Mountain Biking - Slingshot bicycles

Hey I discovered these about a week ago when I was told about a bike that was powered by the vibration of the ground and transferred into energy...It went at 80 mph but no brakes could stop it...it was never made.. THis was in the 1980's or 70's but then i wanted to find out if they reused that technology and i found the slingshot. What can people tell me about it? does it relate to the old idea? and basically just any info u have

I don't know about reused technology. However, Slingshots first appeared in the late 80s and early 90s and are race proven. I'm not sure about the energy transference thing but I do know that Slingshots were originally touted for their ability to act as a suspension design. Nowadays they've taken further advantage of the design by making them foldable.

Hey I discovered these about a week ago when I was told about a bike that was powered by the vibration of the ground and transferred into energy...It went at 80 mph but no brakes could stop it...

I'll take one of the above!!


I haven't heard of the bike that used ground vibrations to do 80mph, but I remember reading about Slingshot bikes. As you've probably seen by looking at pics online, the Slingshot design, to put it simply, uses a cable as a downtube. The myth surrounding the design was that riders were able to flex the frame (because of the cable) coming out of corners, "slinging" them out with speed. I don't think their theory had a ton of truth to it, but the Slingshot design allows for foldable bikes (recently). They also have road,mountain, and cyclocross models. I'm no expert, but that's what I remember.

There was an issue in MBA a few months ago about the design with a test of the design in singlespeed.

EDIT: I wouldn't feel comfortable on one of these things for any kind of rough riding. I'm sure they are stronger than they look, but the design just wouldn't inspire confidence in me when looking over the edge of a drop.
A pic:

Honestly... that looks like an insanely dangerous idea to me.

There's a write-up on these very bikes in the August issue of Mountain Bike Magazine.

im sorry, but that bike just scaries me... i dont know, from what i read in the article, Mt. Bike Mag, there is some kind of flexable plastic where the top top connects to the back triangle, and the cable has some kind of spring which attaches to the head tube...
i just done see durability (plastic fatigue) built into that thing if you take any drop greater then 3 inches and land compressing the frame in anyway
i would never ride that thing

Originally posted by aluckyfiji
im sorry, but that bike just scaries me... i dont know, from what i read in the article, Mt. Bike Mag, there is some kind of flexable plastic where the top top connects to the back triangle, and the cable has some kind of spring which attaches to the head tube...
i just done see durability (plastic fatigue) built into that thing if you take any drop greater then 3 inches and land compressing the frame in anyway
i would never ride that thing

Yeah, and I have a feeling there's tons of people like us out there that would agree. I'm sure that cable is plenty strong and all... but the looks of it scare me. I think I'll just stick to riding a hardtail.

I ride a hardtail myself, but there are a couple of guys riding those bikes in my area, and I must say they seem to stand up to some rough riding pretty well. If the design was causing injuries I'd have to think they would be out of business by now due to liability suits. The guys who ride them really seem to like them.

I would be hesitant too, but the company has been around since the early nineties, which is positively Methuselean in mountain biking terms.

it's on the short list for my next CX bike.

A

it seems to me that if the frame some how flexed in the opposite direction than in its designed to flex ( ie you hit something head on) you would lose all tension in the cable putting a lot of stress on that single plastic pivot or whatever it is on the top tube. A frame with that much flex wouldnt handle all that well IMO, cornering especially. I mean placing all structural rigitity on a single pivot seems like a bad idea to me because the chances of it wearing out quickly are pretty likely.

I'm not defending the bikes or anything (I don't have one), but for clarity's sake I would just say that from what I've been told by those who do ride them, the hinge (made just like a downhill ski, same material and all) is laterally very rigid and tough and strong in the vector of movement, and the bike gives a nice ride. The hinge doesn't have to move very much to make a few inches of "travel" at the front end. As for putting all structural rigidity into one pivot point goes, isn't that what Litespeed does with their Unicoi?

Wait wait i want to hear more about the vibration bike. So if you fart do you go faster or is it just vibrations from the ground? Man if i ate a whole lb of beans and drank a 12 pack of shiner bock i could be world champion!
:)

Originally posted by Buzzbomb
I'm not defending the bikes or anything (I don't have one), but for clarity's sake I would just say that from what I've been told by those who do ride them, the hinge (made just like a downhill ski, same material and all) is laterally very rigid and tough and strong in the vector of movement, and the bike gives a nice ride. The hinge doesn't have to move very much to make a few inches of "travel" at the front end. As for putting all structural rigidity into one pivot point goes, isn't that what Litespeed does with their Unicoi?

Im sure that its a strong pivot and completely safe, but it would make me nervous if i rode one. Its a neat design though, and probably extremely light. I'd like to see that design in a road bike.

