Grtechguy
Grtechguy SuperDork
3/30/09 12:57 p.m.

Saw this while I was out and about today..

neat look, not sure how it rides

Grtechguy
Grtechguy SuperDork
3/30/09 1:05 p.m.

oh yeah..... single side swingarm on the front.

93celicaGT2
93celicaGT2 Dork
3/30/09 1:15 p.m.

Can't see the pic..... this a cannondale "lefty?"

CrackMonkey
CrackMonkey Reader
3/30/09 1:27 p.m.
93celicaGT2 wrote: Can't see the pic..... this a cannondale "lefty?"

Nope.

Not sure what motorbike it is, but the "fork" is a single-sided swing-arm, at first glance it looks a bit like a BMW telelever, but it's truly fork-less, so that's not it.

Grtechguy
Grtechguy SuperDork
3/30/09 2:41 p.m.

lol....it was parked in front of "BMW of Grand Rapids"

but it's not a Bimmer, its a Yamaha of all things

http://en.wikipedia.org/wiki/Yamaha_GTS1000

Grtechguy
Grtechguy SuperDork
3/30/09 2:47 p.m.

found some more pics of one on Pashnit.com

Appleseed
Appleseed Reader
3/30/09 6:55 p.m.

It'd be fun to build a bike with that front end and a VFR rear.

Grtechguy
Grtechguy SuperDork
3/30/09 7:01 p.m.

I'd like to know how that steers to be honest.

Josh
Josh Reader
3/30/09 7:19 p.m.

This is a nice article on James Parker, the designer of that bike:

http://www.motorcyclistonline.com/features/122_0801_gsx_radd_p3/index.html

PHeller
PHeller HalfDork
3/31/09 3:01 p.m.

I can understand it on a bicycle. The heaviest Lefty weighs in at 4.2lbs, with 140mm of travel, that's lighter than all but a few really expensive forks. The lightest Carbon PBR Lefty is scant 2.1lbs.

On a motorcycle however, it just seems like it'd be an engineering and parts nightmare.

Jensenman
Jensenman SuperDork
3/31/09 3:38 p.m.

Husqvarna built a prototype single side fork and swingarm dirt bike for the Swedish Army sometime in the early '80's. They did this because they were trying to make it as light as they possibly could. It was weird looking, it looked like a conventional fork and swingarm setup with one side of each missing. I wish I could find a pic; I seem to recall the front fork was on the riders' right and the rear shock was on the riders' left.

alex
alex Reader
3/31/09 5:03 p.m.

They handle quite well, better, some would argue, than a conventional fork. Parker writes for Motorcyclist these days, and he has been spending a lot of ink on these front ends, for pretty obvious reasons.

The only complaint I've heard about these (and I can only agree by extrapolating from the time I've spent on other 'alternative' front end bikes, like BMW Telelever and girder/hossack forks) is that while they do a very good job of separating steering and braking forces, from a rider's perspective they provide a lot less feedback, so there's a good amount of trust involved in riding them at the edge.

Now, you want to talk about weird front ends...

BAMF
BAMF New Reader
3/31/09 10:11 p.m.

The other thing I've read about steering systems like this and the Hossack fork are that they are too stiff laterally. Telescopic forks have some flex in them and other types tend not to, which makes them chatter a bit in really hard cornering. I sadly have no personal knowledge of this either way.

Jensenman wrote: Husqvarna built a prototype single side fork and swingarm dirt bike for the Swedish Army sometime in the early '80's. They did this because they were trying to make it as light as they possibly could. It was weird looking, it looked like a conventional fork and swingarm setup with one side of each missing. I wish I could find a pic; I seem to recall the front fork was on the riders' right and the rear shock was on the riders' left.

Aside from weight savings, single sided suspensions allow tire changes to be about as quick as they are on a car. That was part of the design brief of the Vespa when it came out in 1946.

problemaddict
problemaddict Reader
4/1/09 6:19 a.m.

One of my fav custom bikes is a GTS1000 built by Lazareth. Its completely euro-blingy and not practical, but single-sided rear AND front just makes me drool. Their site is all flash now, so you gotta find it yourself.

lazareth.fr

There was also a crazy ratbike/streetfigther built off a GTS1000 frame w/ a GPZ900 motor and lots of wacky shadetree engineering. That was in Streetfighter magazine last year. I'll have to see if i can find some links...

Rusnak_322
Rusnak_322 New Reader
4/1/09 9:03 a.m.
BAMF wrote: The other thing I've read about steering systems like this and the Hossack fork are that they are too stiff laterally. Telescopic forks have some flex in them and other types tend not to, which makes them chatter a bit in really hard cornering. I sadly have no personal knowledge of this either way.

Actually, I don't think that new telescopic forks have much flex at all. Flex causes stiction witch is what they are always fighting on sportbikes. That is why you see the gold and black coatings on the fork lowers and the ever larger diameter for legs. They add flex into the frame and swingarm but want the forks and triple clamps as solid as possible so that they will still have suspension travel at full lean.

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