Moebius strip bike

 Before launching into this post I wanted to show a few pics of a moebius strip. It would be best just to make your own though! Cut a strip of paper, bring the ends of the paper together, twist one end of the paper through 180 degrees, and then join the ends. Here are a few pictures.

Moebius Strip

Another view

Strip as mounted in the bike. Imagine the fingers rotating and the mark and join moving across the photo as they rotate.

Chain with twist in top (drive) side.

 When my friend George passed away, his widow Christine gave some of his bikes to me. These were Linears, a bike made in the USA with a long, cherished back story, dating back to before 1985:  before most modern recumbent makers. I sold 2 of George's Linears to raise funds for OzHPV, the Australian Human Powered vehicle association. 

A third Linear from George and Chris's garage was only a frame with remote steering. I spent a bit of time kitting it out with a drivetrain, gearchanger, and front and back wheels and brakes. There was quite a bit of rummaging in the shed involved, and I bought the front wheel along with its tyre and tube from a local bike shop associated with BYK bikes. 

The bike just stayed like this as a rolling chassis as I had other bike projects going. I lacked motivation on this one, so it just stayed there for a while.

Then I accidentally put a half twist ( moebius twist ) in a chain I wanted to assemble onto a bike. This was a mistake, but it made me wonder about the possibilities on other bikes.  Most of the recent bikes I've made and ridden ( like the one here, pic 14 ) have twisting chain front wheel drive, but the chains twist through much less than180 degrees.

A bit later, I found this on the web,  an actual use of the moebius form for producing an output drive on a different plane to the pedals.  My application is a bit different, its just putting a twist in one side of the chain of a long wheelbase bike. In this case, its the top (driveside) of the chain. The wiki page for mobius strips says one of its applications is to even out wear on a drivebelt, and while this is a possibility for my use of the strip, its not really my purpose, it's just to have fun and make something interesting.

Anyway, the moebius chain works, and it works when riding the bike too! The seat I put on the bike is temporary and I can only just ride the bike because my legs are almost impossibly cramped when I ride it. Debut of the bike was on a rainy Saturday afternoon, I rode most of the way around the block on the footpath though, with the awkward riding it's not super safe on the road. Next morning I rode to our local cafe and my good friend Simon filmed and photographed me on the bike.

 I will work on the seat and see if I can make it a bit easier for me to ride. Meanwhile (tada) here is my introductory video and here (tada) is Simon's video of about the third or fourth time it had been ridden. 

This bike mod is very easy to try if you have a bike with a long chain and no chain handling hardware (pulleys and tubes) on the bike, plus a quick link in the chain which can be retrofitted. This bike has about a metre between the front and rear cog centres.

Rest in Peace my Dad, David Nurse, 1931 to 2025.