How far can you lean?

Quoted message said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

Pedal strikes on the ground are common, but this is more to do with
pedalling through corners than excessive lean.

Incidentally, some bicycle tyres now have a motorcycle-inspired v-shape to
give better grip when cornering.

Membrane said:

Typically on a dry road a motorbike can be leaned over in a bend until
the foot pegs begin to scrape the tarmac with little risk of the tyres
losing grip.

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

Check out articles by Jobst Brandt, and look up tyre tests. IIRC, round
about 40 degrees is possible on good clean tarmac. A spot of water, gravel
or grease, though, and you'll risk slipping long before you get that far. A
broken hip is no fun.

~PB

Mark Thompson said:

Incidentally, some bicycle tyres now have a motorcycle-inspired
v-shape to give better grip when cornering.

No they don't.

~PB

Membrane said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

You can go quite far:

http://www.sheldonbrown.com/brandt/images/tiretest.jpg

Comparing the lean angles is tricky though: the important angle is from the
contact patch of the tyres to the centre of mass. Because of the wider
tyres on a motorcycle the contact patch shifts more when the bike is leant,
but OTOH motorcyclists normally hang off the side of the bike, shifting the
COM in the same direction...

http://motorcyclebloggers.com/wp-content/uploads/2006/04/kneedragging.jpg

Anthony

Membrane said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

On the Street Machine I can easily lean far enough to scrape a pannier
on the road if the pannier is on the lowrider rack. To give a vague
idea of how far that might be, here are pictures of my laden SM from the
front and back:
<http://www.colyer.plus.com/danny/cycling/ridereports/century1/15dannym5.jpg>
<http://www.colyer.plus.com/danny/cycling/ridereports/century1/16dannym5.jpg>

I tend to lean further into left hand turns than into right hand turns,
largely because I usually have a pannier on the right and none on the left.

On a 20" unicycle with 5" cranks I will occasionally lean far enough
into a turn to get pedal strike.

--
Danny Colyer <URL:http://www.colyer.plus.com/danny/>
Reply address is valid, but that on my website is checked more often
"Daddy, put that down. Daddy, put that down. Daddy, put that down.
Daddy, why did you put that down?" - Charlie Colyer, age 2

Anthony Jones said:

You can go quite far:

http://www.sheldonbrown.com/brandt/images/tiretest.jpg

Insane in the membrane! :-)

JB did actually break a hip doing something like that. That's when he
learnt how far was too far! I broke mine leaning much less than that.

Quoted message said:

Comparing the lean angles is tricky though: the important angle is
from the contact patch of the tyres to the centre of mass. Because of
the wider tyres on a motorcycle the contact patch shifts more when
the bike is leant, but OTOH motorcyclists normally hang off the side
of the bike, shifting the COM in the same direction...

http://motorcyclebloggers.com/wp-content/uploads/2006/04/kneedragging.jpg

Does the suspension help as well?

~PB

Mark Thompson said:

Quoted message said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

Pedal strikes on the ground are common, but this is more to do with
pedalling through corners than excessive lean.

Incidentally, some bicycle tyres now have a motorcycle-inspired v-shape to
give better grip when cornering.

Motorcycles (at least road) tyres don't have this, it affects handling
to badly. You do get multi compound tyres which have a harder running
band around the center and a soft grippy compound at the edges. I
*think* bicyle tyres can now be bought like this. Marathons?

As for the lean angle, I would think it's a lot to do with the contact
patch. My 32-35 touring/commuting tyres are quite happy until the
pedals hit the deck. Narrow high speed/high pressure tubeless might be
significantly easier.

On 27 May, 23:05, Mark Thompson

Quoted message said:

Pedal strikes on the ground are common

Not a recumbent: yet another advantage of being laid back 🙂
IMHO decent suspension should help on rough roads (aren't they all?).

Tosspot said:

Motorcycles (at least road) tyres don't have this, it affects handling
to badly. You do get multi compound tyres which have a harder running
band around the center and a soft grippy compound at the edges. I
*think* bicyle tyres can now be bought like this. Marathons?

