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@Fishfabs
I'm working on a bike to take to Bespoked in a couple of weeks.
I've been doing a long commute on the previous version that went to Grinduro, and while it's nice and sturdy it's a pig to adjust.
I thought it would be interesting to clamp the seat tube by tightening through and into a mandrel that slides inside. This will obviously mean that the seat tube will need slots machined into it - 2 separated slots with 2 M5 fixings. I've limited the slots to 28mm long centres - so that is the amount of height adjustment that the seatpost will have - Enough for me I think, different shoes/pedals and angles.
I've also gone for a lower clamp onto the frame that is a bit inspired by thru-axle dropouts with aluminium bosses that fit into the steel bosses that are brazed in the frame.
There are bronze bushes on the front mounting and stainless pivot axles.
At the moment the whole assembly (not including seatpost) is around 500grams, so I'd like to get that down by hollowing and removing material as I go.
The seatpost is 28.6 with a 1.5mm wall thickness - straight gauge. It's possibly a bit over the top... but let's see!
It's not quite fully detailed so some surfaces may change shape.... but it's got to be on the CNC machine next door in a couple of days so I've got to settle soon.
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