ccf
Guru
Are you saying that recumbents lean more because they corner faster? I'm pretty sure that DFs and recumbents of equal weight going around a curve at the same speed lean at the same angle.
-Cliff
Climbing and bb height, low gears
- Thread starter Andrei Petrov
- Start date
Are you saying that recumbents lean more because they corner faster? I'm pretty sure that DFs and recumbents of equal weight going around a curve at the same speed lean at the same angle.
-Cliff
ratz
Wielder of the Rubber Mallet
Hi Cliff,
Nope just repeating a common point that needs to be made about understanding that there are different limiters on a Recumbent...
What I am saying is that the average person can lean a recumbent further into a corner and at higher speed than same said person could a DF. (focus being beginner to average rider). In my experience riding with people, average riders do not get their DF's up to 35 mph and then elevate the inside pedal and lean into a 30-40 degree salom turn coasting while preparing to attack out at the apex. If they do it's the exception. Saturday CRIT racers do it a ton but they aren't average.
My point was for people to be aware that when you enter new territory you take on new risks. These bikes expose you to new abilities that should be understood and respected before they are leveraged and enjoyed. Speed and Cornering to name a few.
Your point of clarification is equal speed; for the most part I agree that's valid; but I add on top of that, the idea that recumbents allow people to go faster in the same situation as they can pedal and continue the power input through the entire turn. As a second point most people don't have the nerve to lean a taller DF position as deep in the same corner as the very same person would do on a recumbent.
So with regard to wheel slippage these bike will allow people access to turn conditions with physics they are not familiar with and that can lead to judgement errors. Aka just because you can lean the bike 30 degrees; (enabled by a platform change and accounting for the riders relative skills) doesn't mean that conditions are such that you should do it.
I only do that to get people to think; "Have I done something like this before and what should I consider before I do it" once consideration is given then attack it at your comfort level knowing the risks. etc etc.
hoyden
Well-Known Member
Ah yes, the famous learning experience. Wisdom comes from experience and experience comes from bad judgment. I can really relate to the "just because I can doesn't mean I should" situation.
MrSteve
Zen MBB Master
Wrong.
School yourself.
AlexisBV
Active Member
Wow you must be really fun at parties. You're right if you're considering tyres with no width, then the angle of leaning is the same regardless of CG height. However, with real tyres with non-null width there will be a difference in angle. The difference is greater the thicker the tyre, as the actual point of contact between the tyre and the ground is no longer aligned with the bike's (now inclined) vertical plane. Will it be subjectively noticeable? Maybe, maybe not, I've never measured it myself, nor do I plan on buying multiple tyres to measure it. That being said, I suppose I could have given more details on my original post.
Here's some easy reading on the subject:
http://www.stevemunden.com/leanangle.html ("What's the real lean angle" section)
ratz
Wielder of the Rubber Mallet
LOL don't encourage him; it's a long fostered image..... Former Motorcylce crash tester; usually Mr Steve knows something the rest of us don't or it's from a previous head strike
. What you can't see is him smirking at you with a gleam in his eye to determine which it is.
ccf
Guru
It's a good point. If we're climbing a grade so steep that wheel slippage is an issue, we should be thinking about issues with descending that grade, too.
Charles.Plager
Recumbent Quant
I'm clearly late to this, but my $0.02:
Mr Steve is right. (Which is not to say that everybody else is wrong
)
Mr Steve is right. (Which is not to say that everybody else is wrong
)- I like having low gears. I can spin up very steep climbs. Double cranksets don't usually do it for me.
- I find that spinning helps traction compared to mashing. My stroke is more even.
- When mashing you get PUSH pause PUSH pause and each PUSH makes it likely you'll lose traction.
- Sitting up helps move more weight forward. This is a great core workout (and therefore hard to do for long hills).
- Longer wheel base means more weight on front wheel - better weight for climbing.
- I've climbed short very steep hills.
- Regardless of all of the above, I get wheel slip. It's usually short and it has never stopped me from being able to climb.
- If I stop on a steep hill, I find starting on a steep hill is very difficult. But once I'm moving, I can keep moving. (I was once riding a metric century with a friend of mine and stopped in the middle of a steep hill. I was complaining that I'd never be able to start and he offered me a push. That was enough to start and make it up the rest of the hill. I then hit 45 MPH going down that hill).
tiltmaniac
Zen MBB Master
That page is mostly right, but has some statements which could make it be interpreted the wrong way.
For example "side force == friction". More correct/precise "side force <= lateral friction", and at the limit "side force == lateral friction". I could be dragging a tire while going around a curve at the limit. In that case clearly friction > side force... I'll note that even my statement has inaccuracies since you don't necessarily need friction, you just need force. Thus, if you're riding on a curved/elevated track (e.g. a cyclodrome), you could run into things other than friction being your problems (e.g. ability of tire to resist pinch-flat, or rider to maintain consciousness). This isn't purely theoretical-- F1 drivers have had this problem (with 5.5Gs of force)...
Also the page differentiates "apparent lean angle" from actual lean angle. This is good.
The actual lean angle (a line from the contact patch through the CG) will be the same angle for a given lateral force (otherwise force and reaction wouldn't equal and you'd be accelerating towards the ground).
The apparent lean angle is a function of lateral tire stiffness (i.e how much the contact patch shifts when lateral forces present to the tire), inflation, rider weight (impacts the amount of lateral force required), etc. and not *just* the CG height.
It'd be more correct to say "all other things equal, moving the CG up/down while using a tire which shifts the location of the contact patch when subject to lateral forces, a lower CG will cause a higher apparent lean angle than a higher CG).
imho, whatever, it basically feels the same unless you can get the CG substantially lower than normal, which mostly you can't.
Balor
Zen MBB Master
Good points.
An other point worth considering is that a sizeable chunk of total weight is shifted inside of the turn on mbb (legs plus boom and transmission), providing extra centripetal force to counter centrifugal force (that tries to topple the bike outside the turn and hence must be countered with a lean).
This means that, theoretically, you can get away with no countersteering on mbb (not likely, though) and lean angle on mbb would be less, depending on boom length.
Still, this is a small boon in exchange for huge steering inertia long boom entails.
An other point worth considering is that a sizeable chunk of total weight is shifted inside of the turn on mbb (legs plus boom and transmission), providing extra centripetal force to counter centrifugal force (that tries to topple the bike outside the turn and hence must be countered with a lean).
This means that, theoretically, you can get away with no countersteering on mbb (not likely, though) and lean angle on mbb would be less, depending on boom length.
Still, this is a small boon in exchange for huge steering inertia long boom entails.
bladderhead
Zen MBB Master
Balor is right. If you consider the bike and rider as one thing, the centre of gravity moves sideways as you steer.
Or think of it this way: When you turn, your feet go to one side of the centre of gravity, your hips and the head-tube go to the other side.
Or think of it this way: When you turn, your feet go to one side of the centre of gravity, your hips and the head-tube go to the other side.
super slim
Zen MBB Master
I totally agree that Australia is the best country in the world!!!oh just go out n ride wouldja. you've got the best bike in the world in the second best country in the world. go and enjoy
Balor
Zen MBB Master
Brown snakes and redback spiders tend to agree.
