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How many gears?

(53 posts)
  • Started 10 years ago by bueller
  • Latest reply from i
  • This topic is not resolved

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12

  1. Roibeard
    Member

    Sturmey Archer 2 speed - 115-140% (depending on model)
    Sturmey Archer 3 speed - 115-178% (depending on model)
    Shimano Nexus 3 - 186%
    Sturmey Archer 4 speed - 145-190% (depending on model)
    Shimano Nexus 4 - 184%
    Sturmey Archer 5 speed - 225-256% (depending on model)
    Shimano Nexus 7 - 245%
    Sturmey Archer 7 speed - 280%
    Sturmey Archer 8 speed - 305-325% (depending on model)
    Shimano Alfine 8 - 307%
    NuVinci Continuous Variable - 350-360% (depending on year)
    Shimano Alfine 11 - 409%
    Rholoff - 526%

    Derailleur 24/44 chain ring 12/34 cassette - 519%

    (Although one could perhaps go more extreme than this.)

    Courtesy Sheldon and Rholoff

    Robert

    Posted 10 years ago #

  2. I were right about that saddle
    Member

    @Roibeard

    Thanks! That has motivated me to do the arithmetic on my bike, and conclude that I have twelve gears on the ratty nineties hybrid;

    Front Rear Metres
    1 ......1......1.99
    1.......2......2.60
    1.......3......2.94
    1.......4......3.38
    1.......5......3.97
    2.......4......4.43
    2.......5......5.21
    3.......4......5.49
    3.......5......6.45
    3.......6......7.31
    3.......7......8.44
    3.......8......9.97

    out of a possible twenty four, allowing for duplication and fouling of the chain on the front mech cage.

    The Rholoff looks like a very neat replacement, given that I almost never use 3:8.

    Posted 10 years ago #

  3. chdot
    Admin

    "The Rohloff looks like a very neat replacement"

    Only if you have the sort of usage that can justify the price!

    Posted 10 years ago #

  4. I were right about that saddle
    Member

    "Only if you have the sort of usage that can justify the price!"

    Or the sort of bank balance that makes this a mere trinket, darling.

    Posted 10 years ago #

  5. chdot
    Admin

    "Or the sort of bank balance that makes this a mere trinket"

    To some extent, but if you look at 'lifetime cost', will be better value than a series of carbon racers if yours is the sort of riding/use that would suit a Rohloff.

    Posted 10 years ago #

  6. I were right about that saddle
    Member

    A Rholoff hub is a trinket, a carbon racer is a bauble, sweetie.

    Posted 10 years ago #

  7. cb
    Member

    "Sturmey Archer 3 speed - 115-178%"

    Did the engineers at SA not think that they were wasting their time building a 115% hub?

    Why does Sheldon's gear calculator include crank length? Does it make a difference? It doesn't seem to affect the results.

    Posted 10 years ago #

  8. wingpig
    Member

    If Rohloffen had a few sturdy loops spread evenly around their middles for threading a lock through they'd look a bit more useful for general-purpose use, rather than never-leave-it-unattended use.

    Posted 10 years ago #

  9. kaputnik
    Moderator

    Why does Sheldon's gear calculator include crank length?

    It doesn't change the ratio but it changes the actual gear length - maybe to help people looking for specific gear lengths using available hubs, sprockets, chainwheels etc.?

    Posted 10 years ago #

  10. firedfromthecircus
    Member

    CB, if you read his bit on 'gain ratio' it makes sense.

    Posted 10 years ago #

  11. Roibeard
    Member

    @CB Did the engineers at SA not think that they were wasting their time building a 115% hub?

    Rohloff seem pretty proud of their 14% steps, and have some arguments to defend that spacing of gears.

    Basically, they think you don't notice a step of <10%, whereas steps of >20% are two big a jump. 15-20% is doable, but not for smooth transitions.

    My current Brompton setup (6 speed BWR) has 23/27% jumps, which I can't really distinguish, but it was shipped with 18/33% jumps (i.e. 18%, then 33%, then 18%, etc) and these were noticeably different.

