible.
#7
Senior Member
6804 is the bearing size. Just google that and you will find what you need. But banging out the cups and replacing the whole unit is the better option.
#8
Senior Member
Thread Starter
Thank you. Quick search didn't yield anything promising. Gonna have to order from china to get some. I'll be contacting the LBS I like tomorrow, see what they can do. Thanks guys. I hate how stuff like this isn't fixable. Why can't you just pop new bearings in?
#9
Senior Member
6804 bearings are pretty widely available, by the way — e.g. https://www.universalcycles.com/shop...s.php?id=13357
Also look for 61804, which are the same size but just higher spec.
#10
Really Old Senior Member
How can you have that bad of search skills?
#11
Senior Member
Thread Starter
It is designed to be fixable, but you replace the cups with the bearings not just the bearings. The cups aren’t designed to have bearings banged in and out of so they can be deformed or otherwise damaged in the process, and bearings won’t seat correctly, causing short life and creaks. But it can work if you are determined to try. You won’t just be able to “pop” them in by hand. You need a press.
6804 bearings are pretty widely available, by the way — e.g. https://www.universalcycles.com/shop...s.php?id=13357
Also look for 61804, which are the same size but just higher spec.
6804 bearings are pretty widely available, by the way — e.g. https://www.universalcycles.com/shop...s.php?id=13357
Also look for 61804, which are the same size but just higher spec.
#12
Really Old Senior Member
I would check an "industrial supply" store in your area.
One that sells bearings, hydraulics etc. for trucking, saw mills or other manufacturing plants etc.
One that sells bearings, hydraulics etc. for trucking, saw mills or other manufacturing plants etc.
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https://www.ebay.com/itm/Qty-10-ball...243966968a8bf2
Same number as your picture, here in the US, 10 bearings for under $13 shipped
Same number as your picture, here in the US, 10 bearings for under $13 shipped
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#14
Senior Member
All 6804 and 61804 bearings are the same size.
You might also see bearings marked 7804 or 71804. These will be the same size as well but angular contact bearings. You might be able to use these as well if your cranks allow you to set preload.
You might also see bearings marked 7804 or 71804. These will be the same size as well but angular contact bearings. You might be able to use these as well if your cranks allow you to set preload.
#15
Senior Member
Have you checked out someone like Grainger.com or even Napaonline.com? Once out of the shell it is just a bearing, not necessarily related to anything in particular.
#16
Senior Member
Ok, so correction.I just noticed earlier reference to the FSA cranks having a 19mm spindle, which doesn’t gibe with the standard 6804 bearing, which is confusing. I googled MR129, the other marking on the beaaring, and it equates to an FSA bearing with a tapered inner race. https://www.kineticbikebearings.com/mr129.html
Note in the above reference to the MR129 being specific to the nondrive side, meaning you might need a different size for the drive side.
#17
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I used angular contact bearings. Standard (deep groove radial) bearings have inner and outer races with slots cut and ground and polished into them. They support radial forces but not axial. Since no one has the muscle control to pedal perfectly and to avoid side (axial) forces, I prefer a bearing designed to handle this type of force. Angular contact bearings are someone akin to cup and cone. This means that 1) they resist axial force in one direction, and 2) they have to be installed with the proper orientation. And you have to preload the bearings first, meaning you use a little thumbwheel to tighten the NDS crank arm onto the spindle, then tighten the NDS crank pinch bolts.
#18
Senior Member
Thread Starter
https://www.ebay.com/itm/Qty-10-ball...243966968a8bf2
Same number as your picture, here in the US, 10 bearings for under $13 shipped
Same number as your picture, here in the US, 10 bearings for under $13 shipped
Ok, so correction.I just noticed earlier reference to the FSA cranks having a 19mm spindle, which doesn’t gibe with the standard 6804 bearing, which is confusing. I googled MR129, the other marking on the beaaring, and it equates to an FSA bearing with a tapered inner race. https://www.kineticbikebearings.com/mr129.html
Note in the above reference to the MR129 being specific to the nondrive side, meaning you might need a different size for the drive side.
Note in the above reference to the MR129 being specific to the nondrive side, meaning you might need a different size for the drive side.
To be clear, this statement is correct wrt size. All 6804 and 61804 bearings should fit. But the "2RS" on your bearings means that they have two rubber seals, one on each side. You probably want to replace a sealed bearing with another sealed bearing.
I used angular contact bearings. Standard (deep groove radial) bearings have inner and outer races with slots cut and ground and polished into them. They support radial forces but not axial. Since no one has the muscle control to pedal perfectly and to avoid side (axial) forces, I prefer a bearing designed to handle this type of force. Angular contact bearings are someone akin to cup and cone. This means that 1) they resist axial force in one direction, and 2) they have to be installed with the proper orientation. And you have to preload the bearings first, meaning you use a little thumbwheel to tighten the NDS crank arm onto the spindle, then tighten the NDS crank pinch bolts.
I used angular contact bearings. Standard (deep groove radial) bearings have inner and outer races with slots cut and ground and polished into them. They support radial forces but not axial. Since no one has the muscle control to pedal perfectly and to avoid side (axial) forces, I prefer a bearing designed to handle this type of force. Angular contact bearings are someone akin to cup and cone. This means that 1) they resist axial force in one direction, and 2) they have to be installed with the proper orientation. And you have to preload the bearings first, meaning you use a little thumbwheel to tighten the NDS crank arm onto the spindle, then tighten the NDS crank pinch bolts.
