Would you buy a sub 15lb monobladed bike?

Another thread on aerodynamic priorities set me thinking about the aerodynamics of forks.

Mike Burrows (Lotus bike etc etc) said changing forks, even aero forks, on a bike to a single (mono) bladed fork is the most important things you can do to improve the aerodynamics of a bike.

However bunnyman correctly pointed out that a monoblade set up would weigh nearly 3lb in total. Fair point, but a monoblade would offset any deficit due to weight gain due to vastly improved aerodynamics on all but the hilliest courses. After all weight is only important on an incline, but I concede we rarely race flat courses so weight is important.

I am currently designing a bike which I believe will be more aero than anything seen thus far, and it will incorporate a monoblade.

So my question is if I could produce a bike that was really aerodynamic, fully adjustable, and weighed less than 15Ib, would an exceptionally aerodynamic monoblade weighing 3lb put you off buying it? Ignore price for now!

AndyA

Probably not. too risky. 17 pounds is plenty light for me. Going to “much more aero” and 15 pounds is quite an aspiration. I wager that if it could be done safely, it already would have by Cervelo, Cannondale, Trek, QR, etc…

I only weigh about 130 lbs and I’m still a teenage boy with that whole I’m invincible mindset, so I’m sure if i were able to try it out I would.

I of course am not a good enough biker to justify the purchase of such a machine, especially with my cash inflow. Although you say ignore price for now, I gotta bring it up.

The people that could afford such a bike would be extremely cautious and skeptical of it because of its extreme lightweightness.

The people who wouldn’t be weary of it at all are a bunch of kids like me who have no where near the funding to support something like this.

I am encouraged by your comments that it is too light and would be to expensive.

There are bikes out there less than 10lb and over $20,000 that people are happy to ride.

This would be 100% safe to ride at that weight for any rider, you can be sure of that, and it would cots no more than your top of the line TREK etc fully kitted out

If it was safe, reliable, durable and affordable would you ride it then?

Why havn’t the big companies done it? I don’t know, if there is a reason after a year of research I havn’t come up with the answer.

AndyA

Anybody got any thoughts on the Monoblade?

AndyA

I’m not an engineer, but I’ve followed this stuff for a while. A monoblade sounds great in theory, but there are some real design disadvantages as I see them.

torsional stiffness, as the loads are not balanced, so the diameter / thickness of the fork needs to be increased

the axle design puts a lot of stress on one side of the axle, so the axle clamp area needs to be made larger.

The net result is a fork that is LESS aero than a conventional fork with two very thin blades. At least that is what the Lotus engineers found when they were developing a production version of the Lotus superbike as used by Boardman in the 1992 Olympics. The dual bladed fork put into production was more aero than the monoblade Boardman rode to the gold medal.

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Yogi and any other mono doubters!

Send me an E-mail as per my profile and I will send you a pic of a new monblade. Which is really sleek and aero

Cheers

AndyA

I think the black hole design will have a better chance than a mono blade fork,some people use them on recumbents to help with chain problems.Mono bladed fork would have to be stiff enough to handle the hits you have riding while maintaining steering control(strong verses light verses aero verses steering control.(Black hole was a small mono fork with a inner ring that the rim rode in with three rollers that held the rim and gave the rim rollers to ride in)
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"I could produce a bike that was really aerodynamic, fully adjustable, and weighed less than 15Ib, would an exceptionally aerodynamic monoblade weighing 3lb put you off buying it? "

For climbing the Alps yes. However, for regular riding you’d have to be convincing that you’ve solved the reliability problems associated with “stupid light” bicycles.

I know you said to ignore it, but I’d also have to worry about price.

Hi all,

For the last couple of years I’ve wondered why more individuals haven’t taken on the challenge of developing their own monoblade fork/hub combination. And so what if it weighs ~ 3 lbs. The aerodynamic benefit would “outweigh” those 3 lbs. It’s just a matter of time when they’ll get light enough.

Andy A,

It’s about time more people like you step up and take on the tough engineering challenges. All the easy sh!t has been done already! Your project seems very intereseting and would like to hear more about it. Stay with it.

Is that the same as monocoque? If not, what’s the difference?

http://webmail.netzero.net/webmail/FCFFB9BD/Aero%20Monobike.jpg?attachId=6&folder=Inbox&msgNum=83&count=32225

I just got the pictues of your bike e-mailed to me. That is a wild bike! I think the fact that there are no chainstays (or seatstays) on the non-drive side is the most unique feature. The monoblade has been done before (perhaps most notably by Graeme Obree in his hour records) but the no-chainstay thing is really different.

The aerodynamics look unbeatable, but looks and reality often differ. My primary concern with this unusual geometry would be stiffness–not just at the bottom bracket, but at the back end. It seems a powerful downstroke would tend to turn the rear wheel towards the right. Have you measured any such deflections? Obviously, if it were too wippy back there the tire would actually rub the frame before the alignment was off enough for gears to start “autoshifting.”

