|
|
Post by manxman on Sept 12, 2006 23:52:40 GMT -5
I want to put an 18" mag from an XS400 on the front of my SR but, the XS uses a 15mm axle. Any ideas?
I saw a picture of one of Rod Tingate's SRs on which he used an 18" from an XS250?? It's hard to believe a 250 would use a 17mm axle like our SRs so, there must be a way.
Thanks for any ideas,
Dave
|
|
|
|
Post by StewRoss on Sept 13, 2006 6:11:30 GMT -5
Hi, Shouldn't be a problem. There are a couple of ways...sometimes Yamaha use 'top hat' sleeve on the inside of bearings to sleeve the bearing inners down for a specific axle size...look at the bearings and see if it looks like there is another bushing inside the bearing? If there is, then measure the ID of the bearing on the outer side of the sleeve to see what it is...it might be 15mm...you need to remove one bearing to remove these from the wheel...and also make a longer inner spacer to suit...for this read a couple of paras down. If the bearing is without a sleeve, measure the outside diameter of the XS's bearings and go to a bearing place to see what's available...there are many bearing sizes to choose from. You should find one that has the OD and ID of the one you are after... With regard to using the SR axle; despite successfully sourcing the correct sized bearings, you'll also need to manufacture...(or perhaps drill out the old one)....a new bearing spacer for inside the wheel. These spacers go between the inside edges of the two wheel bearing's inner races. They are there to prevent undue axial loads being placed on the bearings when you tighten the axle...(...keep the inner and outer races correctly aligned).  The new or re-drilled spacer should be a slip fit on the axle and must measure, as closely as possible, the distance from the inner side of both bearing inner races... There will also be a ring on the outisde of the old spacer that maintains the spacer in the central position. If you make a new spacer, make it to the same diameter as the original and slip the ring from the old onto the new... and in about the same position as well. You may also ned to amke up soem new axle spacers as well...no real problems. SR  |
|
|
|
Post by canucksr on Sept 13, 2006 8:59:47 GMT -5
Many years ago a guy I knew had put an 18" mag on the front of a 78 SR. He used a complete front end from an RD350 (mid-eighties model) I'm pretty sure he used the complete front end including forks, rim, brakes etc. The forks slid right into the SR's triple clamps. Anyway it looked real sharp and he had double discs on the front after the installation.
|
|
|
|
Post by manxman on Sept 13, 2006 22:10:18 GMT -5
The spacers wouldn't be too much trouble but, the bearings are.
The SR uses a 6303 bearing at 47mm x 17mm. The XS wheel uses a 6302 at 42mm x 15mm. There is a 6203 bearing available at 40mm x 17mm but, that would require a shim or sleeve of some kind to fit it tight in the wheel.
I thought the RD series used 33mm fork tubes? Besides, the RD wheel is a tube type and ever since I had a blow-out on the back of my RD, I won't run anything but tubeless.
|
|
|
|
Post by StewRoss on Sept 14, 2006 4:14:20 GMT -5
Hi, If you already have the dimensions look around some of the other bikes for the bearings...perhaps other Yams etc. Try the wreckers for the measurements for a start. I looked for ages for different dimension bearings for my new cafe racer's front wheel. Can't recall the dimensions now, but it had to have a 20mm axle go through it...I lucked out at the bearing places, but I eventually found the right one on a Honda SP1 front wheel...an exact fit... Trouble is going to the dealers most of the bearings are by bike manufacturers part number, not size. Have you thought of sleeving the axle, I did this on my black cafe racer on the front axle...silver soldered the sleeve to the axle. How similar is the thread on the end of the axle to the SR's? SR |
|
|
|
Post by StewRoss on Sept 14, 2006 4:20:35 GMT -5
Err, just to clarify, I sleeved the axle end where it goes through the forks...not the axle where it goes throught the bearings... SR |
|
|
|
Post by nzthumper on Sept 20, 2006 6:22:40 GMT -5
I replaced the front wheel of my SR with one from an early RD250. I had a stepped axle made that fitted the standard SR fork on one side, the stepped down to go through wheel bearings and spacer then a sleeve on the nut end, worked a treat. I also tossed the hopeless old master brake cylinder for one from a TZR, added a second standard front brake caliper and a mounting bracket from an XS 650 for the second SR disk, all a bolt on fit. The new caliper is 'upside down', you'll need to unbolt it and temporarily turn it up the right way to get the bleed nipple to the top, I used a small piece of 1/4" plate to give the pads something to push against while I bled it but draping it over the original disk is good too, if the new hose will allow it. I vented the disks in a modest way too, and ended up with all the brakes I ever wanted or needed, wet or dry. Now remove the front guard and redrill the mounting holes so the guard is a nice snug fit. Done right no-one will notice anything except the extra disk.
|
|
|
|
Post by manxman on Sept 20, 2006 22:30:31 GMT -5
NZthumper, that's brilliant! I'm sure a good lathe machinist could turn down the Sr axle to 15mm and fab a sleeve for the nut end. The XS400 uses the same axle nut so the threads could remain untouched. I'm going to use dual disc as well, as the XS400 caliper and mount are a mirror image of the SR's.
Thanks for the tip! I'll let you know how it turns out.
Dave
ya gotta luv this forum!!!!!!!!!
|
|
