Extreme eBike – 2-Up Seat

2-Up Seat

The original Qulbix style frame came with a mountain bike type seat which is OK, but I wanted to carry my, at the time, girlfriend. Don’t worry, we didn’t break up, we got married 🙂 The first seat was too narrow and got welded but never installed. The widened version was OK but a bit short so of course I made a longer one. I made the last version when I widened the frame. I mounted a rear fender and designed it so 12V DCDC and the motor controller could fit inside.

The first thing to do was actually add passenger foot pegs to the rear swing arm. Nothing fancy, just generic foot rests. It’s a bit unfortunate they have to be on the swing arm and not the frame, for comfort, but it simply wasn’t practical to mount them off the seat.

This is my first functional seat. It widens from 75mm to 140mm but it wasn’t long enough and the angle was much too steep. You can fit two people but it’s a pretty tight squeeze and no one is comfortable. It is however the seat that who’s shape I like the best. The foam turned out pretty well and the seat cover was nice and sleek.

This is my current seat. It’s practical and relatively comfortable. Good dense foam is essential when making a good seat. That and 3M 77 spray adhesive. Bonds foam to metal and to itself. Great stuff. When carving I use an angle grinder to carve my foam. It’s quick but messy. I recommend a respirator and tight sealing safety glasses. An air gun helps clean off all the dust off your clothes.

All these seats were laser cut and then bent with a CNC press brake. I received back a bunch of pieces I then welded together to make the final seat. The seat pan was cut and bent in the same way and I welded M8 nuts into it to attach the seat.

On my last seat, I needed to install internal braces to transfer the load of the riders to the center part of the frame. I reinforced the seat mount with an extra layer of 2mm steel. It was showing signs of deformation and this fixed the issue. I also had to reinforce the kick stand mount in the same way. The frame was deforming and was not designed for two riders on a long seat.

By | 2020-03-01T01:37:21+00:00 February 19th, 2020|Featured, Madeit|0 Comments

About the Author:

Brian is an intrepid maker living near Shenzhen China.

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