Trike stability

CoyoteBoy said:

I was perusing the designs of recumbent trikes for commuting (just out
of curiosity really, wondering if they could be a) as fast

With a suitable fairing, considerably faster than even a road bike.
See, for example, http://velomobiel.nl/

Quoted message said:

b) safer (due to being wider and taken as a "car"😉

Not one I've seen any figures for. You won't be decking it on ice or
diesel patches, at least.

c) better for an hours pedalling.

Being in a nice comfy chair, optionally inside a weather protecting
shell? FSVO "better", certainly.

Quoted message said:

But also, to me the two-up-front design would be better at cornering

Generally, but don't write off deltas. The Hase Kettwiesel, for
example, puts the rider far back over the axle so you'd have to work
pretty hard to turn one over. They're used by various Mad folk for all
terrain triking. See http://www.hasebikes.com/ens/media/index.php and
the Kett Action and Operation Kett videos.

Quoted message said:

but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)? Are they
significantly heavier?

This isn't really a feature peculiar to tadpole trikes. Most recumbent
bikes, and delta trikes too, have similarly long chains. My
Streetmachine runs about 2.4 standard SRAM chains so I'm carrying 2.4
times the weight of chain. There must be /some/ loss in efficiency, I
guess, but chains are remarkably efficient and 2.4 times roughly bugger
all still isn't a very big number. In short, I don't really notice I've
got a big chain.
You can get FWD models with shorter chains, but they have their own
problems, generally boiling down to steering the driven wheel while
keeping the cranks in the same line as the rider's legs.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Thanks for the input - nice to speak to someone with experience...

Quoted message said:

With a suitable fairing, considerably faster than even a road bike.
See, for example,http://velomobiel.nl/

Good good!

Quoted message said:

Generally, but don't write off deltas. The Hase Kettwiesel, for
example, puts the rider far back over the axle so you'd have to work
pretty hard to turn one over. They're used by various Mad folk for all
terrain triking. Seehttp://www.hasebikes.com/ens/media/index.phpand
the Kett Action and Operation Kett videos.

The only problem I have with deltas is the fact that with the front
turning (most designs I've seen) you have zero weight over the front
wheel - my car-based perspective makes me assume it wont grip too
well. I know when I unweight my front when MTBing I wash out easily.
Of course the chain would have to be long on both types, thats my
stupid brain 😄 Nice to know its not overly noticable though.
I had considered a low bi-recumbent instead of tri, but im not sure
how bad the problem of lights is. If its low enough you could put a
hand down but then if its that low you're going to be rather hard to
spot on some of the 60mph dual carriageways I ride on!

CoyoteBoy said:

I was perusing the designs of recumbent trikes for commuting (just out
of curiosity really, wondering if they could be

Quoted message said:

a) as fast

My sportyish recumbent trike is almost the same speed as my medium
tourer at commuting, provided there are no traffic queues. Lots of
long queues favour the bike, which filters past more easily.

Quoted message said:

b) safer (due to being wider and taken as a "car"😉

Orders-of-magnitude fewer incidents with idiot motorist near-misses on
the trike than on a bike. I think it's because you're unexpected, so
motorists actually look - when their eyes see a bike, their brain just
filters it out.

Quoted message said:

c) better for an hours pedalling.

More comfortable. Whether that's relevant for only an hour is
debatable.

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Not much - chain length doesn't have much impact on efficiency.

Two-up-front is called 'tadpole'. One at the front is called 'delta'.
Tadpoles corner much better than deltas. Consequently, trikes with
speed and handling as significant design goals tend to be tadpoles,
and it's hard to find a performance-oriented delta. Deltas on average
are higher than tadpoles, and on average possibly heavier and so on.

Quoted message said:

Are they significantly heavier?

Yes. But I don't carry it much, and wind resistance gains help to
offset weight penalties. As noted above, I find journey times to be
similar.

Quoted message said:

Any thoughts?

