Wide range set up for touring?

heavymental
heavymental Posts: 2,094
in Workshop

I've got a Tiagra 10 speed 50/34 11-42 setup on my tourer (genesis CDF) that I modified with a suntour dropper to increase the range on the derailleur. It works fine as long as I avoid big to big (it jams solid). The cables that protrude out of the side of the scruffy shifters have made me decide I need to spruce her up. I initially thought I'd stick a GRX groupset on there but I don't want to lose out on the top and bottom end gears I have currently. I'm struggling to find an off the shelf solution to give me a nice spinning gear ~34/42 and a decent top gear to prevent spinning out on descents ~50/11. Am I missing something or do I have to use my dropper again and stick 105 on there?

Comments

  • oxoman
    oxoman Posts: 537

    I suspect you mean dropout link or extender link rather than dropper which most people will think means seat dropper post. I think you'll struggle to get that wide a range to work tbh. You may get it to work with a 11 36, you may be able to possibly be able to replace your inner chain ring to slightly smaller if you can find the right bcd. You will need to your rear mech screws. Im assuming your using a long cage rear mech. Another alternative is to go single up front with 12 speed, but that's more expensive and you'll to check your bike will convert to it. I did convert my TCX from 11spd 105 46 -32 11 / 36 to single 38 to 42 which worked great for most stuff but not the lumpier stuff I do. Youtube may be worth trawling through as well. Big issue with 10spd will be jumps between gears and some tiagra isn't compatible with other level groupsets. Suspect you'll end up losing out either top or bottom end of your gear ratio which ever way you go.

    Too many bikes according to Mrs O.
  • Mad_Malx
    Mad_Malx Posts: 5,183
    edited July 14

    My tourer has grx 46/30 on the front and 11 sp 11-40 cassette and shifts perfectly in all combos. GRX chainset has +2.5mm offset, so your existing FD might not work. For hidden cables you could go to older 10sp 105 and keep your existing derailleur & cassette (I still have this on an older bike, works fine).

    I suspect your only option is to pedal faster. My setup gets to 34mph at 100rpm, at which point I don't need to pedal much faster.

    SRM XD hubs allow a 10T cassette, but frame may not accomodate new wheel needed, and will prob need full groupset upgrade so it's going to be an expensive route.

  • heavymental
    heavymental Posts: 2,094
    edited July 20

    Thanks folks, yes sorry meant a dropout link to extend the range of the derailleur.

    If I get the GRX RX820 2x12 groupset 31x48 on the front and a 11-36 cassette I will miss out on the top and bottom gears but I'm not sure how much I'll miss them as it'll be (gear inches) 115 vs 120 and 21 vs 23 at the bottom end which isn't a huge difference. Saying that, I'm not pressing on at the moment because I'm still wondering if 23 inches is enough at the bottom end for touring even though I haven't got a route in mind currently.

    Edit:

    Ah, having read around and checked youtube I see I can fit GRX 810 11 speed and an 11-40 or maybe even an 11-42 cassette which should do just fine.

  • froze
    froze Posts: 214

    My touring bike came with 11-36T with 44/32/24T chainrings, with 700c wheels, that means when I'm in the lowest gear I would be doing 5.5 mph at 100 RPM; but since it isn't a road bike the fastest the bike can go at the same cadence is 33 mph.

    That gear range means that with a heavy 60ish load a person should be able to ride up a pretty steep climb.

    When I bought my bike that particular one had the best gear ratio for climbing of all the bikes I looked at.

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