Mono forks /struts or whatever they are called

t4tomo

I saw one this morning, what i believe was a Giant halfway folding bike with mono srut / stay both front and rear.

One of the ugliest things I've seeen for sometime.

I think Cannondale also do a Mtb with a mono fork - similarly freaky / ugly.

I can half see the point on the folder as it reduces folded size, but surely these things are weaker than a traditional fork. I wouldn't want to pootle around the city on one, let alone go mtbing.

Anyone gpt one and if so what in gods name possessed you to buy it / is there some benefit tat makes up for it hideousness.

Aidy

Cannondale call them leftys.

Advantages? Well, you can change a tube without removing the wheel...

EKE_38BPM

Lefty has been around for 10 years now. Cannondale even do active suspension (a la F1) Lefty forks (is it right to call a Lefty a fork)?

http://www.pinkbike.com/news/cannondale ... -2010.html

greg66_tri_v2.0

They are the work of the devil.

Designed by a one eyed man though.

notsoblue

I feel queasy when I see them about.

veronese68

EKE_38BPM wrote:

Lefty has been around for 10 years now. Cannondale even do active suspension (a la F1) Lefty forks (is it right to call a Lefty a fork)?

http://www.pinkbike.com/news/cannondale ... -2010.html

I'd say it's a strut. I think that you have to make them heavier than you can make a fork to get the strength. It's effectively a McPherson strut as used on cars. Cars can't use forks for various reasons and weight isn't such an issue.
Ducati 916s had a single sided rear swing arm, the design after had twin sided for strength and weight reasons. People liked the single sided so the following design reverted to single sided for style reasons. So forks lighter and stronger for a given weight. Single sided just for the sake of being different.

el_presidente

Pancho needs your prayers it's true,
But save a few for Lefty too
He just did what he had to do
Now he's growing old

bails87

They're stiffer than a normal fork because you can use the same amount of material to make a single wider tube, compared to making two narrower tubes. Doubling the diameter of a tube makes it 8 times stiffer.

Likewise, if you halve the number of tubes, you halve the weight.

So meet somewhere in the middle and you get something that's stiffer and lighter.
http://www.cannondale.com/innovation/lefty_headshok

veronese68

bails87 wrote:

They're stiffer than a normal fork because you can use the same amount of material to make a single wider tube, compared to making two narrower tubes. Doubling the diameter of a tube makes it 8 times stiffer.

Likewise, if you halve the number of tubes, you halve the weight.

So meet somewhere in the middle and you get something that's stiffer and lighter.
http://www.cannondale.com/innovation/lefty_headshok

Hmmm, I may be wrong then. I thought having to support the wheel on just one side added the weight. They're still wrong though. I often pass a bloke on a 'dale with a lefty, I worry he's going to fall off.

SimonAH

Apparently the Cannondale Lefty fork is actually extremely tough - although I grant that it does look a little weird.

A friend uses the halfway for commuting and really rates it too.

MonkeyMonster

I quite like the idea of a left with disc brake but then I'm not like most of you Less bike to sweat over!

greg66_tri_v2.0

Doesn't it put a lot of pressure on one side of the hub?

SimonAH

Actually a lot less than you'd think. Don't forget that the hub is very narrow so there is relatively little leverage. By far the bulk of the force is transmitted vertically just as in a standard two-pronged fork.

SimonAH

Also, remember Adam Hart-Davies' excressence of a bicycle?

http://mirror-uk-rb1.gallery.hd.org/_c/ ... D.jpg.html

Built for him by Mike Burroughs I believe....

rjsterry

Greg66 wrote:

Doesn't it put a lot of pressure on one side of the hub?

Axle acts as a cantilever rather than a simply supported beam, but it shouldn't make any difference to the bearings (I think). Not suitable for CP

t4tomo

having the axle attach at only one side just seems inherently weaker. 'd be worried it snapped / bent, not to mention the hideous aethetics.

MonkeyMonster

t4tomo wrote:

having the axle attach at only one side just seems inherently weaker. 'd be worried it snapped / bent, not to mention the hideous aethetics.

Given it was built for mtbing and by cannondale you'd have thought they might have done some numbers on the forces involved...

bails87

MonkeyMonster wrote:

t4tomo wrote:

having the axle attach at only one side just seems inherently weaker. 'd be worried it snapped / bent, not to mention the hideous aethetics.

Given it was built for mtbing and by cannondale you'd have thought they might have done some numbers on the forces involved...

I think it's safe to assume that t4tomo doubles up on stems, seatposts and handlebars, seeing as having just one of something makes it too weak to trust

rjsterry

MonkeyMonster wrote:

t4tomo wrote:

having the axle attach at only one side just seems inherently weaker. 'd be worried it snapped / bent, not to mention the hideous aethetics.

Given it was built for mtbing and by cannondale you'd have thought they might have done some numbers on the forces involved...

See also: How do masts work? How come car wheels don't fall off? How...