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


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 12-16-07, 04:48 PM   #1
brett jerk
zizeked
Thread Starter
 
brett jerk's Avatar
 
Join Date: May 2007
Bikes:
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
chain... slipping question

I wish that I could better explain this problem, but here's what happens:
I'll be mashing on my mountain bike (this virtually always occurs when I'm going uphill or putting extra force on my bike) and all the sudden their will be no resistance (usually on the downstroke) which has caused me to wipe out and come close to wiping out a few times. Immediately after doing this the chain will resist again, without any adjustments (if I can keep from wiping out, I can keep going)

what might be the cause of this/how can i fix it? I'd post relevant details, but its just a ****ty old trek 800 frame with a bunch of swapped in parts as old ones broke (their virtually all cheapo)

thanks!
brett jerk is offline   Reply With Quote
Old 12-16-07, 05:19 PM   #2
frankenmike 
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Bikes: rigid 29er moto, s-works stumpjumper fsr,black fixie,masi roadbike, ugly old hardrock commuter
Posts: 1,379
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Sound like either a slipping freewheel or missing/worn tooth.
frankenmike is offline   Reply With Quote
Old 12-16-07, 05:21 PM   #3
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How many miles are on your chain and cassette? It sounds like they may be worn.
barba is offline   Reply With Quote
Old 12-16-07, 05:28 PM   #4
brett jerk
zizeked
Thread Starter
 
brett jerk's Avatar
 
Join Date: May 2007
Bikes:
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
the chain and casette haven't been ridden very much, few hundred miles at most (i replaced them and then got a new bike so I haven't put much on them)
although the riding I have done has been in the snow and salted roads, so they probably took a decent beating (I didn't really know how to care for a bike at the time).
brett jerk is offline   Reply With Quote
Old 12-16-07, 05:29 PM   #5
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Measure the chain just to be certain.
barba is offline   Reply With Quote
Old 12-16-07, 05:29 PM   #6
joshandlauri
Got another new bike
 
Join Date: Nov 2007
Location: dundalk, md
Bikes: pacific elite 3.1 w/upgrades and street slicks, got an iron horse maverick now, cannondale sr800, gt gtr pro rival
Posts: 584
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i just had this happen to me and found several missing teeth on the freewheel, it only skipped when taking off and under a load (hills)
joshandlauri is offline   Reply With Quote
Old 12-16-07, 06:29 PM   #7
brett jerk
zizeked
Thread Starter
 
brett jerk's Avatar
 
Join Date: May 2007
Bikes:
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
the freewheel is a pretty decent shimano casette and I've switched gears all over the place (i leave my bike on one gear for the most part) so it may actually be the chain? this never really occurred to me. what should i measure? how should I match this measurement up?
brett jerk is offline   Reply With Quote
Old 12-16-07, 06:34 PM   #8
Br1an1127
Member
 
Br1an1127's Avatar
 
Join Date: Dec 2007
Bikes: Iron Horse Warrior 4.0
Posts: 32
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by brett jerk View Post
I wish that I could better explain this problem, but here's what happens:
I'll be mashing on my mountain bike (this virtually always occurs when I'm going uphill or putting extra force on my bike) and all the sudden their will be no resistance (usually on the downstroke) which has caused me to wipe out and come close to wiping out a few times. Immediately after doing this the chain will resist again, without any adjustments (if I can keep from wiping out, I can keep going)

what might be the cause of this/how can i fix it? I'd post relevant details, but its just a ****ty old trek 800 frame with a bunch of swapped in parts as old ones broke (their virtually all cheapo)

thanks!

It sounds like you may have a worn chainlink or crank tooth. If thats not the case you may need to adjust your front derailleaur becuase you may be overshifting of the crankset
Br1an1127 is offline   Reply With Quote
Old 12-16-07, 06:43 PM   #9
Cannondaler
Senior Member
 
Cannondaler's Avatar
 
Join Date: Dec 2007
Location: Atlantic Beach, FL
Bikes: Cannondale F600sl, Windsor Falkirk Carbon
Posts: 205
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you are not feeling any grinding or popping in the pedals when this happens it could be the freehub body, especially if the chain and cassette aren't that old and there aren't any obviously missing teeth. If it is just completely letting go as if you are pedaling air this would be my guess. If you have another wheel that you could try using the same cassette you are using now you could test this.
Cannondaler is offline   Reply With Quote
Old 12-16-07, 06:50 PM   #10
barba
Senior Member
 
barba's Avatar
 
Join Date: Nov 2005
Bikes:
Posts: 4,083
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by brett jerk View Post
the freewheel is a pretty decent shimano casette and I've switched gears all over the place (i leave my bike on one gear for the most part) so it may actually be the chain? this never really occurred to me. what should i measure? how should I match this measurement up?
Each complete link should measure exactly one inch. The standard method is to measure 12 links worth against a ruler. It should be one foot on the nose for a new chain. If the final rivet is more than 1/16th of an inch past the mark (at the center of the rivet), the chain should be replaced. If the final rivet is more than an 1/8th of an inch past the mark, there is a good chance that the teeth of the freewheel/cassette is worn as well and should be replaced.

Oh, and a new chain on a worn cassette can skip badly as well, as cassettes and chains wear together. People often buy a new chain and then are confused why their shifting suddenly gets worse.
barba is offline   Reply With Quote
Old 12-16-07, 07:14 PM   #11
brett jerk
zizeked
Thread Starter
 
brett jerk's Avatar
 
Join Date: May 2007
Bikes:
Posts: 288
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
sounds like its finally time to convert my crappy mountain bike to a single-speed! (new crankset/freewheel)
thanks everyone for your help
brett jerk 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 12:57 AM.