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Conference noted::bicycle

Title:	Bicycling
Notice:	Bicycling for Fun
Moderator:	JAMIN::WASSER

Created:	Mon Apr 14 1986
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	3214
Total number of notes:	31946

2402.0. "A different Shifting setup..." by NCBOOT::PEREZ (Trust, but ALWAYS verify!) Sat Aug 29 1992 22:22

    Today I tried a bike from the NordicTrack company called "the Fitness
    Bike".  It is a rather conventional looking "sort of" hybrid that you
    might see someone using to trundle down to the corner store...
    
    But, the interesting things, and the ones I was curious about were the
    shifting and the brake:
    
    The shifting uses no derailleurs.  Instead the chainring is a two-piece
    composite "clutch" that operates similar to what a snowmobile clutch
    does.  As you shift up the chain moves outward "onto a larger
    chainring".  Shifting is done by pressing and holding a thumb lever
    then pedaling forward to upshift or backward to downshift.  Instead of
    a derailleur on the rear there is a set of jockey pulleys just to take
    up the chain slack.  This particular bike has 9 gears and I found it
    quite easy to shift up or down - so did my wife.  Future plans call for
    a mountain bike version with 14 speeds and a road bike with 16 although
    they had no specifics on gear ranges.
    
    Could this be the future of shifting?  I can imagine weight savings by
    having a small fixed gear on the rear and a lightweight composite
    clutch - no freewheel, no front or rear derailleurs, no chainrings, no
    double shifters and cables...
    
    Braking was by a single rear brake which, rather than a rubber pad
    pressing the sides of the rim was done by a kevlar wrapped cable that
    went completely around the rim in a small track parallel to the tire. 
    It worked quite well.  The Nordic folks also insist that it isn't
    affected by wetness.
    
    Has anyone else seen bikes with either of these "features"?

T.R	Title	User	Personal Name	Date	Lines
2402.1		JURA::PELAZ::MACFADYEN	fading into the continuum	`Sun Aug 30 1992 04:25`	11
	I wonder how the transmission efficiency compares against a conventional tranmission? There are always engineers ready to criticise the perceived crudeness of derailleur systems but in fact they achieve high transmission efficiencies. We humans don't develop enough power that we can afford to lose any of it in transmitting it to the road. Still, sounds interesting! (He said quickly, trying not to sound too much like a luddite.) Rod
2402.2	izzat right?	NOVA::FISHER	Rdb/VMS Dinosaur	`Sun Aug 30 1992 14:30`	7
	Did I understand this? This is for use on the road? You pedal backward to downshift? Can you lose "all momentum" if going slow enough on a steep hill? [and fall over!] ed
2402.3		NCBOOT::PEREZ	Trust, but ALWAYS verify!	`Sun Aug 30 1992 23:22`	13
	>This is for use on the road? You pedal backward to downshift? >Can you lose "all momentum" if going slow enough on a steep hill >[and fall over!] Yup. I suspect if you were going slow enough it could be a problem. But, the distance you pedal while shifting is probably less than an inch. And, in a normal system you still lose momentum while downshifting... Efficiency SHOULD be about as good as a standard system. You still have the loss of going through the jockey pulleys but since the chain never moves horizontally you don't have the loss from friction due to the chain being angled.
2402.4	IN SOME OTHER LIFE?	WMOIS::GIROUARD_C		`Mon Aug 31 1992 07:52`	7
	In a racing situation, less than an inch can cost you many yards... This isn't new, is it? This stuff has been around for quite some time (or the conceptual equivalent)... Chip
2402.5	Seen this bike before?	NQOPS::CLELAND	Centerline violation...	`Tue Sep 01 1992 11:25`	7
	I've seen a recent article on this bike, but it didn't mention Nordiktrack or whomever... I think it was in Bicycle Guide magazine? Perhaps this company has bought the patent on this machine? Anyone else seen the article?
2402.6	Bike mag.	MIMS::OLSEN_R		`Thu Sep 03 1992 22:18`	8
	Yep. Its the same bike. It was in Bicycle Mag. The Bicycle mag. article was about the inventor and his little company where he produced the bike. They seems to be favorable in their opinion toward the product, as much so for the guts the guy has to build it, as for it being a neat product. I saw one at an Atlanta Mall, and it was the same bike. So Perhaps, the little guy gets a break!!! :-) Ron