Correct High Speed Wobbles and Descend Properly

If you haven't descended down big mountains before you might not have experienced high speed wobbles. They're a frightening thing and knowing how to correct high speed wobbles is a key tool to descending properly and with confidence.

This will be especially important for those of your tackling the big climbs, especially at a fast pace on Etape Alpes. Etape Alpes has a very long, very fast descent from the top of the Galibier down to the base of Bourg D'Oisans, and you will need to be careful here, given the number of riders on the road.

Descending properly is part technique, part skill (that is, getting good at the technique) and part confidence.

Personally, I barrel down big descents with not much consideration for life and limb, and can descend pretty well. This took a lot of practise and still takes a lot of confidence.

Speed Wobbles

Speed wobbles are a horrifying experience. I've only had them a few times, once at 95km/h, and it is not a pleasant experience.

Speed wobbles can happen for a variety of reasons including loose spokes, a bad tyre, buckled wheel or a seat that's too high. It can also be caused when the only contact between you and the bike is your hands and feet (pedals).

Sheldon Brown has a great run down on the phenomenon, but to summarise:

Bicycle shimmy is the lateral oscillation of the head tube about the road contact point of the front wheel and depends largely on frame geometry and the elasticity of the top and down tubes. It is driven by gyroscopic forces of the front wheel, making it largely speed dependent. It cannot be fixed by adjustments because it is inherent to the geometry and elasticity of the bicycle frame. The longer the frame and the higher the saddle, the greater the tendency to shimmy, other things being equal.

The key tips to correct them, if you get them, are:

• Keep your weight forward
• Keep your bum off the seat
• Don't straighten your arms
• Soft hands on the handlebars
• Clamp your knees against the top tube, which braces and stiffens the frame, or press one leg against the frame.

Descending Properly

My key tips, keeping in mind I am NOT a cycling coach, are:

• Keep a low centre of gravity.
• Be able to quickly brake, always.
• On corners and bends, assume a position with your inner foot at 12 on the pedals and outer foot at 6, and plant weight on your outer foot. This will allow you to really lean into the corner and stick to the road.
• If you're REALLY going fast, use your legs as suspension and don't plant your bum on your seat as you normally would.
• Keep both hands on the handlebars, always. You're (most likely) not a pro, so don't act like one.
• If in doubt, SLOW DOWN.
• Like in mountain biking, lean the bike, not your body.
• Keep your eyes up on your line down the road. Unless you're epically skilled and have straight road, keep your eyes front, only ever glance back momentarily.
• Like in a race car, come into a corner wide, come through the apex and out wide.
• If you have heaps of riders around you (Etape) and are going slow, keep right (if in Europe) and keep out of the way. Make it obvious what you're doing, this isn't a ski run and the Alpine Responsibility Code does not apply. Don't move off your line suddenly.
• Brake early, and use both brakes if needed.

It's also ULTRA important to have your bike checked to make sure the brakes are functional, tyres and wheels are ok, and all the bolts and nuts are done up. This is a basic safety check I undertake before all races and big descents. Commonsense is needed here.