M61 wheel bearing and hub help !!!

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Macabry
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M61 wheel bearing and hub help !!!

Post by Macabry » Tue Jan 07, 2020 5:29 pm

So, I finally got the "wheel bearing adjuster nut" off my front wheel and got a look at the bearings ....wtf :o

They are not 204 size !!!! Without even measuring both they and the adjuster nut look much bigger than standard M72 ones. So I measured:

The bearing is 57mm outer diameter and 20mm inner and its marked 305
20200107_212149.jpg
20200107_212105.jpg

The adjuster nut is 67mm outer diameter with the 50mm (at centres) spaced pin wrench holes.
20200107_212003.jpg
20200107_212028.jpg
And as if that isn't all frustrating enough my bushings and spacers seem totally wrong too .... :x
20200107_212239.jpg
20200107_212216.jpg
My question is: what the hell have I got !!! :!:

I would have imagined m61 and m72 hubs were identical if not similar and I am not aware of a different set up for m62's ..... does anyone know a likely explanation !!!

(Oh, and to be clear, the actual axles appear standard )
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"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

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Macabry
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Tue Jan 07, 2020 5:32 pm

Just for reference .... here is an M72 adjuster nut:
Screenshot_20200107-191918_Chrome.jpg
Take a look at it and at the dimensions ... totally different !
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"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

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Macabry
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Tue Jan 07, 2020 7:24 pm

Ok .... so I have finally worked out that this part:
Screenshot_20200107-211734_Gallery.jpg
Is a combination of parts 1 and 2 in this pic:
20200107_231949.jpg
Though why mine doesn't have them separate is a mystery .... ?
As for the bearing, I'll have a good look away it tomorrow :|
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"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

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Lmo
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Re: M61 wheel bearing and hub help !!!

Post by Lmo » Wed Jan 08, 2020 1:57 pm

:lurker:

Part #1 is an anti-rotation locking ring ... what 'locks' your part?
Lew Morris
Dnepr w/ '06 Ural Drive Train
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1973 BMW R75/5 (original owner)
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Macabry
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Wed Jan 08, 2020 4:05 pm

:roll: Nothing !!!

No locking ring, the large diameter of the nut makes it a pain to turn.... so I suppose thats the lock ???

The bushings are different too .... but its the bearing thats really confounding !!! I CANT FIND A STANDARD BEARING THAT SIZE :evil:
"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

User avatar
Macabry
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Posts: 184
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Wed Jan 08, 2020 5:24 pm

I will also add that upon closer inspection and cleaning that the adjuster nut has a felt washer inside the inner ring:
20200108_211836.jpg
And this would make me revise the initial idea and include number 3 as the inner part of this assembly .... this then retains the shorter bushing just as normal (except my inner bushing is also different, but thats another story)

So:
20200108_212013.jpg
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"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

User avatar
Macabry
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Posts: 184
Joined: Sun Oct 20, 2019 11:20 am

Re: M61 wheel bearing and hub help !!!

Post by Macabry » Wed Jan 08, 2020 5:28 pm

This is all fine .... but what bearing is it ?????? .... the 305 marking is a bit misleading I think as that would make it 62mm OD x 25mm ID

I have gone through size charts and I can't find anything !!!

Anyone?
"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

GregAus
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Re: M61 wheel bearing and hub help !!!

Post by GregAus » Thu Jan 09, 2020 2:36 am

I couldn't find any bearings with a 57mm OD in any brand, let alone one with a 20mm ID. Closest was a 52mm OD 20mm ID. Is the other bearing the same? How about the other wheel?

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Claus
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Re: M61 wheel bearing and hub help !!!

Post by Claus » Thu Jan 09, 2020 4:06 am

Macabry, don´t get me wrong, but are you serious with that 57 mm? When I see your photo measuring the bearing seat with the calliper´s outside measuring tip, did you add the thickness of the calliper´s tips to what you read on the nonius? Or did you measure the bearing on the table (outside diameter measured with the inner measuring tips of the calliper),this would read the real diameter on the calliper´s nonius

Regularly the Russian 305 would be a 6305 bearing. inner Ø 25mm, outer Ø 62mm, thickness 17mm. 5mm measuring mistake due to that oldfashioned calliper?
owned bikes: 93 Ural rig domestic model, 95 Suzuki DR 650 RSE, BMW R100GS, Suzuki GSX1100G rig, BMW R100R rig with Ural sidecar, Ural rig with BMW drivetrain under construction,

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Macabry
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Thu Jan 09, 2020 10:31 am

:x Yep .... it's a 305,

Measured again with a proper vernier and in daylight, what an idiot :oops: .... I ultimately blame my eyesight and rushing, I've been a metalworker for 23 years plus and my old mentor would be beating me right now if they knew :shock:

Anyway, it's a 305 which is great news, but I'm still unsure if I can get replacement hub bushings and stuff for this model or if I can retrofit some of the m72 or Dnepr parts.

Thanks for your help anyway guys !!! And if you know where I can get these hub parts please let me know 8) (not the bearings, that part is easy ... now :D )
"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

User avatar
Claus
Hero of the Soviet Union - 2020
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Joined: Sun Jan 04, 2015 1:19 pm
Location: Germany
Contact:

Re: M61 wheel bearing and hub help !!!

Post by Claus » Thu Jan 09, 2020 12:34 pm

The hub bushing can be made easy on a lathe. It´s of mild steel.

And well, these old vernier callipers are not very vommon anymore. I´ve got one for 20" and one for 25" in that old style. That´s why I know abot the minor details. My former apprentice sometimes fell for it, after working with the newish type for a while . :lol:
owned bikes: 93 Ural rig domestic model, 95 Suzuki DR 650 RSE, BMW R100GS, Suzuki GSX1100G rig, BMW R100R rig with Ural sidecar, Ural rig with BMW drivetrain under construction,

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Macabry
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Re: M61 wheel bearing and hub help !!!

Post by Macabry » Thu Jan 09, 2020 2:28 pm

Thanks Claus !!!
"There are only three sports: mountain climbing, bull fighting, and motor racing. All the rest are merely games"

History:
Honda C70, Honda C90, Mobylette (various), Suzuki GP125, Suzuki DR100, Suzuki DR400, Suzuki GN400, Dnepr K750 rig, BSA M20 (1940),

Current:
IMZ M61 - exact year unknown (Reg'd as 1961)
Suzuki DR400 (Basket case)

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