vintagejack 0 Posted August 31, 2005 -------------------------------------------------------------------------------- I have an old 1970's Pb Racing Double but the cluch (unusual system) rubs on the clutch housing when the drum brake is applied. The problem is not with the bearing as i thought but with with the shaft it runs on, it is a roller needle bearing and the shaft it runs on is so worn it wobbles, this means when I apply the drum brake it pushes the drive cup back in contact with the clutch plates, thus transferring drive whilst trying to brake... Anyhow in the unlikely case any of you have one of these shafts I have removed it, the third picture on the page of the PB Racing Double in my showroom..has it with the corresponding letters for measurements.. The crank shaft it screws into is 5mm more or less... A: 12mm B: 5mm C: 28mm D: 5mm Cheers Jack Share this post Link to post Share on other sites
fastboy 0 Posted August 31, 2005 just measured some 1/8th ones. a=11mm b=5.8mm c=24.5mm d=4.93mm you might struggle to get a match...however,wondering if you can get normal bearings to fit in the clutchbell and turn the shaft down to fit the bearing? just a thought now the shaft i just measured is a 2 piece affair,the actual shaft is held onto the nut by an allen bolt behind it..is yours a one piece or 2 piece?..if 2 piece,you could just add a new shaft. dave Share this post Link to post Share on other sites
vintagejack 0 Posted August 31, 2005 Hi, Thanks for looking fastboy! Unfortunately the 1/8th one you measured would be no good... I had a look and mine is a one pice! so unfortunately I can't just replace the shaft... Share this post Link to post Share on other sites
fastboy 0 Posted September 1, 2005 hmm wonder if 1/10th ones are the same size,unfortunately i dont have any if your really really stuck i could probably do one on the lathe for you,but i think you would have to use normal type bearings as opposed to needle bearngs since i wouldnt be able to harden the shaft for you,needle bearings are very destructive on untreated metal. whats the internal measurement on the clutch bell housing for where the bearing goes?.. wonder if you can use a modern clutchbell with normal bearings,know it sounds a bit daft but you can actually clean the old shaft up and fill in the grooves with silver solder then just resize it on the lathe and use normal bearings,or as i say,turn the shaft size down and use normal bearings or sleeve it. dave Share this post Link to post Share on other sites
vintagejack 0 Posted September 1, 2005 You know, your idea about resleeving it might be the best one yet!! sounds the least complex to me... the needle bearing seems to be moulded into the Clutch Cover/Belt rive cog/Drum brake ( its all one piece) with very little room, so replacing the bearing might be difficult and replacing the whole thing even harder.... I'll try my local egineering place and see what they say! Jack Share this post Link to post Share on other sites
stuie-t 0 Posted September 2, 2005 Given the age of the car, the original part will almost certainly be to imperial measurements rather than metric. Maybe a modern uS part can be made to suit? [?] Share this post Link to post Share on other sites
steponit! 23 Posted September 2, 2005 Just across my mind....what happened to PB Racing? I still remember during my school days (about 20 years ago or more..) it was very well knowned, very well made and won several races in the uK. Would appreciate if anyone could tell me.... Share this post Link to post Share on other sites
aconsola(2) 0 Posted September 2, 2005 find a well-stocked hobby shop and see what you find that is close and can be trimmed/shimmed to fit something like this: http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXBCK5&P=7 May work if you really need metric and not imperial. The length of your shaft is bigger than most regular 1/10 clutch pilot shafts, so likely you will need one from a model with a 2-speed as they tend to be longer to accomidate the extra gear. if you do a search at tower for either "pilot shaft" or "clutch nut" you will find a bunch of potential candidates. unfortunately they do not list dimenstions for most of them. good luck, -Anthony Share this post Link to post Share on other sites
vintagejack 0 Posted September 3, 2005 Thanks Anthony, I never even though of looking at modern stuff..!!! Steponit, there has been a long dicussion on PB cars, all the info is here: http://' target="_blank">http://www.tamiyaclub.com/xforum/topic.asp?TOPIC_ID=8050&SearchTerms=pb Share this post Link to post Share on other sites
steponit! 23 Posted September 3, 2005 Thanx vintagejack! Share this post Link to post Share on other sites
