Double Duty or 2X2- Mtbr.com
Results 1 to 5 of 5
  1. #1
    Just Ride!
    Reputation: kustomz's Avatar
    Join Date
    Jan 2004
    Posts
    1,191

    Double Duty or 2X2

    I currently ride an old Gary Fisher Supercal 29 as a single speed using 32-19 in magic gear mode. My current economic status will require me to ride about 5 miles of gravel road to get on the trails, so I am thinking of making it a 2X2 and then just dropping the wheel and flipping to the next ratio. My question is will a 38-13 use the same link count as my current 32-19 setup and does that sound like a good gravel grinder ratio?

  2. #2
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    10,035
    According to the Fixmeup calculator 38x13 using the same length chain will have too short of a required chainstay length to work on your bike. You will have to use a second chain to get another magic ratio that fits but is geared substantially higher.

    What extra parts do you have laying around? This sounds like a good situation for a dinglespeed setup using a single rear cog with an old rear derailleur as your chain tensioner and using two rings up front with a front derailleur and shifter to choose between your two gear ratios.

    Or you could do a two-speed rear using a rear derailleur, two ss cogs, and one of these shifters

  3. #3
    Just Ride!
    Reputation: kustomz's Avatar
    Join Date
    Jan 2004
    Posts
    1,191
    No extra parts, always been an SS'er since going to 29 back in '03. The calculator just seems to confusing.

  4. #4
    mtbr member
    Reputation: boomn's Avatar
    Join Date
    Jul 2007
    Posts
    10,035
    The horizontal axis tells you the maximum effective chainstay length for the gear combos, i.e. how far away the rear cog would be with a certain length chain in order to get the chain tight.

    Chain length is coded by color, check the bottom of the chart for a key. 47" chain = 47 full links, 47.5" 47 full links and 1 half link, etc.

    The vertical axis is sorted by gear inches, i.e. how hard the gear combo is. Larger number means a harder gear.

    According to the GF archives your bike has 43.3cm chainstays. Plugging that into the calculator you need to find gear combos that are listed with that length or longer, i.e. to the right of 43.3cm on the chart. The further to the right a gear combo is on the chart the looser it will be when installed with that length chain on your bike.

    The link in my first post should have most info you'll need for your bike already entered. You can see how far from the 43.3cm your current 32x19 combo sits, so anything between there and 43.3cm will be tighter, and anything further to the right will be looser. Looks like 44x14 would fit about the same, though with a 2" longer chain

    Hope that helps

  5. #5
    Just Ride!
    Reputation: kustomz's Avatar
    Join Date
    Jan 2004
    Posts
    1,191
    Perfect, thanks boomn!

Similar Threads

  1. Replies: 45
    Last Post: 08-16-2011, 05:54 AM
  2. Double duty - xc/dh
    By Castle Rocker in forum Ibis
    Replies: 0
    Last Post: 07-01-2009, 01:10 PM
  3. Help me tailor Inbred for double duty
    By onkel in forum 29er Bikes
    Replies: 14
    Last Post: 02-01-2009, 05:52 AM
  4. Forge MStreet for double duty?
    By Clumpy Rump in forum Beginner's Corner
    Replies: 3
    Last Post: 01-23-2009, 06:07 AM
  5. double duty rims? disc and rim brakes.
    By 207maine in forum Wheels and Tires
    Replies: 4
    Last Post: 09-10-2007, 06:30 PM

Members who have read this thread: 0

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2019 VerticalScope Inc. All rights reserved.