Whatever you do, don't try one out, because then you'll have to have
one.

regards, Ian SMith
--
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CoyoteBoy said:

Thanks for the input - nice to speak to someone with experience...

Quoted message said:

With a suitable fairing, considerably faster than even a road bike.
See, for example,http://velomobiel.nl/

Good good!

There's an article by an owner in Wales in the last but one VeloVision.
He reckons it gives him approx 10 mph boost compared to his "normal" bike.

Quoted message said:

The only problem I have with deltas is the fact that with the front
turning (most designs I've seen) you have zero weight over the front
wheel - my car-based perspective makes me assume it wont grip too
well.

In theory I'd agree, but in practice the silly buggers playing on them
in Hase's videos don't seem to have heard about the theory and
accordingly aren't letting it cramp their style!

Quoted message said:

I had considered a low bi-recumbent instead of tri, but im not sure
how bad the problem of lights is. If its low enough you could put a
hand down but then if its that low you're going to be rather hard to
spot on some of the 60mph dual carriageways I ride on!

I don't think so, on open road like dualies usually are. Can you see a
large pothole in a road in your car? That's a lot lower than a
lowracer! In practice, mount any lights above the back wheel and it'll
be in about the same place as most other bikes. Similarly, a lamp from
boom or overseat steer handlebars will be higher than a standard
Brompton headlamp, and I've never found that's a problem.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

There's an article by an owner in Wales in the last but one VeloVision.
He reckons it gives him approx 10 mph boost compared to his "normal" bike.

Wow, that would be nice, I average 18 to work so 28 would be pleasant
lol! I can get 30 when drafting a wagon (with his permission) but not
without!

Quoted message said:

In theory I'd agree, but in practice the silly buggers playing on them
in Hase's videos don't seem to have heard about the theory and
accordingly aren't letting it cramp their style!

🙂 I like that sort of person!

Quoted message said:

I don't think so, on open road like dualies usually are. Can you see a
large pothole in a road in your car? That's a lot lower than a
lowracer!

Good point (said James, who happens to be wondering where to get his
bent alloy fixed as we speak!). With a few bright LED lights
strategically placed I suppose its as visible as most things.

I might go and test a few!

Ian Smith said:

My sportyish recumbent trike is almost the same speed as my medium
tourer at commuting, provided there are no traffic queues. Lots of
long queues favour the bike, which filters past more easily.

I dont tend to scoot through traffic queues - it really riles the
drivers, if I could hold a higher average it wouldnt make much
difference as most of my journey is a long seperate cycle path.

Quoted message said:

Orders-of-magnitude fewer incidents with idiot motorist near-misses on
the trike than on a bike. I think it's because you're unexpected, so
motorists actually look - when their eyes see a bike, their brain just
filters it out.

Most of my near misses on a bike are from people either a) sweeping
too close when passing or b) people pulling out. I reckon a trike
could stop better and, being wider, would force people to overtake
properly. I might get more road rage incidents though!

Quoted message said:

Quoted message said:

c) better for an hours pedalling.

More comfortable. Whether that's relevant for only an hour is
debatable.

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Not much - chain length doesn't have much impact on efficiency.

Two-up-front is called 'tadpole'. One at the front is called 'delta'.
Tadpoles corner much better than deltas. Consequently, trikes with
speed and handling as significant design goals tend to be tadpoles,
and it's hard to find a performance-oriented delta. Deltas on average
are higher than tadpoles, and on average possibly heavier and so on.

Quoted message said:

Are they significantly heavier?

Yes. But I don't carry it much, and wind resistance gains help to
offset weight penalties. As noted above, I find journey times to be
similar.

Quoted message said:

Any thoughts?

Whatever you do, don't try one out, because then you'll have to have
one.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

CoyoteBoy said:

Ian Smith said:

My sportyish recumbent trike is almost the same speed as my medium
tourer at commuting, provided there are no traffic queues. Lots of
long queues favour the bike, which filters past more easily.

