Viewing 16 posts - 1 through 16 (of 16 total)
  • Road bike gearing ratios, easy change?
  • bigmandh
    Free Member

    Been looking around at few threads as I’ve bought a second hand road bike with 52-38 chainset and 11-25 cassette. I think it’s going to be too much for climbing (thoughts on this?) and want to change to 11-28 to start with. Looking at the difference it’s just one cog,lose the 16t on the 11-25 and add the 28t at the top. To save me buying a whole new cassette can I just buy the 28t cog? If so does anyone know where I can buy it as can’t see any online or on eBay. Thanks

    pistonbroke
    Free Member

    There is no easy answer to any of this.
    You need to clarify what type of climbing you are aiming at, your fitness level, etc etc. Generally 38/25 bottom will be fine for general knocking about but if you’re looking to do long steep stuff then changing the small chainring to a 34 will give you less grief than trying to mess with the cassette ratios. Unfortunately you will also need to get a 50t big chainring as the max difference is 16 on most front mechs. By the time you’ve bought 2 rings, depending on the chainset the bike came with, it may be better to get a new chainset, such is the lunacy of parts pricing these days. If you try to increase cassette size, you will run into possible issues around rear mech capacity and chain length without getting the significant reductions you may be looking for.
    In a nutshell, it’s a minefield. Best bet would be to get out on the bike and get training.

    m0rk
    Free Member

    When I was a boy….

    42Tx21T was my bail out gear on my road bike.

    Admittedly I only weighed 10 Stone and was all leg muscle

    Now I can drag up most steep things with 34Tx28T because I’m older & 50% heavier

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    globalti
    Free Member

    Get a compact chainset, which is 50/34 then change the cassette to an 11-28. This is the gearing that’s on most of the bikes sold to born again cyclists and is appropriate for the untrained rider. Like me.

    mrblobby
    Free Member

    I think it’s going to be too much for climbing

    Why do you think that? Just get out and ride what you’ve got, see what gears you find yourself in most, see how you get on, then decide. You could always just swap the little ring for a 36t, or both for a 50/34.

    edhornby
    Full Member

    http://singletrackworld.com/forum/topic/big-rings-moving-to-5339 there is another thread alive at the moment…

    I switched from 11-25 to 12-28 to give more options – if you are talking about a week in the alps/pyrenees then get a 34-50 compact and keep the cassette you have

    dovebiker
    Full Member

    You’ll need to buy a new cassette rather than change a single sprocket – few break-down to individual sprockets these days. Your chainset probably takes 130mm BCD chainrings – a smaller inner chainring won’t fit so easier/cheapest is simply to change the whole chainset. Whether your current gears are suitable for climbing depends on your fitness and where you are riding – probably fine for Essex, Suffolk, Cambridgeshire, Norfolk, Leicestershire and Lincs but maybe less so elsewhere.

    jonba
    Free Member

    You will need a whole new cassette. You might be able to get an 12-30 or 12-32 if you look.

    Are you sure it is 52,38 at the front. I thought the common ratio was 52,36?

    What is too much for some is fine for others. Depends on the climb, rider fitness and preferred style. The right answer is not dependent on what others think it is what works for you.

    You might be able to get a 36 ring for the front relatively cheaply.

    The easiest way compare gears is to divide the number of teeth at the front by those at the rear to get the ratio. Smaller number = easier gear.

    mattsccm
    Free Member

    If its Shimano you won’t go smaller than 38 and that one is a replacement as the standard was 39/53. (Now I call that the new standard). Sticking a 12-28 or even a 13-28 cassette on will help. I’d try that first.
    If its still too much get a compact chainset. As fitted as standard to most bikes this century. Normal will be 34/50. That should really be more than enough unless you are a porker or live in the hills and climb Rosedale every day.
    Oh for those gears as a kid.
    It was 42/52 with a 5 speed block of 13-23.
    My TT wheels were 5 speed 13-17. I even rode those gears with a heavily laden Carradice all the way from the FoD to Poole, the hilly way when I was 17. Ah, those were the days. 😆

    whitestone
    Free Member

    It was 52/42 and a six speed 12-24 block for me in the 1980s in the Lakes. I wonder why I’ve such big legs? 🙄 Got the bike just as SIS came out

    These days I’ve gone the MAMIL compact route.

    wilburt
    Free Member

    Get a compact 50/34 chainset and a 12-27 11-28 or even 12-30 cassete anything big basicaly and a new chain.

    bigmandh
    Free Member

    Thanks for comments. I definitely agree with the just get out and see how it is concept. That was the plan this weekend till a fall and some stiches in the leg at Glentress on Thursday night put heed to that for a week or 2. I just got into road biking last year after years of mtb,bought a giant defy (with compact on it) and have enjoyed it,hence the new purchase. Love my climbing and I’m decent enough at it plus being up in Scotland it’s a bit hilly in places. Have entered etape royal and kom sportive this year so will be a fair bit of climbing involved. Was over in Tenerife with the giant at Xmas as well and needed all the gears for Mount Teide. It’s dura ace Di2.on the new bike so won’t be a cheap fix but can hopefully sell the nearly chainset and/or cassette I have and not lose too much, though probably less demand for the 52-38 by the sounds of it if compact is the most popular now.

    pitchpro2011
    Free Member

    Compact and 32t rear its the way forward.

    wilburt
    Free Member

    Are you sure its 52/38 sounds like a new bike with mid compact which would be 52/36 so a bit more flexible than first thought. Either way I wouldnt sell it, full fat gearing is better for the flatlands as quoted above but I would actually just by a compact chainset.

    ianfitz
    Free Member

    If it’s the new 4 bolt asymmetric cranks I thought the bcd was the same? If so you can swap chain rings as any size will fit. You will need to make sure the size difference stays the same though. 34/52 will probably be too big a gap

    bigmandh
    Free Member

    Yeah it’s definitely a 52/38

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