Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Singlespeed & Fixed Gear "I still feel that variable gears are only for people over forty-five. Isn't it better to triumph by the strength of your muscles than by the artifice of a derailer? We are getting soft...As for me, give me a fixed gear!"-- Henri Desgrange (31 January 1865 - 16 August 1940)

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-30-07, 07:33 AM   #1
kdsola
Junior Member
Thread Starter
 
Join Date: May 2007
Location: Long Island
Bikes: Fuji Monterey, Gary Fisher Paragon
Posts: 7
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Mountain Bike Fixed gear

anyone know the gear sizes that would work for a mountain bike frame with vertical dropouts... its an older GT with the triple triangle. thanks.
kdsola is offline   Reply With Quote
Old 06-30-07, 07:38 AM   #2
bonechilling
Run What 'Ya Brung
 
bonechilling's Avatar
 
Join Date: Jun 2006
Bikes:
Posts: 5,694
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You'll have to figure this out yourself. This is impossible to
know without having the exact measurements of the frame,
and even then, there are only a few people I'm aware of
who could calculate that kind of thing.
bonechilling is offline   Reply With Quote
Old 06-30-07, 08:06 AM   #3
Tadashi
Senior Member
 
Join Date: Jun 2007
Bikes:
Posts: 266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Tadashi is offline   Reply With Quote
Old 06-30-07, 08:16 AM   #4
FlatFender
Senior Member
 
FlatFender's Avatar
 
Join Date: Aug 2006
Location: Raleigh NC
Bikes:
Posts: 1,015
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Yep, My solution was to weld in some track dropouts.

FlatFender is offline   Reply With Quote
Old 06-30-07, 08:39 AM   #5
threeoneseven
Senior Member
 
threeoneseven's Avatar
 
Join Date: May 2007
Location: rural america
Bikes:
Posts: 245
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i have a later 90's gt avalanche frame, with surly 36t ring, 18t rear, and sram 8spd chain. also, mine measures 16-13/16 inch (sixteen and thirteen sixteenth inch) from center of crank bolt to center of skewer (rough stay length). it has perfect chain tension and alignment, but i have to take the back wheel off to get the chain on/off. not sure if this helps or if this setup would work for your bike though...
threeoneseven is offline   Reply With Quote
Old 06-30-07, 09:37 AM   #6
MrCjolsen
Senior Member
 
MrCjolsen's Avatar
 
Join Date: Nov 2004
Location: Davis CA
Bikes: Surly Cross-Check, '85 Giant road bike (unrecogizable fixed-gear conversion
Posts: 3,957
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
http://www.eehouse.org/fixin/formfmu.php

This calculator should give you an idea of what combos might work. The problem is that fixed gear chain tension has to be just right, so you will need to be lucky. I tried converting my wife's hybrid to a singlespeed and I ended up having to choose between a rather loose chain or 53-17 combo. The loose chain was fine for a singlespeed, but I would not ride it like that fixed.
MrCjolsen is offline   Reply With Quote
Old 06-30-07, 05:14 PM   #7
Ken Cox
King of the Hipsters
 
Join Date: Jan 2005
Location: Bend, Oregon
Bikes: Realm Cycles Custom
Posts: 2,128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I wouldn't even try to make a fixed gear mountain bike out of a frame with vertical drop outs.

It makes more sense to put a "singleator" on it and ride it as a single-speed.

Yesterday, I commissioned Webcyclery to build a fixed gear mountain bike for me, using a Surly Karate Monkey frame as the starting point, with the intent of creating a winter ice commuter that will really work for me.

A person on a more severe budget than mine could probably do better with a Redline Monocog 29'er, and transer most of his bike parts to the Redline frame.
This would require only a new rear wheel and a Redline frame.
One can find a new Redline frameset for under $250 without much searching.
A new rear wheel with low cost as the priority?
I don't know.

How much would it cost to change the dropouts on an existing, owned mountain bike frame?
And then, wouldn't one still need a new rear wheel?

To me, for safety, the proper chain tension made possible by horizontal dropouts justifies the expense.