I dont tend to scoot through traffic queues - it really riles the
drivers, if I could hold a higher average it wouldnt make much
difference as most of my journey is a long seperate cycle path.

Some days 5 of the 6 miles of my current commute is past
near-stationary traffic. Most days about 2.5 of the 6. I don't use
the trike for this route.

Quoted message said:

Quoted message said:

Orders-of-magnitude fewer incidents with idiot motorist near-misses on
the trike than on a bike. I think it's because you're unexpected, so
motorists actually look - when their eyes see a bike, their brain just
filters it out.

Most of my near misses on a bike are from people either a) sweeping
too close when passing or b) people pulling out. I reckon a trike
could stop better and, being wider, would force people to overtake
properly. I might get more road rage incidents though!

Exactly, and in a trike

1: they pass wider

2: they don't pull out in front of you

On the very rare occasion that they do hit you, you're better in a low
trike - I've been side-swiped hard by cars once on the trike (it bent
the mudguard fixing, I had to stop and bend it back) and one on a bike
(I went in an ambulance to hospital). I've never been left-hooked on
teh trike. I've never had a car pull out in front of me necessitating
emergency stop when I'm on the trike, I have had on teh bike (and I've
been over a bonnet once).

When on the trike, I don't get noticeably more road-rage reactions,
and I do get many more positive reactions.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

In article <[email hidden]>,
CoyoteBoy
[email hidden] says...

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Power loss in a chain really only occurs where it touches anything, and
particularly where it wraps around anything. The only additional chain
drag on a recumbent is where it passes over an idler wheel or through a
tubular guide (and this is usually on the slack side of the chain) so
it's not going to have much effect, certainly less loss than in a tandem
transmission.

Rob Morley said:

In article <[email hidden]>,
CoyoteBoy
[email hidden] says...

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Power loss in a chain really only occurs where it touches anything, and
particularly where it wraps around anything. The only additional chain
drag on a recumbent is where it passes over an idler wheel or through a
tubular guide (and this is usually on the slack side of the chain) so
it's not going to have much effect, certainly less loss than in a tandem
transmission.

Fair points.

I might have to get trying one 🙂

CoyoteBoy said:

I might have to get trying one 🙂

Usual Suspects are:
London Recumbents, http://www.londonrecumbents.co.uk/, London
Bikefix, http://www.bikefix.co.uk/, London
Futurecycles, http://www.futurecycles.org/, E. Sussex
Norman Fay, http://www.normanfaycycles.co.uk/, S Shields
Kinetics, http://www.kinetics.org.uk/, Glasgow
Westcountry Recumbents, http://www.wrhpv.com/, Derbyshire
Rainbow Recumbents, http://www.rainbow-recumbents.co.uk, Wirral
D-Tek, no website, Google for contacts, Ely

D-Tek probably has the biggest range to play with, a lot of it second
hand so possibly more acceptable pricing too (Quite a few pristine
'bents seem to be sold on, I suspect people buy something according to
preconceptions and buzz that turns out to be completely unsuitable in
the flesh, which in turn is I suspect due to people thinking "recumbent"
is a fairly limited functional class like "road racing bike"... if
someone asked "what is the best upright bike you can buy?", and were
told "A Trek Madone" and they bought one though their real ideal machine
was a Brompton, you can see the problem!)
Since this started on trikes, note that Westcountry (starring u.r.c.'s
very own Carol Hague) only do trikes, the others typically stock a mix.

They all seem quite keen on folk having a go, which is good 'cause
'bents are very different between makes and models and trying is
definitely the best way to get what you want.

Alternatively you might try over the other side of the channel. As one
might expect, you'll get a good choice in NL.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch twisted the electrons to say:

Quoted message said:

I don't think so, on open road like dualies usually are. Can you see a
large pothole in a road in your car? That's a lot lower than a
lowracer! In practice, mount any lights above the back wheel and it'll
be in about the same place as most other bikes. Similarly, a lamp from
boom or overseat steer handlebars will be higher than a standard
Brompton headlamp, and I've never found that's a problem.

