billybob Posted December 5, 2015 Report Share Posted December 5, 2015 Hi, Just purchased a twin bearing upgrade set for my Sherpa, (No modification needed) the top bearing looks straight forward, however, before I start, can anyone give me a tip on the lower bearing assembly? I take it that the old ball bearing racer has to come off to allow the new bearing to locate correctly, not entitly sure how to remove it without force. I als take it that the lower bearing has to slide from the top to the bottome, however, it to tight to move over around 10mm of the shaft, does this need a tap or should it slide free to the bottom? And another, in one of the forums, its said that there should be four wires coming off the flywheel, I only have three and the missing colour is that of a red wire. If anyone can help, it will be most appreciated, Cheers, Andy Quote Link to comment Share on other sites More sharing options...
johnjsy Posted December 5, 2015 Report Share Posted December 5, 2015 Hi Andy,the red wire is used for a horn,but beware,the current is AC,so you will need the correct horn. A DC (battery) type will not work.I assume the bearings you mention are taper roller? They can be really tight on the steering stem. I put a thick piece of alloy on a small gas ring then place the new bearing onto that to heat up. 3 to 4 minutes should do it,the bearing will slide on quite easily.Have a long piece of tubing ready to tap it down if it needs a little help.Hope this helps,John. 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted December 5, 2015 Author Report Share Posted December 5, 2015 Cheers John, Have you had a go at getting the old ball bearing racer cup off, would this just need a decent amount of heat? Cheers Andy Quote Link to comment Share on other sites More sharing options...
billybob Posted December 5, 2015 Author Report Share Posted December 5, 2015 Cheers John, Have you had a go at getting the old ball bearing racer cup off, would this just need a decent amount of heat? Cheers Andy Quote Link to comment Share on other sites More sharing options...
guys Posted December 5, 2015 Report Share Posted December 5, 2015 Cheers John, Have you had a go at getting the old ball bearing racer cup off, would this just need a decent amount of heat? Cheers Andy To remove the bottom bearing race, I use a small angle grinder with a cutting disc. Make two cuts in the race at a 45° angle in the race as deep as possible but without damaging the bottom yoke or steering tube. You can then split the bearing race with a chisel or if that doesn't work, the heat generated by grinding, will expand the race enough to remove it. 2 Quote Link to comment Share on other sites More sharing options...
smelling123 Posted December 5, 2015 Report Share Posted December 5, 2015 Hi Andy They are tight! If you have an arc welder, if you run it around the old bearing face it seems to heat the bearing locally and it falls off. Alternatively, you can cut through it very carefully with a disk cutter - take care not to catch the stem or yoke ! Stu 3 Quote Link to comment Share on other sites More sharing options...
billybob Posted December 5, 2015 Author Report Share Posted December 5, 2015 To remove the bottom bearing race, I use a small angle grinder with a cutting disc. Make two cuts in the race at a 45° angle in the race as deep as possible but without damaging the bottom yoke or steering tube. You can then split the bearing race with a chisel or if that doesn't work, the heat generated by grinding, will expand the race enough to remove it. Many thanks Quote Link to comment Share on other sites More sharing options...
billybob Posted December 5, 2015 Author Report Share Posted December 5, 2015 Hi Andy They are tight! If you have an arc welder, if you run it around the old bearing face it seems to heat the bearing locally and it falls off. Alternatively, you can cut through it very carefully with a disk cutter - take care not to catch the stem or yoke ! Stu Cheers Stu, Quote Link to comment Share on other sites More sharing options...
bultacorock Posted December 6, 2015 Report Share Posted December 6, 2015 Hi Billybob, I fitted a new head set, asked an old biker friend how he would do it he said put the bottom of the yokes with the bottom part off the old head set in the deep freezer over night get a barbecue hand held gas lighter the one with the little flame and warm just the bearing up then face it down and tap the end on a bit of wood till it falls off ..... i needed to tap it quite a bit to get it moving but it came off then and the old cover ( lose fit ) came off to, i put the yokes back in the freezer, later heated a new cover ( tight fit ) and the part of the bearing on the gas cooker and they just dropped on i could not believe my luck ! Got my head set off Stu feel really smooth. BR 3 Quote Link to comment Share on other sites More sharing options...
bondy Posted December 6, 2015 Report Share Posted December 6, 2015 It's easy to do make sure you don't hit the fine threads on the stem or you will never get the nut on i use a nylon block to hit the stem or a block off wood should not need alot off heat some can be more stubon than other's. To slide the new bearing on the stem only needs a small amount off heat then will slide on with ease. Hope this helps. 1 Quote Link to comment Share on other sites More sharing options...
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