Instructions 1- Rear Swingarm

I normally start the build with the rear swingarm and once it is assembled, you should have a swingarm that is lovely and rigid with a free spinning rear hub.

Parts Used

2 * Bearings – 13*6*5mm – for the rear hub – BRG001
2 * Bearings – 13*6*5mm – for the rear swingarm – BRG002
2 * swingarm plates – GRP002
1 * swingarm block – SHP001
1 * Rear hub and 42t pulley – SHP002
1 * Belt – BLT001
1 * Rear axle – CNC003
1 * Rear axle spacer – CNC004
6mm shims – SPR004

Build Tips

i) You can use an M3 taper tap to start the threads off in the printed parts but don’t over do things, as it’s best to have the threads tight than loose. Alternatively run a 2.5mm drill in to the holes to clear out any unfused nylon and then it should be easier to start the threads.
ii) Once you have you rear axle shimmed nicely, you can use a drop of superglue gel to tack on the rear axle spacer. That way when you change a wheel there is no risk of losing the spacer and all your carefully worked out shims!
iii) The standard bike does not come with a belt tensioner but if, over time, you time your belt has stretched and is slipping then you can easily make one up using an M3 bolt and some bearings fitted to the ‘lug’ provided on the swingarm block.
iv) The bearings are normally a nice press in nylon parts. If they are loose then you can secure them with a tiny drop of super glue gel and if they are overly tight then use a hobby knife to carefully chamfer the outside of the hole a little and ease them in.


1) Push two of the bearings in to the swing arm block.
2) Attach the left hand swingarm plate – using three M3*10 low cap head screws.
3) Place the belt in the right place, as per the photo. If you forget to do this then you’ll soon be unscrewing the right hand plate to fit the belt!
4) Attach the right hand swing arm plate – using three M3*10 low head cap screws.
5) Push two of the bearings in to the swing arm block. Then fit the rear axle. The rear axle has a 6mm spacer built in and this sits on the pulley side with the 8mm rear axle spacer on the non-pulley side.
6) Fit the rear hub/rear axle using two M4*10 button head screws. You then need to shim the rear axle using some 6mm shims.   The shims are very important and may vary a little depending on the machining of the rear axle etc. The key points are that the rear pulley needs to run a tiny distance (around 0.2mm) from the right hand plate and this normally needs no shimming but may need 0.1-0.2mm of shims slipped on the rear axle before you feed it through the pulley. The other side then  needs shimming to ensure there is no sideways play and that the hub rotates freely when the axle bolts are tightened – this normally needs around 0.2mm of shims placed on the axle under the rear axle spacer.



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