The only problems relating to the 'not being seen' idea I've had on my
trike have been people saying that I wouldn't be seen - they don't seem
to conprehend that obviously they saw me just fine?

The worst example of this being my manager at work who reported that some
of the disribution drivers had reported not being able to see me (I
wonder if they often report not being able to see things and, if so, how
do they know?). The result of this is that I've been told not to ride
the QNT in the yard - I'm waiting for the complaint about me blocking the
entrance/exit for the yard as I stop, rotate the trike by 180 degrees,
remove the pannier and put it on the seat before walking the trike across
the yard ...
--
These opinions might not even be mine ...
Let alone connected with my employer ...

Alistair Gunn said:

The only problems relating to the 'not being seen' idea I've had on my
trike have been people saying that I wouldn't be seen - they don't seem
to conprehend that obviously they saw me just fine?

"You're so low, nobody will see you!"
"Well, sat here, I'm at the same height as you in your car"
"Oh yes. But it's *so* low. Nobody will see you".

/Or/

"That can't be comfortable!"
"Why not, I'm in a big padded, suspended chair. A bit like the one in
your car"
"But it just isn't natural!"

and so on...

Basically translating as "I can't handle 'different', my mind is
exploding!" Related, picking up a fridge from Comet on the freight
bike: "That looks very dodgy. We can't be responsible for your safety
if you take it away on that"; "So you feel you would be responsible for
my safety if I drove it away in my car?"; "Errrrrrr"...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Alistair Gunn wrote:

<snipped lots of funny thoughts>

I think the general thought is that they may not see you //until its
too late//. I would worry that if I were keeping up with a car in a
traffic queue, but in its blind spot or to one side, they might not
see me before pulling left into my lane. Christ they dont even see me
when I'm on the normal bike and I'm sat upright on a shiny silver
frame with a bright orange reflective 80 litre rucksack lol. Also if
you're lower than a car (which the faster trikes seem to be from the
pictures) they might say... overtake a car that is overtaking you ( i
ride some 3 lane sections) and whip right in in front of you - but
then again I've had this on my normal bike too so I suppose its
probably down to lower seeming somehow more vulnerable.

CoyoteBoy said:

I think the general thought is that they may not see you //until its
too late//. I would worry that if I were keeping up with a car in a
traffic queue, but in its blind spot or to one side, they might not
see me before pulling left into my lane. Christ they dont even see me
when I'm on the normal bike and I'm sat upright on a shiny silver
frame with a bright orange reflective 80 litre rucksack lol.

The basic problem there is if you don't look, it doesn't matter /what/
is there, you won't see it.

I once encountered a friend of mine on a roundabout. He didn't see me,
as he didn't look. I know he didn't look, I watched him not looking...
A sharp "OI!" sorted that, and he pulled over shortly afterwards to
get out of his car and apologise profusely. But I think he still came
away from the incident thinking the problem was I was "so low" (my 'bent
bike has the seat at car-seat height).

Usual case is be aware of the limitations of others in seeing you. Some
trucks have stickers on the back, "If you can't see my mirrors, I can't
see you", and it's a point well taken.

Quoted message said:

you're lower than a car (which the faster trikes seem to be from the
pictures) they might say... overtake a car that is overtaking you ( i
ride some 3 lane sections) and whip right in in front of you - but
then again I've had this on my normal bike too so I suppose its
probably down to lower seeming somehow more vulnerable.

Seems rather than is. If you have to ram on your hydraulic disc brakes
on a low slung trike you're a lot less likely to take a flyer than on a
conventional bike.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

CoyoteBoy said:

I was perusing the designs of recumbent trikes for commuting (just out
of curiosity really, wondering if they could be a) as fast

Bit quicker, but nothing to write home about.

b) safer (due to being wider and taken as a "car"😉

Seems to wake up the drivers a bit. Dogs really go for mine though.

