Not sure how helpful these pics are at showing the bolt size compared to an AA battery but this is an M10 bolt from the supermoto caliper bracket to suspension tube mounting bracket: So just to conclude the thread, if you're bolts and corresponding fork bracket mounting holes are M10 (2001-2004 SMs) then the bushings will not work. You will need to get the enduro caliper drilled and tapped to accept M10x1.25 pitch bolts and space them with nuts that are 5mm wide. Thanks for helping me to get to the bottom of this darnold87.
Right, after months of supermotoing I have decided to explore the trails again and this time I was determined to get the front brake to a safe condition which involved getting the bracket drilled and tapped to m10x1.25 pitch (originally forgot to specify 1.25 and they did it 1.50 so had to go back and get it modified to 1.25) and I finally found some spacers from eBay. These are known as "stand off spacers" at least on eBay UK, they might be called something different in other countries. It is easier if you can find them for sale rather than having to wait weeks for a machine shop to make something up for you. Or you could stack multiple M10 washers to get the correct spacing but proper spacers are a far neater solution. Anyway, they are these, m10, 6mm inner diameter: The outer circumference looked like it might have been too big initially, but it just touched the gaiter on the caliper slider: Find some with a smaller outer circumference if you can. Regarding the width of the spacers, the lowest I could find was 6mm wide although I figure anything from 3-6mm will be fine, with the ideal being 4mm or 5mm. I still need to sort some proper bolts, I ordered some m10x1.25mm thread pitch bolts but for some reason they had 1/4 of the thread shanked which wasn't in the description of the product, hence why the bolts aren't tightened up in the pic because they are slightly too long and when I tighten the top one it jams against the disc eventually and for the bottom one the head of the bolt is too big for me to fit a wrench on because there is not enough space between the fork casting and the head of the wrench. But finding bolts will be the easy bit now after getting the caliper bracket drilled and finding suitable spacers at least.
Any bolt that is above a certain length will have a percentage of straight shank, if your after a full thread they're called set screws.
Frustratingly, despite being armed with that knowledge, I am having no success locating allen head bolts in m10 with the correct thread pitch (1.25) in 45mm length. I may end up having to buy a die and cut threads in what I've already bought. Or take them to a local engineering shop.
Have you got a fasteners company near you? I use fix and weld they know their stuff. Arb fasteners try small independent places they specialise in stuff people like screw fix are useless.
