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 08-08-05, 11:00 AM   #1
thesweaterkid
Senior Member
Thread Starter
 
Join Date: Aug 2005
Location: philly
Bikes: '04 Fuji Track, 80's Schwinn Prelude (conversion), Nishiki Linear TT Bike, 80's Raleigh BMX
Posts: 64
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Track bike with gears

i saw a OK Cycles track bike with a fixed cassete on the back, and 2 chainrings on the front. it wasn't for sale though. anyone else come across anything like this?

also...there was an 80's Olmo with campy record components, that the dude was trying to sell for $4,000. kinda ridiculous.
thesweaterkid is offline   Reply With Quote
Old 08-09-05, 04:06 AM   #2
gnat
Senior Member
 
Join Date: Jun 2005
Location: brooklyn
Bikes: iro markvpro, eai bareknuckle
Posts: 161
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
mark what you babbling about? fixed cassette? really?
gnat is offline   Reply With Quote
Old 08-09-05, 04:54 AM   #3
LóFarkas
LF for the accentdeprived
 
Join Date: May 2005
Location: Budapest, Hungary
Bikes:
Posts: 3,549
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Why not? I always thought it could be fun for touring... You could climb mountains properly fixed. The splines for standard cogs could be machined straignt into the hub body. Looks like sombody did produce some hubs like that.

I wonder what happens if you try to backpedal with any force...the derailleur bends up into the chainstay?

Edit: Sheldon says: You CanNOT use any sort of pulley type chain tensioner on a fixed gear bike! You cannot use a derailer on a fixed gear bike, even as a chain tensioner, because when you resist the rotation of the pedals, you would bend the derailer. This presents a problem if you want to use a frame with vertical dropouts as a fixed gear, because there's no easy way to adjust the chain tension. This is also true of chain tensioners sold for singlespeed coasting bikes, such as the Surly Singleator.

So, no go.
LóFarkas is offline   Reply With Quote
Old 08-09-05, 05:33 AM   #4
bostontrevor
Retrogrouch in Training
 
bostontrevor's Avatar
 
Join Date: Sep 2004
Location: Knee-deep in the day-to-day
Bikes:
Posts: 5,484
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I don't know about OK Cycles, but they used to do 'em like this: http://www.campyonly.com/retrobikes/...clo_piave.html
bostontrevor is offline   Reply With Quote
Old 08-09-05, 05:37 AM   #5
LóFarkas
LF for the accentdeprived
 
Join Date: May 2005
Location: Budapest, Hungary
Bikes:
Posts: 3,549
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Way cool... One of those (the original vintage shifter+QR rods and axle only!) were recently sold for $1300 or so...

Actually, I would sort of be interested in a cheap replica if it works well. The trouble is it's said to need a special dropout. But the thought of leaning back that far while pedaling... Hmmm
LóFarkas is offline   Reply With Quote
Old 08-09-05, 07:12 AM   #6
frameteam2003
Senior Member
 
Join Date: Feb 2005
Location: Pleasanton Tx
Bikes: old,older.and very old
Posts: 1,119
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Shamino made a fixed rear 5 speed block,and put the freewheel in the bb.I have on idea if back pressure would un-screw the sprockets.Anyone know more on those hubs?---sam
frameteam2003 is offline   Reply With Quote
Old 08-09-05, 07:30 AM   #7
ryan_c
troglodyte
 
ryan_c's Avatar
 
Join Date: Jul 2004
Location: the tunnels
Bikes: Soma DoubleCross, Surly Steamroller, various others
Posts: 1,284
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by frameteam2003
Shamino made a fixed rear 5 speed block,and put the freewheel in the bb.I have on idea if back pressure would un-screw the sprockets.Anyone know more on those hubs?---sam
Positron, on old Schwinns. Interesting early indexing system with only one adjusting screw on the derailleur.

Actually running one fixed would be similar to a "bumbike" setup - the fixed block threads onto the hub like a normal freewheel. There shouldn't be anything out of the ordinary about the hub.
However, a little loctite may go a long way. With the right setup, you could run two chainrings, use the two rear sprockets that up with them, and figure out your chainring sizes so that the chain lengths for the two combos are identical or very similar. Voila, a fixed-gear with two potentially very different ratios. You just have to get off of your bike to change them.
ryan_c is offline   Reply With Quote
Old 08-09-05, 07:43 AM   #8
Kogswell
Matthew Grimm / Flunky
 
Kogswell's Avatar
 
Join Date: Jan 2005
Bikes:
Posts: 656
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by frameteam2003
Shamino made a fixed rear 5 speed block,and put the freewheel in the bb.I have on idea if back pressure would un-screw the sprockets.Anyone know more on those hubs?---sam
Shimano called it FF, Front Freewheel. Or was that the Suntour copy?

