RollCNY

Hubris?

Dead Roman

learned this from racing sportbikes and drag racing cars. Makes the bike feel less stable/wobbly, but the tire is still tracking properly. The bike is just wobbling around on that loose pad of air. takes time to get used to, but its worth it.

lineinthewater

Seems there would be a nice scratch/gouge across the side of your pedal if you hit ... maybe take a look.

... not to mention, based on your description, it wouldn't have taken any significant "road debris" to send you flying. A few small, loose rocks would do it. Many of the country road intersections around here are littered with fine pebbles; it's like an ice skating rink. I take them extremely wide and slow.

Hlxdrummer

Lots of responses to I won't answer them individually but thank you.

That youtube video was helpful, thanks! I was countersteering (weight on inside handlebar) but I'll keep the other tips in mind.

I'll have to try lowering the pressure next time. Any idea what a good starting point would be? I weight ~130lbs Also, the tire does has a raised center ridge. Does that mean it isn't a great tire for cornering?

I wasn't pedaling and if I was on the brakes it was very lightly. When it started to wobble a bit I may have lightly applied the brakes but I try to either coast through the bends or gently ride the brakes (very gently). The pedals are beat up (got them off my 80's schwinn) so I can't tell if I hit the ground with them or not.

So as far as positioning, when I am applying weight to the outside pedal, should I parallel my body with the lean of the bike or should I be more upright?

Thanks again!

jsharr

I set up for a corner but getting my outside pedal down and ready to weight. If I need to brake, I do it in a straight line before corner. I point my inside knee into the corner, spot my apex, weight my inside bar and lean/lower my inside shoulder. I would assume I am in line with the bike or leaning into the corner a bit. After the apex I exit wide out of the corner if possible and begin to pedal again as I straighten back out. I am not a racer, just a long time recreational rider, got my first Trek road bike in 1984, so my hard corners are just to push myself, so take this all with a big grain of salt.

surgeonstone

You are over thinking this- go with the flow, use common sense.

TromboneAl

I often ride here:



and sometimes on the slanted section (which is more slanted than it looks). It's fine until I hit a tiny pebble, and then I'll lose traction. Twice, I've actually fallen.

Young Version

Why are you resisting the idea that you may have just tried to take a corner faster than the conditions allowed? There's no voodoo magic you can do to magically take a corner at any speed.

clausen

At 154 I was running 23mm 100/105. Never had a pinch flat. All tires are slightly different but that may be good place to start.

coasting 

was there any warning before it gave way?

banerjek

The reason I suggested the headset is it didn't sound like a speed wobble. Based on his description, I couldn't identify a likely cause but suggested the headset since many people ride with incorrectly adjusted ones and that wouldn't help him.

You're overthinking this. If you try to deliberately introduce countersteer, you're likely to exaggerate the movement which will mess you up. It feels very natural if you do it right. As far as pressure goes, psimet's formula is pretty popular around here:

Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33
Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67

It's a good rule of thumb, but you adjust any formula for conditions. I'm not a fan of your tires, but your technique and judgment are what messed you up -- you need to account for all factors at all times when riding and you were outside your limits. Tires are a compromise. If you get supple sticky tires that do great in corners, they'll be more prone to flats and won't last as long as ones that would be great on flats and rollers.

There are exceptions, but you should avoid braking in corners since that will tend to destabilize you. Bike is leaned more than your body -- that's what introduces the countersteer you'll hear people talk about.

Again, this should all feel natural. If everything feels under control, it is. If you wonder if things are under control, you're riding outside your ability.

Hlxdrummer

I'm trying not to overthink it but I feel like the bike should have been able to handle that speed/corner so I feel like something was off. Like I said, the most enjoyable part of riding for ne is taking corners fast so the better I can do that (safely), the happier I am.

As far as the headset, I am not real familiar with bike mechanics but I'll look into it.

Like I mentioned, I felt in control and the lowside was very sudden. If I felt unsafe I would have backed off/straightened out.

Basically I just want to improve my technique and/or fix any mechanical issues if there are any.

clausen

The bike can handle that speed. The operator can not. Improving your technique and your setup will get you more speed through the corners. You just have to learn where that edge is, unless you want to go down more. You need to go slow before you can go fast.

Nick Bain

the only time I lean inside is when cornering around loose debris, not really lean but shift my weight inside while the bike stays upright. If you stay centered on the bike that leaves maximum room for any possibility of correction. If you lean on top or outside of the bike, you loose the ability to correct.

rpenmanparker 

Tsk, tsk! Bob! Bob! Bob! I greatly admire your single minded determination to discredit every single item that I post, but I have to wonder. Did it never occur to you that I may get it right SOMEDAY? You really should be more careful.

