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 12-12-07, 10:50 AM   #1
ghostofcrujones
Much better Mr. Buckles
Thread Starter
 
ghostofcrujones's Avatar
 
Join Date: Sep 2006
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
chain + chainrings for conversion problem

I was wondering if maybe someone here could lend some help to this wall i've run into. I am trying to convert my trusty old trek road frame that i've had forever, into a fixed gear. I purchased a phil hub that is spaced to 126 (the correct size for my trek), installed cog etc, and bolted on the rear wheel. I removed the outer chainring from the previous double that was on there because on sight it looks like the inner lines up pretty well.




I was adjusting the chain length, as i have done in the past and realized that the chain is just too loose, it looks like removing one link will cause the hub to have to move too far forward, and apparently these horizontal droupouts arent really that long (at least not long enough to support that). So, first question is Is there someplace that i can get a half-link that will work with this type of chain? (Kool Chain). Or is there a manufacturer that makes a chain that has different chain link lengths, that might result in smaller, removable units?




The second (related) wall is that i was hoping to run a larger chainring (46) that what is on there now (42) but it looks like running that inner chainring will not allow me to, leading to a situation where the chainring will rub against the right chainstay. any idea how to get around this? using the outer chainring will screw up the chainline. The phil wood hub has these fixed width axel caps that prevent any play in any direction, so i dont think there is much wiggle room there. Perhaps i will need to get a whole new bottom bracket? i dont know if that will work even.




any input is greatly appreciated. Hope these photos help illustrate what i am talking about.
ghostofcrujones is offline   Reply With Quote
Old 12-12-07, 11:06 AM   #2
axelfox
Senior Member
 
axelfox's Avatar
 
Join Date: Sep 2004
Bikes:
Posts: 487
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Perhaps you can get a chain tensioner?
axelfox is offline   Reply With Quote
Old 12-12-07, 11:12 AM   #3
Aeroplane
jack of one or two trades
 
Aeroplane's Avatar
 
Join Date: Jun 2005
Location: Suburbia, CT
Bikes: Old-ass gearie hardtail MTB, fix-converted Centurion LeMans commuter, SS hardtail monster MTB
Posts: 5,637
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by axelfox View Post
Perhaps you can get a chain tensioner?
That won't work for fixed.

Cru's Ghost: what you want is a half-link. I did a conversion on a trek that had the same dropouts, and it's necessary for some setups. Here is a picture of what it looks like:



You can get them in 3/32 or 1/8 widths.

Alternatively, you can get a chain that is all half-links.

Aeroplane is offline   Reply With Quote
Old 12-12-07, 11:12 AM   #4
1fluffhead
Senior Member
 
1fluffhead's Avatar
 
Join Date: Aug 2005
Location: baltimore
Bikes: Pake Track; Bianchi XL EV2 El Reparto Corse, Kona Jake the Snake
Posts: 1,663
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
KMC who makes the Kool Chain makes half links. I would contact them to see if the would be any issues with the half link and that chain. KMC also makes a complete half link chain. Shadow Conspiracy does too.
1fluffhead is offline   Reply With Quote
Old 12-12-07, 11:19 AM   #5
PunctualAlex
sucker for lugs
 
Join Date: Jun 2006
Location: Denver
Bikes: Shogun 800 (had to cull the herd)
Posts: 364
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, the Phil hub probably has 42.5mm between the cog and the centerline of the hub/bike, so you want a chainring that is the same distance from the center of the bottom bracket. Unfortunately, your Trek frame has wide-ass chainstays that were designed to have a smaller inner ring. You'll never be able to fit a bigger ring there and maintain the chainline if you can't now. Your two options are to somehow respace the hub to the right and redish the wheel, which seems like a pretty terrible idea to me, or to just buy a smaller cog if you want a bigger gear ratio.
Welcome to the great and terrible world of road conversions.
PunctualAlex is offline   Reply With Quote
Old 12-12-07, 11:20 AM   #6
ghostofcrujones
Much better Mr. Buckles
Thread Starter
 
ghostofcrujones's Avatar
 
Join Date: Sep 2006
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks, Aero + Fluff. that's good news. I have definitely seen half links before. Now i will go hunt one down. Any other ideas re: the chainring size and rubbing the chainstays? I guess my LBS might have a better idea how to pin down the straightest chainline when they can actually review it all.
ghostofcrujones is offline   Reply With Quote
Old 12-12-07, 11:23 AM   #7
ghostofcrujones
Much better Mr. Buckles
Thread Starter
 
ghostofcrujones's Avatar
 
Join Date: Sep 2006
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Yeah, smaller cog was the only last resort i could think of. Somehow on previous conversions, the chainstays were always quite a bit more accomodating, or even have indentations on drive side to allow larger rings to fit. cant believe i didnt think to measure that **** first! Thanks, alex.
ghostofcrujones is offline   Reply With Quote
Old 12-12-07, 11:44 AM   #8
Aeroplane
jack of one or two trades
 
