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.

2 out of 3 is BAD !

Old 09-19-07, 08:32 PM
  #1  
ItCostsWhat?
Member
Thread Starter
 
Join Date: Aug 2007
Posts: 46
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
2 out of 3 is BAD !

I need your help, I have become a self taught biulder. I recently built 3 bikes from E-Bay parts. two of them have problems with jumping/sliping gears ,only in the mid 3 gears of a 7 spd freewheel. the feewheel is new and spins true.chian is new,the derailer is used, and the shifters are off brand,and index perfectly on the first 2 and last 2 gears. It only jumps under hard peddle presure. I'm guessing it's a worn derailer. But before I replace that, What do you all recomend.
ItCostsWhat? is offline  
Old 09-19-07, 11:34 PM
  #2  
Tapeworm21
Senior Member
 
Tapeworm21's Avatar
 
Join Date: Jan 2007
Location: Berkeley
Posts: 2,265

Bikes: 2010 Tarmac SL, 2013 Fairdale Weekender, 2013 Fairdale Coaster, 1995 Specialized M2 Pro, 1972 Schwinn Heavy Duty, 2014 Surley Long Haul Trucker

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
It's not the derailleur. Have you messed around with the barrel adjusters?
Tapeworm21 is offline  
Old 09-20-07, 06:14 AM
  #3  
Kotts
Recreational Commuter
 
Join Date: Apr 2006
Location: Central Ohio
Posts: 1,022

Bikes: One brand-less build-up, and a Connondale Synapse Carbon Ultegra Disc. A nicer bike than I need, but it was a good deal, so... ;-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 3 Times in 1 Post
Originally Posted by ItCostsWhat? View Post
I need your help, I have become a self taught biulder. I recently built 3 bikes from E-Bay parts. two of them have problems with jumping/sliping gears ,only in the mid 3 gears of a 7 spd freewheel. the feewheel is new and spins true.chian is new,the derailer is used, and the shifters are off brand,and index perfectly on the first 2 and last 2 gears. It only jumps under hard peddle presure. I'm guessing it's a worn derailer. But before I replace that, What do you all recomend.
It sounds to me like a badly worn casette, particularly with a new chain. The middle gears tend to get used more, and therefore take more wear. A new chain actually makes the situation worse, because the chain matches the spacing properly only on the unworn gears.

Check this link out:
http://sheldonbrown.com/chains.html
Go about 2/3 the way down the page.

Kotts
Kotts is offline  
Old 09-20-07, 08:20 AM
  #4  
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,524

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 33 Post(s)
Tagged: 0 Thread(s)
Quoted: 1161 Post(s)
Likes: 0
Liked 33 Times in 30 Posts
Are you sure the freewheel is really new? It's not uncommon to have things badly mis-represented on E-bay. I agree it sounds like a new chain on a worn freewheel.
HillRider is offline  
Old 09-20-07, 08:23 AM
  #5  
edzo
Senior Member
 
Join Date: Feb 2006
Posts: 1,564
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 1 Time in 1 Post
it sounds like the spacing on the freewheel is not compatible with the index of the shifters

unfixable unless you have friction mode, or find different shifter/freewheel combo that does match
edzo is offline  
Old 09-20-07, 08:26 AM
  #6  
rjacob
Senior Member
 
rjacob's Avatar
 
Join Date: Apr 2007
Posts: 175

Bikes: 90' Trek 1000, Trek 700 cyclocross conversion, Legnano, 54 Indian Scout, 1980 Trek 412, Zeus Professional?, Raleigh Team USA, Raleigh Technium, Scott Spark 60,...