Regarding the question of whose opinions are informed:

There is this by Jobst Brandt, a well-respected authority on the engineering aspects of cycling.
“Shimmy is not related to frame alignment or loose bearings, as is often claimed. Shimmy results from dynamics of front wheel rotation, mass of the handlebars, elasticity of the frame, and where the rider contacts the bicycle. Both perfectly aligned bicycles and ones with wheels out of plane to one another shimmy nearly equally well. It is as likely with properly adjusted bearings as loose ones. The idea that shimmy is caused by loose head bearings or frame misalignment seems to have established currency by repetition, although there is no evidence to link these defects with shimmy.”
See the entire article at: https://sheldonbrown.com/brandt/shimmy.html

And here is similar discussion by Dan Empfield at https://www.slowtwitch.com/mainheadin.../geometry.html
“When a customer brings his bike into his LBS and complains of speed wobble (death wobble, front-end shimmy) often the typical bike shop mechanic immediately starts farting around with the headset adjustment. There is no adjustment problem, nor are the wheel bearings loose, and in fact it is most likely that nothing is wrong at all."

Most significantly here is the topic treated explicitly by Tom Kellogg (who needs no introduction by me) of Spectrum Cycles:
"Because a tight headset increases the effective mass of the bicycle structure by partially including the fork and front wheel in the frame's mass, it also increases the chance of shimmy. Another reason it causes the problem is that the tight headset increases the shear forces applied to the frame by not allowing the headset to absorb them. The tighter the headset, the more it affects shimmy potential. A slightly loose headset will negatively affect handling, but it will actually lower the tendency of the bike to shimmy." His entire article is extremely illuminating and can be found here. https://www.spectrum-cycles.com/geometry.php

And just to be perfectly clear, I never suggested that prevention of the wobble by a loose headset was an advantage of a loose headset that justified taking the other risks associated with that condition. My point was that a tight headset is no advantage toward avoiding shimmy.

Sorry I couldn't let you win this one, but to paraphrase Meatloaf, don't be sad, 99 out of a hundred ain't bad.

And by the way, not only do I ride a bike, but the speed wobble is my peculiar specialty. Made my brown cycling shorts worth every penny I paid for them.

Robert

Hlxdrummer

Any suggestions where to read more on technique?

Also, will tight cycling pants/long sleeve shirt help? I was wearing shorts, a t shirt and gloves and the worst part of rash is under my shorts (basketball shorts). I'm not gunna spend the money on fancy clothes unless they will help protect me.

Ferrous Bueller

Here's a video with a rockin' soundtrack. https://www.youtube.com/watch?v=RTunW-3uW24
One of the elements mentioned (that relates to your crash) is braking in the corner. Avoid it, or do it as lightly as possible if needed.
Your speed is best controlled before you start your turn. If you are already on the limit of control in a corner, grabbing a handful of brake will put you on the ground for sure.

Cycling clothes usually are aerodynamic, make you slide through the air more easily, and are designed to be comfortable. Lycra doesn't protect, though I wish it did.
There are bike clothes with crash protection built in, but they're not really the type for riding around the city.

popeye

Not always, I have had it go both ways. Seated the front, out of the saddle the rear which is saveable.

banerjek

Cycling clothes provide a surprising amount of protection. I've gone down a couple times over the years and found the clothing helpful. I once actually melted my tights during a slide. In that case, my skin was burned but not shredded. Having said that, road rash is always a possibility when you're sliding on the rough stuff.

Rather than read on technique, you just need to practice more. If you ask for advice, people will give you diagrams showing entry and exit points, weighting, etc. For the egghead stuff, just watch the video FB pointed to. It's short but contains what you need to keep in mind. Real world conditions practically always introduce factors (e.g. a crack or a bit of slick/loose stuff in the optimum line) so it's really about reading circumstances and working with them.

sfrider 

Steep downhills often develop a sort of wavy pattern in the pavement around corners when cars and trucks when drivers consistently brake in the same areas as they enter the turns. It's not bad enough to be particularly visible or noticeable in a vehicle with suspension, it's just when you haul at 40+ mph on a bicycle you'll feel it as a wobble.

bubbagrannygear

That would be my guess. (and maybe when things were beginning to feel weird you were transitioning back and forth over the ridge) Would try new tires for sharp cornering. For me its outside pedal at 6 oclock, weight off of seat and distribted between outside foot and hands

gc3

I knew we could count on you, Bro!

Bob Dopolina 

This may be true. I could be a bit over zealous here.

Reason number one why having a loose headset is a bad idea. Reason number two is the irreparable damage it will do to your frame.


I can accept this idea in theory but it's like saying an outrigger could add stability and eliminate speed wobble. It may but it is impractical and potentially dangerous.



You should get your frame alignment checked.

Bob Dopolina 

gem.

Beneficial Ear

LOL

This I've seen - I always think I'm flatted and wish I had brown shorts.