The freewheeling was built into the cranks, just like the current version used for trials. Oh, sorry, you said that.

The idea was that you could shift while the bike was rolling, without having to pedal.

It did not change the world.

Now the observed trials folks have revived the idea.

And now the hubs have fixed cassettes.

Not sure what that means for the future of FG cycling. Could be pretty kool. Kogs will shear off in a whole new way now.
Kogswell is offline   Reply With Quote
Old 08-09-05, 07:56 AM   #9
bostontrevor
Retrogrouch in Training
 
bostontrevor's Avatar
 
Join Date: Sep 2004
Location: Knee-deep in the day-to-day
Bikes:
Posts: 5,484
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I was thinking that trials cassette hubs were fixed, didn't quite know how they accomplished that.

Anyhow, I would think as long as you didn't have too much of a tooth difference, you could run a rear der that didn't wrap too much chain. Maybe go with a long cage so that when the chain was under back tension it wouldn't be too far off straight and would minimize the chances of ripping it apart.

Maybe.
bostontrevor is offline   Reply With Quote
Old 08-09-05, 09:34 AM   #10
jacobs
Senior Member
 
jacobs's Avatar
 
Join Date: Apr 2005
Location: Boston, MA
Bikes: http://www.jacobsbicycles.com
Posts: 787
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It's not the cassette thats fixed on Trials stuff, it's the hub's free-hub body that's fixed. Seems like it would be awesome for conversions. Totally adjustable chainline on the cheap with spacers and a BMX cog. There was a post about one of the hubs a few days back.
jacobs is offline   Reply With Quote
Old 08-09-05, 09:37 AM   #11
jacobs
Senior Member
 
jacobs's Avatar
 
Join Date: Apr 2005
Location: Boston, MA
Bikes: http://www.jacobsbicycles.com
Posts: 787
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
http://webcyclery.com/product.php?pr...cat=419&page=1

Fixed trials cassette hub. They have a "6 speed" version as well. I assume it just has a shorter freehub body.

Edit: They're both 6 speeds, the other one is just mo' money.
jacobs is offline   Reply With Quote
Old 08-09-05, 01:09 PM   #12
thesweaterkid
Senior Member
Thread Starter
 
Join Date: Aug 2005
Location: philly
Bikes: '04 Fuji Track, 80's Schwinn Prelude (conversion), Nishiki Linear TT Bike, 80's Raleigh BMX
Posts: 64
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
the cassette was fixed, but there was no derauiler. it was 5 gears on the back cassette, and there were 2 front chainrings. i think it was more of an option to switch gears before a ride....as opposed to while riding.

no one replied about the dude trying to sell the Olmo for 4 grand with the Campy Record components
thesweaterkid is offline   Reply With Quote
Old 08-09-05, 01:33 PM   #13
isotopesope
shoot up or shut up.
 
isotopesope's Avatar
 
Join Date: Nov 2003
Location: colorado springs, co
Bikes: yes please.
Posts: 1,961
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by thesweaterkid
no one replied about the dude trying to sell the Olmo for 4 grand with the Campy Record components

oh you poor baby. i'll reply: who gives a crap?
isotopesope is offline   Reply With Quote
Old 08-10-05, 12:46 PM   #14
Ya Tu Sabes
Rebel Thousandaire
 
Ya Tu Sabes's Avatar
 
Join Date: Sep 2004
Location: Hartford, CT
Bikes: Public D8, Yuba Mundo (cargo), Novara Buzz (1-speed, soon to be 2-speed w/ a kickback hub), Xootr 1-speed folder
Posts: 733
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LóFarkas
Edit: Sheldon says: You CanNOT use any sort of pulley type chain tensioner on a fixed gear bike! You cannot use a derailer on a fixed gear bike, even as a chain tensioner, because when you resist the rotation of the pedals, you would bend the derailer. This presents a problem if you want to use a frame with vertical dropouts as a fixed gear, because there's no easy way to adjust the chain tension. This is also true of chain tensioners sold for singlespeed coasting bikes, such as the Surly Singleator.

