So skeeming a bastard full suspension. I have aquired a rear end of a santacruz bullet e bike and this got me thinking. There is room under thoes links for a pinion or some cool gear box. And i want to buld a freeride bike for our new bike park that is being built at out local ski hill. So ya could be fun will be difficult. What has other folks built with a off the shelf suspension platform?
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I’ve never done it but I think it’s a good idea. My wife’s bike is a Santa Cruz Bronson and I have worked on it over the years and I really like how all the bearings are contained in the links and the pivot axles and hardware are really well made. I assume your bike is similar so you’ll have a lot of hard work normally associated with full-suspension bike builds sorted. Not all, obviously but I think it would be a good place to start something ambitious like a gearbox build.
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Generally a very good idea to build a full suspension bike with an existing swingarm. It takes away the complexity of the kinematics since it’s already done. I have built two front triangles for my old bike’s back end and it has been relatively smooth sailing.
In your case it might be a bit tricky to find the exact locations for the links, the BB and the shock mount. The VPP arrangement is particularly sensitive to even tiny deviations of a few millimeters.
Here are a few pictures of my franken-bike, swingarm and linkage taken from an older version of the Last bikes “Coal”
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You should! I built my first frame (front triangle) to match a megatower rear end that I had sitting around after cracking the original front triangle. The hardest part is getting the clearance between the shock/tunnel/seatstay. I did my best to model the rear triangle in fusion but mostly got lucky.
If I were to do it again I would use sheet metal service to cut and bend the tunnel out of a single piece the way zoceli bikes does theirs.
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I also have a Santa Cruz 5010c with damaged front triangle which I am intending to build a new front end for. I have not finished this project yet, have been working on it on and off for a while.
To start, I mounted the damaged frame in a jig and took very detailed measurements from a datum plane. This gave me the pivot locations in X/Y coordinates which I then related to the BB center. I drew all this in CAD and then drew the frame around the pivot point/BB relationship modifying the front triangle to the fit I wanted.
As a sanity check, just to make sure I didn’t make any egregious mistakes, I loaded a high resolution photo of the frame into CAD and marked the pivot locations on the photo and then compared this drawing to the one I had produced from my measurements. The camera lens I had tended to distort the image slightly, but it was a good way to make sure things weren’t way off.
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