transition from steep descent to steep ascent

john mac54
john mac54 Posts: 3
edited January 2013 in Road beginners
Couldn't find anything on this subject and I'm looking for some advice.

Been cycling for a couple of months now and something I find dificult is selecting the correct gear to be in when changing from a steep descent to a steep ascent.

I never seem to be in the correct gear. Tried both staying in the high gear and changing down as I ascend (dont seem to be able to change down quickly enough before pedaling get very difficult) and changing down before the start of the ascent(legs spinning but not actually doing anything) but never seem to get it right.

Any thoughts on what I should do

Cheers

Comments

  • rolf_f
    rolf_f Posts: 16,015
    Just make sure you change to the small chainring first. You need to cover a much longer distance to shift the front and the change is horrible under load. Once you've got that sorted, you should be able to run up the cassette fairly quickly. On a steep climb you'll not carry any speed far anyway so, if you are worried, it is probably better to get into a low gear and coast up until you reach a speed you can pedal at - that's a lot more efficient than stopping and having to restart again!
    Faster than a tent.......
  • smidsy
    smidsy Posts: 5,273
    It takes practice and experience. You get to know what hills you can take on in the big chainring and which ones need the small one.

    Once you have that sorted it is fairly easy to change into the small ring (if needed) and the just worry about the rear cassette. If you can start in a small sprocket (12 or whatever you have) you can then move up the cassette as your speed slows. The idea being to maintain momentum and keep your cadence in your sweet spot.

    Also if you need to you can flick down to the small chainring AND up or down the cassette at the same time (with practice) which saves you time and helps to minimise the speed deficit you describe.
    Yellow is the new Black.
  • john mac54 wrote:
    Tried both staying in the high gear and changing down as I ascend (dont seem to be able to change down quickly enough before pedaling get very difficult)
    Sorry if this is a dumb question, but are your gears actually working properly?

    On mine, ok, so changing from large chainring to small takes maybe 1.5s before it's running smoothly, but the rear ones change pretty much as quickly as I can click the lever.

    And if I'm going from a medium gear on the large ring, to a hill, I change large to small at the front while clicking three times up at the back, which is more or less the same ratio, and then I change down from there. I ease off on the pedal pressure during that process - it seems to be smoother than if I keep pushing hard all the way through.

    I only have Tiagra, so nothing stellar there. It just works, and I'd be a bit concerned if it didn't?
    Is the gorilla tired yet?
  • nawty
    nawty Posts: 225
    Assuming you have a modern bike with shifters in the break levers (as opposed to levers on the downtube) then it should be fairly simple.

    I do as above, as in assess the hill and select the chain ring appropriately and then go down the gears as necessary to keep cadence up. That said, there aren't that many hills around me that necessitate the small chain ring so I just stay in the biggie and try and power up!
    Cannondale CAAD 10 Ultegra
    Kinesis Racelight Tiagra
  • pinno
    pinno Posts: 51,195
    Grab the bumper of the first car that passes you on the way down and hang on :D

    On a serious note, I change to somewhere in the middle of the cassette on the last bit of the descent and then as you run out of momentum and pedalling speed, flick off the big chainring and suddenly your in a light gear which you can adjust (up or down 1 or 2 sprockets) quickly. Coming off the big chain ring is pretty rapid so long as you are not forcing the pedals over.
    I'll bet my bottom dollar you will chabge 2-3 times during the ascent (if its long enough). On a good day you'll maybe carry the big ring for longer before coming off it and on a bad day, you'll be red in the face before you can say 1 in 6, so there is no exact way to do it except remember the gear you are first in during the climb. Say its the 19t sprocket, hypothetically. Then be on the big ring and also on the 19t sprocket before ascending and hey presto. Bit crude but once you have done the hill a couple of times, you'll know exactly what gear to be in and get a march on yer mates.
    seanoconn - gruagach craic!
  • nolight
    nolight Posts: 261
    It is hard for me to imagine a situation where I have problem transitioning from steep descent to steep ascent, not sure is it because of where I live.

    On 11-25T rear, 53/39 front:

    When I am descending at high speed, say front high (53) + rear 6th gear (15), gear ratio 53/15 = 3.53
    A single front gear shift down (39) leads to gear ratio 39/15 = 2.6
    At such high speeds, surely the momentum will allow me to shift down a couple to rear 4th, gear ratio 39/19 = 2.05

    3.53 to 2.05 with just 3 easy shifts. Surely this drastic change of gear ratio is enough to get through a sharp transition which you can then adjust to even lower with further shifts (I seldom need to). Or are we talking about a monster of a valley?
  • rolf_f
    rolf_f Posts: 16,015
    nolight wrote:
    It is hard for me to imagine a situation where I have problem transitioning from steep descent to steep ascent, not sure is it because of where I live.

    On 11-25T rear, 53/39 front:

    When I am descending at high speed, say front high (53) + rear 6th gear (15), gear ratio 53/15 = 3.53
    A single front gear shift down (39) leads to gear ratio 39/15 = 2.6
    At such high speeds, surely the momentum will allow me to shift down a couple to rear 4th, gear ratio 39/19 = 2.05

    3.53 to 2.05 with just 3 easy shifts. Surely this drastic change of gear ratio is enough to get through a sharp transition which you can then adjust to even lower with further shifts (I seldom need to). Or are we talking about a monster of a valley?

    Quite common in Yorkshire to find yourself descending steeply into a deeply inscised stream valley only to cross a bridge, round a corner and find a 20%+ climb immediately infront of you without warning - you can need to change from 50-12 to 34-25 in seconds. Any fast descent of any gradient can lead rapidly to a steep, unexpected climb - not by any means necessarily 'a monster'.

    You need to come to cycling country and try it out! :wink:
    Faster than a tent.......
  • ShutUpLegs
    ShutUpLegs Posts: 3,522
    As others have said its practice, but also being familiar with the ascents you are riding and knowing your capability.
  • bigmat
    bigmat Posts: 5,134
    I have been caught out a few times like this and have ended upp dropping my chain a few times, snapping a chain, and the worst occasion in the Peak District bending my big ring at 45 degrees! Front shifting under extreme power is a risky business. Best bet if you know there is a climb coming is to power down, move to roughly middle sprocket at the end of the descent, as you hit the climb power up to use your momentum and before that momentum has gone shift down to the small chainring. This tends to work for me. Great example here:

    http://www.strava.com/segments/central-hill-798134

    The stretch preceding the climb (Crown Dale) is a 30mph+ descent which very quickly turns into a 10%+ climb - if you get your shifting right you can really power through the steep start to the hill.
  • Kieran_Burns
    Kieran_Burns Posts: 9,757
    Gawd... I am doing this so wrong!

    I power all the way through and up the other side in the highest gear I can then click down 4 gears as needed (9 speed rear on the Tricross). Once I'm in the middle of the cassette I flick it to the middle ring, and spin up the rest.
    Chunky Cyclists need your love too! :-)
    2009 Specialized Tricross Sport
    2011 Trek Madone 4.5
    2012 Felt F65X
    Proud CX Pervert and quiet roadie. 12 mile commuter
  • Thanks for the advice

    Looks like I need a bit more practice getting into the correct gear and in changing down/up the chainring and cassette at the same time, keeping my cadence up before any momentum runs out.
  • rolf_f
    rolf_f Posts: 16,015
    john mac54 wrote:
    Thanks for the advice

    Looks like I need a bit more practice getting into the correct gear and in changing down/up the chainring and cassette at the same time, keeping my cadence up before any momentum runs out.

    You just need to plan the shifts a little in advance. The more practice you get, the less advance it needs to be.
    Faster than a tent.......