Lefty suspensions



Solanog

New Member
Feb 12, 2004
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Is there any advantage with this suspensions comparing it to regular ones?
I don't understand the advantages if it has any. Would it be stronger or tougher or lighter than a regular one? Cheaper to produce and more expensive to buy?
 
I dare say one advantage is changing tyres...you don't have to remove the wheel first!!

Big dissadantage is there is not quick release to remove the front wheel if you use the back of the car etc. Also special hubs (only a few brands make hubs/wheels to fit).

The design is taken from the cannondale head shock, but allows greater travel without extending the head tube to house the suspension mechs and all the movement.

The design uses needle roller bearings along a machined 4 sided shaft. Very low sticktion (static friction) thanks to the roller actions instead of bushes. I would expect this to be very durable as well compared to bushes. It is an "upside down" design which leaves the largest diameter, and stiffest tubes at the top, and very little unsprung weight connected to the wheel to improve sensativity.

Reportedly the design is very stiff as well, but you'll need to get a report from somebody with more MTB fork experience than myself.

Personally I think they look really cool, but I have work mates that won't buy cannondale because they hate the look.
 
I just bought a new Cannondale Prophet with the Lefty fork. One of the sales pitches that was given to me was that with the lefty fork, while riding at a slant, the tire remains true to the upright position. What that means is, with a conventional fork, the uphill side of the fork has to compress more than the downhill side, causing your tire to lean downhill, slightly.

I really find that hard to believe due to the modern engineering of new forks and the materials that companies use to make new forks.

My main reason for getting the Cannondale with the Lefty fork was price. The whole bike, with XT/XTR components was cheaper than some of the others I was looking at with LX/XT or LX.

Other than looks, I think it performs like any other fork. It did take me some time to get used to riding without one side (mental), but I really like my new Cannondale and would recommend both the bike and fork to anyone looking for a new mountain bike.

Mark
 
I think what the slightly full of it shop guy was talking about was binding of double legged suspension designs.

If you have a load not perfectly in line with the angle of fork travel it puts a large torsional load on the bushings inside the legs. If it is a lateral load one side of the fork will try to compress differently to the other.

This clearly is an issue that designers have over come with large widely spaced bushes. Many forks now have a spring element in only one leg, or only has a damping unit on one side. The internal loads on each leg would mean one side wants to move differently than the other, all resisted by the bushes.

While "normal" forks work well, this level of over design to resist these forces can result in increased stiction/friction, and make the fork less sensative or less smooth. The cannondale forks have always had great bump sensativity thanks to the bind proof roller bearings. Its probably only a small benefit, but it is a benefit.
 
Since suspensions (good quality ones) are very rigid and are linked by the axle in the hub would they really have this issue of one side responding that differently than the other?
They look to me that if being hit hard enough they will be more prone to break than the regular ones since the hub is attached to just one side.