Mountain Bike Frame Repair

I ride a 2016 Evil Wreckoning and in late 2022 I ovalized the suspension pivots in the carbon frame. I decided to try and repair it by designing some aluminium sleeves to be epoxied into the pivot points on the frame, then machining some new axles and bearing shims to fit into these sleeves.

After sketching some initial designs, I rendered them in CAD and created some engineering drawings. After reviewing my design with the workshop at the UKATC, I then modified the it to ensure the parts would be simple to manufacture.

I found an open-access workshop with a metal lathe. After being inducted on how to use it, I went about machining the parts I had designed which was a trial-and-error process being my first time machining precision parts on a lathe.

After I had finished machining the parts, I was able to epoxy the sleeves into my frame and assemble it with the new shims and bolts. I have since done nearly a year’s riding and it has held up well. This was a great insight into the design and manufacturing of machined parts, along with mountain bike suspension and frame design. 

Please see the pictures below of the CAD assemblies and the finished parts mounted on my frame.

Below is the main pivot CAD assembly, complete with the custom machined 2 piece axle, highlighted in blue and green, designed to fit inside the two-piece sleeve, highlighted in yellow and orange, that was epoxied into the main pivot point on the front triangle. 

The bearings and spacers, highlighted in grey, could then fit onto the, with an m8 bolt to tighten things up.

Below is the smaller suspension linkage CAD assembly. It is designed in a similar way to the main pivot assembly, but given the smaller 11mm outer sleeve diameter, a custom stainless steel m8 bolt was ordered that fitted through the two-piece sleeve that was epoxied into the frame, along with the two custom machined aluminium bearing spacers, highlighted in pink.

Below is the fitted main pivot axle.

Below is the fitted linkage axle and aluminium bearing spacers.