RunForrestRide wrote:Can't say I'v ever had speed wobbles. Is it the conditions/speed/bike? Or combination of all?
This, plus the rider.
This, plus the rider.
There are four phases of bicycle commuting; first there's fear, then rage, then self-righteousness and finally, fun.
A lot of its down to confidence in yourself to go as fast as you can down whatever comes your way but also to know your limits
Hi Strange Rover, that link has excellent advice and point 3 is the likely offender ... slightly raise your bum up from the seat and be in a strong tuck position with your arms very bent (even easier if your hands are on the drops). For even more control while in the tuck position, and with your shoes/pedals in a horizontal position, grip the seat with your inner thighs. You should feel better braking modulation and braking control, with this approach. You may also find that to get into a really strong tuck position that your pelvis will move slightly rearward and feel like it is positioned behind the seat a little
BTW, this is how you corner at speed ... your face needs to be close to the top tube and head stem but your pedal is usually down on the outside of turn, which helps pull your body down into a low tuck position on the bike (It feels like you are in a really low position on the bike but in reality you are simply in a really low, strong, semi rigid tuck position). It all happens quite quickly (unless it is a sweeping corner) and it quite alot of fun. I always like to control the lean angle by putting pressure (with my hand) on the same side of the bars that my leg is extended (outside of turn/corner) and relax the hand pressure on the opposite side of the bars (inside of turn/corner). I sometimes also extend my knee to the inside of the turn/corner (like you would do on a motorcycle) just to keep the bike in a little more upright position
OP, glad you were not hurt in any way, shape, or form
My descending tip. Get down low and go, go, go. That second video is a prime example of why you need to descend in the drops. Not the hoods.
Another point, which is a pet whinge of mine. Modern cyclist ride frames that are to small. It's all well and good to have this light, twitchy thing with the slammed stem for flat roads and criteriums but when you hit some real descents with some real speed, ie 70 km plus, you will appreciate the stability of a larger frame and the ease of being able to comfortably ride in the drops. That's what drops are for. Going fast and aero with control.
Sorry forgot this point which is just as important ... always look ahead and always look in the direction that you want the bike to travel. Looking ahead also helps slow everything down ...
Seems simple but when you start to panic you need to have a basic approach that keeps you calm
Looking ahead is something you learn from riding an MTB on the trails, also falling and moving your weight about to control the bike.
Another tip is not to try to brake over rough surfaces, when the tyres are making poor contact with the road then you're just going to have to wait before you squeeze the levers. And pulsing the brakes is more effective than keeping them locked on.
I had a bad descent down Torrens Hill Rd in Adelaide once, was doing 70kmh+ when I found that I had a sharp righthand bend up ahead, a drop off behind that and an intersection with Gorge Rd too soon after. Had real trouble getting rid of speed as I kept hitting rough patches of bitumen, eventually had to push the bike right over to the left coming to the corner, swing my body over to the right and lean the bike over to the left while pushing my weight down through the cranks, managed to just make that righthand turn. Two days later while riding up Greenhill Rd the seat tube and half the bottom bracket shell came apart. The bike wasn't as important as surviving; do what you have to, you can always upgrade frames. Or brake blocks, rims, shoes, gloves ...
Descent yesterday was a bit scary after I worked hard at bumping into a riding partner, I have realised that I can't push myself if I am not familiar with the road AND my riding partners. Once the gradient is up around the 10% mark, and you can't pedal to speed up, the penalty for failing to take the right line or copping some rough road is severe. I've had a couple of incidents recently where I've looked away from the road and it has taken me outside my ability to control the bike. I typically don't push the limits when I'm doing 60 down the hill already, and squeezing another 10kmh isn't going to help me get around that corner easier!
I think if you are interested in getting better at descents, then spending a bit of time doing 60-80kmh going downhill in a straight line will help you develop your confidence in the bike. Even if your tyres shred at 80, you'll be able to slow down and get yourself together if you're going straight. My charge down Bellbird felt largely under control despite spending most of the time screaming through the curves. Croozin's ability to switch off his brain for a quicker descent is quite spectacular!
Just googled the corner. BROWNPANTS. I think your seat tube and BB collapsed after being upset by the trauma of being covered in excrement
until it is scientifically researched, it's profoundly ignorant speculation.
