i was thinking and i came up with this. would it be at all possible to adapt the idea of a cannondale lefty fork to a unicycle? it would cut down quite a bit on wight and the lefty has proved itself time and time again in the MTN b*ke world for strength and stability. i just thought it would be a neat idea. any comments or discussion welcome
p.s. for those of you who are not familiar with the lefty there is a pic below.
what the heck … what would the point be of having shocks?
im just curious… i mean the only reason I would want one is if im ridin a long distance down a bumpy trail and im goin fast… but thats just me
you could find a way to adapt it and put it in the rim… i found a japanese uni w/ a training wheel and handlebars, but it looks like that would be REALLY hard to make
the lefty fork isn’t exactly light weight. for it’s travel, it’s actaully pretty portly and isn’t that great though. plus if you use search you’ll see that suspenion on unicycles isn’t really a great idea.
Suspension forks and seatposts on a unicycle are not a great idea only because no one’s made a very good one yet. But I think the concept will catch on and it will be the next step in innovation beyond geared unicycles. I think the main problem currently is fork flex which screws up the moving parts very quickly. Also, saddle bob could be a problem when pushing and pulling on the handle.
It wasn’t that long ago that MTBkers were debating whether suspension forks were a good idea.
lol not exactly … it was a japanese contraption that i ran across ( im kickin myself in the rear for not saving the page) it had a roller blade wheel for a training wheel that looked like it stayed off the ground once you learned to handle it and some adjustable handlebars
The thing about a suspension fork on a unicycle is that it doesn’t help you very much. On a bike, suspension isolates you from the wheel, and Ken is right that bicyclists used to argue over whether that was a good thing or not. But now, pretty much everyone realizes that being isolated from the wheel is good, and no one would try to claim that a fully rigid bicycle is faster or more able to take obstacles than a suspended bike.
However, a suspension frame on a unicycle doesn’t isolate you from the wheel; it only isolates your butt from the wheel, while your legs still have to take all the impact. The benefit of that seems quite marginal to me, considering the extra weight and complexity that suspension would bring.
The one thing that would be nice about it is that you could run your seat at normal height (full leg extension), which would make easy sections and uphills less tiring. Maybe it would be nice for big-wheel distance riding. I don’t see the benefit for technical MUni.
Unless you can build the suspension into the wheel somehow, which is a significantly more difficult engineering problem.
The Cannondale fork supports the weight on the front wheel only. On a unicycle, it would have to support all of the weight and impact. Plus, as stated before, it only isolates your butt from the frame. Your feet are attached directly to the wheel.
tholub- i’d argue that a fully ridgid bike is faster over lots of situations. anything smooth for one. and not just roads, but many offroad situations too. comfort is certainly less, but not speed. suspension helps you maintain control in more intense situations where you need the greater margin for error and the less abuse to your body.
the biggest problem i see for it on the unicycle is the mid-pedal stroke change in seat height. even on full suspension mtn bikes, they try to remove that quality.
My sense (for muni) of this is that true suspension won’t work very well no matter if it’s in the seat post or the frame or the hub or the cranks. However I can almost believe that a dampening seat post–adjustable, with perhaps one half inch of play at the most–might work very well to smooth out the jarring rock/root/etc. hits that often buck us off. No need for much play–your quads are the true dampener. Someone’s just going to have to try and build one. The bike versions are too springy and have too much play, absorbing too much pedal energy–like shooting a canno out of a canoe. Gotta be easier than building a frame.
Hmm. I don’t agree. It has upsides and downsides. Many of you are imagining a suspension fork on a hardcore rock-hopping uni. For that type of riding it would just get in the way. Unlike on a bike, you can’t use the suspension to allow you to bash through bigger bumps. Long as your feet are on the pedals, there’s a limit to how much return you’ll get for your suspension.
But having ridden Daniel Hopkins’ early suspension fork unis many years ago, I still remember what a sweet ride that was. It is probably best suited to fast riding on rough but not-too-technical terrain. For any ride that’s long it would be great. As someone else mentioned, some form of short-throw suspension would be great for road unis.
Simpler, and a lot lighter, is the idea of a suspension seatpost. I have used a few of those, and they are also great for taking the edge off, especially on longer rides. But I think the idea here is to overcome the engineering challenges of that fork, not necessarily to build a better mousetrap.
Things to consider:
Suspension forks tend to be wider, so make sure you won’t have knee clearance problems. Some people don’t like suspension forks because they bang their knees on them. This is mostly a factor of your height, and the height/width of the fork.
Suspension forks are made for front wheels, not drive wheels. When you put pedaling force through your suspension fork, you’ll be constantly twisting it from side to side, a force it was not built to handle. This may wear it out pretty fast, or just create more play than you’re going to like. Don’t underestimate the amount of twist that gets applied to a uni fork, especially if you hold the seat!
It looks like you’ll have to custom-design and build an axle/hub system to work with that fork. You’ll need a machinist, because I imagine you’ll have to build the thing from scratch or do major modifications to an existing one. Have you thought about that part? The rest will be easy.
But in the end, if you can make it work, you’ll have one of the most unusual unicycles out there; one I would really love to try out.
GB4 has a suspension seatpost on a coker that i rode around his driveway for a while. it took some getting used to, but it wasn’t too bad. he said it took the edge of potholes and such but other than that wasn’t so great. i just think locating the shocks in the fork would be strange at best.