The rear wheel bearings in my two speeder bitza are quite pitted, the bearings are Hoffman #5632 and have metric dimensions (22mm id x 50mm od x 17mm wide). I can’t find this size in any bearing catalogue so i’m assuming it’s an obsolete bearing ? Does anyone know where I can find a pair of these bearings or know of an easy to fit alternative ?
Which kind of bearings are they? Single row deep groove ball bearings? Single row angular contact ball bearings? taper roller bearings? 22x47x17 is listed as taper roller bearings (SKF T2CC 022).
You may contact Ransome Hoffmann Pollard Ltd, UK. They may give information about obsolete bearings in the Hoffmann range:
AHR International LTD
Suite 2, Stanta Business Centre
3 Soothouse Spring
Tel: +44 (0)1727 738430
Fax: +44 (0)1727 899394
Chstorm is too fast for my hunt-and-peck typing dammit!!!
Vincent use taper roller bearings but they require shoulders on the wheel spindle and some method of adjusting for end float/pre-load.
FAG, (usual disclaimer), make a twin seal corrosion resistance treated deep groove ball bearing measuring 25 x 47 x 12 (Part No. S6005-2RSR).
Although overall smaller this bearing has sufficient strength. They would require the manufacture of two pairs of “top hat” type sleeves to make up the size differences; a nice turning exercise, possibly saved by a drop of Loctite . . . ?
I would also add that I have used twin sealed bearings on another machine with every satisfaction. Seals by the way should not be confused with shielded bearings, they cannot prevent the ingress of contaminants as will seals.
Just over a month ago I changed the bearings in the rear wheel of my TS. As I could not find the Hoffmann size bearings I have used a doublesealed bearing 2RS 22x50x14. This is single row. So the same size as the Hoffmann, just 3 mm narrower.
As my bearings were a very tight fit in the hub I simply pressed them in with a little loctite and filled in the extra space with a washer. I have yet to try the bike on the road (a bit difficult without a front wheel) but the weel turns freely without play.
I did a similar job at the front replacing the old cup and cones with double sealed bearings.
Hope this helps.
For the record the bearings are double row roller bearing and not tapered. I think Erik’s solution sounds straightforward, ie. using a slightly narrower bearing but with same id/od and a spacer. As the bike is not heavy or particularly fast i’m assuming the slightly reduced load carrying capability of the narrower bearing will not be too much of a problem (it was probably over engineered in 1926 anyway ?).
I have seen heavier bikes with smaller bearings. So I think it will be ok.
The original bearings (two different manufacturers). Hofmann on the right.
The new bearing in the hub. I turned a taper in the distancepiece because there was a little bit of play between this piece and the axle
I turned this tapered and slotted washers. When tightened this takes up all the play in the axle.
The washer in situ. Works a treat when the axle nuts are in place. The circlip is more for show I guess. As I did not relace this wheel I did not have the opportunity to turn the groove in the hub where the circlip should fit. The whole wheel simply did not fit my lathe ;o)