Quoted message said:

and c) better for an hours pedalling.

Not tried.

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Hmmm...I'm of the opinion the tadpole is far less stable that a frog
because your weight is back over the rear wheel, not between two of them.

Quoted message said:

Are they significantly heavier?

I've got an Anthrotech, is is very heavy. Going up hills is *not* fun.
Going down hills *is* fun!

Quoted message said:

I was considering welding one up myself as I have a few bits like
carbon fibre swingarms lying around that could give me a semi-
suspended and light rear end.

Any thoughts?

From my limited experience with the Anthrotech, in terms of weight,
design etc, you'd be hard pushed to make a pigs ear of it.

CoyoteBoy said:

Peter Clinch said:

Alistair Gunn wrote:

<snipped lots of funny thoughts>

I think the general thought is that they may not see you //until its
too late//. I would worry that if I were keeping up with a car in a
traffic queue, but in its blind spot or to one side, they might not
see me before pulling left into my lane.

Indeed - my previous commute (which I did on a low trike) featured a
length of one-way system with parallel lanes and cars filtering from
one to another. Nervous of the situation you describe, I had a
fluorescent, reflective flag that was tall enough that it was at eye
level for a driver in anything from normal car to land-rover.

No-one ever (in several years) came across into me on the one-way
system.

The only person to ever side-swipe me pulled out into the other lane
of a two-lane single carriageway first, and you can't claim not to
have seen someone if you've just pulled into the oncoming traffic lane
to get alongside.

Quoted message said:

Christ they dont even see me when I'm on the normal bike and I'm
sat upright on a shiny silver frame

.... but they do come across into me about once every two or three
months on a normal upright, despite being upright, at their eye-level
and clad in fluorescents.

Basically, 'sorry mate I didn't see you' is basically never about not
seeing, but always about not noticing, and on a recumbent you are very
VERY noticeable.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

Rob Morley said:

In article <[email hidden]>,
CoyoteBoy
[email hidden] says...

Quoted message said:

But also, to me the two-up-front design would be better at cornering
but has an extraordinarily long chain length - how much does this
cause efficiency problems (the chain, not the two-up-front)?

Power loss in a chain really only occurs where it touches anything, and
particularly where it wraps around anything. The only additional chain
drag on a recumbent is where it passes over an idler wheel or through a
tubular guide (and this is usually on the slack side of the chain) so
it's not going to have much effect, certainly less loss than in a tandem
transmission.

All true, but the chain is noticeably more draggy on my recumbent than
on the fixed wheel. Either are relatively little compared with air
resistance of course!!

CoyoteBoy said:

On 16 Aug, 14:34, Peter Clinch <[email hidden]> wrote:> Alistair Gunn wrote:

<snipped lots of funny thoughts>

I think the general thought is that they may not see you //until its
too late//. I would worry that if I were keeping up with a car in a
traffic queue, but in its blind spot or to one side, they might not
see me before pulling left into my lane. Christ they dont even see me
when I'm on the normal bike and I'm sat upright on a shiny silver
frame with a bright orange reflective 80 litre rucksack lol. Also if
you're lower than a car (which the faster trikes seem to be from the
pictures) they might say... overtake a car that is overtaking you ( i
ride some 3 lane sections) and whip right in in front of you - but
then again I've had this on my normal bike too so I suppose its
probably down to lower seeming somehow more vulnerable.

I must admit I do get tired of people telling me how hard I am to see
on my recumbent, and how dangerous it must be. As Peter said, it's
the my head is exploding syndrome, whilst in reality I feel
significantly safer on the 'bent.

I too get less not seen incidents and less stress riding my Hurricane
in London, often in heavy traffic, than on my fixed wheel Langster.
What's more, the Hurri is set very low, my eyes are below 90cm AGL.

http://www.londonskaters.com/cycling/my-bikes-hurricane-refurb.htm