News
Spot joins Orange with belt drive
Carlton Reid Sep 22 2007, 10:00am
Bikes equipped with Poly Chains could be next big thing? Outdoor Demo has 30...
Orange of the UK and Spot Bikes of the US believe one-piece belt drives, corded with carbon, could relegate the roller chain to history.
Spot Bikes will have 30 singlespeeds ready for testing at Interbike's Outdoor Demo. There's a YouTube promo video from Gates here.
Like Orange, Spot Bikes are using a Poly Chain synchronous belt drive made by Gates Corporation, a multi-national power transmission specialist. Gates has produced many bike belt drives, such as the rubber belt used on the 1980s Strida, wide belt drives for Raleigh, and the Kevlar-corded Poly Chain belt drive used by Errol Drew's 2004 US commuter bike, the iXi.
The carbon-corded Poly Chain by Gates stands a better chance of acceptance because of greater strength and efficiency. Companies such as Trek, GT, Pacific Cycle, and Whyte have been trialling the latest Poly Chain incarnation since last year. None have so far gone beyond the prototype stage because belt drives can't work on derailleur systems and there are frame production problems: a roller chain snaps into place on a frame, bikes need to be built around a one-piece Poly Chain or need a 'cut and shut' process on the chain stay or seat stay.
Orange - introduced to Poly Chains by G-boxx innovator Karl Nicolai – hopes to have a production city bike ready for March, equipped with a low-maintenance, quiet and super-efficient Poly Chain along with a Shimano Alfine internal hub. YouTube video of Orange bike (and a Whyte), Michael Bonney and the Gates factory viewable here.
Orange hasn't asked Gates for exclusivity, instead it's hoping for first mover advantage.
However, Spot Bikes of the US has been granted a one year exclusive deal for sale of its singlespeed MTBs in North America.
Transmission chains have a long history. Leonardo da Vinci sketched chain designs in the 16th century. However, the fast-emerging bicycle industry threw up an innovation which was later used on the first aeroplane and the first cars. This was the roller bush chain, invented and patented in 1880 by Hans Renold, a Swiss engineer living in England. Renold's chain was incorporated into the Starley safety bicycle and helped popularise cycling around the world.
Chains may get a bad press because they wear, they need frequent lubing and hence they're 'oily' and attract dirt, but they are super efficient at the transmission of power. In 1897, Professor R.C. Carpenter of Cornell University conducted experiments which showed that even a well-worn chain was up to 98 per efficient.
In 1930, the National Physical Laboratory at Teddington measured the efficiency of a bush roller chain as between 98.1 and 98.9 percent.
According to a 1998 paper by Matt Kidd and others, delivered at the Engineering of Sport conference at Heriot Watt University, a bicycle chain is 98 percent efficient.
Gates claims its Poly Chain belt can match or exceed such efficiency.
There's a fuller feature on Poly Chains in the November issue of BikeBiz magazine.
