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I saw a 1977 Masa Slingshot leaflet on ebay (source), copied below.

It has a lot of differences from a modern tadpole, in particular what looks like a "spoiler" on the front.

Is this similar to a spoiler on a sports car that is intended to provide more downforce to the wheels at high speed? Would that be effective / beneficial on a trike? I have read that this design was intended for oval track racing, so I assume the riders would get up to a good speed, so maybe that makes sense. I also read that with its long wheelbase a lot more weight went onto the rear wheel than on today's trikes, which also support the idea. And the brake seems to be on the rear wheel as well which seems consistent with that impression of weight distribution.

On the other hand, is this device just intended for something else? It actually isn't very wide or large in comparison to the frame, you'd think for relatively low-speed spoiler more surface area would have helped and looks like it should have fit. Would extra downforce even be needed? Plus, a larger "spoiler" might have acted somewhat like a fairing to reduce drag. (Is that actually all it really is, just an early or inexpensive / lightweight fairing design?)

Looking around I can find other images of these Masa trikes but very few which have that attachment. The few examples I did find lacked any explanation, though a forum post did use the same term "spoiler". No examples of modern racing recumbents or trikes that I could find had anything like this.

enter image description here

StayOnTarget
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    I also doubt this smaller spoiler would create any appreciable amount of downforce. Maybe it’s supposed to improve aerodynamics? But it looks too low and wide for that. Maybe it’s intended as luggage rack? Also seems unlikely. – Michael Feb 05 '21 at 08:30
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    Are " oval track racing" courses banked on the turns like a velodrome? If so, the bike is essentially going "straight-ahead" on the turns so downforce would be unnecessary and simply add drag. I'm stunned that an advert from the late `70s shows a helmet and claims a disc brake. Nice find. – Criggie Feb 05 '21 at 08:33
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    It looks like a perfectly designed ramp to shot every flying small rock, debris or other things flying around, directly into the smiling face of the pedaling earthling.

    Nonetheless, it looks good to place some advertising.

     – EarlGrey Feb 05 '21 at 09:23
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    It could be some kind of bumper to protect the steering link too. – ojs Feb 05 '21 at 10:03
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    A sharp edge to slice the ankles of unsuspecting pedestrians. – Carel Feb 05 '21 at 11:04
  • It appears to be a cowcatcher, allowing the rider to plow through a herd of cows without even slowing down. – Kyralessa Feb 05 '21 at 12:14
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    It's a snow plow, obviously! – Daniel R Hicks Feb 05 '21 at 13:57
  • I doubt very much that without the spoiler, this trike's aerodynamics would create any lift, and even if it does, I am certain that it would be almost impossible to get it up to a speed where lift would be a problem. – Adam Rice Feb 05 '21 at 15:35

4 Answers4

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According to this post from an owner the wing is for looks:

Earlier models came with an aluminum ‘wing” over the front axle, probably more for looks than anything, and a bullet-shaped, sports car-styled rear mirror on the left side.

According to the post the trike was made specifically for on track racing against like trikes.

MASA was a Japanese company, but targeted the US with this form of racing. In 1975 they finally brought a few of these over here and did some exhibition races between their own staff. It never really caught on, but they still imported about 1500 of these into the US over a three year period.

and later

Since these trikes were focused on track racing only against like trikes, the lack of braking and their size was not a problem. Their wide, long front end was thought to be better protection for the rider.

David D
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    The owner does say "probably" which suggests that in his experience it wasn't effective. But that doesn't really go to what the maker's intent for it was. Interesting that post also notes it was relatively heavy, which also discounts the idea that a functional spoiler would be needed. – StayOnTarget Feb 05 '21 at 16:28
  • To put the makers claims in context, they also claim its "almost like piloting a grand prix racing car". – mattnz Feb 05 '21 at 19:49
  • @StayOnTarget: Why would a spoiler be unnecessary on a heavy vehicle? Without a spoiler (or other aerodynamic device) velocity in a turn is entirely independent of vehicle weight. – Michael Feb 06 '21 at 15:23
  • @Michael I was thinking that lighter vehicles benefitted from the spoiled helping to push them downwards to grip the road/track surface better. I'm not sure I got your point about velocity and weight though. – StayOnTarget Feb 07 '21 at 12:23
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    @StayOnTarget: Why do you think that a spoiler would be unnecessary on a heavy vehicle? Some people are under the misconception that lighter vehicles have an easier (or some also think harder) time going around turns. In reality (discounting aerodynamic effects) it doesn’t matter. It’s friction vs. centrifugal force which both have a linear relationship with mass. Of course if we consider aerodynamic forces, for a heavier vehicle the spoiler would have to be larger to have the same effect. – Michael Feb 07 '21 at 14:31
  • @Michael did I say that somewhere? – StayOnTarget Feb 07 '21 at 14:34
  • @StayOnTarget: “Interesting that post also notes it was relatively heavy, which also discounts the idea that a functional spoiler would be needed.” sounded like you thought a heavy vehicles doesn’t benefit from a spoiler. – Michael Feb 07 '21 at 14:40
  • @Michael thanks. What I meant is that all else being equal more weight should reduce the need for downforce from a spoiler, assuming you need a certain amount of downward force from the tires on the road. – StayOnTarget Feb 07 '21 at 14:41
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    But vehicle weight (or more precisely mass) has nothing to do with grip or speed or braking distance. There is no scenario where a light vehicle would need a spoiler but a similar but heavier vehicle wouldn’t. – Michael Feb 07 '21 at 15:36
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I found another source of images of a similar brochure with more detail.

