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13

By this do you mean pedalling when unnecessary (and without increasing the bike's speed), for example, on descents? I will do this on long descents just to keep my legs turning over and to prevent them getting too cold. But I will mix it with coasting. There is a theory that keeping the legs moving will keep your blood flowing and help pump lactic acid ...


9

The main thing you have to consider at speed is drag: The force F on you+bike (mass m) is: F = ma = mg sin Q - F_d - F_rr where a is your acceleration, g is the acceleration due to gravity and Q is the hill angle to the horizontal. F_d is the drag force which doesn't scale with mass. Try dropping a balloon and a (soccer) football of the same size and ...


7

In addition to the response provided by PeteH, I use "soft pedaling" when coasting to a stop on my downtube shifter/derailleur-equipped road bike in order to change gears before a stop. Some bikes (such as those with internal hubs) do not need any chain motion to shift gears, but my bike does. That's the only concrete reason why I would employ this ...


6

A neck brace limits range of motion to protect the neck and spine BikeProducts A neck brace restricts any extreme movement of your neck during a crash. In other words, it prevents your head from tilting too far forward, backward, or to the side, all of which can damage the spinal cord. A spinal cord injury can, at best, keep you off the bike for ...


5

A lot depends on what you mean by "trail/downhill" and by "work". It wasn't that long ago that a full squish 100mm fork bike was a full on downhill machine. However, the big drawback to that bike as a descender is the relatively steep head angles. Putting a bigger fork will help with that, but it won't help with the issue of how robust the parts are ...


4

The reason for locking suspension uphill is efficiency converting the power you produce into forward momentum. If you are losing forward momentum by slipping, its because you have too much power going to the rear wheel. This needs to only be for a very short (instantaneous) burst. Once traction is lost, it takes a lot to regain it. Give this, there is no ...


4

I should think that they only work in conjunction with a full face helmet in that the helmet's angular motion range (up, down, left/right tilt) is restricted in such a way that on crashing, the typical "break-neck" motion (sharp snap of the neck) is avoided. However, this is just an educated guess.


3

The pros you see on the videos set their saddle depending on the DH course. If the course has a lot of possibilities for pedalling and not many drops - set it high, so on flat sections they can rest their bum on the seat and give it a full pedalling power. If the course is rough and steep - no racer will have the seat high. So you should do. You know what ...


3

Am I correct in thinking (based on your PinkBike comment) that you've never personally participated in a DH race? I would very highly recommend you compete in a few before trying to put on one of your own. There's a ton of things you'll need to think about, and the best way to get a good list is by attending one yourself and looking around with a ...


1

83mm bottom brackets were designed specifically for use with a 150mm rear dropout width. You would be able to shim the bottom bracket across 5mm to bring it to where it would sit on a 73mm bb to align the chain line but you would be pushing your non drive out 10mm which would have an anatomical impact on the rider. This is a significant amount of q-factor ...


1

If you're banging the boys against the seat even when it's low, it's the result of poor technique. The pros are using a of proper technique in conjunction with their suspension. Unfortunately, it's very difficult to learn proper technique riding a full suspension bicycle. The suspension does the work that proper technique should be doing and you just never ...


1

In a practical sense, increased weight will make you go downhill faster, for the same reason decreasing weight will make you go uphill faster See this interactive calculator. If you set the gradient to "-10", set "Power P (watts)" to 0.001 (i.e almost zero): With rider weight set to 50kg you will go about 59.54km/h With rider weight set to 75kg you will ...


1

This may be half-remembered physics coming into play here, but I've raced (substantially heavier) friends down hills where they've been on bikes which should - be all accounts - be slower than my own, yet they've won. Could momentum come into play over rougher terrain? By that, I mean if a rider carrying a heavier weight were to hit a bump, or hole etc, they ...


1

The short answer is yes. See Chris's post for the long answer. The main reason for this "answer" is to encourage great caution. As a teenager (in the previous millennium), I grew up in hilly area. There were two descents we used to do regularly - a two mile run from my friends farm to home, and a steep hill of one mile. My best time to get home was 2:11, ...


1

If there were friction it'd be the exact same (remember the hammer and feather on the moon deal). However - your net drag isn't really going to be proportional to your mass. The air resistance isn't proportional at all to your mass (although the rolling drag is). Due to this, you'll have less drag per kilogram with more weight which will cause you to go ...


1

I would not worry about it. I run my shocks with ProPedal on most of the time, and something else has always broken well before the rear shock gave out. You're not going to do any extra harm to the shock just because you ran it down a descent with ProPedal on. You should be more worried about bottoming the shock out or not keeping it properly serviced.


1

While shocks are certainly meant to be locked out and ridden, even over semi-rough terrain, there are probably some limits to the design. I'm not a fork/shock mechanic, but what I know about fluid dynamics tells me that you shouldn't do this too often! When you lock out your fork/shock it limits that compression of the fluids inside or prevents compression ...


1

Although I'm sure it's not the same, in MTB I use a very brief lapse of smooth pedalling while downshifting in a difficult ascent, it helps reducing noise and wear in the gearset. I accelerate a little before the shift, then, as I actuate the shifter I pedal without load relying on inertia. When I feel the new gear is fully engaged I resume normal pedalling. ...


1

I have often heard, and I agree, that the "muscular pump" is partly responsible for higher blood flow to specific muscle regions during activity. The reason is that between muscular contractions the difference in pressure is such as to draw blood from the arterial side to the venous side. It is a hypothesis and has not been conclusively proved. That may be ...


1

When riding in a group you often find that small changes of speed can mean that you do not need to pedal when it slows down and have small bursts of power when it speeds up. By soft pedaling when the group slows down your legs will already be spinning when its speeds up again.



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