Best way to change gearing

Discussion in 'HOW TO' started by RatRodDad, Dec 27, 2006.

  1. RatRodDad

    RatRodDad

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    Rat Rod got me into bikes again recently after many years of not riding one. I bought a 3 speed cruiser a month or so ago and found that the gearing is a little higher than I would like. Low gear is not low enough at times, medium is pretty good, and high I rarely use. So I was wondering how I would go about changing the gearing to make it all lower than it currently is.

    Is it better to change the front sprocket or the rear? I see that the front one comes off pretty easily so that could be changed without much problem - assuming someone sells smaller ones. I'm not sure about the rear gear, though.

    The bike is a Caloi Rio Cruiser and it has a Shimano Nexus 3 speed rear hub. The front chainring has 44 teeth, which appears to be standard on cruiser bikes.

    So if anyone has any thoughts on which is the best gear to change - front or rear, and what to change it to (number of teeth), please pass them along.

    Thanks,
    Rat Rod's Dad
  2. aka_locojoe

    aka_locojoe

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    I'm no expert on gearing (I'm no expert on anything now that I think about it) and don't know if there are advantages of changing one over the other.
    If you're not partial to your existing front sprocket (chain ring) I would change it and try to find a really cool looking one.
    Any pics of the bike?
  3. karfer67

    karfer67

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    if i remember right the nexus 3 spd hub uses a standard 3 prong sprocket meaning that you can change the gearing easily. you could also change the front but changing the rear one tooth will make a bigger difference than droping one in the front. what gear combo are you using as of now?
  4. Vroom

    Vroom

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    :D Hi Rat Rods Dad , watch out you don't get hooked
    on this stuff!
    Personally, I like to change the rear cogs. This means usually
    changing the chain length. For this buy a chain removal tool ,
    they are inexpensive.
    Of course you need some donor chain,
    I find buying a 22 or 23 tooth cog will make a huge difference
    over the original 18 or 19 tooth cog and you keep the same
    front chainring.

    I done this on a half dozen or so 'cruisers and it is
    usually the first change I make to make them much more
    "rider" friendly.
    With this change I have not found a need for an any
    lower gear . I am not a pro mechanic but only speak
    from personal experience. 8)
  5. karfer67

    karfer67

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    good call vroom but you should mention that with some frames the chain line starts to become a problem when using a 22 t or above in the rear. i have found that this normally happens with mid weight frames and that full fat tire frames work just fine.
  6. Vroom

    Vroom

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  7. RatRodDad

    RatRodDad

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    Thanks for the feedback so far. I will consider both options - front and rear gear swap - before doing anything.

    I will try to take some pics of the new bike and get them out on the site. Not too "rat" at this point - but it's been fun to ride so far and actually gets me out of the chair during the day.
  8. 62Higgins

    62Higgins

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    Well I guess I'll be the odd man out here.

    I favor changing the front chainring. One of the main reasons is that when you stockpile alot of parts off donor bikes, you wind up with different size chainrings laying around, especially if you seperate multiple ring set ups off of ten - eighteen speed bikes which have one piece cranks with two or three rings on them.

    I built up a bike last spring using a three speed Nexus rear wheel. The front chainring was from a 70's Kmart womens 10 speed (smaller of the two on the cranks). It was 39 teeth and had a really cool 3 arm/spoke look to it. I thought the overall gearing worked pretty well around here (not real flat).

    Another option we used when I was a kid (picking parts from the town dump) was to run a dual chainring set up on the cranks and add in a second section of chain and utilize the larger of the 2 rings for "road trips".