As for the lean angle, I would think it's a lot to do with the contact
patch. My 32-35 touring/commuting tyres are quite happy until the
pedals hit the deck. Narrow high speed/high pressure tubeless might be
significantly easier.

Dual compound cycle tyres have been available since the late 1980's.
As for lean angle, with a dry road, tyres pumped up hard (120psi) and
a bit of bravado, I have hit pedals on the ground. Not done that for
quite a few years as I now feel my mortality somewhat more than I did
as a late teen/early twenties rider.

...d

Quoted message said:

Quoted message said:

Incidentally, some bicycle tyres now have a motorcycle-inspired
v-shape to give better grip when cornering.

No they don't.

Does so :-P

<http://www.specialized.com/bc/SBCEqProduct.jsp?spid=30660>

.... motorcycle-inspired dual radius design (DRT) that minimizes contact in
straight lines, while maximizing contact surface and traction in corners.

.... DRT design for low rolling resistance and great cornering ...

in message <[email hidden]>, Membrane

(') said:

Typically on a dry road a motorbike can be leaned over in a bend until
the foot pegs begin to scrape the tarmac with little risk of the tyres
losing grip.

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

Depends a lot on tyres, road surface, and courage. I have never had tyres
let go sideways on a clean dry road in good condition. On the other hand I
have had tyres let go on wet roads, ice, loose gravel, diesel or other
contamination. Find a quiet road with a nice tight downhill bend, and push
it to find your limit. And be prepared to scrub gravel out of grazes...

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; lovely alternative to rice.

in message <[email hidden]>, Tosspot

(') said:

Motorcycles (at least road) tyres don't have this, it affects handling
to badly. You do get multi compound tyres which have a harder running
band around the center and a soft grippy compound at the edges. I
*think* bicyle tyres can now be bought like this. Marathons?

Stelvios, for sure. Stelvio Evolution have different compound patterns back
and front, and wear into noticably different profiles.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; IE 3 is dead, but Netscape 4 still shambles about the earth,
;; wreaking a horrific vengeance upon the living
;; anonymous

Mark Thompson said:

Quoted message said:

Quoted message said:

Incidentally, some bicycle tyres now have a motorcycle-inspired
v-shape to give better grip when cornering.

No they don't.

Does so :-P

<http://www.specialized.com/bc/SBCEqProduct.jsp?spid=30660>

... motorcycle-inspired dual radius design (DRT) that minimizes contact in
straight lines, while maximizing contact surface and traction in corners.

... DRT design for low rolling resistance and great cornering ...

Well, I'm not going to argue but the profile of a motorbike tyre is
critical. Dunlop do one that has harder compound in the middle, and
softer on the outside, but it's still nowhere near a 'V' shape.

However, I don't see why the technology couldn't be applied, after all,
what we are talking about is increasing grip in corners without
adversely affecting the handling.

<thinks> But if you can't pedal through, there's probably no point.

"Mark Thompson"
<pleasegivegenerously@warmmail*_turn_up_the_heat_to_reply*.com> wrote in
message news:[email hidden]...

Quoted message said:

Quoted message said:

Quoted message said:

Incidentally, some bicycle tyres now have a motorcycle-inspired
v-shape to give better grip when cornering.

No they don't.

Does so :-P

<http://www.specialized.com/bc/SBCEqProduct.jsp?spid=30660>

... motorcycle-inspired dual radius design (DRT) that minimizes contact in
straight lines, while maximizing contact surface and traction in corners.

... DRT design for low rolling resistance and great cornering ...

x-posted to uk.rec.motorcycles to see if there's any truth in this idea...

My schwalbe city jets took on that sort of profile on my mountain bike's
wheels. They were hideous - the slightest bit of lean and they got slidey.
OTOH Schwalbe Blizzards on my road bike, which have pretty much dead on a
circular profile, are grippy as.

On 27/05/2007 22:55, Membrane said,

Quoted message said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

I don't know what the angles are in degrees, but I've had pedals hitting
the ground before when foolishly attempting to continue pedalling in a
steep lean. I don't think that needs to be a particularly steep lean
though.

