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 12-27-04, 08:12 PM   #1
Feltup
Pain Cleanseth
Thread Starter
 
Feltup's Avatar
 
Join Date: Mar 2003
Location: The only drug in me is beer.
Bikes: On*One Imbred (commuter), Specialized Rockcombo(commuter)
Posts: 1,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Light tension; Heavy tension.

I am having a problem with the chain tension on my SS. I have a 17" steel Specialized Stumpjummper. I am running a 32t ring and a 18t cog. I am able to do this without a tensioner. The problem is the tension is greater at certain points in the cranks revolution. It looks like the chain is actually going up also. Is the chainring squashed? I cant tell by looking at it. Any ideas would be great. It isn't really causing a problem besides probably wearing the ring out faster.

Also I am using an older 9 speed chain(about 300 miles). I held the chain up tp another 9 speed with more miles(road) and the one I have on the singlespeed is about a 1/4'" longer at the same link. Can a chain stretch that much? I tried the chain off the road bike and it was so tight the wheel wouldn't go all the way into its groove. I was hoping to be able to go without a tensioner. Would it be a better idea to just put a tensioner on and buy a new chain and add 2 links?
Feltup is offline   Reply With Quote
Old 12-27-04, 08:25 PM   #2
legalize_it
legalize bikes
 
Join Date: May 2003
Location: bucks county, PA
Bikes: too damn many
Posts: 1,250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sounds like your chainring is worn, or just poorly made to begin with. no chainring is perfectly round, but some are better than others. salsa rings arent too much money and are pretty round. if you can, avoid tensioners.

if you replace your chainring, you might as well get a new chain and freewheel to avoid compatibility problems due to worn parts.
legalize_it is offline   Reply With Quote
Old 12-27-04, 09:58 PM   #3
seely 
The Rabbi
 
seely's Avatar
 
Join Date: Apr 2004
Bikes:
Posts: 5,087
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Its very normal to have tightspots, but if you are using one of the original ramped rings from your crankset, they are very poorly made (the stamped steel ones anyways). Mine on my ghetto beater SS is ovalized to the point where I had to file the crank to fit it. If you order a good Surly steel CNC'd ring it will be about as perfect as possible and very resistant to bending/warping.

For the chain, you can add a KMC Half Link to the chain which is just as it sounds, a half a chainlink to replace a full link, so you can get that new chain to fit. It might make it too long as the chain wears, however. I usually use a PC1 BMX chain since they stretch very minimally in my experience.
__________________
commuter turned bike mechanic turned commuter (also a Velocity USA employee, but this is my personal account)
seely is offline   Reply With Quote
Old 12-27-04, 10:33 PM   #4
pgringo69
Senior Member
 
Join Date: Dec 2004
Location: austin/san antonio corridor
Bikes: a dozen or more at any given time. currently: pro concept pro, badd 24", hutch trickstar, looptail pk ripper, reynolds quad, 82 hutch pro racer, yamaha "a" model, matthews monoshock, and several more.
Posts: 114
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
did you bolt the chainring on tightening one bolt at a time? that usually sets up the chainring off center. you should tighten each bolt a little at a time in a star pattern until they are all tight.

also, if you are using a thead-on freewheel, most have tight/loose spots in them. from all the white industries eno freewheels i have seen or heard of, none have this problem. cassettes usually do not have this problem either.
pgringo69 is offline   Reply With Quote
Old 12-27-04, 10:41 PM   #5
Surferbruce
Senior Member
 
Surferbruce's Avatar
 
Join Date: Jul 2004
Location: Los Angeles/Aveyron France
Bikes:
Posts: 5,308
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
check out http://www.sheldonbrown.com/fixed.html#tension
he describes a method for centering your chainring. i've yet to actually try it but i need to cause i'm having the same issue on a bike.
still sounds like you need a new chain though.
Surferbruce is offline   Reply With Quote
Old 12-28-04, 07:19 AM   #6
Feltup
Pain Cleanseth
Thread Starter
 
Feltup's Avatar
 
Join Date: Mar 2003
Location: The only drug in me is beer.
Bikes: On*One Imbred (commuter), Specialized Rockcombo(commuter)
Posts: 1,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks everyone. I figured it was a poorly made ring. It is a middle ring off a Race Face Prodigy crank. It is a stamped ring.

I have never heard of a half link I will look into that thanks.

I was planning on getting a new ring as soon as possible. I will get a chain at the same time. The cog is a DX cog with less than 50 miles so I figure it will be fine.
Feltup is offline   Reply With Quote
Old 12-28-04, 09:32 AM   #7
legalize_it
legalize bikes
 
Join Date: May 2003
Location: bucks county, PA
Bikes: too damn many
Posts: 1,250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sweet. im always glad to hear of new SS MTB converts. this forum is mostly fixxers, not enough SS MTBrs. fixed gears are the best training tool for SS MTBing though, IMO.
legalize_it is offline   Reply With Quote
Old 12-28-04, 03:18 PM   #8
Feltup
Pain Cleanseth
Thread Starter
 
Feltup's Avatar
 
Join Date: Mar 2003
Location: The only drug in me is beer.
Bikes: On*One Imbred (commuter), Specialized Rockcombo(commuter)
Posts: 1,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I think I will post some pics.
Feltup is offline   Reply With Quote
Old 12-28-04, 03:35 PM   #9
Feltup
Pain Cleanseth
Thread Starter
 
Feltup's Avatar
 
Join Date: Mar 2003
Location: The only drug in me is beer.
Bikes: On*One Imbred (commuter), Specialized Rockcombo(commuter)
Posts: 1,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Oh yeah, bought a Salsa ring and a new chain today.
Feltup is offline   Reply With Quote
Old 12-28-04, 04:29 PM   #10
2manybikes
Dog is my co-pilot
 
2manybikes's Avatar
 
Join Date: Jun 2003
Bikes: 2 many
Posts: 15,554
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 51 Post(s)
There is a clearance around the spider where it butts against the chain ring too. This accounts for a lot of the variation. I actually used shim stock and shimmed my chain ring to the exact middle. This does not help any off center in the rear wheel, but I am able to run my chain a little tighter without having to have an extremely loose spot. I think that helps keep the chain on at high rpm or stress. There will always be a little variation due to manufacturing tolerances of all the parts.
2manybikes 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 04:29 PM.