Safety doesn't seem all that important until one picks himself up off the pavement and realizes he has several broken ribs and a collapsed lung.
Ken Cox is offline   Reply With Quote
Old 07-01-07, 01:35 AM   #8
mander
Senior Member
 
Join Date: Sep 2006
Location: Van BC
Bikes:
Posts: 3,744
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like fun Coxy. The bike I mean, not the injuries.
mander is offline   Reply With Quote
Old 07-01-07, 04:17 AM   #9
AfterThisNap
Taking "s" outta "Fast"
 
AfterThisNap's Avatar
 
Join Date: Dec 2005
Location: Zoo York City
Bikes:
Posts: 1,989
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
a ghetto solution is to use a singelator under the chain, so the arm puts pressure upwards. It works, works well, but is noisy and looks funky.
AfterThisNap is offline   Reply With Quote
Old 07-01-07, 06:56 AM   #10
SSSasky
Mo' Senior
 
SSSasky's Avatar
 
Join Date: Oct 2004
Location: Ottawa, ON
Bikes: 1984 Norco Monterey SL (Ishwata 3X butted), matte black, 42-15 fixed
Posts: 371
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by AfterThisNap
a ghetto solution is to use a singelator under the chain, so the arm puts pressure upwards. It works, works well, but is noisy and looks funky.

That's no safer for fixed gear than the 'push down' mode ... well, it probably won't rip the tensioner off, but you'll lose all chain tension when you backpedal ... singlators really are for SS only.

You could try the ENO eccentric hub. I have one, and it works pretty well, although it's definitely more of a hassle to deal with than track ends.
SSSasky is offline   Reply With Quote
Old 08-13-07, 07:17 PM   #11
DDYTDY
Senior Member
 
DDYTDY's Avatar
 
Join Date: Nov 2006
Location: Methuen, Massachusetts
Bikes:
Posts: 519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
White Industries Eccentric Eno hub.
http://www.sheldonbrown.com/harris/white-hubs.html
DDYTDY is offline   Reply With Quote
Old 08-13-07, 07:30 PM   #12
doofo
thomas masini lives
 
Join Date: Sep 2006
Location: i aint dh no mo'
Bikes:
Posts: 3,495
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DDYTDY View Post
White Industries Eccentric Eno hub.
http://www.sheldonbrown.com/harris/white-hubs.html

do you work on commission
?
doofo is offline   Reply With Quote
Old 08-13-07, 07:42 PM   #13
wearyourtruth
Ride for Life
 
wearyourtruth's Avatar
 
Join Date: Jun 2004
Location: Baltimore
Bikes:
Posts: 2,729
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Tadashi View Post
word.


but i started out with an eccentric hub, it's a little pricey, but with MTB it's really the only way if you really want to go fixed and really don't want to buy a new frame. have you ridden fixed on the trails before? it's nuts. i hope you've at least ridden SS, not because i'm saying anything about being able to handle it, but when you only got one gear, the one you get needs to be dialed in, it can't be based on what you can figure out works on your frame.

good luck!
wearyourtruth is offline   Reply With Quote
Old 08-13-07, 07:45 PM   #14
Bushman
Grumbly Goat
 
Bushman's Avatar
 
Join Date: Jul 2007
Bikes: bicycles with round wheels
Posts: 895
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Its very possible to make a fixed mountain bike using vertical dropouts.

First off is cog choice - you want THICK cogs, without ramps, or precut shifting cutouts. Tall teeth are your frined here.

Cog size, go a little bigger, for more tooth contact. I use a 20 - 26 range.

Chainring size: again, no ramps or shifting cutouts. I use a 30 - 36 range for my offroad setup.

Chain. use a KMC BMX or track chain., They is beefy! Or best of all is a FULL "halflink chain".Really easy to setup chain tension with a halflink chain.

now the tricky part, chain tension.......install the wheel/cog on the rear and snug up the skewer or nuts. add the chain and wrap it around the cog and chainring, until your holding one end in each hand. Figure out how much cahin you need and remove links accordingly. To join the chain, you may need to use a couple of halflinks. Tension should be "snug", just enough so that when you turn the wheel backwards you can feel a bit of tension.

Good Luck.

Fixed offroad bikes are freeaking incredibly fun, you can POWER thru mud and snow without bogging down, its like positraction.

my next project project is a Surly Pugsley with their 4" wide tires, 26 x 24 fixed gear, disc brakes. Hopefully they will have their 4" wide tires in 29" too.....
Bushman is offline   Reply With Quote
Old 08-13-07, 07:56 PM   #15
DDYTDY
Senior Member
 
DDYTDY's Avatar
 
Join Date: Nov 2006
Location: Methuen, Massachusetts
Bikes:
Posts: 519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by doofo View Post
do you work on commission
?
Naw, just happy with the product.
DDYTDY is offline   Reply With Quote
Old 08-13-07, 08:25 PM   #16
yonderboy
Lurker for Life
 
yonderboy's Avatar
 
Join Date: Nov 2004
Location: PDX
Bikes:
Posts: 908
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Ken Cox View Post
Yesterday, I commissioned Webcyclery to build a fixed gear mountain bike for me, using a Surly Karate Monkey frame as the starting point, with the intent of creating a winter ice commuter that will really work for me.
Glad to hear you got your winter commuter figured out. Hopefully Mean Todd and the boys really set you up nice.