I would love to test ride your bike. It’s definitely very sexy. If nothing else, triathletes are usually eager to try new things.

Hi all,

For the last couple of years I’ve wondered why more individuals haven’t taken on the challenge of developing their own monoblade fork/hub combination. And so what if it weighs ~ 3 lbs. The aerodynamic benefit would “outweigh” those 3 lbs. It’s just a matter of time when they’ll get light enough.

.Let me tell you, unless you do not have a life and want to spend all of your time developing a product its hard to become a expert on something and try to bring a product to market,i offered custom stems,frames,aerobars and unless it is the latest,lightest,material with all of the catch words attached it will not sell.Done it with bikes now trying it with a photo thing i made.I made a bar setup eight years ago that looks so much like the hed you would think they copied mine,but without it being made from carbon and having a name behind it it would never sell.

I have a pic of the same bike (or perhaps an earlier version). No chance of autoshifting, as the bike is a fixed-gear track bike, hence no brake cables, levers, shift levers, cables, etc… The rear cog (if it’s the original Lotus track frame) is mounted outboard of the rear chainstay, with the wheel on the other side of the chainstay, so that’s a very short lever arm. Frame is probably based on the Giant MCR series from a couple of years ago (which Burrow, IIRC, had a hand in), and is somewhat similar to the GT SB2 from Project 96. I’m assuming the 15lbs figure is for the fixed gear version, so probably looking at least about 2lbs or so more for a fixed version for the extra drivetrain and brake pieces.

The monoblade concept is pretty cool, although I do recall that when Lotus switched to the 2 blades they were able to make them thinner, and actually tested more aero (or at least just as aero), but also lighter. I thought the Wear-n-Tear Black Hole was a pretty cool concept, and was actually rideable (I had a chance to test ride it once). Unfortunately, I think it was just too wild for most people. Wonder how many were actually produced, and where they’re sitting now?

If anybody wants a copy of the pic I’ve got, just send me an email with “Burrow” or “Monoblade” or something like that in the subject line (so you don’t get blocked), and I’ll send you the jpeg (it’s about 89kb).

Tailwinds,

Dave

How many of the great inventors/designers do you know that had a “real” life? That’s a given. Anything worth pursuing is going to take an inordinate amount of time. Training for an Ironman for example.

I agree that it’s very difficult to bring a product to market, even if you have the proper backing . Marketing is a whole different animal. Just look at Microsoft. They have never had the best product out there yet they rule the software biz.

Personaly, I think you might be ahead of your time. Your talent might never be fully appreciated until you are long gone. Good luck with your “photo thing.”

Hey, another teenage triathlete. (John C) Sometimes I feel like the only one. But, addressing the original post. I would say go with a regular fork. Do you know the mono will be as strong or as comfy? I tend to think go for the fifteen pound. Just a few thoughts from a rodent.

Thanks for all your replies

All good stuff. I will briefly respond to just a couple of points raised:

First, for anybody who has seen the pictures I have E-mailed out; that is **not **my bike, its Mike Burrows. I am designing one which has certain similarities i.e. a monoblade but I am not ready to unveil my design just yet!

Second, if anybody knows how to post the pics on this site E-mail me I will send them to you and you can do so, because I can’t work out how to do it.

Third, my design is a geared bike, with brakes, bottle cages, pedals, even a bike computer etc, etc all for under 15lb, and with a 2lb monoblade (on paper at least).

Four, handling is my major concern with the monoblade but I have some ideas to improve that to an acceptable level. The monoblades weight isn’t an issue for me, total bike weight (rotational weight etc) is. It has to be reliable and of course safe, no compromises there.

Five, mono-coque comes from the French/Latin *mon coque *shell, and *coccum *cocoon. As I understand it in the bike world it refers to single piece molded type of frame in which the outer skin carries all or a major part of the stresses. This is possible with the use of materials like carbon fiber. (it starts to get complicated from there on).The inner of the frame is often just a very lightweight honeycomb material. A mono-blade is just the particular name given to this single ‘legged’ fork, a knife if you like.

Six, I don’t need to be rich, but my marketing strategy is simple put a good athlete (I wasn’t to shabby in my time!) on a great bike and if he/she wins races the bike will sell.

Thanks for all your words of encouragement and pearls of wisdom, keep them coming

AndyA

Two weeks ago returning from a week long photo trip i stopped and talked with guy that runs a carbon fiber business,to see if my photo and a few bike projects could be made from carbon/was told sure,can do, first making stuff from aluminum is about two dollars/pound,carbon30 dollars/pound AT LEAST two to three thousond for a Very simple mold, lets say you have the mold every part 30 dollars/pound of carbon plus the labor to lay up the carbon.It all gets very expensive,very fast,with a very steep learning curve.Good Luck
.

Thanks

I know it will be expensive at first and I am thinking $50k plus but if Stealth can sell a carbon frame and fork for about $600 it must be financialy viable?

Cheers AndyA