    You could also find a "spider" to use with 1 piece cranks and then the gearing options are pretty much unlimited, as they typically use 110 bcd chainrings which are available in all different numbers of teeth. These spiders can be found on some low to mid level BMX donor bikes (which is where I got one).
  9. karfer67

    karfer67

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    vroom it is the same problem that some BMX bikes have when they go to a "micro" drivetrain using small gears front and rear. the chain can come dangeriously close to the frame and i had this happen using a large rear gear with a schwinn mid weight frame. i will say that the large rear gear looks really cool most single speed nirves come with a large gear.
  10. new_dharma

    new_dharma

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    change the rear
    after years of riding my SS bike both on & off-road, it's easier to swap the back...plus if you look at derailer bikes, the rear cassette has little difference between gear size, but the fronts always make a huge jump...a small change in the back makes a noticable difference while a small change in the front does not.

    just mu $.02
  11. RatRodDad

    RatRodDad

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    Thanks

    Thanks new_dharma. I'm all for easy.

    The bike had some cross threaded pedals on it when I got it, so I bought a new crank that came with a new 44 tooth front gear and I changed those out already. So I played around with the old one and found that the gear can be removed fairly easily.

    I haven't looked at the back gear yet, but from the posts is appears that's fairly easy to change too. I'm assuming it either bolts on - or maybe screws on - to the end of the hub.
  12. Vroom

    Vroom

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    :) Just a snap-ring
  13. new_dharma

    new_dharma

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    also...it depends on the hub...most of the hubs I've delt with have a clip that holds them on (except my SS...it has a threaded BMX freewheel).
  14. RatRodDad

    RatRodDad

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    Thanks, Vroom.

    Do I need a rear gear that's specific to the Shimano Nexus rear hub? I don't know how universal they are.

    Also, I'm not sure what to call them. I tried various searches on Ebay and only find front chainrings. So I'm not sure what to search for to find the rear gears.
  15. new_dharma

    new_dharma

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  16. Vroom

    Vroom

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    The Shimano Nexus that you have uses a "cog" that
    is interchangable with Shimano333, old and new Sturmey Archer.

    I would source your LBS , they should have some. :D
  17. RatRodDad

    RatRodDad

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    new_dharma, thanks for the link. I think I read one of his articles before, so it was good to read this one about the Shimano hubs.
  18. PastorRat

    PastorRat

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    Mir See, Hal and Louie, the Creator has a Creator! Pea Rays the Lawd, and pass the Phil Wood green grease! Rat Rod never said anything about a Rat Daddy? Or is that a Daddy Rat? O Daddy, O Daddy, Daddy O, what's P-Ratty to do?

    Now solving your gearing: You said you had a 44 tooth front chainring. If so, droping to a 40 or 38 might give you the gearing you find more suitable. But you need to be concerned with BCD or Bolt Circle Diameter. That's the distance between two of the bolts next to each other holding the chainring to the crank spider. Measure this distance in mm and multiply by 1.7. Round to the nearest whole number. Do you have five bolts or four? Go to Loose Screws to look for a smaller chainring. Good luck and don't mind my pulpit talk. Rat Rod will tell you I'm harmless.
    http://www.thethirdhand.com/index.cgi?c=Crank/Chainring&id=802228627254
  19. RatRodDad

    RatRodDad

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    Thanks, PastorRat. My bike has a 1 piece crank, though, and no spider so I will need to find a 1 piece sprocket - which there seem to be plenty of - probably because all the BMX bikes use those too.

    Thanks for the tip on which one might work well, though, since I see ones out there from 36 teeth all the way up to 48 teeth and I wasn't sure which one to try. Fortunately most can be had for around $15 or less, so a wrong guess on my part wouldn't be too expensive. I will try your suggestion, though.

    And as you can see, RatRod does have a Dad, haha. I just haven't been messing with bikes until lately. After seeing some of the ones RatRod has now and going with him to a bike show a couple of months ago I decided having my own to ride would be good. So I got one of my own - well, I have 2 now - and so it's all new to me. I've enjoyed riding, though, and try to get out for a ride every day - which has been good exercise for me.

    Back when I was young we were just happy to have a bike to ride - period. We really didn't care what it looked like or what kind it was - as long as it worked. Our biggest "mod" was putting playing cards or ballons in the spokes to make a little extra noise on a ride. I guess that would be called "old old school" nowdays.

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