I've known elite A's to get a new bike, and demand their money back after getting speed wobbles in the first week.
do a bit of reading into motor bike tank slapping to get a more informed view.
2. Look way ahead, faster you are going further ahead you look
3. Be smooth
4. Wipe of speed before the corner, not in the middle of it. Braking upsets the balance and inertia particularly when leaned over, i.e. try to do all your braking when the bike is in a straight line
5. Stand up and grip seat with knees over any bumps and rough sections, this will give way more stability. By stand up I man 5-10mm off the seat but maintain position on the bike, sort of push your ass back a little to put your weight over the rear wheel. This is hard to explain, its more a a feel thing, it's all about shifting your weight as required.
I echo all the great suggestions offered above but would like to reiterate that the two most useful tips for me were:
1. Look further out as possible, especially cornering ... try to look as much around the corner as possible and at where you want to go ... never (even glance) at where you may hit if you were to lose control!
2. Know you brakes well and brake well before the corner.
I would also like to add for any noobies getting back into cycling (i.e. maybe from a long break since getting your driver's licence!), as it hasn't been actually pointed out in the thread (as I'm sure its assumed knowledge) when braking into the corner at high speed ... use your front brake not your rear brake! This also flows into why people are mentioning about hanging your backend slightly over the back to apply the counter-force required to avoid any over-the-bar incident!
Yes brake before the corner using both brakes. The front brake before the corner will stand the bike up a lot and the rear will stand it up a small amount ....let the front brake off first and then after that the back. As you release the front brake the bike will fall into the corner naturally. You can feather the rear in the start of the corner then let go of it as well and it will help you lean into the corner more. If you get into trouble grabbing the front brake will stand the bike up and compound your problem. The solution is usually to lean over more. Same as on a motorbike.
This. Is. The. Biggie!
...whatever the road rules, self-preservation is the absolute priority for a cyclist when mixing it with motorised traffic.
London Boy 29/12/2011
Difference between a rear blowout and front blowout below, especially when the bike is slightly leaned over. Not that I want this to happen to me again, but I would like to have know if the outcome would have been different if the bike was in a straight line. In this instance I would have applied rear brake only.
These are from 1 week after my 60km/h crash as a result of a front tube blowout. I was leaning into a gradual right hander when the tube blew, so out from underneath me the bike went. Bike slid for 10m, I slid for 20m. The descent this happened on was about 8-9%, so speed could have easily been 75-80km/h. Has a big graze on my ass cheek 15x10 and on my leg also, I considered myself lucky. Hand was the worse, yes I was wearing gloves, they just sheered off. And yes, I happened to be wearing my BEST kit, which was ruined in the crash
Not to make you paranoid or anything.
Front wheel blowouts, even in a straight line, are pretty dangerous. I've been fortunate enough to have had only one 'fast' loss of air from front wheel, was descending, in a straight line. Fortunately it was only 5-6% at that point and I was just cruising so speed wasn't crazy.
Managed to keep it together and pull up, but it was hairy.
I've had a few fast blowouts and pinchflats on the rear, and while they put a few hairs on my chest, they were far easier to control.
does anyone query why they have blowouts when descending?
- high speed combined with cornering = tire deforms significantly, rolls off rim and pinches tube.
- application of brakes leads to rim heating, which leads to tube over-inflation and blowout.
anyway, comes back to one of my pet topics - how to avoid rim heat blow outs on descents.
I am guessing Doggas was due to his new carbon clinchers. So your second point.
I don't believe mine to be a result of an overheating rim, I'd been climbing for 4kms and was 800m or so into the descent, of which very little braking had occurred. I'll put mine down to remounting that particular tyre on so many different wheels the bead of the tyre was compromised and in hindsight, an accident waiting to happen.
I was grateful not to have broken anything, and my mate who was behind me was able to avoid me. It was a low impact crash as the gradient of the hill was such that I can best describe my landing to that of a motorbike landing a jump smoothly on a down ramp. I just happen to slide down the road a fair distance.
Funnily enough, earlier on in the day I had registered the 2nd fastest descent time on a well known hill in hobart. I actually enjoy descending a lot, in fact I love it. I am not one to drag the brakes the length of a descent, if I don't feel like going fast I don't pedal.
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