What SS teeth ratio

mountaincookie
mountaincookie Posts: 292
edited January 2012 in Commuting general
I'm building a SS commuter (not fixed) and I need some advice on what ratio to use? I need versatility (I live in notts, so not flat paticularly). I was thinking 40-12 but concerned it will be lacking in umph. I don't have any monster hills (derby road going from lenton to notts city centre is the biggest is that means anything to anyone).

Cheers

Comments

  • jejv
    jejv Posts: 566
    Umm, 87.5" on 23-622 tyres. Sounds fairly mental to me. Then I don't do SS.
    Do You do Bryan Chapman on SS ?? Some folk do.
    There is somone on Commuter chat who claimed her cranks only turned 1.5 times on her 7 mile London commute.
    Something nearer 70" might be saner. 42-15 ?
  • mountaincookie
    mountaincookie Posts: 292
    Contary to what my ignorance may have implied I'm not going for the hard core 40 year old MAN SS RIDER - I shall bear your advice in mind and go for something less mad! cheers!
  • craker
    craker Posts: 1,739
    Have a look at this recent thread

    http://www.bikeradar.com/forums/viewtopic.php?f=40004&t=12829584

    FWIW I'm on 42-17 (66") on a hilly commute.
  • mountaincookie
    mountaincookie Posts: 292
    Thanks for the tread link, very helpful

    Being on a small budget it's looking like the crank will be whatever I can get hold of - looking like a 40 tooth at the moment. I'm guessing I can just play around with 12/14/16/18 tooth sprokets until I find the perfect combo?
  • mountaincookie
    mountaincookie Posts: 292
    Apologies for my double posting - not bumping my post, just had an after thought!

    40 tooth chainring + fire eye conversion kit. 12/14 combo or 16/18? (the kits are sold with both combos in).
  • andyrr
    andyrr Posts: 1,823
    On a hilly commute I use 44x17 which equates to 70" ish.
    With that I can get up most things without to major a struggle, whilst not losing loads on the quicker bits.
    Depends on fitness as well obviously but I'd suggest something that gives that sort of ratio.
  • roger_merriman
    roger_merriman Posts: 6,165
    I'd say 70-80 inches is the sweet spot.

    get you up most hills and also get you to 30mph.

    My bike came with 48*16 and it's fine even with paniers and so on.

    steep hills are a issue but very few are undoable.
  • mountaincookie
    mountaincookie Posts: 292
    So how do you calculate this inches thing then? (please don't refer me to good ol sheldon - too complicated!)
  • jejv
    jejv Posts: 566
    mountaincookie wrote:
    So how do you calculate this inches thing then? (please don't refer me to good ol sheldon - too complicated!)
    on 23mm tyres, roughly:

    26.2 * (teeth at front) / (teeth at rear)
  • Salsa
    Salsa Posts: 753
    mountaincookie wrote:
    So how do you calculate this inches thing then? (please don't refer me to good ol sheldon - too complicated!)
    I always use the Rabbit calculator to work out this stuff, very easy :)
    http://software.bareknucklebrigade.com/ ... pplet.html
  • Blue Meanie
    Blue Meanie Posts: 495
    Smaller cogs wear quicker, I'm riding a 700c wheel with a 19t cog and 49 chainring. I could function the same gear at 16cog and 42 chainring (ok, maybe a 41), still around the 70" mark. Try avoid factors as you'll get wear spots on your tyre if you retard or skid your rear wheel, but you're not riding fixed so don't worry.
    FWIW, ride fixed, MTFU.
    FCN16 - 1970 BSA Wayfarer

    FCN4 - Fixie Inc
  • mountaincookie
    mountaincookie Posts: 292
    Since I don't require basing my manliness on whether I ride fixed or not, I'll just ride ss
  • mountaincookie
    mountaincookie Posts: 292
    Also - is this any good? £30 is my max budget. Never sure with ebay whether to trust unbranded bike stuff

    http://www.ebay.co.uk/itm/7075-T6-ALLOY ... 692wt_1037
  • bamish1000
    bamish1000 Posts: 44
    I bought my SS cranks from that ebayer and they have been spot on. The bottom brackets they sell are also cheap but good. I'm running 48-16 on mine as well.
  • StefanP
    StefanP Posts: 429
    I went down to the local bike shop, asked if they had a square taper crankset. They did. Cracking, £10 for a second hand crankset and then a nice 48t chainring, sorted! I would honestly check your LBS first, you never know what they might have ;)
  • mountaincookie
    mountaincookie Posts: 292
    Might just do that! need to go down anyway, just not having a car, it's a long walk with a bike frame slung over your shoulder. Soon as this dissertations written I'll get down there!
  • thistle_
    thistle_ Posts: 7,218
    roger merriman wrote:
    I'd say 70-80 inches is the sweet spot.
    I feel so inadequate with my 59" :(

    Maybe I should go higher and just jump off and run on the hills.
  • roger_merriman
    roger_merriman Posts: 6,165
    thistle (MBNW) wrote:
    roger merriman wrote:
    I'd say 70-80 inches is the sweet spot.
    I feel so inadequate with my 59" :(

    Maybe I should go higher and just jump off and run on the hills.

    Maybe not selective cropping though, look at the OP question and my full reply.

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