Wheel Flop?

[Bethany1]

Could someone explain this better?

After going through my Madone 4.7 geometry and my Sirrus geometry and a few google searches I realized why I can't get on/off my Madone without crashing! If I understand what I read, I think it's in relation to head tube angle/rake/trail angles and numbers.

If I lay my Madone bike at an angle to get on/off, the wheel "flops" over given the numbers on Trek's site and I end up eating pavement or the bike falling into me. Add in that the bike's top tube is straight and I really struggle between "flop" and getting over that bar. It makes for a faster bike but less stable if I got the angle relationships right and understood what I was reading.

My Sirrus has the same measurement for the top tube but has different angles making more stable but not as fast. It's amazing what a couple of degrees make on a bike.

I feel SO much better after discovering this. It's not me being clumsy or inept at riding my Madone. It's how the bike was designed to react and when I overcompensate, the bike does this to me.

Now to figure out how to get on/off without making the front wheel "flop". I love this bike as she flies so fast and races down hills with ease. It's getting on/off that makes me scared to use her.

[KnottedYet]

Try turning the wheel (bars) the other way when you get off.

Long trail (like a cargo or touring bike) creates a self-correcting reaction in the bike where the wheel steers itself into the direction in which it is trying to fall and lifts it back up.

If your bike's short trail is steering itself into a collapse, try turning the wheel and bars the other way.

Motorcyclists do something like this on turns when they counter-steer.

How far are you "laying" the bike to get on and off? You are off the saddle with your weight on the bike pedal and the bike is actually upright before you even get close to stopping, right?

[OakLeaf]

All inline two-wheeled vehicles counter-steer. It's just easier and less dangerous for bicyclists to fight it, than it is for motorcyclists. That has more to do with lower speed than anything else.

If you're interested in the physics, Wikipedia (https://secure.wikimedia.org/wikipedia/en/wiki/Countersteering) has a decent explanation.

Getting off a bicycle is one of the easier places to observe it, actually. When you're getting ready to stop, turn your bars away from the foot you intend to put down. Your bike will automatically lean toward that side.

[Velocivixen]

I'm confused a bit, so please bear with me. Why do you have to lay your bike down to get on it? Don't you just hike your leg up and over the seat? Do you mean that you angle the bike down a bit toward you prior to hiking your leg over, then the bike somehow falls onto you? I guess I've never experienced this or I'm just not understanding it.
Thanks.

[Velocivixen]

Okay, I googled it. Don't need an explanation. Sorry.

[Bethany1]

I really don't have the flexibility to get over the saddle and I'm tall with a 33-34 inch inseam so the saddle sits fairly high. It doesn't help than when I get on and lift up into the saddle, my cycling shorts get tangled up in the nose having to balance everything while I get untangled.

When I got my fit he put my saddle up pretty high. It works perfectly while riding as my knees don't hurt and I get a lot of power out of it. If I lower it, my legs start aching again and I still get caught up.

I have men's Pearl Izum's x-large shorts. Nothing else seemed to fit right and the women's clothing I tried on were way too small.

[OakLeaf]

If the edge of your chamois is just catching in the saddle a little, learn to bring your hips a little more forward while you're mounting the bike. Also learn not to panic and get off balance if your shorts do catch :) - it happens, especially when standing to climb.

But if your shorts are actually getting "tangled" or hooked, they're way too big. There shouldn't be that much extra fabric.

If men's sizes fit you better there's nothing wrong with that, but according to PI's sizing chart, there's only a 1"-1.5" difference at the hip between their men's and women's XL, and their women's XXL is actually 1"-2" larger at the hip than men's XL. So it doesn't make sense that women's would be "way too small" for you. Maybe they don't fit you right, but they can't be too small if the men's shorts fit.

Maybe try a men's L. (But be aware from the other thread that PI is apparently notorious for different clothing models fitting differently.)



Also I'm not sure I'm reading your OP right, but make sure you have good footing on the first foot you put down, before unclipping the other foot and bringing it over the wheel. Keep a hold of the handlebars to control the bike's leaning. The soles of cycling shoes are slippery, so it does take a little getting used to, making sure your foot's not going to slip out from under you before committing your whole weight to it.

