hoodie2 Posted January 8, 2010 Report Share Posted January 8, 2010 can anyone tell me what size ball bearings would fit the original steering head bearings of an M92? Building up from bits and want to reduce costs and re use the standard bearings for now, but the balls are missing. Also what mods are needed to accomodate tapered needle roller bearings? Cheers Hoodie Quote Link to comment Share on other sites More sharing options...
rcgods Posted January 8, 2010 Report Share Posted January 8, 2010 (edited) My owners manual says 3/16th diameter, 22 of them in each race. I buy them in bags of 50 from an online bearing supplier at Edited January 8, 2010 by rcgods Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted January 8, 2010 Report Share Posted January 8, 2010 (edited) Think they are metric, did have the decimal but not sure if I still have. Micrometer on an old one should verify one way or the other? Edited January 8, 2010 by Nigel Dabster Quote Link to comment Share on other sites More sharing options...
woody Posted January 8, 2010 Report Share Posted January 8, 2010 My owners manual says 3/16th diameter, 22 of them in each race. I buy them in bags of 50 from an online bearing supplier at Quote Link to comment Share on other sites More sharing options...
hoodie2 Posted January 9, 2010 Author Report Share Posted January 9, 2010 Thanks very much for the help. When I checked out Woody's link there was a big saving on the tapered bearings, so I've gone for those. Cheers Hoodie. Quote Link to comment Share on other sites More sharing options...
wayne_weedon Posted January 10, 2010 Report Share Posted January 10, 2010 (edited) There is only one "gotcha" with these conversions. The Sherpa has a lot of angular offset between the headstock and forks so you should not deviate too far from the original yoke mounting distance to avoid alignment problems. The original bearing set had a total length of 12mm, some of the conversions use modified 32005 bearing which have a assembled length of 15mm. there is one set I have seen with correct diameters but still a lenth of 14.5mm. So for 2 bearings the yokes are 5 or 6 mm further apart. That difference is almost all the total thickness of the preload adjuster nut. Just trigged this out based on a 2 deg offset, and it may not be too siginificant actually, 6mm futher apart would equate to about just over 0.2mm or 8 thou misallignment. Only other issue is possibly the extra height may not be shrouded well by the original pressed bearing shrouds, and adjuster nut. Wayne..... Edited January 10, 2010 by wayne_weedon Quote Link to comment Share on other sites More sharing options...
hewson Posted January 10, 2010 Report Share Posted January 10, 2010 (edited) Hi all, just received some taper roller bearings today which are the right size( bore25mm dia 45mm width thickness 12mm)got these off pyramid parts adverting in classic dirt bike . (WWW.PYRAMID-PARTS.COM) TEL 01387 269985 ( Edited January 10, 2010 by hewson Quote Link to comment Share on other sites More sharing options...
penno350 Posted January 10, 2010 Report Share Posted January 10, 2010 3/16ths is near enough to 4.7mm which are available fairly cheaply from most good cycle shops or on line. Quote Link to comment Share on other sites More sharing options...
bultaco49 Posted January 10, 2010 Report Share Posted January 10, 2010 Only other issue is possibly the extra height may not be shrouded well by the original pressed bearing shrouds, and adjuster nut.Wayne..... I noticed this when I fitted these bearings to my model 221. I slipped an '0' ring over the lower headstock and when the forks were re-assembled I rolled the 'o' ring into contact with the bottom shroud. This shroud faces up anyway diverting anything liquid into the bearing, however, next time I serviced the bearing they were the cleanest and water/muck free I have ever seen them so all my bikes now have an 'o'ring in this position. Quote Link to comment Share on other sites More sharing options...
woody Posted January 10, 2010 Report Share Posted January 10, 2010 I fitted some of these taper roller bearings over 2 years ago on my 199B .......... Yep, I have them in all mine too - The Miller conversion used a thicker bearing but those from Pyramid are the same dimensions as the original as far as I recall. Quote Link to comment Share on other sites More sharing options...
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