Tuesday, July 23, 2013

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

Thursday, July 18, 2013

Cruzbike Quest seat fitting

A customer wrote me the other day with a fitting issue regarding his Cruzbike Quest.  While he pedaled, he had contact between the backs of his thighs and the front edge of the seat pan.  Over time this can be uncomfortable.  I've encountered the same issue, both with customers, when fitting them for test rides, as well as for myself.  For me, it seems to only happen on the Quest 20.  For this rider it was occurring on his Quest 26.

The source of the problem is that when the front boom of the Quest is extended -- to fit long-legged riders -- the pedal axle moves lower in comparison to the seat pan.  If the front of the seat pan is raised, for example when it is set as far forward as possible, this, combined with the low pedal axle position, may result in contact between the rider's thigh and the front of the seat pan on the downward pedal stroke.

The solution involves making minute adjustments in several places with the aim of raising the feet in comparison to the front of the seat.  Keep in mind that the more you are able to shorten the boom on a Cruzbike, the higher will be the foot position.

Try these changes. I suggest beginning by making small adjustments in each area.

1. Move the seat pan backwards.  There are a series of bolt holes in the bottom of the seat which allow the rider to adjust the seat fore and aft.  Due to the curves of the seat and frame, when you move the seat to the front, the front of the seat pan becomes higher; move the seat towards the rear of the bike and the front of the seat pan becomes lower.  After you've done this, you'll also be able to shorten the boom, which will raise the pedal axle in comparison to the front of the seat.

2. Set the seat back at a lower angle of recline.  This will also enable you to shorten the boom (which will raise the pedals).  You don't need to recline the seat very much.

3. Check the location of your feet on the pedals. If you're wearing cleats, try moving the cleats down -- towards your instep -- by a few millimeters. This will raise your feet.

4. Make a simple shim out of a thin piece of plastic like from a yogurt container. Use this to increase the thickness of the rear-most rubber pad under the seat.

If you (reader) have any additional suggestions, please send them in!

Have fun and stay healthy,
Robert Matson
New York City Recumbent Supply
The Innovation Works, Inc.
copyright 2013 Robert Matson