Scottydog Posted March 20, 2012 Report Share Posted March 20, 2012 Looking for some thoughts regarding bearings and my options. I have a small capacity Honda which uses 22x56x15 and 25x56x15 main bearings. These sizes are pretty unusual it seems as they are difficult to find in normal bearing catalogues. In Euope they seem to be priced better than in the USA. So the older model of this bike use to run the typical 6205 bearings which are a pair of 25x52x15 which got me thinking whether I could just get the machinist to make a couple brass or bronze rings to press into crankcase. I'm sure I've seen bronze inserts done on race machines. Finding a 22x52x15 bearing is pretty easy. The rings would be 2mm thick and 15mm deep and I'd locktight them in with the strong type. So just looking for the pros and cons to why or why not bothering. One positive reason to go with the mod is the 6205 bearing type comes in many specs and even ceramic which for a potential race machine might be nice. cheers for thoughts! Link to comment Share on other sites More sharing options...
cagimaha Posted March 20, 2012 Report Share Posted March 20, 2012 I know that some of the crank bearings for older Suzuki T500's are now unavailable so people mod them with aluminium inserts to take a smaller, readily available bearing. As long as the sleeve can be accurately machined and if possible incorporate some method of stopping the bearing spinning in the cases (some sort of peg/dowel arrangement) then it shouldn't be detrimental in terms of strength. Link to comment Share on other sites More sharing options...
Scottydog Posted March 21, 2012 Author Report Share Posted March 21, 2012 Hey guys thanks for the input. So yeah looking into it, if I convert to the smaller bearing type the world of very cool bearings opens up! Basically race karts and motocross engines use the smaller size. With the bigger ones the bike uses it's common in the Honda Accord, Goldwing and Suzuki RM. Other than that kinda unknown! Why the change who knows, maybe they wanted to ensure owners rebuilt the bikes with their parts! So just to add, I spoke to my friendly machinist at work and he mentioned with a 2mm bush there could be shrinkage and would be better to press in and bore after. Or better still, press both bushes in and line bore to ensure the crank is evenly loaded! I gather one could just drill, thread and use a grub screw to lock the sleeve as a precaution. Still good to know others have been doing it, will see which route I go, I do have plenty casings to use. Going to investigate when the change occured as might be possible to puchase new older style casings also. Link to comment Share on other sites More sharing options...
porter_jamie Posted March 21, 2012 Report Share Posted March 21, 2012 How much are the genuine parts, exactly? How much are the 'pattern' ones Link to comment Share on other sites More sharing options...
Scottydog Posted March 21, 2012 Author Report Share Posted March 21, 2012 How much are the genuine parts, exactly? How much are the 'pattern' ones It varies a fair bit to honest. Out of the UK or Europe the genuine items are not expensive, not sure of the spec however. $30 for pair? Out of the USA the choices are not for my model, but used in the gearbox section for a Suzuki and Hondas. $75 for pair With the 6205's could go for C4 rated bearings at about $40 or even ceramic if one desired. Basically the choices are limited. Discussing it further with the machinist today, just thinking will keep the idea on the backburner for the future and go with the less hassle setup. I notice the race cranks I have run a pair of 25mm ID bearings where the standard item has 22mm and 25mm ID bearings. With the 25mm ID it means I can keep to the lower cost Honda bearings. Link to comment Share on other sites More sharing options...
porter_jamie Posted March 21, 2012 Report Share Posted March 21, 2012 Buy them from europe?? Link to comment Share on other sites More sharing options...
Scottydog Posted March 21, 2012 Author Report Share Posted March 21, 2012 Yeah will buy a set from Europe for sure as well, just they seem too good price wise. I've seen them as low as $20 for the pair which makes me wonder. Link to comment Share on other sites More sharing options...
wazrs257 Posted March 21, 2012 Report Share Posted March 21, 2012 http://www.sp125racing.com/PerformanceEnginePartsRS125%202011.htm Have a look at this page, at the work they do with RS125 cases. Yours would want to be done in a similar fashion, depending on application. This is a full race engine, but if its not done properly, you'll run into problems even on a commuter bike. Link to comment Share on other sites More sharing options...
Mark/Foggy Posted March 21, 2012 Report Share Posted March 21, 2012 Last RS125 engine that I had that done, 'cause it span it's mains in a big sieze, ended up with a line bore and brass, top hat inserts. Theory was to spread the load a little and increase the bearing surface area of case and insert to control further problems with rotation. No bearing fit or grub screw that would cause immense damage if it dropped out, just good interference tolerances. Sadly the magician that did the work passed away a couple of years ago, so I can't confirm the tolerances, though I seem to remember 5/6 thou. Lovely old fella, came to Oulton on the Thursday, before I got there, had them back to me 07-30 Friday for me to rebuild when I arrived on track. 2nd practice was about 10am . Why oh why am I contemplating going racing with a 1960's smoker. Link to comment Share on other sites More sharing options...
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