So, no go.
I always wondered if you couldn't make a fixed-gear tensioner that wasn't spring-loaded like a derailleur, but instead mounted to the chainstay and had to be adjusted manually with a screw or something. It wouldn't work for a fixed cassette but would be good for bikes with vertical dropouts. It would function kinda the way a ghost chainring does, as a solid piece that added tension. Any ideas on whether this could work? [/off topic]
Ya Tu Sabes is offline   Reply With Quote
Old 08-10-05, 02:25 PM   #15
bostontrevor
Retrogrouch in Training
 
bostontrevor's Avatar
 
Join Date: Sep 2004
Location: Knee-deep in the day-to-day
Bikes:
Posts: 5,484
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
That would probably fare worse. The issue is that when the chain comes under reverse tension, it naturally pulls taught. When running through a derailleur, this can cause it to put outward pressure on the jockey wheels and bend the cage. With a tensioner, it can hyper extend the armature or smash it into the chainstay. If you build a rigid tensioner, it'll need to be strong enough to withstand that force.

I've never tried it, so I can't say for sure, but I'm of the opinion that you could run a tensioner safely so long as you insure that it's capable of safely moving to whatever position it would be in when the chain is straight. If it's in push down mode, move it a little forward so that it won't be smashed against the stay when the chain goes taunt, if in push up, move it back so that fully extended is still within its limits.
bostontrevor is offline   Reply With Quote
Old 08-10-05, 03:16 PM   #16
Sheldon Brown
Gone, but not forgotten
 
Sheldon Brown's Avatar
 
Join Date: Jul 2002
Location: Newtonville, Massachusetts
Bikes: See: http://sheldonbrown.org/bicycles
Posts: 2,301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by Ya Tu Sabes
I always wondered if you couldn't make a fixed-gear tensioner that wasn't spring-loaded like a derailleur, but instead mounted to the chainstay and had to be adjusted manually with a screw or something. It wouldn't work for a fixed cassette but would be good for bikes with vertical dropouts. It would function kinda the way a ghost chainring does, as a solid piece that added tension. Any ideas on whether this could work? [/off topic]
It could work in theory. In practice, there's the question of how to attach it. It would need to attach to the chainstay, which is typically a round tapered tube. Any sort of clamp-on device that I can imagine for a tapered tube would not be secure enough to handle the very high stresses that would result.

If you rigged some sort of braze-on mount, I could see that working. Cheap tandems use something similar to adjust the tension of the synch chain.

However, if you're going to take a torch to your bike and wreck the paint job anyway, why not just install horizontal dropouts instead?

Sheldon "What's The Point?" Brown
Code:
+-----------------------------------------------------------+
|   Yield to temptation.  It may not pass your way again.   |
|                                    --Robert A. Heinlein   |
+-----------------------------------------------------------+
Sheldon Brown is offline   Reply With Quote
Old 08-10-05, 03:57 PM   #17
p3ntuprage
Senior Member
 
p3ntuprage's Avatar
 
Join Date: Dec 2003
Location: birmingham
Bikes: a tvt soon to become a s/s...
Posts: 829
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
why not use two spring loaded chain tensioners? on on the bottom half [before the cog as the chain runs] of the chain and one on the top half [after the cog]?

someone go try it for me. i don't have enough money or inclination to buy two chain tensioners right now.

apart from that, i'm sure i read somewhere *ages* ago that there was a way of making internal gear hubs fixed...

fsnl
sparky
p3ntuprage is offline   Reply With Quote
Old 08-11-05, 08:26 AM   #18
Ya Tu Sabes
Rebel Thousandaire
 
Ya Tu Sabes's Avatar
 
Join Date: Sep 2004
Location: Hartford, CT
Bikes: Public D8, Yuba Mundo (cargo), Novara Buzz (1-speed, soon to be 2-speed w/ a kickback hub), Xootr 1-speed folder
Posts: 733
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, of course, as Sheldon points out, this is all silly, idle speculation, especially since all the frames I ever use come from the trash and I can spot and avoid a vertical dropout from fifty yards. I think, though, that two chain tensioners would be as problematic as my idea 'cause where would you attach the second one?
Ya Tu Sabes is offline   Reply With Quote
Old 08-11-05, 08:40 AM   #19
bostontrevor
Retrogrouch in Training
 
bostontrevor's Avatar
 
Join Date: Sep 2004
Location: Knee-deep in the day-to-day
Bikes:
Posts: 5,484
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There are a few chainstay mounted tensioners intended for DH rigs. Here's some now, including a rigid design. http://www.bikemannetwork.com/biking/c/COMPCHTFRM
bostontrevor 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 01:15 AM.