[Velocivixen]

@Bethany1, thanks for the time to explain. I have never heard the term "wheel flop" and am visual, so I watched a video on the topic and now see what you mean. I can understand being tall with the seat up high and the flexibility trying to get that leg up & over. No worries. My only suggestion, and this is a long term thing, would be to increase your flexibility. I found that when I started doing yoga regularly my balance improved a lot. Balance requires practice and uses muscle memory just like other physical activities.
Good luck. Let us know how any adjustments you make affect the situation.

[Bike Writer]

@Bethany1, thanks for the time to explain. I have never heard the term "wheel flop" and am visual, so I watched a video on the topic and now see what you mean. I can understand being tall with the seat up high and the flexibility trying to get that leg up & over. No worries. My only suggestion, and this is a long term thing, would be to increase your flexibility. I found that when I started doing yoga regularly my balance improved a lot. Balance requires practice and uses muscle memory just like other physical activities.
Good luck. Let us know how any adjustments you make affect the situation.

I also am having a hard time with the visulization but I think I'm getting it. I googled wheel flop video and have not had the results I am looking for.

VV, could you post the link to that video please?

I believe I have this problem also, or should say that I had this problem and have overcome it pretty much but from time to time I struggle with it. When I first started riding again after many years absence, I found that bikes nowdays seemed to do "something strange" and I don't recall that as a kid. By "something strange" I am refering to what I believe is wheel flop (if I'm getting wheel flop correctly), namely that being short and very short legged I have to lean my bike to get a leg over the wheel when mounting and dismounting the bike. I am much more stable at it now but when I first returned to riding I fell alot when I was either mounting or dismounting the bike and while it all happened so fast, it always seemed like the bike was falling on me or causing me to fall because the front wheel spun and flopped toward the ground and would take me with it. I don't recall wheels being so heavy when I was a kid and wonder what changed?

This rarely happens to me now, but I am assuming that it doesn't anymore because of a few factors:

I am getting stronger
I am getting more flexible
My balance has gotten better
I have found a way to counteract this or compensate for it
All of the above.


:confused: and :o

[Velocivixen]

@Bike Writer, it's not a video of a person or a bike, but it gave me the idea. Here's the link to this video: http://www.youtube.com/watch?v=gf47CX4S5Do

Watch the whole video.

[Bike Writer]

VV, thank you. That was one of the videos that came up when I googled it and it does help to visualize what is happening but the thing that threw me off was that in wikipedia it specifically mentioned this happens in two in-line wheeled vehicles and left out trikes or motorcycles with side cars.

I still wonder what is different about bicycle construction now because I just don't remember this being a problem when I was a kid. The only time I struggled as a kid was if I tried to ride a bike that was too big for me and if I did I got that same sense of lack of control when starting and stopping. For quite a while I assumed that the first bike I got last year was too big for me and that is why I had problems.

My new bike is better sized for me but I still had this happen once, that feeling like it was just getting away from me while dismounting.

[OakLeaf]

Keep ahold of both brakes. Don't let go until both feet are on the same side of the bike. Then the wheel won't go anyplace you don't let it.

As you slow to a stop, remember to turn your bars AWAY from the foot you intend to put down. (If you unclip left, e.g., turn your bars to the right.)

Choose which foot you prefer to put down first, and make a habit of that so you don't have to think about which foot it's going to be each time. It's good to be able to unclip either side, in case of poor footing or emergency stops, but that's something you can practice after you're confident unclipping with one foot.

Practice standing on the pedals when you aren't stopping. Get used to how your balance feels standing. Stopping and starting is just standing on the pedals for a moment.

[Velocivixen]

@Oakleaf, that's a brilliant suggestion about keeping the brakes on until both feet are on the same side of the bike! The way you describe how to turn the handlebars in the opposite side of the foot you put down is exactly how I do it without thinking. Interesting to actually hear someone describe it. Thanks.

[Bike Writer]

@oakleaf, I paid more attention to myself when slowing/stopping and realized that I do hold onto the brakes until I have feet firmly planted on the ground. I don't think I always did this but I do now. I also noted that I turned my handlebars slightly away from the side I was going to dismount from. I don't know when I started doing this but my body must have figured out a way to deal with this through trial and error.

I don't use clipped or clipless pedals, yikes that would add another whole dimension to this experience that I am not ready for!