Downhill then immediately up : gear selection ?

[sylvestermorgan]

Learning my way around a road bike, so here goes the scenario. I’m descending a hill and I can see hill climb on the other side – so a straight down then up again. So I figure I’ll charge down the hill in the highest gear I can muster to get as much momentum as possible onto the hill climb on the other side. For this, I’m in the big ring as I go down hill pedalling hard. What I normally do is drop to the small ring just before the hill climb starts and move to a moderate gear (to avoid cross chaining). The problem is that I then enter this dead zone of wasted effort where pedalling is futile because the bike is going faster than the gear I’m in so I end up being slowed by gravity on the climb until eventually I reach a peed where I’m able to apply pressure to the pedals.

Doing this, I always feel I could have done more to carry my momentum further – as in pushed a bigger gear up the climb for awhile before dropping down the gears. Obviously, if I did that it means I’d have to drop onto the small ring mid-climb, which is surely a no-no. Is there a better way of doing this?

[Graham]

Er . . .. . stay on the big chainring for the early part of the climb.

Drop to a smaller chainring as necessary whilst climbing. Any extreme chain angles are transient - this is not a problem.

EDITed to add . . .
If you are fearful of dropping onto a smaller chainring during a climb, there may be some problem with your technique.

Please describe any chainring downshifting problem. Maybe we can help.

[Brucey]

depends how steep the hill is and how much effort you can apply for the duration of the climb really.

If the hill is not too steep and you know your gears well, I'd suggest that you

a) shift to a middling sprocket just before you start to climb again

b) spin that gear (at a higher cadence than normal) until you start to slow down slightly, (i.e. so that you are pedalling at a normal cadence but still slowing up)

c) drop onto the small chainring so that your cadence is maintained

d) shift again as needed (in a normal way) according to gradient and power available.

So if you are doing 35mph downhill, you can shift to a ~90" gear and use that until you are doing about 20mph or so, then drop onto the small ring where a gear of ~60" might take you a bit further before you have to downshift again.

The trick is of course to downshift promptly in all cases, so that you shift quickly and smoothly. Apologies if this seems obvious, but the speed of shifting (esp at the front) is everything to do with cadence and very little to do with road speed, so don't let your cadence drop too much if you think you might have to downshift again.

cheers

[sylvestermorgan]

I know I sound really silly, but at the point I decide to drop to the small ring mid- climb I have to crunch my chain as I force it across under high torque risking snapping my chain and/or damaging teeth. I always thought this was a no-no, or is there a technique to doing this well?

[thirdcrank]

In addition, be grateful for modern gearshifters which allow you to keep both hands on the bars.

[sylvestermorgan]

depends how steep the hill is and how much effort you can apply for the duration of the climb really.

If the hill is not too steep and you know your gears well, I'd suggest that you

a) shift to a middling sprocket just before you start to climb again

b) spin that gear (at a higher cadence than normal) until you start to slow down slightly, (i.e. so that you are pedalling at a normal cadence but still slowing up)

c) drop onto the small chainring so that your cadence is maintained

d) shift again as needed (in a normal way) according to gradient and power available.

So if you are doing 35mph downhill, you can shift to a ~90" gear and use that until you are doing about 20mph or so, then drop onto the small ring where a gear of ~60" might take you a bit further before you have to downshift again.

The trick is of course to downshift promptly in all cases, so that you shift quickly and smoothly. Apologies if this seems obvious, but the speed of shifting (esp at the front) is everything to do with cadence and very little to do with road speed, so don't let your cadence drop too much if you think you might have to downshift again.

cheers

Ahhh, you might have answered my question about how to do it - it's a question of high cadence to get the smooth shift, not what I do now which is typically allow my cadence to drop too low before dropping to the lower ring.

[ndwgolf]

I’m interested to find out about this too
Neil


I'm a trendy consumer. Just look at my wobbly bog brush using hovercraft full of eels

[Graham]

? Overly slow cadence = the rate at which you are spinning the cranks around

. .. possibly related to . . . .

? Too high a gear selected while hill-climbing = too much brute force

. . . . and / or . . . . .

