From: etxorst@eos.ericsson.se (Torsten Lif)
Newsgroups: rec.bicycles.misc
Subject: Re: Recumbents
Date: 27 Jan 93 08:58:21 GMT
Reply-To: etxorst@eos.ericsson.se
Organization: Ericsson Telecom AB

In article 18709@hpcvusn.cv.hp.com, harry@cv.hp.com (Harry Phinney) writes:
>What I intended to communicate was that I am unsure of the relative
>safety of the various types of bikes.  I perceive advantages and
>disadvantages for each, and am unsure what the overall safety record
>will be for each type.  While I will agree that the recumbent rider's CG
>is lower than that of an upright rider, the short wheelbase recumbents I
>have ridden have placed enough of the rider's mass in front of the front
>wheel that they have been prone to planting the cranks into the
>pavement.  This has in fact limited the braking ability of these bikes
>to the point where I am quite certain an upright could out brake these
>particular SWB recumbents.  A long wheelbase recumbent should have
>better braking capabilities than an upright, but will suffer in terms of
>maneuverability when compared to either an upright or a SWB recumbent.

Everything is relative. On a long-wheelbase recumbent, you can brake
either wheel so hard that it locks up. You still don't want to do this
with the front wheel since even when it doesn't cause you to do a
faceplant (like it would on an upright or an SWB), a skidding front
wheel will keel you over sideways very fast. But yes, you can brake
VERY hard on an LWB bent and I've gone down steep slopes with my locked
rear wheel digging a rut in the gravel. Even on a mountain bike, you'd
have had problems negotiating some of them (the trick is, apparently,
to sit on the rear rack - if you don't have one you're SOL).

As for maneuverability, an LWB 'bent can't turn as sharp as a shorter
bike can do AT LOW SPEEDS. The emphasis is important. At speeds above
10 km/h (6 mph) this becomes a non-issue since you no longer need the
greater wheel deflections. At speed, most recumbents have much greater
ground clearance than any uprights and thus can corner sharper (lean
steeper) while still pedalling. A 'bent with under-seat steering can
corner until the handlebars touch ground. Since this is way beyond 45
degrees lean, the limit is in reality tire traction, just like with
over-seat steering.

Yes, zig-zagging between parked cars on an LWB is a pain and sometimes
when pushing the bike I need to lift the front to swing it round. These
are minor inconveniencies.

>Both forms of recumbent place the rider's head lower than an upright,
>which should mean less risk of serious head injury in equivalent falls,
>but also means poorer vision in traffic.  How do these differences
>balance out?  I don't know, and neither do you.

The poorer vision is a myth. Yes, you sit with your head a foot or so
lower than on an upright, but you sit with your back and neck straight
and can look around in traffic all the time without straining to lift
your head. You're still higher than most car drivers. The only "vision"
aspect where uprights have an advantage over 'bents is rearwards and
that is easily solved with a helmet mirror.

As for crashing, I had quite a confrontation with a curb last year. I
tried a silly stunt and ended up going too fast (peak reading [AVO-50]
said 61 km/h) to negotiate a sharp S-turn. I dented both wheels and
dislocated the CURBSTONE! What happened to me? I landed on my butt in
the plantation, scooped up a rear pocket of plant soil and a minor
bruise. Now, I'm the first to admit that one sample makes no
statistics, but If I'd had a similar crash on an upright I would at
least have scooped up that plant soil with my mouth instead of with my
hip pocket.  :-$ (<- Smiley with expensive dental work)

A friend with a shorter 'bent had the misfortune of seeing his (very
small) front wheel disappear down a hole in the street. He ended up
running away from the bike. I really DO like under-seat steering
arrangements...

>: Experimental evidence seems winning and if 'bents lose when riders are
>: equally matched then the issue seems clear.  My disagreement here lies
>: with the quality of the experiment.
>
>I agree that there has in general been too little open competition to
>conclusively prove the performance differences.

Well, Richard and I are going to perform a little experiment to broaden
the database. We're entering this year's "Vaetternrundan" - Sweden's
largest cycling event. We'll see how our 'bents stand up to the
challenge of a double century (300 km). Reports will be forthcoming -
at least if we make it... :-}

>Harry Phinney   harry@hp-pcd.cv.hp.com

---
 Torsten Lif                          |   Upright bicycles are
 Ericsson Telecom AB, EO/ETX/TX/AD    |   a pain in the ass!
 S-126 25  STOCKHOLM, SWEDEN          |   
 Tel: +46 8 719 4881                  |   Be comfortable - ride a recumbent.
Newsgroups: rec.bicycles.misc