covered front end options for this model/frame in another thread so... tons of info out there for back end options for other makes/models, just gonna ad pertinent info here as i run across it, turns out, goes back ..some time in this info from ~ 66 (click on pix to enlarge), http://showandgo.blogspot.ca/2009/12/extended-swing-arms.html http://victorylibrary.com/brit/chassis-2a.htm from an ebay ad google - BSA C15 B40 B44 Victor trials vmx vintage motocross mx AHRMA swingarm extenders https://www.a7a10.net/forum/index.php?topic=10028.0 https://www.a7a10.net/forum/index.php?topic=10028.msg73591#msg73591
If you have a cut-off wheel, torch, welder, grinder, lathe, mill, and stock materials, you can make ANYTHING fit ANYTHING. There is a nice, simple swingarm bracing scheme for classic Britbikes also. These welds were NOT mine, I inherited it; I beefed up the birdpoop stuff to where it actually adds strength...
I cut 2 C15 swing arms so the 4 cuts when the halves were swapped gave 1" longer arms on one swingarm plus some bits which could be used to make a short one, but are in the scrap bin. Into the longer arm joints I inserted some short sections of tube with OD matching ID or the swingarm tubes and left 1/4" gaps for a welder to fill and joint the halves up. Dressed the weld and ended up with an extended C15 swingarm.
looks like there were 3 diff swingarms for pre oif a65, for years 62-4, 65-8, 69-70, no details yet other than mounting part(s) diffs for 65-8 vs 69-70 https://www.draganfly.co.uk/index.php/bsa/bsa/a50-a-a65/1967/category/271-swinging-arm https://www.draganfly.co.uk/index.php/bsa/bsa/a50-a-a65/1970/category/347-swinging-arm i'm gonna focus on 67 cos thats what i have i don't have many of those skills, or experience, in making a change, first thing most folks look for/at is what options & info is out there, having access to info allows easier decision making to then move forward with, if you google xs650 swingarm swap, there is tons of available info, along with other makes & models vs practically diddly for a65, ran across some stuff tho, an oif a65 deal http://www.bikebound.com/2015/08/11/1972-bsa-thunderbolt-custom-hill-climber/ high end http://www.malarkeyengineering.co.uk/bsa-a65 vs home brew https://www.ebay.co.uk/itm/1969-BSA...576678?hash=item43c3e818e6:g:hWYAAOxydlFSr111 _______ i'm looking for all dimensions like these http://www.xs650.com/threads/swingarm-pivot.35933/#post-363215 xs650 - Pivot Tube: ID - 16.02 mm - (0.631") OD - 21.95 mm - (0.864") norton mk3 spindle OD https://www.oldbritts.com/13_100005.html Swingarm Pivot Spindle, MK3, .8745" O.D. a65 pre 69 "Spindle Diameter: 5/8" (16mm)" https://www.feked.com/bsa-swinging-arm-spindle-solid-type.html 5/8" = 0.625 _______ some of the options for xs650 http://www.motolanna.com/ourshop/prod_2637748-Swingarm-Aluminum-Alloy-SuperLite.html key point, the SR500 and XS650 swingarms have the same pivot dimensions http://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html other stuff https://www.ebay.com/itm/XS650-xs-6...brace-weld-on-kit-1-joe-wiseguy-/263209242491 https://www.ebay.com/itm/XS650-xs-6...wder-coated-braced-new-bushings-/263121267436 https://www.ebay.com/itm/XS650-xs-6...-weld-service-xs400-rd350-sr500-/391850435325 https://cognitomoto.com/products/xs650-weld-on-swing-arm-extenders http://www.xs650.com/threads/b-1982-3-25-extended-swingarm-125-b.42154/ diy jig http://xs650temp.proboards.com/post/29281/thread it would be sweet, if a xs650 swingarm swap was doable via some cheap easy mod, pretty sure the yam tx750 swingarm, bit bigger, beefier & longer is a direct bolt in for the 650 frame some mods with a kz1100 conversion, https://www.kzrider.com/forum/11-projects/599144-another-kz1100-cafe-streetfighter-build#684560 luv this guy, sez in the thread "This is the first engine I've ever worked on, so any tips would be very appreciated" lol
