Fairing on a Cruzbike. No, for the front; yes, for the rear. But wouldn’t you rather have an aero helmet?

From a customer:

On Thu, September 12, 2013 10:10 am, James L______ wrote:
Robert and Maria
The ADEM headrest has been wonderful.
I am riding almost 100 miles a week to and from work
I want to go the next step and get a fairing to improve efficiency.
Any recommendations

Hi James,

Your weekly mileage is fantastic!  Great job!

Fairing on a Cruzbike.

Fairing: front

I advise NOT using a front fairing on a Cruzbike.  (Front fairings work better on traditional, non-Cruzbike recumbents and trikes.)

Although I’ve read a few posts and have seen one photo on-line of people using front fairings on their Cruzbikes, I believe a front fairing is dangerous on a Cruzbike for two reasons: 1) front fairings are heavy and that weight is likely to negatively effect steering; and 2) front fairing are sail-like and they catch wind from your back, therefore wind gusts will cause the front wheel to turn in unexpected ways on a Cruzbike.

I’d also mention that, generally speaking, small front fairings — which would impact steering less — give very little aerodynamic benefit (a customer and I once did a series of tests to measure it).  The main benefit of the small front fairing is to keep your feet warm during the winter.  (And they do this well.)

Large front fairings (like the one from HP Velotechnik) — which would impact steering more — help keep you drier in the rain and warm in the winter (and for this, they are GREAT), and will give more aerodynamic benefit than a small fairing, but I haven’t measured this.  At any rate, it’s hardly worth the downside (on a Cruzbike).

So, I don’t recommend a front fairing on a Cruzbike.  However, you may be able to find posts on the Cruzbike forums of riders using a front fairing on a CB with success.  Also, while there have been rumors that John Tolhurst, the Cruzbike designer, once toyed with designs for a front fairing, it hasn’t been introduced.

Instead of using a front fairing, I suggest you experiment with a steeper recline of the seat.  This will give a significant and comparatively safe aerodynamic advantage.

Fairing: rear

A REAR fairing (a.k.a., tail box, tail sock, etc.) gives significant aerodynamic advantage without as much effect on steering.  (My customer and I measured this as well.)  TerraCycle sells a “Tail Sok” but you’re on your own in terms of figuring out how to attach it to a Quest (or any other Cruzbike).  If you figure it out, please tell me, because I like the TC Tail Sok!

An inexpensive and practical alternative to the rear fairing is an aerodynamic bag on the seat back or rack, such as those from Radical Design or Ortlieb.  This doesn’t give as much benefit as a rear fairing, but I’ve measured a benefit.

The easiest and cheapest way to improve your aerodynamics is with a time trial aerodynamic helmet which you’ve bought on sale.

In a conversation, Maria Parker recommended using more aerodynamic clothing, such as a lycra race kit (a.k.a., roadie clothing, spandex, etc.).

I believe an aerodynamic wheelset helps a lot, but these can be expensive.

On that note, another inexpensive option is to look at the tires you’re using.  Schwalbe makes excellent race tires, that are also durable, and are available in 26″ sizes.  This isn’t to improve aerodynamics but to decrease rolling resistance.

If there’s a reader out there who has had a different experience, or would like to share a solution they have tested with great success, please post a note.

All best,
Robert Matson
New York City Recumbent Supply
The Innovation Works, Inc.
copyright 2013 Robert Matson


Reader question: Ortlieb Recumbent Backpack or Radical Design Rack Bag?

Dear Robert,

I have an HP Velotechnik Speedmachine, using one Ortlieb Classic Plus.  In time it made the rack bend and it touches the rear triangle when the suspension works.  Wanted to move to a rack bag- more aero and balanced.

Read your article about the Ortlieb Recumbent Backpack, but the Radical fits me more IF its convenient to fit to the rack. So how is it compare in that area?

Thanks a lot,
Aero and Balanced

Speedmachine mit Untenlenker
HP Velotechnik Speed Machine

Dear Aero and Balanced,

Congratulations on your good taste as demonstrated by owning a Speed Machine. Before we talk about bags, I need to say that I’m surprised that the rack of your Speed Machine has become bent on one side to the point that it touches the rear swing arm when the suspension is compressed. Have you overloaded the rack? Have you been carrying cinder blocks in your saddle bags? Or sand? Is your rack broken? Is your bike broken?

The contemporary design of the Speed Machine and its rack are such that it’s hard for me to imagine how they could come into contact. Though, I suppose if you actually bent the rack, and twisted it sideways, and bottomed-out the suspension, you could make the two come into contact (while voiding your warranty).

Keep in mind that racks (and the bikes on which they are mounted) have payloads and intended usage. If you exceed that payload, or use the thing for something other than that for which it is designed, you may break or bend the thing, whether it’s a rack or bike or shock or wheel or whatever. The rear rack of the Speed Machine has a maximum payload of 55 lbs. (not kg, but lbs.). The max. payload of a Speed Machine is 286 lbs. (not kg.), including you and whatever bricks and cinder blocks you’re carrying. Bending of the rack (or whatever) shouldn’t occur as long as you don’t overload (and thereby damage) the rack (or whatever). At least, this is true for HP Velotechnik’s machines. For other manufacturers, this may not necessarily be the case.

[Later.] To satisfy my curiosity — could it be true that the HPV SpM’s rear rack can touch the swing arm? — I went over to the shop’s demo Speed Machine here, which has a rear rack that has been (properly) installed and which rack (and bike) is neither bent nor broken. I sat on the rack, all 165 lbs. (not kg.) of me in order to bottom out the shock and see if the rack can touch the frame or swing arm. It doesn’t. It doesn’t come anywhere close. Nor does it jiggle. Nor does the rack bend when I sit my ass on it. If you have a Speed Machine (or any HP Velotechnik) where the rear rack contacts the frame or swing arm, then you have a damaged machine or rack. Was your bike assembled incorrectly? Was it in an accident? Did your cousin run over it with his car and not tell you?

Rackbag Extended
Radical Design, Rackbag Extended

Ortlieb Recumbent Backpack

As for the Radical Design Rack Bag versus the Ortlieb Recumbent Backpack, they are both great, durable bags and I’ve used both for hundreds of miles. They are equally easy to mount and un-mount to the rack-top. The RD bag has a nice capacity (30 liters), is lightweight (720 grams), and is water resistant (waterproof fabric, but no waterproof zipper or seams). The Ortlieb is almost half the size (17 liters) and is comparatively heavy due to the excellent waterproofing (980 grams) — it’s so waterproof it’s nearly a dry bag — and the backpack straps are a cool thing; the Ort. also has nice pockets for organizing and a port for the hose from a water/drinking bladder. Both will give you some aerodynamic benefit. The rack on the Speed Machine is short compared to that on touring bikes like the Street Machine or Grasshopper, but my experience has been that both bags fit fine.

In summary, I’d make my decision based on capacity and whether I was riding/living in a wet climate.

All best,
Your Recumbent Bikologist.

Robert Matson
New York City Recumbent Supply
The Innovation Works, Inc.
copyright 2013 Robert Matson