I wouldn't personally run a MTB as a fixed gear. So much of the riding experience on trails depends on the "flow", which really gets derailed by running a fixed gear. There's also the odd occasion that you get into a rhythm section and the cadence of the cranks are synced with the bumps, which equals double ejection over the handlebars.
yonderboy is offline   Reply With Quote
Old 08-13-07, 09:28 PM   #17
Gurgus
is as Gurgus does.
 
Gurgus's Avatar
 
Join Date: Feb 2004
Location: Otisburg
Bikes: A whole bunch o' bikes.
Posts: 910
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I've got an ATB sitting in the garage waiting for a fixed conversion. I got this bike from my father in law and it's got forward facing dropouts. Should be fun.
Gurgus is offline   Reply With Quote
Old 08-13-07, 09:36 PM   #18
PanPanX
Ride On!!
 
PanPanX's Avatar
 
Join Date: Oct 2004
Location: Temple City, CA
Bikes: 2004 OCR3, 1989 Nishiki Sport, 2003 Kona Blast, 2007 Fuji Track
Posts: 467
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Bushman View Post
Its very possible to make a fixed mountain bike using vertical dropouts.

First off is cog choice - you want THICK cogs, without ramps, or precut shifting cutouts. Tall teeth are your frined here.

Cog size, go a little bigger, for more tooth contact. I use a 20 - 26 range.

Chainring size: again, no ramps or shifting cutouts. I use a 30 - 36 range for my offroad setup.

Chain. use a KMC BMX or track chain., They is beefy! Or best of all is a FULL "halflink chain".Really easy to setup chain tension with a halflink chain.

now the tricky part, chain tension.......install the wheel/cog on the rear and snug up the skewer or nuts. add the chain and wrap it around the cog and chainring, until your holding one end in each hand. Figure out how much cahin you need and remove links accordingly. To join the chain, you may need to use a couple of halflinks. Tension should be "snug", just enough so that when you turn the wheel backwards you can feel a bit of tension.

Good Luck.

Fixed offroad bikes are freeaking incredibly fun, you can POWER thru mud and snow without bogging down, its like positraction.

my next project project is a Surly Pugsley with their 4" wide tires, 26 x 24 fixed gear, disc brakes. Hopefully they will have their 4" wide tires in 29" too.....

Where can you get a FULL "half link" chain? Also.. doesnt two half links just make one regular link? so.. wouldnt you just need to have a regular chain and one half link? Also it depends on the length of your chainstay.. for my mtn bike, if i remember correctly, i had a 16.1in chainstay length.. and the only way i could run a fg/ss without a tensioner is if i had some crazy combo like 22/9 or something..
PanPanX is offline   Reply With Quote
Old 08-15-07, 09:30 AM   #19
mrsalty
Senior Member
 
Join Date: Jul 2007
Bikes:
Posts: 68
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by PanPanX View Post
Where can you get a FULL "half link" chain? Also.. doesnt two half links just make one regular link? so.. wouldnt you just need to have a regular chain and one half link? Also it depends on the length of your chainstay.. for my mtn bike, if i remember correctly, i had a 16.1in chainstay length.. and the only way i could run a fg/ss without a tensioner is if i had some crazy combo like 22/9 or something..
http://www.bikemannetwork.com/biking/p/COMPCHSS/CH1009
mrsalty is offline   Reply With Quote
Old 08-15-07, 09:40 AM   #20
mathletics
jerk store
 
mathletics's Avatar
 
Join Date: Mar 2006
Location: Boston
Bikes: '80s Chimo Garbage fixed 36/14, Centurion fixed 42/17
Posts: 605
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Depending on how much room you have in the dropouts, it may be possible to file the opening a little wider. You don't need a lot of space to fix your chain tension, just a few mm on each side if you get the chain right. I've never done it, but I know it can be done.

Unless I am mistaken about the identity, the BF member chimblysweep (or some variation of that) is a woman named Julie. Her brother, Scott, used to ride a Fetish Cycles frame that had been filed in this manner.
mathletics is offline   Reply With Quote
Old 08-15-07, 09:57 AM   #21
DDYTDY
Senior Member
 
DDYTDY's Avatar
 
Join Date: Nov 2006
Location: Methuen, Massachusetts
Bikes:
Posts: 519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Lots of off road fixed info here.

http://www.63xc.com/index.htm
DDYTDY is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 08:35 AM.