Bearing question or "Are my balls obsolete?"

C

chris78jota

Senior member
Location
England
At the risk of starting a Vasectomy thread :eek:, I hope some of the forum's more technically minded members can help me..

I've just finished dismantling the engine of my '54 Laverda 75 Sport.

I've found it is in generally pretty good nick, but as a matter of course I intend replacing all the oil seals and bearings.

I've managed to order all the seals and one 25x52x9 gearbox output shaft bearing on line from a localish bearing factor.

However, the 20x52x10 bearings I need for the crank (two) and the gearbox mainshaft (one) aren't listed - the nearest they have is a 20x52x15. I've tried some other sites but with no success either.

I'm hoping that they aren't obsolete for some reason - my ineptitude with google must be the answer, or how could anyone with a 75/100 ever rebuild them?

HELP!

Chris
 
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Hi Chris,

The bearings are obsolete, but Nick (Alcock, wasn't it?) was kind enough to source them in the UK and supplied me with 2 sets for my 100 a couple of years ago.  They were new items, made by Hoffman(I think, no longer have the packaging).

I have since managed to rebuild the crank with a new big end/conrod assemby and stuff the engine back together.  Just need to do the electrickery to finish off a 10 year resto..... ::)

Then there's this guy, www.peters-bearing.de  , stocks them but is far too expensive imho.....

piet
 
There's a mob in California who sell them (well, 20x52x10.8 bearings, might need to machine 0.8mm out of the case) as special order scooter parts, maybe for ancient Vespas, who knows? Try http://www.spi-parts.com/catalog/product/view/id/22022/, drop them an email anyway and see what they'd charge you.
Otherwise there's a standard sized bearing, 20x42x8, that you can get just about anywhere and it might work, just have an insert machined and pressed into the case on each side. Will it hold up as well as the somewhat larger original? Who knows? The worst thing that could happen is that the crank bearings could seize at full throttle, but at 75kph that's a relatively minor risk.

Ken
 
I do a lot of vintage and italian stuff and I'm always coming up against this obsolete bearing deadend.

Be aware that a lot of bearing suppliers don't put their old and obsolete bearing stock on line... a personal approach often pays dividends. I work through two bearing wholesalers local to me, both of whom are interested in what I do - this helps a lot.
Strangely there's a lot of obsolete stock held in backblocks Australia - Aermacchi gearbox bearings from Bendigo of all places.

If the 20x52x10.5 is the correct rating and clearance it should be possible at reasonable cost to have it ground back to 10.0 mm wide.
This is considerably easier than machining cases....
 
      Hi Greg and welcome to the forum.  Did Conrad tell you about us??  He mentioned or alluded to you in one of his postings some time ago.  Are you full or part time working on Italian bikes???
      I take it you are somewhere in Canterbury.

      Cheers Shorty Oxford NZ
 
Chris,
This company lists the bearings as available to order on a 7 day basis.

http://www.spi-parts.com/catalog/product/view/id/22022/

I'm sure you'll find them elsewhere but if you get stuck at least you know a potential source.
 
Bob

Yep, that's the mob in California, with the 10.8mm wide bearing. Closest anyone's come so far. I do like the idea of asking bearing houses for their old stock, but it'll only work if they subscribe to a less "modern" business model and don't throw everything over 6 months old in the rubbish. That may be why some country town operations in Australia still have inventory; they never throw anything out!

Ken
 
I just checked out www.simply bearings.com
20/52/10 deep groove ball bearing 98304  26.50 GBP
R22 or R23 seals in the same size 2.33 GBP
they will post anywhere.

I have been useing this company for a good few months now, for bearings/seals/o rings, for anything from my Laverda's, to my sons washing machine, with a scooter gearbox and an enduro bike shock linkcage thrown in,excellent all round and a very user friendly web site, I cant remember who it was who steered me to them, Rob Lawton ? or maybe Paul Haynes, A N Other? never mind thank him very much for me when you see him.
CLEM
 
Clem, I'd like to see a washing machine with a scooter gearbox and an enduro suspension.  :D  :D  :D
 
Fantastic, as usual, Guys.

You've given me plenty to go at, many thanks.  I had visions of having to build up the outside of the cases with weld, then having them (and the oilseal retainers) machined out 5mm. Phew.

Clem, I am proven to be stupid, as I'd been searching on the "simply bearings" site for ages and come up with nothing.

endebted
Chris

p.s. a bike with washing machine bearings did actually set a world record...
 
well,
my son Tom's washing machine has set a world record as well, for silent running.The thing was trying to destroy itself and he took it apart, well totally apart actually, and removed the two bearings that the drum rotates on, got onto simply bearings (by phone) and quoted the number on the bearings to get replacements, they asked "what is the intended application" and he told them, they then said that ALL washing machines should be fitted with XYZ bearings with XYZ clearance (can't rememer the spec) and not the crap Chinese items they are built with, he invested, and rebuilt the machine, it now hums, rather than runs, he is very pleased, Simply bearings, said that if people dismantled their new/unused machines and did this they might well get five times the life from the whole cabooddle.Tom got going again for about twenty quid, and his 400 quid for a new machine stays in his pocket.
CLEM
 
chris78jota said:
p.s. a bike with washing machine bearings did actually set a world record...
Click to expand...

Chris,
Indeed it did! Flying Scotsman Graeme Obree set one or two records with his unique device. I think he machined the bottom bracket arrangement out of some old washing machine parts. He's a very clever lad...

 

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