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Coast to coast

goldcolgoldcol Posts: 20
Hi there,
I am all signed up to do the c2c on the 29th June and had a question regarding the gearing on my bike. I have a 12-25 which I recently used on the wye valley warrior which is a hilly route. However c2c has 4600 meters of climbing and takes in hardnot pass, possibly 30%.
What are your thoughts on a 12-25 for this kind of event. My rear mech will take a 27 but I only recently replaced the 25. Would the 27 make much of a difference and is the 25 fine ?



Cheers.
Col.

Posts

  • lc1981lc1981 Posts: 820
    You probably need to say what chainrings you have as well, in order to get a meaningful answer.
  • goldcolgoldcol Posts: 20
    Arh yes, thanks for the tip. It's a rival 50/34t compact.

    Cheers
  • t4tomot4tomo Posts: 2,643
    I very much depends on your legs but you SHOULD be Ok with 34X25, but 34X27 is ~10% lower. petty hard to simulate a longish climb with bits of 25-30% in it, but if you do something steep locally are you always in the 25 sprocket? If yes then mighy be worth spending £30 on a 12-27 cassette.
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  • RuntothehillsRuntothehills Posts: 184
    Time for some boring numbers, main thing I'm trying to highlight is the sheer force you need to push on the pedals with and the power requirements compared to flat riding.

    On a 30% slope at 40 rpm in a 34X25 you'll be going at 4.5 mph, and need a power output of 500W to maintain speed. For a 34x27 this drops to 4.2mph and 450W ish (depending on body weight, I'm just under 80kg) you'll also need to be pushing down with 1.14 times the combined weight of you and the bike with each pedal stroke even in the 27.

    For reference a steady 20mph on the flat, no wind on a road bike needs around 200W (ballpark figure)

    I'm doing the coast to coast in a day as well on a 34x27 (the gearing the bike came with)- but unless you really think the 27 will allow you to ride the entire thing I'd stick to the 25 and be prepared to push the steepest sections, it won't be much slower (at this point you'll be doing 4mph anyway) and chances are it won't destroy your legs as much for the 100miles+ to go.

    I'll be trying to tell myself this so I don't completely destroy my legs by pushing too hard out of pride to get up the climb without getting off - I don't think it'll work
  • goldcolgoldcol Posts: 20
    Thanks for your comments. Its a complicated to say the least. It's not necessarily hardpoint i am worried about. I did the Wye Valley Warrior a couple of weekends and the climbs were becoming much more difficult the more mileage i had done. Granted i was going a lot quicker than my training and managed it in 5hr 45min but suffered with cramps from 60 miles onwawrds.

    Obviously i will be taking it a lot easier for C2C but some of the climbs later on in the ride are beast too, it seems to be continuos up and down.

    The bike shop have told me yesterday my cassette is worn anyway(slipping gears) I may put the 12-27 or 11-28 SRAM on or opt for the Ultegra 12-30 if my der can take it.

    Would there be noticable difference going from the 12 to the 11, i am just thing that gives me an extra tooth for climbing???

    P.S what time you looking to do the c2c in or is it case of just getting to the end. Time is secondary for me!!

    Thanks
    Col
  • t4tomot4tomo Posts: 2,643
    goldcol wrote:
    The bike shop have told me yesterday my cassette is worn anyway(slipping gears) I may put the 12-27 or 11-28 SRAM on or opt for the Ultegra 12-30 if my der can take it.

    Would there be noticable difference going from the 12 to the 11, i am just thing that gives me an extra tooth for climbing???
    Thanks
    Col

    You will hardly notice the switch of your top gear being 11 and not 12. I imagine you are rarely spinning out in 50x12, it will be marginally harder (10%) to spin out in 50x11). Wiggle sent me a 11-25 rather than 12-25 when i last replaced my cassette and i couldn't be fagged to change it - I barely notice the difference tbh.

    What the 11-28 does give you is a slightly lower bottom gear for climbing - but then also more gaps in the gears as it has to jump 2 extra teeth somewhere in the range. If you've never thought damn I which I had a higher gear than 50x12 then the 12-27 is probably the best choice or 12-30 if you feel you want more lower gears.
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    Carrera Vengeance Ultimate Ltd
    Gary Fisher Aquila '98
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  • edhornbyedhornby Posts: 1,780
    if you are doing whitehaven to sunderland then you may not have to do hardknott - when I did it we did whinlatter and hartside which aren't quite as nasty (both are 15%ish) but that was over 2 days just following the sustrans signs

    I did it on 39/25 bottom gear because they were the gears I had on my bike, it was ok but when the cassette is due for replacement I will get a 27
    "I get paid to make other people suffer on my wheel, how good is that"
    --Jens Voight
  • goldcolgoldcol Posts: 20
    Thank you for the advice. I think I will go for 12-30 as I love the hills, if I ever become contador like I will change it down but I think it will be a pretty safe bet to go with the 30.

    I have just downloaded the gpx file from the open cycling webbie and it looks really hilly and does take in hardnot pass. This is my own fault as I normally over prepare for a challenge and normally breeze it, all a little different now with 2 kids so I tend to worry more.

    Based on my limited training 150 miles, 12000ft of climbing, I think this may be a tough one, better pack the lights :)
  • RuntothehillsRuntothehills Posts: 184
    I'd agree with the 11 vs 12 thing - looking at some of the descents I'm not planning on peddling down them, more worrying about slowing down enough! I'm on a 12 at the moment and it gets me to 40mph just fine.

    30 sounds nice, unfortunately I live in Cambridge (not the hilliest) so can't really justify spending the money to go from a 27 to a 30. Having to row for cross training to get leg strength up :)

    In terms of time I'm not too concerned, I think I should take around 10hrs. Only previous sportive is the Exmoor beast (100miles) which took me less than 7hrs but looking at the times last year was a slow year, that was enough to put me about a tenth of the way down the list of finishers!
  • smidsysmidsy Posts: 5,273
    Having bigger cassettes is like the american thing for guns.

    It is better to have one and not need it than the alternative.

    Get the 28 or 30 if your mech will allow.
    Yellow is the new Black.
  • durhamwaspdurhamwasp Posts: 1,238
    Really shouldn't need to go over Hardknott pass, that's not the normal way to do that C2C, infact ive never heard of it.

    First real climb should be Whinlatter, and the second one Hartside. Both are easily doable on a 34 x 25, but a 27 or 28 on the back would be a great insurance policy!
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  • Coast to coast in a day sportive isn't the normal coast to coast route, more details on this website

    http://www.opencycling.com/

    There's no need to go over the Hardknott, but then again there's no need to do the thing in the first place so why not?
  • How did it go goldcol? Personally I though it was a great ride: well signposted, good route and nice weather!
  • Well done all who took part, we were running the feed station at Hardraw, Great to see so many peolple taking on an epic. A few pics can be seen here.
    http://www.racingsnakes.com/c2cphoto.php
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