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Gear (not clothing) question. I just can't get my head around it.

Spartacus1981Spartacus1981 Posts: 254
edited April 2016 in Road general
I'm thick I think so can someone help me as I don't understand gear calculators. Long and short I'm doing Fred Whitton (that's another thread) but let's say for example I have one bike with 53/39 and 11-32 ... And another with 50/34 and 11-28. How close are the easiest gears to one another ?? As in the 39 with 32 combo VS the 34 with 28 combo ? Can someone help me with this ?

Posts

  • WheelspinnerWheelspinner Posts: 5,015
    edited April 2016
    Eh?
    39/32 is 1.219:1
    34/28 is 1.214:1

    The difference between these two is less than half a percent, or put another way, censored all. You won't notice anything.

    HOWEVER if they're both 11 speed cassettes (or the same number of gears anyway) then the 11-28 will have closer ratios than the 11-32, meaning your lowest two or three gears will be better matched, and give you more options to find the right gear to spin up a climb. Bigger gaps between ratios just means you sometimes either spin like a hamster or grind too slow.

    All other things being equal between the two bikes, you're better off riding the 50/34 and 11-28 combo in a very hilly course.
    Open O-1.0 Open One+ BMC TE29 Titus Racer X Ti Giant MCM One Cannondale Prophet Lefty Cannondale Super V SL Cove Handjob Cervelo RS
  • All you're going to get is a number - inches or ratios can help you to compare one to gear to another. It's obviously a lot more useful if you have some idea of what the differences feel like. Speed at cadence can be useful for this too.
  • Thanks for your responses. I guess that's what I was hoping for Wheelspinner. In actual fact I was more likely to be riding the bike with the 53/39 and 11-32 combo, which I don't yet have actually and is why I asked !! Plus I don't want to get dropped by my mate who'll be on 50/34 and 11-28 for the occasion. Let's say we're of similar uphill ability for the sake of the question.
  • Hopefully I'll just be able to spin like a hamster still with the 39 and 32 lowest gear. Time will tell when I get the bike in a day or two. Personally I normally ride 52/36 with 11-28 anyway so I've got a fall back. Was just hoping to use this new bike.
  • ravey1981ravey1981 Posts: 1,111
    The real question is why are you speccing a bike with a standard double if you need a 32 cog to go with it? With that combo you have the best of no worlds so to speak....
  • I didn't spec the bike. That should be clear from my second post. Does that help ? I just wanted to know how close the easiest gears were when compared with one another. If it were any normal ride I would just ride what I had.
  • Sorry, maybe it wasn't clear. It's a bike I bought on eBay. I wouldn't have opted for this combo personally but it is what it is.
  • 6wheels6wheels Posts: 411
    This should help, you can compare all your gear ratios...

    http://www.bikecalc.com/gear_ratios
  • fenixfenix Posts: 5,437
    Swap the wheels over and see if you can get away with running 34-32 on the hills ? Nobody ever complains that they have too low a gear...
  • markhewitt1978markhewitt1978 Posts: 7,614
    Sorry, maybe it wasn't clear. It's a bike I bought on eBay. I wouldn't have opted for this combo personally but it is what it is.

    Well it is and it isn't. If the chainsets both take the same BB you can just swap the 50/34 onto the new bike and have 34/32 as your lowest, and knowing the Witton you'll need it.
  • davep1davep1 Posts: 777
    Thanks for your responses. I guess that's what I was hoping for Wheelspinner. In actual fact I was more likely to be riding the bike with the 53/39 and 11-32 combo, which I don't yet have actually and is why I asked !! Plus I don't want to get dropped by my mate who'll be on 50/34 and 11-28 for the occasion. Let's say we're of similar uphill ability for the sake of the question.

    In my experience you need to spin up the hills, so go with the compact. I used to have a 53/39 with 11-25, and all my mates on compacts would stay seated far longer into the climb, and all would pull away from me as the climb went on. I change the cassette to a 11-27 and eventually 11-29 and started to feel the benefits.

    I now have a 52/36 which was on 11-28, but have swapped to 11-32 for the Fred. Every hill seems that little bit easier, the need to get out of the saddle comes later. The South Downs doesn't have anything like Hardknott though!
  • philbar72philbar72 Posts: 2,228
    compact all the way. most cyclists that have trained for the fred Whitton should be able to climb, and 34 x28 should just about be enough for the tough stuff.
  • Thanks for the answers guys. Might chuck a compact chainset on in place of the standard and benefit from the 32 on the cassette as well. I'm not afraid of climbing by any stretch but might need all the help I can get on this route.
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