Aeroplane's Avatar
 
Join Date: Jun 2005
Location: Suburbia, CT
Bikes: Old-ass gearie hardtail MTB, fix-converted Centurion LeMans commuter, SS hardtail monster MTB
Posts: 5,637
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Chainline wise: I'd either go with a smaller cog and the smaller chainring (super-easy, kinda $), or else throw a BB spacer on the inside of the cog to push it out a little bit, and then put the chainring on the outside of the spider. That might not work depending on how straight you want your chainline, how much threading you have left on your hub, etc.
Aeroplane is offline   Reply With Quote
Old 12-12-07, 11:48 AM   #9
brett jerk
zizeked
 
brett jerk's Avatar
 
Join Date: May 2007
Bikes:
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
why don't you just buy a smaller rear cog? then you can remove a full link no problem.
both problems at the same time
brett jerk is offline   Reply With Quote
Old 12-12-07, 02:04 PM   #10
trons
yo yo yo yo yo
 
Join Date: Nov 2005
Location: delaware
Bikes:
Posts: 2,518
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
it looks like with the current tension + where it is in the dropouts you should be able to remove a link just fine.. worst case get a half link, both are cheaper than a new cog...
trons is offline   Reply With Quote
Old 12-12-07, 03:35 PM   #11
nelzar13
Senior Member
 
nelzar13's Avatar
 
Join Date: Feb 2007
Location: Coventry RI
Bikes: 1958 raleigh fixed , specialized P2, standard S250, giant cross country bike
Posts: 293
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
shadow inter lock maybe? check albes.com
nelzar13 is offline   Reply With Quote
Old 12-12-07, 03:43 PM   #12
maddyfish
Senior Member
 
maddyfish's Avatar
 
Join Date: Jul 2006
Location: Ky. and FL.
Bikes: KHS steel SS
Posts: 3,944
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Get a cog with another tooth?
maddyfish is offline   Reply With Quote
Old 12-12-07, 03:44 PM   #13
queerpunk
aka mattio
 
queerpunk's Avatar
 
Join Date: May 2005
Bikes:
Posts: 6,023
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 39 Post(s)
to answer a few more of the questions you asked - almost all bicycle chain has links that are a half-inch long. this is called "pitch." some very old gear is "inch-pitch," and for a hot minute in the (i think) 80s, shimano made dura-ace "10-pitch" - instead of a half inch, the links were 10mm long. however: if there were a chain with smaller removable units, it wouldn't fit on your cog and chainring. it's all made for half-inch pitch chains.

also, it never hurts to measure your chainline, to be right. that phil wood hub will put the cog at 43mm from the bike's centerline. use a ruler to measure from the center of the seattube to the center of the chainring. it should also measure 43mm. if not, you might want to consider moving the chainring, or getting a bottom bracket with a longer or shorter (as needed) spindle [if you need to move your chain 2mm outward, you'd need a spindle that's 4mm outward].

that trusty trek ought to make a lovely conversion.
queerpunk is online now   Reply With Quote
Old 12-12-07, 04:16 PM   #14
baxtefer
Cornucopia of Awesomeness
 
baxtefer's Avatar
 
Join Date: Oct 2004
Location: not where i used to be
Bikes:
Posts: 4,847
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It looks like you have enough dropout room to remove a full link. Removing a whole link from your chain will only move your axle ~1/4" forward.
It also looks like a 46T chainring might fit. if not, just have a your LBS or local framebuilder dent the chainstay for clearance.
baxtefer is offline   Reply With Quote
Old 12-12-07, 05:05 PM   #15
ghostofcrujones
Much better Mr. Buckles
Thread Starter
 
ghostofcrujones's Avatar
 
Join Date: Sep 2006
Bikes:
Posts: 128
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
46 wont fit. the 42 is almost hitting the stay as it is. I'm not sure how close to the end of the dropout the hub can bolt on and still be secure.
ghostofcrujones is offline   Reply With Quote
Old 12-12-07, 05:18 PM   #16
pyze-guy
Yup
 
pyze-guy's Avatar
 
Join Date: Jan 2004
Location: where the sunbeams end and the starlight begins
Bikes: Kona Unit, planet X cx bike, khs fixed gear
Posts: 3,054
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ghostofcrujones View Post
46 wont fit. the 42 is almost hitting the stay as it is. I'm not sure how close to the end of the dropout the hub can bolt on and still be secure.
I have short horizontal dropouts on my mtb and so far have not had any problems at all with the axle and bolts this far forward. I use a halflink that I add/remove when switching cogs.
__________________
When sadness fills my days
It's time to turn away
And then tomorrow's dreams
Become reality to me
pyze-guy 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 04:09 PM.