RM 250 A, B and C Swingarm dimensions

[jerry]

Can any body help? First off are they all the same? Looking for accurate dimensions for swingarm width including bushes, pivot diameter, pivot to shock mount centres, shock mount to shock mount internal dimension. Also pivot to middle of slotted axle hole. Any help much appreciated. Thanks Jerry

[LWC82PE]

They are all the same (length inc 77-79 PE's) from pivot to center of axle slot and that being 508mm

76 - pivot to shock mount 371mm
77 - pivot to shock mount - 340mm

the above specs are from offical suzuki docs

I have been told the 78 alloy arms are 344mm pivot to shock mount. I cant personally verify this though.

wheel gap for 76 is 216mm and i expect 77 would be the same
bare width at pivot on 76 is 175mm off the top of my head but i will have to verify it for you. I got it somewhere in my note book but i have not found it yet. if i cant find it i will go and measure my swingarm though.

Pivot bolt OD on all of them are 14mm but could be made to suit anything from 12-16mm with different bearings and a few custom machined bits if you are doing some sort of custom fitment.

I will update this with left to right shock mount spacing once i double check my notes/measurements.

[TT5 Matt]

rm250A's had a tubular straight swingarm while the B and C's has a bent rectangle swingarm which was less prone to bending the shock shafts

[David Lahey]

As far as geometry goes, the bottom (and top I think) shock mounts were differently located relative to the swingarm pivot between A and B models (or was it B and C models?) and Suzuki made a big fuss in their advertising about how much improved the rear suspension was because of the geometry change.
I think a better set of shockies would have been on my wish list if there was going to be a change made

[LWC82PE]

163 and 132 are not to center of the slots. Those measurements are a bit forward of center at the factory initial chain adjustment spot.

[jerry]

You guys are awesome. Much appreciated. Thanks. Jerry

[LWC82PE]

Updated 76 measurements. I was 1mm out with my guess on the pivot width. Measurement on photo is of the bare width. It looks like there are press in bushes in the photo but there is not. That's just bare steel from where i masked it off. 216mm wheel gap may vary a mm or two and may close down to 214 or 215mm depending on width of wheel parts and Suzuks tolerance here but the relaxed gap is 216mm. Other measurements are shock mount spacing's to the inside plates and outside plates. They may also become 1mm or so smaller when its all bolted up with wheel fitted too.

[jerry]

Thanks Leith exactly the stuff I'm looking for. Cheers Jerry

[jbrad5]

As an aside - After I had a PE250C swing arm sandblasted and powdercoated, the 216mm opened out to 221mm..I had to put the swing arm into a press to close it back up again.

John