#20
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But the dimensions are 20x32x7, not 19x32x7. I know its only 1mm but that is a lot of play inside the core spindle area. Yes, and they all have the 20x32x7 dimensions for the bearing unfortunately. Thank you! This is what I was talking about when I said I can't find them. The dimensions on the ones that I am finding have an inner core diameter of 20mm not 19mm. Which I think would not be a good idea to use with the 19mm spindle.
Yes, I was going to replace with the same type of bearing. I'm gonna go to the bike shop today, see what they can do.
Yes, I was going to replace with the same type of bearing. I'm gonna go to the bike shop today, see what they can do.
Back to your problem. If you had 6804 bearings in the bike, then you were probably using the "wrong" bearings with that 19mm spindle. All 6804 bearings have a 20mm inside bore. There are no 19mm 6804 bearings. Using a 20mm bore with a 19mm spindle is not acceptable practice. You'll destroy your spindle. The proper size spec for bearings that are 32 x 19 x 7 bearings are 19BSW07. These seem pretty impossible to find at a retail level (as teh evil product manager jerks at FSA probably knew well). My understanding is that your Trek has a PF bottom bracket. If so , you want to find those 19BSW07 bearings. The following may work (write them and ask for bearing dimensions first!)
https://www.amazon.com/FSA-Cartridge-bearing-MegaExo-19-MR087/dp/B001GSSHPA/ref=sr_1_2?dchild=1&keywords=bearings+for+fsa+megaexo+19&qid=1574699793&s=sporting-goods&sr=1-2
If I'm mistaken and you have a threaded BB, then this might work:
https://www.amazon.com/FSA-Mega-Bottom-Bracket-BB-1000/dp/B001GSSMCI?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B001GSSMCI
Last, you might use 6804 bearings with a shim. Finding this size (20mm OD x 19mm bore x 7mm) is gonna be difficult if not impossible.
#21
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Never, ever an FSA component on a bike I buy.
#22
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I have a local bearing supply source here called Tri State Bearing. I take the old one in and they match to an exact replacement. Smiles, MH
#23
Senior Member
Thread Starter
It seems like FSA chose a 19mm spindle diameter to ensure a captive aftermarket. In my view, that's an unforgiveable sin: I would never buy FSA anything because of their decision to be so anti-consumer. Additionally, I view 19mm as inferior to the more standard, stronger, and stiffer 24mm.
Back to your problem. If you had 6804 bearings in the bike, then you were probably using the "wrong" bearings with that 19mm spindle. All 6804 bearings have a 20mm inside bore. There are no 19mm 6804 bearings. Using a 20mm bore with a 19mm spindle is not acceptable practice. You'll destroy your spindle. The proper size spec for bearings that are 32 x 19 x 7 bearings are 19BSW07. These seem pretty impossible to find at a retail level (as teh evil product manager jerks at FSA probably knew well). My understanding is that your Trek has a PF bottom bracket. If so , you want to find those 19BSW07 bearings. The following may work (write them and ask for bearing dimensions first!)
https://www.amazon.com/FSA-Cartridge-bearing-MegaExo-19-MR087/dp/B001GSSHPA/ref=sr_1_2?dchild=1&keywords=bearings+for+fsa+megaexo+19&qid=1574699793&s=sporting-goods&sr=1-2
If I'm mistaken and you have a threaded BB, then this might work:
https://www.amazon.com/FSA-Mega-Bottom-Bracket-BB-1000/dp/B001GSSMCI?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B001GSSMCI
Last, you might use 6804 bearings with a shim. Finding this size (20mm OD x 19mm bore x 7mm) is gonna be difficult if not impossible.
Back to your problem. If you had 6804 bearings in the bike, then you were probably using the "wrong" bearings with that 19mm spindle. All 6804 bearings have a 20mm inside bore. There are no 19mm 6804 bearings. Using a 20mm bore with a 19mm spindle is not acceptable practice. You'll destroy your spindle. The proper size spec for bearings that are 32 x 19 x 7 bearings are 19BSW07. These seem pretty impossible to find at a retail level (as teh evil product manager jerks at FSA probably knew well). My understanding is that your Trek has a PF bottom bracket. If so , you want to find those 19BSW07 bearings. The following may work (write them and ask for bearing dimensions first!)
https://www.amazon.com/FSA-Cartridge-bearing-MegaExo-19-MR087/dp/B001GSSHPA/ref=sr_1_2?dchild=1&keywords=bearings+for+fsa+megaexo+19&qid=1574699793&s=sporting-goods&sr=1-2
If I'm mistaken and you have a threaded BB, then this might work:
https://www.amazon.com/FSA-Mega-Bottom-Bracket-BB-1000/dp/B001GSSMCI?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B001GSSMCI
Last, you might use 6804 bearings with a shim. Finding this size (20mm OD x 19mm bore x 7mm) is gonna be difficult if not impossible.
Sadly I got the bike for a steal in 2016 - $700. I honestly love it and had zero issues with it but I was also keeping up with maintenance, where now I neglected it and paid the price.
I may just stick the bearing back in, ride it with a seized bearing, destroy the spindle, and then upgrade the whole thing later down the road. I don't think anything else will get ruined with a seized BB bearing.. But it all depends what the LBS can do for me.
#24
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Not so much a rubbing salt into the wound, as an informational note to try for a local source. Search bearing suppliers in your area and you might be pleasantly surprised. Har,Har! Smiles, MH