CRAZY70MAN
03-07-2013, 09:22 PM
Well, I am currently building another big bore 70 for a friend. He also wanted the trurned down hubs to adapt to cart pattern wheels that most of us use. So...without wanting to pay a machine shop, and not having a lathe..we came up with this. http://i388.photobucket.com/albums/oo321/andyatc70/th_makin70hubs_zpscbfefc74.jpg (http://s388.photobucket.com/albums/oo321/andyatc70/?action=view¤t=makin70hubs_zpscbfefc74.jpg) With the axle still mounted into frame, we braced it up on a stand I have. Installed the stock hub on the spline and rigged a pipe wrench up to back up the axle to prevent turning while he drilled. The key here was to use a thru type arbor for the holesaw that the pilot bit will adjust to any depth and to leave the pilot bit a bit loose so it will move as you drill . We ground the pilot flat as to not screw up the axle end also. Next using a standard metal holesaw size 3 1/4" and a good strong electric drill..we began. I was the oiler while he gradually started to drill. You only want to leave the pilot bit in till you get some good cutting marks started then remove. It worked great and took some patience when cutting..slow and lots of fluid. A little dremel work and bench grinding and presto!! http://i388.photobucket.com/albums/oo321/andyatc70/th_makin70hubs2_zpsf5f52a55.jpg (http://s388.photobucket.com/albums/oo321/andyatc70/?action=view¤t=makin70hubs2_zpsf5f52a55.jpg) We also used a template to carefully mark the new cart hub pattern and drilled them out on drillpress and he tapped them with a 5/16 standard thread. This is a great way for someone who can not afford to have hubs machined make their own to run cart tires on any 70. It would be nice in the future to have an old axle end and some type of mount to be able to mount on my drill press instead of having to drill them while in a bike. It worked out well. Keep this engineering marvel in mind:lol:... Hope it helps someone out..