It states that the trike has an:

"aerodynamically-designed polished chrome steel front spoiler"

So it was clearly intended for aerodynamics, although not specifically to increase downforce.

Actually this text seems to be very carefully (weaselly) worded - it says "aerodynamically designed" rather than "aerodynamic". It seems to me they are not claiming it actually had any real benefit.

Original text:

enter image description here

Cut from the bottom left of this page:

enter image description here

Brochure cover image:

enter image description here

StayOnTarget
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It may be worth quickly reviewing some background on what spoilers are. In Formula 1 automotive racing, cars go fast enough and they are shaped such that the car body can generate aerodynamic lift. Needless to say, this would lift the wheels off the ground, and thus some of the engine power goes to waste as it just spins the wheels freely. Spoilers are devices that affect the airflow around the car to reduce lift, either by disrupting the airflow in general or by redirecting it to create a downward force. Aircraft also deploy spoilers when they want to reduce lift, e.g. during landing, deploying spoilers will reduce lift and will place the full weight of the aircraft on the wheels such that the brakes are more effective. This ~12 min video by Mentour Pilot (a commercial pilot whose YouTube channel targets aviation enthusiasts) discusses that use case in some detail if interested.

I'm not an engineer. Nevertheless, I'm pretty confident that human powered bicycles can't get fast enough to generate enough lift where they'd need downward force to counter it. Also, I doubt that a recumbent is the correct shape to generate sufficient lift. For example, Formula 1 cars appear to have smooth undercarriages, and that bicycle definitely doesn't. Therefore, I doubt that bicycles in general need any assistance in generating downward force to keep their wheels planted.

Spoilers on cars more generally affect the airflow around the car's body, often to reduce aerodynamic drag, but sometimes just for decoration. However, if that plate does anything aerodynamically, I think it might be better characterized as a fairing. In aircraft, Wikipedia's definition is

... a structure whose primary function is to produce a smooth outline and reduce drag.

Backing up a bit, round tubes have poor drag coefficients, as discussed in this answer. In road racing bicycles, the frame tubes and sometimes handlebars are shaped to reduce their drag coefficients, and to a lesser designers try to reduce the total surface area exposed (hiding shift and brake cables/hoses, dropping seatstays).

That aluminum fairing on the front of this recumbent is changing the shape of a section of round tubing to something with (we hope) a more favorable drag coefficient. However, I'm not sure what the drag coefficient of the resulting shape is, because it's not a teardrop or anything approaching that. Also, the plate is possibly adding some exposed frontal area, and if so, the reduction in drag must offset that added area. Nevertheless, if there's any aerodynamic benefit to that plate, it's probably via that mechanism - changing the shape of a round tube to something more favorable.

Weiwen Ng
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    It is possible to produce enough lift to get off the ground with human power, but it requires some serious engineering: https://en.wikipedia.org/wiki/History_of_human-powered_aircraft – ojs Sep 20 '21 at 19:33
  • @ojs good point, it’s the interaction of the input power with the shape of the vehicle. Unless proven otherwise, I’m going to state instead that a recumbent shouldn’t be able to generate enough lift under human power. Again, I’m open to being proven wrong, but it would have to be a recumbent with a fairing, and probably a very light body. – Weiwen Ng Sep 20 '21 at 20:01
  • "Nevertheless, I'm pretty confident that human powered bicycles can't get fast enough to generate lift." This is sentence is strange if not outright incorrect. Lift is always generated. Perhaps not enough lift to fly? The lift force of such a sloped plate can be computed quite reliably by simple formulas. – Vladimir F Героям слава Sep 21 '21 at 13:55
  • @VladimirF good point, clarified sentence. I meant more like insufficient lift to raise the wheels off the ground to a meaningful degree. – Weiwen Ng Sep 21 '21 at 14:00
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I have six of them.. What would you like to know?

Edit: I have been informed that my answer is not an answer. Well, it was a question so...

The common principles of aerodynamics would suggest that the front spoiler does create downforce as it creates drag. The real question should be,, does it provide any benefit? The short answer would be no. I do not know of anyone that has done any actual testing on these (including the original Honda engineers that designed it) but I would presume the spoiler is just for looks. It is not of a sufficient size nor shape to direct any air over the rider's feet, legs or body. I own six of these trikes and have ridden many miles with the wing and without. I have observed no noticeable difference. I have had one without the spoiler up to 32 mph. I have not attempted to reach that velocity on one with the spoiler because it is on the original tires and I have not transported it to location that would lend itself to such a test.

Hopefully that answer will satisfy the uppity-ups. As the creator of the original MASA Slingshot & R&R TryCycle Registry I believe I can answer most questions related to these trikes.

Charles Eberhardt
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