Wildguzzi.com
General Category => General Discussion => Topic started by: Haioku_Mantan on June 17, 2025, 02:07:03 AM
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Ordered a pair of swingarm bearings from Harper's (cheapest shipping to SE ASIA I could find) and was surprised to find out they were Koyo/JTEKT 33005 JRLFT parts.
Spoke with the local bearing distributor here and he started by asking me what was my use for these bearings, whether I was affiliated with the automotive industry etc... Was a bit surprised as I thought bearings were not on any kind of restricted item list, but he mentioned that some of the bearings he carried from Koyo are specialized for OEM and he could not sell to individuals and businesses but these were ok.
You have to make sure to get the JRLFT - the LF part meaning low friction.
$25 SGD = $19.5 USD for a single bearing.
Moto Guzzi part ROLLER BEARING (#92249224)/ GU92249224
https://imgur.com/a/S1SPrCV
Dunno if this is old news or generally well known but I was expecting some kind of bearing sealed in a olive wood box, encased in cork with Piaggio livery and O sole mio playing when I opened it.
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Bearings tend to be pretty standard parts categorized by size, etc.
Not so much when working on bikes (fewer bearings in general) but often with cars you can look up the number printed on a bearing and get it directly from the OEM...most bearings on almost anything automotive/moto (and maybe everything else) are made by a small number of companies. Koyo in particular is used in most Japanese cars and bikes -- good quality stuff!
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I am a bearing snob all but in one instance and that is the swingarm bearing fro R1200GS swingarm. They are 30203 - 17 x 40 x 13.25 sealed one side tapered roller and while this is a common bearing it is only avalaible through SKF and BMW as sealed one side. The good news is the swingarm has very little movement and while I normally do not buy offbrand bearings in this instance I buy whaterver 30203 bearig I can find on Amazon usually for about $11 a pair verses $45 a bearing if going through BMW. The interesting thign is the seal on th eSKF beainrg easily prys off and can be applied to the replacment bearing or just pack them with ease and forget about the seal as it really does not block anythign.
FWIW KOYO are excellent quality bearings we use them at work in industrial electic motors and since I get them at cost I also used them for wheel bearings and carrier bearings with excellent results. I also have access to FAG, SKF and all the other "name brand" bearings but stick to KOYO when possible for value and quality.
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I can tell you that there is a small trap that awaits you when fitting the new bearings.
There is a seal that sits inboard of the bearing that is there to slow down the ingress of water and contaminants into the grease space.
When you slide the pivot pin in from the gear lever side, it pushes the seal into it’s register and no problems arise…
But.
As the pin enters the seal/bearing couple on the brake lever side, the pin can and usually does, dislodge the seal and it falls into the void, leaving the right side race fundamentally without a seal.
To circumvent this state of affairs, I made a spacer to go between the seal and race, with a small amount of “float” to allow for movement when you adjust the tapered rollers.
The inclusion of this spacer prevents the seal from dislodging upon assembly. When I replaced my first set of dry/rusted races in London at 90,000 km, they fell out as dry, rusted pieces onto the floor and the crushed seal was lying in the cavity where the grease should have been…(and never was…).
I think it’s a good precaution.
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.. I was expecting some kind of bearing sealed in a olive wood box, encased in cork with Piaggio livery and O sole mio playing when I opened it.
:grin: :cheesy: :weiner:
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To circumvent this state of affairs, I made a spacer to go between the seal and race, with a small amount of “float” to allow for movement when you adjust the tapered rollers.
Oh Great One please show us your seal secrets before we too embark on this bearing quest of ours.
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To circumvent this state of affairs, I made a spacer to go between the seal and race, with a small amount of “float” to allow for movement when you adjust the tapered rollers.
The inclusion of this spacer prevents the seal from dislodging upon assembly.
Hi Huzo, first I heard about this from you.
Did you fabricate the spacer, or is it something readily available?
The suspense is killing me.
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I have mentioned it before.
But you don’t need to own a lathe to make it, just a suitable piece of tube will suffice, my memory tells me it’s about 6 mm long, but the thing is that there must be some play in the dimension length wise, or when you adjust the tapered rollers, the inner will bear against the spacer and chew into the seal.
I saw a seal chewed into once by a killer whale and it wasn’t very nice…!
The seal is not a very good fit in the frame and this is why it is easily dislodged upon assembly. I did post about this in 2019.
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After a massive crawl of the site and searching through many many posts, the best pic and thread I could find was from Brider (https://wildguzzi.com/forum/index.php?topic=122179.0) and shows a 0.312" (whatever unit that is) which equates to around 7.9248mm in proper units.
(https://i.ibb.co/gL9jByR4/Norge-swingarm-seal.jpg) (https://ibb.co/gL9jByR4)
Huzo mentioned it being 6mm thick so it seems about right. Given that the bearing is 47*25*17.5 mm, I can only assume you would have to machine up a spacer that is less than 47mm outer diameter and with an inner diameter of minimum 25mm and a thickness between 6-7mm.
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After a massive crawl of the site and searching through many many posts, the best pic and thread I could find was from Brider (https://wildguzzi.com/forum/index.php?topic=122179.0) and shows a 0.312" (whatever unit that is) which equates to around 7.9248mm in proper units.
(https://i.ibb.co/gL9jByR4/Norge-swingarm-seal.jpg) (https://ibb.co/gL9jByR4)
Huzo mentioned it being 6mm thick so it seems about right. Given that the bearing is 47*25*17.5 mm, I can only assume you would have to machine up a spacer that is less than 47mm outer diameter and with an inner diameter of minimum 25mm and a thickness between 6-7mm.
It doesn’t have to be an absolutely neat fit. Just to stop the seal travelling once installed.
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Thanks for reposting this. I totally forgot about it.
So the spacer needs to cover that slot inside the the race as the seal slides past it?
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Thanks for reposting this. I totally forgot about it.
So the spacer needs to cover that slot inside the the race as the seal slides past it?
It isn’t as complex as all that.
It simply sits in the void between the seal and the race. Fit the seal grease the spacer to hold it in place while you bring the swingarm up and it just sits in there.
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Thanks for reposting this. I totally forgot about it.
So the spacer needs to cover that slot inside the the race as the seal slides past it?
It doesn’t cover it, it takes up the space between the seal and race.
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It isn’t as complex as all that.
It simply sits in the void between the seal and the race. Fit the seal grease the spacer to hold it in place while you bring the swingarm up and it just sits in there.
So are the dimensions I quoted in the ballpark?
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So are the dimensions I quoted in the ballpark?
Well I don’t know, but this is all you need.
The outside diameter of the spacer has to be a loose fit in the bore that holds the seal.
The inside diameter has to slide easily over the pivot pin.
The length of the spacer has to be about 20 thou’ less than the space that exists between the race and the seal.
I can’t remember how I got the dimension for the length of the spacer, but it does not have to be a precision amount.
My memory of it leads me to think you’re on the money.