You are here

just how fast is a P-38

I know this is a loaded question but one that is messing with my head. I have been on lightning bikes for one year now, six months on a 2012 Phantom II and six months on a 2004 P-38, both with mesh seats. Unfaired my speeds on a typical 40 mile route with 2500 feet of climbing on rolling hills that do not exceed 8% grade and typically are less than 1/2 mile in length are in the 17.2 - 17.8 range.

Recently I have started riding with some DF guys and one of them is smoking through this course, to the point that if i can keep him in sight 1/4 to 1/2 mile I'm doing good.

So the question begs, is this all I'm going to get out of the P-38? the engine is a 55 year old that is riding 125-150 miles a week and typically climbing 1500-2800 feet per ride. The P-38 is stock and running gator skin 700/28 on the rear with a schwalbe durano 20/1.1 on the front. I do pick up some speed when using the zipper full fairing but prefer not to ride with it in the Texas summer where temps are in the mid 90's before 11am when I am typically finishing my ride.

Like many others I have looked at going to a DF or the CA 2.0 or metabike but I do love my lightning bikes.

Counsel please.

Hi Joseph,

One guy that rides with your group is smoking the course on his upright bike. Perhaps he is just cranking out more power, because he is more fit than you. There is always somebody in better shape.

My experience is that an unfaired Lightning bike (with the traditional heads-up mesh seat) on the flats is similar in speed to an upright road bike with the rider in a full tuck. But the Lightning bike is comfortable for hours of riding, while most people do not like being in a full tuck for very long. Especially most middle aged riders.

On the hills things change. Lightning bikes are better climbers than other recumbent bikes of similar weight, but still are at a disadvantage in comparison with traditional upright bikes when the hills get bad. Exactly why this happens is controversial. I think that you can use muscles in your back, abdomen, and upper body better on an upright bike. With recumbents it is almost all legs and hips. Also, upright bikes let you shift position more, and this lets you give some muscles a little rest while emphasizing others. Recumbents do not let you do this to the same extent.

Should you try a high racer style bike? It depends on the how hilly the ride is. I think the Lightning will climb faster and easier than the more laid-back high racer bike, but the high racer will be faster on the flats and downhills. The laid-back seat of the high racer will give it an aero advantage over the more heads-up Lightning. Though the smaller Zzipper fairing that mounts on the Lightning handlebar should pretty much make up for the more upright seat angle.

Lighting sells a more laid-back carbon fiber seat that can be retrofitted to your bike. This is one option to consider, along with trying a high racer type bike. Will either of these changes improve your speed on your course, and give you a better shot at keeping up with the "smoker"? I don't know. Only your own personal experimentation can determine this. Not a very helpful answer, but that is the best I can do.

If you really want to smoke the smoker, consider a full F40 fairing for your bike. If you keep your head and neck exposed to the wind, you will not cook, even when riding in Texas. On climbs you can unzip the Spandex partially to let more air flow over you too.

There is a rider in Texas named Carl Murdock who has been riding a Lightning F40 for many years, and he manages to deal with the heat issue. He sometimes posts notes on the Bentrider Online forum, and you could probably get in touch with him in order to correspond. He uses the name "crmurd" on the BROL site.

From your description of your riding, it sounds to me like you are doing great for a guy in his middle fifties. Don't feel bad because somebody else is doing even better.

Safe riding,

Today I discovered the "smoker" is 5-10 years my junior which makes me feel somewhat better. my flatland speeds are typically in the 20-24 range with moderate effort and downhill, well lets just say the P-38 loves to roll at mid 30's coasting and 40 is nothing with some effort.

You make very good points(as usual) regarding the aerodynamics of the bicycle. I also have a 2012 Phantom that I may consider trying the midracer seat on, I really don't want to cut the P-38 stays without knowing the results of the change. The F40 would be very cool but at a significant price tag.

do you or any other member have experience with the midracer mod?

Today out of sheer boredom and surfing the net I learned of the Terracycle Tailsok. Curious if there is any knowledge and experience here with this product. Off the cuff it appears to be a relatively inexpensive way to come close to the F40 by using my full size Zzipper fairing with it.


If you get the Terracycle Tail sock in a screaming yellow or blaze orange color, it will help enhance your conspicuity to the rear and to the sides. This is a good safety benefit.

But I do not think it will be of any significant help speed-wise. Maybe if you are descending a long steep hill at very high speed it could help a little bit. But not at normal speeds.

If you have a larger front-mounted Zzipper or Windwrap fairing, I would experiment with stretching Lycra Spandex cloth from the front fairing to the rear of the bike. You could easily make a tail framework out of fiberglass tent poles, old fiberglass fishing rods, or the like. Or you could use Coroplast sheets. Even if you had no tail framework at all, and merely stretched the fabric around the back of the Lightning seat, it would still help. I would do a tail framework or simple Coroplast tail fairing though.

This would not give you the same speed as an F40 fairing, but it should definitely make an obvious improvement. And it would be very cheap to do, since you already have the front fairing.

There is a photo in the gallery area of a bike like this: Zzipper or Windwrap in front, and golden yellow Lycra stretching backwards.

Safe riding,

Thanks Joel, after posting this I did go through the gallery and saw a few things that look tempting. As always, appreciate the insight.

I do not have any experience with the Lightning carbon fiber seat. However, a) reliable sources tell me the seat makes it easier for height-challenged riders to get their feet firmly planted on the ground at stops, and b) I do have experience with a different hardshell seat mounted on a P-38 bike.

My hardshell-equipped P-38 has an old Turner fiberglass seat with the seat bottom corners cut away. It is more reclined than the Lightning full mesh seat, but may be more upright than the new Lightning carbon fiber seat. I am not sure of the exact angle. Their is a fuzzy picture of the bike in the gallery area of this site, about half way down. I mounted this seat in order to use the bike with a front fairing built by Rick Wianecki many years ago.

The hardshell seat is not as comfy as the original mesh seat, but gives me an aerodynamic advantage when used with the Wianecki front fairing. Someday I will have to take some pictures of the bike with the fairing and post them in the gallery area. This bike is kludged together with an Answer Proforx shock absorbing front fork, a Shockster rear suspension, cut down Vision handlebars, and other bizarre modifications too numerous to mention.

It is my Frankenstein Lightning bike.

Safe riding,


User login

Powered by Drupal