Originally posted by Buzzbomb
I'm not defending the bikes or anything (I don't have one), but for clarity's sake I would just say that from what I've been told by those who do ride them, the hinge (made just like a downhill ski, same material and all) is laterally very rigid and tough and strong in the vector of movement, and the bike gives a nice ride. The hinge doesn't have to move very much to make a few inches of "travel" at the front end. As for putting all structural rigidity into one pivot point goes, isn't that what Litespeed does with their Unicoi?

the litespeed doesnt have any pivots or hinges.

Originally posted by The Toninator
the litespeed doesnt have any pivots or hinges.

Neither does the Slingshot. The Ti in the Litespeed's case flexes, and the fiberglass in the case of the Slingshot.

THis was taken from the slingshot website and to me it seems like it might be using that old technology




Its important to note that in every pedal rotation of a traditional bike design there is a "dead" portion in the power stroke where the rider is getting no benefit from the expended effort. With the Slingshot design, we have provided the most efficient use of pedal energy throughout the entire pedal revolution resulting in greater speed with the same expended energy. This difference is achieved as pedal energy is stored in the spring compression - then released at the "dead" portion of the pedal stroke, effectively increasing the length of the power stroke. Any energy not going directly to the rear wheel (forward power) is momentarily stored, returning 100% in the "dead" portion of the power stroke. This returned energy helps balance the power through the pedal stroke and reduces the effect of the dead spot. The net effect is what we call "Sling Power".
We call it "Sling Power", here are the components that allow for the stored energy - release.




Fiberglass Board - Located just in front of the seatpost, this board provides independent mid-suspension.

Coil Spring - Located where the head and top join, this spring absorbs shock and stores pedal energy.

Stainless Steel Cable - Attached to the coil spring and the bottom bracket, the cable links the front and rear frame components.

Another benefit of the spring, cable, fiberglass board relationship is that the Slingshot frame has the potential to turn every bump in the trail into forward motion. Every bump becomes a boost. This is achieved by utilizing the same stored energy concept explained above - with the added feature of the mid-suspension fiberglass board. When the rider hits a bump in the trail, the front of the bike will absorb the shock by compressing the spring and flexing the fiberglass board (suspension), temporarily increasing the bikes wheelbase. When the bike returns to its normal state, the Slingshot redirects the forces of trail shock into forward motion.

Also, every Slingshot bike folds for easy transportation. It is the only folding bike that does not require significant modifications of geometry, wheel size or materials to accommodate the folding process.

All I know is that the design is well proven in many an MTB race since the early 1990s. And some of them were downhill competitions. I think the first design which used the single Boomtube top-tube was introduced in 1991. Before then I think there was a double top-tube. Don't dismiss the design based on looks. Slingshot has 15 years and plenty of race wins to back up their design.

Originally posted by copper RS
Its a neat design though, and probably extremely light. I'd like to see that design in a road bike.

Road:
http://www.slingshotbikes.com/images/showroom/rd_stn_photo_detail_lg.jpg

Triathlon:
http://www.slingshotbikes.com/images/showroom/rd_tt_photo_detail.jpg

Cyclocross:
http://www.slingshotbikes.com/images/showroom/cc_race_photo_detail_lg.jpg

Originally posted by khuon


Those are VERY cool :eek:

I saw a road version of this bike at my lbs. A woman brought it in for service while I was there. She said it was a 20 year old hand-me-down but that she loved it. I guess it's real light. They've had a relatively specialized market, mainly touting the foldability for sales. Check out the MBA article, it's interesting.

This is not a joke. I saw a one armed man riding one of this bikes. He only had half a handlebar and he was kicking a$$. I heard he raced it.

Good grief!

Yes, the Slingshots have been around for a long time, and they did aggressively market to the MTB crowd when suspension was in its early stages. I used to see them at races and events and was privileged enough to ride one at Interbike.

They may be great as roadie or CX bikes, but they certainly were not as MTB's. I never heard of the hinge plate breaking, that's not the problem. It's that the bike "rides funny", especially in rough terrain. The head tube wanders a bit, the flexion of the frame "just isn't right" and there are plenty of designs that work better.

Think of the MTB's as "Novelty Frames"

wait.......so does anyone know anything about this technology that supposedly gives the bike extra power bursts or something to that effect.

Slickmobster,

Haven't heard of the bike picking up vibrations to generate speed, but the theory regarding the Slingshots is that the flex alllowed by the spring/cable setup allows riders to "pump"
the bike through corners, using the stored energy of the frame, or spring/cable, as they come out of them. Whichever MTB mag tested a slingshot not too long ago didn't find much basis for the claim.

-Moab

technically, you could create power from vibrations of the road... which would be made by going over bumps etc.. similar to watches that use kinetic energy to operate without a battery or being wound up.


however, i dont think that you could get enough energy like that to power a bike