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
If the freewheel is new, and the chain is new.... I am leaning to the derailluer adjustment being very slightly off. Is the rear derailluer straight? Is it bent at all?
rjacob is offline  
Old 09-20-07, 08:47 AM
  #7  
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,524

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 33 Post(s)
Tagged: 0 Thread(s)
Quoted: 1161 Post(s)
Likes: 0
Liked 33 Times in 30 Posts
Originally Posted by edzo View Post
it sounds like the spacing on the freewheel is not compatible with the index of the shifters

unfixable unless you have friction mode, or find different shifter/freewheel combo that does match
Good point. The OP said the shifters were "off brand". I wonder if they are Sun Tour 7-speed. The spacing would not only be different but varies from cog to cog.
HillRider is offline  
Old 09-20-07, 08:57 AM
  #8  
rjacob
Senior Member
 
rjacob's Avatar
 
Join Date: Apr 2007
Posts: 175

Bikes: 90' Trek 1000, Trek 700 cyclocross conversion, Legnano, 54 Indian Scout, 1980 Trek 412, Zeus Professional?, Raleigh Team USA, Raleigh Technium, Scott Spark 60,...

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
From his first post, it sounds like the indexing works fine while not under load. So I am guessing the indexing is compatible. And it's only on the middle 3 gears. If the indexing was not compatible, then it seems like the shifting would be off while not under load too.
rjacob is offline  
Old 09-20-07, 05:51 PM
  #9  
ItCostsWhat?
Member
Thread Starter
 
Join Date: Aug 2007
Posts: 46
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks for reading the whole question. Yes it is a SunTour,but a 6 speed,as Sheldon Brown stated in one of his articles. I'm going over today and try it in friction mode. If it still jumps I'll change to a derailer I know works. The other bike with that problem does have a new chian with a used everthing else.I'll get to that one later. D.S.
ItCostsWhat? is offline  
Old 09-21-07, 11:41 AM
  #10  
Sheldon Brown
Gone, but not forgotten
 
Sheldon Brown's Avatar
 
Join Date: Jul 2002
Location: Newtonville, Massachusetts
Posts: 2,301

Bikes: See: http://sheldonbrown.org/bicycles

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by ItCostsWhat? View Post
Thanks for reading the whole question. Yes it is a SunTour,but a 6 speed,as Sheldon Brown stated in one of his articles. I'm going over today and try it in friction mode. If it still jumps I'll change to a derailer I know works. The other bike with that problem does have a new chian with a used everthing else.I'll get to that one later. D.S.
Jumping is not generally the fault of the derailer, it's usually caused by worn chain/sprockets.

See: http://sheldonbrown.com/chains

If you have SunTour _6-speed_ indexed shifters, there's a cool hack ou can do:

Get a _7-speed_ freewheel and a Shimano rear derailer (any Shimano derailer, even a $20 Tourney) and it will actually index properly with your SunTour shifters!

Sun Tour indexed shifters pull less cable per shift than Shimano systems use. Thus, generally, you need to match Sun Tour indexed shifters with Sun Tour rear derailers.

However, it turns out that Sun Tour 6-speed shifters index pretty well with 7-speed clusters if you replace the old Sun Tour rear derailer with a Shimano unit!

The mismatch in cable travel cancels out the mismatch between 6 and 7 speeds. There won't be a "click" for the lowest gear, but the derailer's low-gear limit stop will provide the "indexing" for that gear.

Sheldon "Serendipity" Brown
Sheldon Brown is offline  
Old 09-24-07, 08:32 AM
  #11  
ItCostsWhat?
Member
Thread Starter
 
Join Date: Aug 2007
Posts: 46
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Sheldon is so right on, I replaced the chain with a new one and so far no problems. I used his web sight extensively when planning my E-Bay bikes,and saved a lot of $.
I owe a huge Thank You to Sheldon Brown.
ItCostsWhat? is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Psychkle
Singlespeed & Fixed Gear
10
11-12-10 09:55 AM
Wiggle
Electronics, Lighting, & Gadgets
3
09-18-08 12:42 PM
imabeliever1
Classic & Vintage
4
09-26-07 06:37 PM
Cyclingmaniac
Road Cycling
5
04-09-04 07:44 AM
Joe Gardner
General Cycling Discussion
0
07-08-01 11:24 PM

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.