Rowan nailed some important issues. A few thoughts on them, in addition to his excellent points:
Originally Posted by
Rowan
Fixed riders will experience much higher cadences on hills, and there is a need to experiment with this on the prelim 400 miles. In particular, a rider needs to ensure bike fit/saddle height is such as the hips don't rock at all when pedalling. If they do, even a little, the action is exacerbated at high cadence. There's also the body's unique "harmonic frequency" that the rider either should remain under or above -- I can't remember, but IIRC it's around 120rpm, and that's when it can be a bit disconcerting as everything jiggles out of control.
I run my saddle a bit lower on my fixed bicycles than on my geared ones. The slightly lower saddle helps me to get my legs and feet around quicker on those descents, which keeps my upper body quiet. It also prevents that hip rocking deal.
I think descending on a fixed gear is all about two things: (1) keeping your upper body relaxed and quiet and (2) staying ever so slightly ahead of the cadence you’d be at were gravity to just take you down the hill (which, you’ll find, keeps your upper body quiet). You actually want to pressure the pedals a bit. Ride the bike, don’t let the bike ride you.
As you gain experience, the cadence you’re able to turn over will increase. Take things gradually.
Practising the transition from sitting to standing and from standing to sitting also will become useful to help prevent struggling to maintain momentum (or stay upright!) in the first instance, and butt-slap in the second.
Modern cycling technique for climbing is to remain seated for as long as possible. Climbing from the seated position is more efficient than standing. I violate the heck out of this rule when riding a fixed gear bike.
When one stands, by choice or necessity, is going to be driven mainly by the rider’s fitness, gearing, length of the climb, and its characteristics (grade, whether you get any rest mid-climb, and the quality of the pavement). I find standing gives me some much needed rest and time out of the saddle. I can use my body weight to drive the pedals and stretch out my legs and back. Rest is rare on a FG bike, so I’ll take it when I can get it!
Proper climbing technique, especially on a FG bicycle, is a whole ‘nother thread topic, but your takeaway is this: when climbing on a long ride, especially on a fixed gear bike, your goal is one thing only, and that is to NOT go anaerobic. You want to do whatever you can to keep your heart rate as low as possible, for as long as possible on the climb. I accomplish this by slowing way down as I start up the hill, I stand up, and I pick a cadence that will hopefully get me all the way up without having to alter it. Steady is your friend. If I have to, I’ll shoe-lace or tack to get up the hill. There have been several hills/mountains I’ve had to stop on so I could get my heart rate down. Totally valid, as is going for a little walk.
Don’t worry about your ‘mates riding off and dropping you on the climb. If you’re a lousy climber, riding in lumpy terrain on a fixed-gear bike will quickly whip you into shape. You’ll also find, no matter your climbing prowess, that trying to stay on top of your gear, even at a very low cadence, will keep you moving along at a very good clip. I find that most FG distance riders are fine on the ascents. It’s the descents where we tend to get dropped!
You might also mention a little about the need to consider crank length and BB height, or at least checking on the prelim 400 miles that the cranks aren't going to hit the road when cornering.
Great point. Pedal strike is a real issue when riding fixed. I ride the same length cranks as on my road bikes, but some prefer shorter cranks. Be mindful that many FG bikes come stock with 165s because that’s a common length for track events. But just because it makes sense in a 1km TT on a velodrome doesn’t mean it makes sense on your fixed-gear century. Pick a crank length suitable for your riding style and body geometry.
Also, if you’re riding in groups, be especially careful cornering. The line you want through the turn is probably different that the lines riders with freewheels will take. Don’t get crossed up with other riders.
I don't know if it's worth emphasising the need for at least a front brake. I think you are able to moderate downhill speeds with your legs; I can but I do so reluctantly to preserve my legs, and use my brakes instead. This also comes in handy to moderate cadence on steeper downhills.
Amen. Brakes, brakes, brakes. You’re not on a track. And God didn’t make your legs for stopping bicycles. I run two brakes and I’ll feather them the descents to ditch speed and keep my cadence reasonable. Those ludicrous cadences will impress your friends, but they do take a toll, especially on long rides. Another benefit to dual brakes is that you’ll get the brake hoods to use as a hand position.
Oh, and it might be worth pointing out that there is no shame in walking on hills that are too steep to pedal up. Some people get a bit uptight about the notion of "failure" if they have to get off and walk.
Walking is definitely not shameful or a failure. You’re still moving down the road, which in my book is success. Rather walk and finish than not walk and DNF.
One problem on a FG is gravely pavement. You’ll see some pitches that are too steep to remain seated on but that, if you stand, you’ll spin out the rear wheel (because you unweighted it). This is totally frustrating, but there’s nothing for it but to hop off and walk when that happens.