Possible aero mods for conventional frame bicycle

[Ragtag]

I rode Gardner Martin's Gold-Rush bike, but with a different fairing. It consisted of a formed front fairing, and lycra sides stretched back to a pole mounted behind the rear wheel. My head stuck out a hole on top. The fairing was a very good, practical design that made an excellent aerodynamic shape. He was tight for money and I almost bought the bike (but not the record fairing) before it went to the Smithsonian. But I was tight for money then too. So I didn't. I learned some things from it though. And I shook hands with Fast Freddy Markham.

On a cool day in Watsonville, that fairing was hot as the hinges of hell. Yes, I could go faster, but it would have killed me (literally) to keep up the energy output.

A relatively light breeze exerted serious force when I turned broadside to it. That could be adapted to, but it could also be very dangerous in traffic. I've been buffeted by passing trucks on country roads and I think there is very serious danger of being blown into traffic behind a big truck speeding by. Turning broadside at an intersection into a 20 mph headwind (very common around here) I'm not sure I could control the bike. That's a BIG sail. It's like riding your bike with half of a 4x8 plywood sheet tied to your side.

A fairing on a recumbent is probably ok health-wise. But recumbents do have an anatomical problem that is the real reason why racers don't use them even if they are allowed to. Our bodies are designed to return blood from our legs with our feet below us. Sitting with your legs out front our bodies do too good a job. Makes the feet go numb. It can limit blood to muscles too, because venous blood is returned too quickly.

If you lie down prone, either on your back or your front, this problem is worse.

When riding long distances on aerobars, keep in mind that maintaining that radically arched lower back position is not normal for humans to keep for long periods. Doing it causes disc problems after many years for quite a few people. It can also be hard on the neck over time. Our bodies are mostly adapted to an upright posture.

I commuted for some years 25 miles each morning into San Francisco. I found that I ended up with a touring frame with mountain bike tires. It's more important to know you can ride through any pothole, or even ride right off the road if you have to. Drop bars are good.

I commuted in Chicago on a recumbent for a year about 10 miles each way. That worked well, but I found i was slower than I could be on a regular diamond frame bike. Again, wider tires were more practical for commuting. They have give too, which makes the ride more pleasant.

I liked the recumbent most for slide-outs on ice. When it falls, you don't fall far, which is great.

These days I don't commute by bike because it's not practical. I do pick things up at the Farmer's Market after recreational/fitness rides. I have a Klein Mantra with a rack and aerobars. I find that the nicer ride is relaxing. I don't worry about road hazards. I can do 23-24 MPH in a sprint and cruise faster than a lot of people. And I enjoy it. Takes a bit of maintenance of the air shocks, but it's worth it. I use the aerobars on long rides to give myself a different riding position, take weight off my hands. They don't mean a lot speed-wise.

If you really want speed on your commute, and the roads are good, then look for a time-trial bike. It's true that aerobars are useless in traffic. Also, understand that you have to train for using it. You use different muscles, and it takes time to strengthen them so the aerobars are meaningful. Then, expect maybe a gain of 1 mph average speed over a 20 mile ride.

[Ragtag]

Easy Racers Recumbent Bicycles | Bicycles | Easy Racers Series | C-Rush - Gardner's current.
This is probably the best recumbent made. It's light, it's fast, and the foot position is fairly far below the heart.

[veloman]

This fairing I built for my ebike has worked pretty well, though it is far from ideal.

It helps a lot to have a low seat, which is not possible on a bike which is to be pedaled when seated. I only pedal - standing - when getting up to speed or on hills.

This bike is vastly more efficient than my other standard mtb position non-faired ebikes, even though I pedal it a lot less.

[Ragtag]

Lightning F-40: World's Fastest Production Bicycle

Title - A faring for a standard upright bike.

[dmac257]

So have you decided to switch to a recumbent bike or still want to aero-mod the diamond frame?? Seems the discussion has shifted from your diamond frame to getting a BUNCH of cash and getting something else to ride. Which way are you leaning??
dmac257

[Xringer]

Originally Posted by veloman

This fairing I built for my ebike has worked pretty well, though it is far from ideal.

It helps a lot to have a low seat, which is not possible on a bike which is to be pedaled when seated. I only pedal - standing - when getting up to speed or on hills.

This bike is vastly more efficient than my other standard mtb position non-faired ebikes, even though I pedal it a lot less.

That low rear seat reminds of the seat I once had on a 50cc Moped.
My seat was a pad on the carrying rack.. I sat behind the regular seat
I once made the mistake of sitting too far back..
My CG was near the rear axial. I was going about 20-25 MPH, in a turn,
when a can rolled out from behind a parked car and I hit it with my front tire.
The front end bounced way up in the air, I slipped backwards,
the CG went way back and the bike shot out from under me..
I kept turning backwards until my legs were over my head.. Ruined my new helmet..




That bike was French made junk.. Hey! I was 17 at the time!

[Frank Lee]

I sat on the passenger rack on my Songi electric bike until i did a rack delete (about 20 lbs off!) and modded up a low banana seat. I noticed the same thing- without the crash- that sitting back there made for a frighteningly light front end. Also noticed that the pedals on the Songi weren't much more than a legal formality- as far as locomotion, pushing it was almost better than pedaling it. Another plus for the low seat- get out of the air, more comfortable, and didn't hurt pedaling anyway.

[veloman]

The front end is definitely lighter, but I've never had any issue with it. I carry my chain in the front fairing rack, and batteries in the center of the frame, so the front does have SOME weight on it. My butt is just about center over the rear axle. It's really not that low, about 30". Cruiser motorcycles and scooters have lower seats.

My setup is quite comfortable in fact. The efficiency at 30mph, combined with the upright bike handling for city traffic can't be matched. I pull about 600watts from the battery at 30mph (no pedaling of course). I've had this bike up to 54mph down a hill running 86volts and 120% speed setting in the controller. Felt perfectly safe. The bike is definitely safer than a road bicycle at any speed, (mostly because of the 2" tires and full suspension).

[Frank Lee]

Love your crutch repurposing!

[Galane]

If I were going to get another bicycle, I'd get one with a comfortable, upright riding position. Comfort has its place!

If you're subscribed to the Gizmag e-mail newsletter, they frequently have articles on bicycles. Almost every one is a hunched over, back breaking crotch pounder, often with the handlebars lower than the seat.

How about a semi-recumbent design with a seat that has a back with boattail and a fairing and windshield out front. Put the rider's center of mass a bit in front of the rear axle and the pedals forward enough so the rider can push against the seat back. Arrive at your destination without needing a couple of Ibuprofen for your back and an icepack for your...