    So, yes, I'd suspect that having only ~8% between each of the three gears would be pointless except for the racer.

    <wanders off to check>

    Yep, Sheldon records that such ultraclose range hubs were made for timetrials and racing!

    Robert

    Posted 10 years ago #

  12. Dave
    Member

    I wonder if anyone has done studies with continuously variable transmissions to see how much people change gears by when they can choose any amount for themselves.

    Personally I quite like having big jumps, especially at the top and bottom end. 20% means a cadence shift from 110RPM to just under 90 (or vv) which is often quite manageable.

    In the middle I do appreciate closer spacing, it's true. When you are in a sort of steady-state and just want to tweak things, it's nice not to be interrupted by a gear shift.

    Luckily with modern transmissions you can have it all. My 10 speed 11-32 is literally like an 8 speed 11-25 with two even bigger cogs... magic!

    Posted 10 years ago #

  13. sallyhinch
    Member

    Spotted on Twitter

    https://twitter.com/KarlOnSea/status/486423311162036224

    Posted 10 years ago #

  14. paulmilne
    Member

    A sturdy Dutch sit-up-and-beg bike needn't break the bank. I've always liked the look (and price) of these, and they come fully-loaded with all the extras as standard - dynamo lights, kickstand, skirt/coat guard, bell, mud-guards, etc.

    Oh, and free delivery.

    http://www.dutchie.co.uk/dutch-bikes/

    Posted 10 years ago #

  15. bueller
    Member

    @Paulmilne, these do look great and good price, they are a bit cagey on declaring the weight though hmmmm

    Posted 10 years ago #

  16. gembo
    Member

    Weight on the dapper eight speed in the specificatins is 20kg

    So pretty light. Maybe not steel tubing? Not sure how reliable the sturmey archer eight spd is. But the price is keen.

    Three speed chic has a shimano three speed hub, again not sure how reliable range 186per cent compared with 325 on the eight speed.

    NB wheel size is 28 inch so replacing tubes, tyres etc ever so slightly more complicated.

    Chic three speed weighs 19.5 kg they are made in holland is the claim.

    Come with front wheel and pedals detached but should be straightforward to assemble.

    Two hundred odd quid cheaper than Pashley as I guess no brooks saddle, no marathon tyres, no Reynolds steel. But much lighter and still has lights, frame lock etc. nice.

    Further investigation reveals the bikes are steel. No mention of Reynolds. However, the lights are not dynamo.

    Posted 10 years ago #

  17. chdot
    Admin

    "Weight on the dapper eight speed in the specificatins is 20kg

    So pretty light."

    If you say so!

    "wheel size is 28 inch so replacing tubes, tyres etc ever so slightly more complicated."

    Suspect they are just normal 'fat' 700c.

    "

    Size designation 37-622 28 x 1.40"
    28 x 1 5/8 x 1 3/8" 700x35c

    "

    http://www.schwalbetires.com/tech_info/size_markings

    http://sheldonbrown.com/tire-sizing.html

    Posted 10 years ago #

  18. Greenroofer
    Member

    Just seen one of these in the bike park at work. A thing of rather elegant beauty, I thought.

    http://www.retrovelo.de/paula-en.html

    No idea about price or anything...

    Posted 10 years ago #

  19. Greenroofer
    Member

    Ah. Now found the price. It's four figures...
    http://www.velorution.com/catalogsearch/result/?q=retrovelo

    Posted 10 years ago #

  20. bueller
    Member

    Oh my, that's a pretty bike.....
    I'm leaning towards a bobbin birdie or metropole at the moment....

    Posted 10 years ago #

  21. Stickman
    Member

    And just as importantly, what colour?

    Posted 10 years ago #

  22. bueller
    Member

    Black for the Metropole pale blue if the Birdie, just wish they did the Birdie with more gears or the Metropole with the same amount of gears but hub gears - sigh !

    Posted 10 years ago #

  23. i
    Member

    There's also continuous transmission with 360% range. Efficiency is probably around 90% percent, but I like the idea of no gear jumps.

    Posted 10 years ago #

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