--
Paul Boyd
http://www.paul-boyd.co.uk/

Paul Boyd wrote on 28/05/2007 10:52 +0100:

Quoted message said:

I don't know what the angles are in degrees, but I've had pedals hitting
the ground before when foolishly attempting to continue pedalling in a
steep lean.

You don't ride a fixie then?

--
Tony

"The most savage controversies are those about matters as to which there
is no good evidence either way."
- Bertrand Russell

Pete Biggs said:

Anthony Jones wrote:

Quoted message said:

Quoted message said:

You can go quite far:

http://www.sheldonbrown.com/brandt/images/tiretest.jpg

Quoted message said:

Insane in the membrane! :-)

Quoted message said:

JB did actually break a hip doing something like that. That's when he
learnt how far was too far! I broke mine leaning much less than that.

Quoted message said:

Quoted message said:

Comparing the lean angles is tricky though: the important angle is
from the contact patch of the tyres to the centre of mass. Because of
the wider tyres on a motorcycle the contact patch shifts more when
the bike is leant, but OTOH motorcyclists normally hang off the side
of the bike, shifting the COM in the same direction...

http://motorcyclebloggers.com/wp-content/uploads/2006/04/kneedragging.jpg

Quoted message said:

Does the suspension help as well?

Enormously. The coeff of sliding friction is less than that of static,
i.e., once you start sliding you have to back off the forces further
back than what caused the slip to stop it. An uneven road surface
causes the unsprung weight of the vehicle to be thrown up and down,
temporarily losing some the downwards force which is holding the tire
to the road. Motorcycle tyres have a bigger contact patch, thus less
disturbed by tinier patches of low friction, lower tire pressures,
thus fitting into the road micro irregularities better, and very much
better ratio of unsprung to sprung weight, making it possible
implement efficient suspension which keeps the tires in better contact
with road despite bumps.

For various technical reasons, including that fashion dictates poor
engineering design, bicycle suspension is not much good at keeping
grip in road cornering.

Last but not least, unlike cyclists, motorcyclists often wear clothing
in which they can happily hit the road, slide along for a bit, and
then get up and walk away ungrazed and unbruised.

--
Chris Malcolm [email hidden] DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

Doki said:

Quoted message said:

Quoted message said:

> Incidentally, some bicycle tyres now have a motorcycle-inspired
> v-shape to give better grip when cornering.

No they don't.

Does so :-P

<http://www.specialized.com/bc/SBCEqProduct.jsp?spid=30660>

... motorcycle-inspired dual radius design (DRT) that minimizes contact in
straight lines, while maximizing contact surface and traction in corners.

... DRT design for low rolling resistance and great cornering ...

x-posted to uk.rec.motorcycles to see if there's any truth in this idea...

If you've come here looking for truth, I fear you may be
dissappointed.

I don't think motorcycle tyres have "a V shape to minimise contact in
straight lines". Motorcycles, due to their horsepowerer, weight, and
braking capabilities, can exert considerable stresses on their tyres
when upright, so you wouldn't want a minismised contact in such a
scenario. While some motorcycles *do* have a V shape to the tyre,
it's usually just on the front one, and usually to promote faster
transition from upright to lent over

I also ride bicycles myself (although not to the extent of a couple of
regulars here), but I note that the bicycle market is not immune from
the hype and marketing bollocks that afflicts the rest of the modern
world. I'd suggest that this claim is exactly that.
--
Champ

ZX10R | GPz750turbo | GSX-R 600 racer
My advice as your attorney is to buy a motorcycle
To email me, neal at my domain should work.

in message <[email hidden]>, Paul Boyd

(') said:

On 27/05/2007 22:55, Membrane said,

Quoted message said:

On my pedal bike I haven't yet found the confidence to lean at similar
angles during fast speed descents. Anyone know if similar lean angles
are possible?

I don't know what the angles are in degrees, but I've had pedals hitting
the ground before when foolishly attempting to continue pedalling in a
steep lean. I don't think that needs to be a particularly steep lean
though.

You can lean a lot more if you remember to keep the inside pedal up! This
is one of the reasons that frames designed as fixies tend to have high
bottom brackets.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

There are no messages. The above is just a random stream of
bytes. Any opinion or meaning you find in it is your own creation.