Archive for August 2012

XS650: K&J Swingarm   Leave a comment

Been busy lately. Summer (well not really much of one) riding. Work. And, best of all, play.

Our son turned 6. School. Need to get him there and pick him up. Started a while ago collecting bits to turn my SR500 into a sidecar. Velorex 562. Leading link forks. Box section swingarm. Steering damper. Better shocks. May yet even add a battery. Had a subframe made up – bolts directly to the frame. 4 point sidecar connection bolts to this – no welding to the frame – better load distribution. Easier to get certified.

Got a K&J box-section swingarm for a price I couldn’t refuse. Included all the bolts, bearings, axles … ca 5.7kg.


k&j box-section swingarm … shock mount bolts, axles and chain tensioners¬† not shown


Checked the existing bearings – OK. But the bearing races showed definite wear marks where the rollers have contacted. No internal spacer!! Checked their website. This is standard-no spacer. Means the bearings take all axial load. Anyone who has left the internal spacer out of their wheel when replacing bearings soon learns not to do this. Their instructions say to tighten the swingarm pivot to the point that the swingarm slowly lowers itself from a raised position. Fully loaded bearings – no wonder the races are marked. New bearings.

Measured it up. Figured there was 164.5mm space between the bearing centres. 16mm internal diameter. 22mm OD would fit inside the bearing cages. Cut myself a bit of pipe. Fitted it – too long – too much play. Remove. File. Refit. Did this 3 times before I got the fit I wanted. Now, there is no sideplay and the swingarm can move freely.


spacer … 164.5mm long …. 16mm ID … to the left is one of the bearing carriers, greased, ready for installation


Next problem. No chain-rub protector and the pivot tube has a larger OD than the original. Had a polyeurethane bread board the wife wont miss. Grabbed my holesaws and cut myself a new rub protector.

Mounted the chain guard. Shock mount bolt is in the way.


shock mount bolt blocking the chainguard


A bit of violent grinding soon fixed that.

For some reason K&J decided to reinvent the wheel. Put the brake plate anchor topside. Original is underneath. Must rotate the plate. The brake actuation geometry is now all fucked up. Bright. On researching they fixed this later – gave the choice of over or under. Later models are fitted for the original anchor. This didnt help me. Made myself a new anchor. A comprimise, but helps.

External dimensions of this swingarm are slightly larger than original – means the brake rod runs real close. A little judicious bending solved this. Also took the time to remove the brakearm pivot. Like the XS650, the SR500 has no grease nipple here and people forget to regularly repack it. Tends to seize when least desired. Fucking Murphy!!


brake arm pivot – getting a bit dry … caught just in time


Things to do:

  • Dechrome the swingarm – i hate chrome just as much as i do policemen
  • reposition the brake plate anchor
  • powdercoat it black
  • replace the missing grease nipple – swingarm pivot shaft
  • keep riding

If you’re wondering why I’m writing this, you may not have figured out that the SR500 and XS650 swingarms have the same pivot dimensions.


Posted August 31, 2012 by xscafe in Frame - Handling, SR500

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