? a technical / adjustment problem with your gears

Most experienced cyclists spin the cranks around 80 - 90 r.p.m. Easing off for a moment whilst changing gear, whilst climbing, is more than a good idea ( especially at the chainring end ).

[Cyril Haearn]

Freewheeling is the word, even non-cyclists use it, are you on the way to an emergency?
Might be a good idea **not** to use large chainring and large sprockets, if the chain is not long enough this could cause disastrous damage, it is a middle gear that one does not have to use

[Vorpal]

As above, it depends on a number of factors.

For me, it also depends how much of a hurry I'm in.

On my way to work, I go through the gears I need to maintain my pace. My route to work is mostly up hill, so I shift to easier gears when it gets steep, and harder gears when it get a bit less so. The couple of bits where I have some flat or downhill, I go right up through the gears. Going home, I'm in the top gear most of the time, and freewheeling only when pedalling doesn't do anything for me. The couple of bits that are uphill, I go down a couple gears in the back, but usually stay in the big ring at the front.

On the other hand, if I am on a leisure ride, and stopping to take photos or look at things, I tend to put my bike in an easier gear and freewheel, then start pedalling approximately when the gear matches my speed and pace.

I also pilot a tandem, which has slightly different shifting needs. I cannot easily shift down on the big ring whilst going up hill, so I put it in the small ring before we start up, and only shift on the back, or preferably not at all. That does require a certain amount of advance planning and judgement about the nature of the hill. When I was learning, I forgot, or got it wrong a few times, and ended up pushing.

[foxyrider]

It's always a good idea to make the front change before you get to the grinding point and just easing the pressure on the pedals slightly will aid a quick down shift.

One 'trick I use on some 'known' climbs is to down change the front in the bottom but keep the rear in a small sprocket. No front change needed on the climb but a good range of gears to go through on the ascent.

[ndwgolf]

Most experienced cyclists spin the cranks around 80 - 90 r.p.m. Easing off for a moment whilst changing gear, whilst climbing, is more than a good idea ( especially at the chainring end ).

i just find 80 plus cadance to fast for me. My comfort cadance is between 65 and 75...... so my question is is it really necessary to strive for a higher cadance at my weight and age ??
Neil

[thelawnet]

I know I sound really silly, but at the point I decide to drop to the small ring mid- climb I have to crunch my chain as I force it across under high torque risking snapping my chain and/or damaging teeth. I always thought this was a no-no, or is there a technique to doing this well?

This depends but basically if you are currently pedalling very hard then changing is never really a good idea, regardless of any hill - you need to ease off just slightly to change.

Essentially you should find that as you start climbing the hill, your residual momentum makes it very easy to change down, providing you are also not putting through a high amount of torque through the pedals. If you wait too long climbing the hill, or if you are pedalling hard, then it will crunch. The change should come as you start climbing the hill, not before, but you must ease off the pedals slightly.

[mjr]

In addition, be grateful for modern gearshifters which allow you to keep both hands on the bars.

Keep your brifter advocacy out of this topic, please! It has literally nothing to do with this. The difficulty is knowing the correct point to downshift before your cadence drops too low and you crunch the chain.

Anyway, my usual approach is to coast down the hill, shifting into top early on, then pedal to take the strain just before the bottom of the downhill and shift down as needed as normal as I ride up the next hill. Pedalling downhill seems wasteful unless I'm confident that I'll clear the uphill at speed (more common in the rolling midlands where I grew up).

[Vorpal]

Ahhh, you might have answered my question about how to do it - it's a question of high cadence to get the smooth shift, not what I do now which is typically allow my cadence to drop too low before dropping to the lower ring.

Yes, that will help, but one thing that I don't think anyone has said, is that the trick is *not* to go all the way in (easier) in the back before you shift the front.

Apologies if I'm teaching granny to suck eggs, but to me, the best way to avoid cross-chaining is shift to an easier gear in back, perhaps halfway through the gears, then to an easier gear in front, then in the back again. With a triple, if I want to use all the gears, I shift easier in back, two or three gears, then easier in front, then two or three in back, then front again.