Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Big problems while switching gears

Search
Notices
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.

Big problems while switching gears

Thread Tools
 
Search this Thread
 
Old 02-17-12 | 03:55 PM
  #1  
sen2two's Avatar
Thread Starter
ROOKIE!!!
 
Joined: Apr 2011
Posts: 86
Likes: 0
Big problems while switching gears

I have a 2008 Giant Defy 3 with Shimano sora equipment, which is original. I am pretty sure I need it to be adjusted. I am very much a do-it-your-selfer and I have a backround in mechanics. So with a little instruction from some of you pros, I am sure I can make my shifting much smoother...

Anyone want to help this newbie out here?
sen2two is offline  
Reply
Old 02-17-12 | 03:58 PM
  #2  
contango's Avatar
2 Fat 2 Furious
 
Joined: Nov 2010
Posts: 3,996
Likes: 2
From: England

Bikes: 2009 Specialized Rockhopper Comp Disc, 2009 Specialized Tricross Sport RIP

Try taking a look here:

https://www.parktool.com/blog/repair-...nts-derailleur

This will show you how to adjust the rear derailleur, I'm sure there's something similar for adjusting the FD if that's what you need.
__________________
"For a list of ways technology has failed to improve quality of life, press three"
contango is offline  
Reply
Old 02-17-12 | 04:08 PM
  #3  
Mechanic/Tourist
 
Joined: Apr 2007
Posts: 7,522
Likes: 12
From: Syracuse, NY

Bikes: 2008 Novara Randonee - love it. Previous bikes:Motobecane Mirage, 1972 Moto Grand Jubilee (my fave), Jackson Rake 16, 1983 C'dale ST500.

Originally Posted by sen2two
I have a 2008 Giant Defy 3 with Shimano sora equipment, which is original. I am pretty sure I need it to be adjusted. I am very much a do-it-your-selfer and I have a backround in mechanics. So with a little instruction from some of you pros, I am sure I can make my shifting much smoother...

Anyone want to help this newbie out here?
If you really are "very much a do-it-your-selfer" You could start by reading the first entry in: https://www.bikeforums.net/showthread...ease-READ-THIS so that you understand how to post something that we can respond to in a helpful manner (rather than "I am pretty sure I need it to be adjusted")

and also checking out: https://www.bikeforums.net/showthread....com-shortcuts

as well as the Park Tool repair instructions at: https://www.parktool.com/blog/repair-help.

It's very unproductive on both sides to come with no real question at all and with no knowledge of how to explain the issue. It is much better to study first so you understand how a particular system, such as the drive train, works. Then you can carefully and methodically attempt to correct the issue. Finally if you hit a snag you can tell us what you have tried and use the proper terms so we understand the problem you are having.

Last edited by cny-bikeman; 02-17-12 at 04:13 PM.
cny-bikeman is offline  
Reply
Old 02-17-12 | 04:39 PM
  #4  
ljsense's Avatar
Senior Member
15 Anniversary
 
Joined: Sep 2009
Posts: 771
Likes: 166
From: Madison, Wis.
Try pressing on it hard with your foot.
ljsense is offline  
Reply
Old 02-17-12 | 04:56 PM
  #5  
Senior Member
 
Joined: Jan 2012
Posts: 2,243
Likes: 4
From: Spokane, WA

Bikes: Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520

Make sure your rear derailleur isn't bent at an odd angle respective to the rear cogs.

You have a rear derailleur. It has 2 screws. H and L-High and Low. The low is the BIG gear/cog. The high is the LITTLE gear cog. I would put the chain on the middle wheel in the front. SHift the rear so its all the way in the highest gear (littlest cog). Adjust the H screw so that the centerline of the pulleys on the derailleur line up with the smallest rear cog. Now shift all the way to the lowest gear (biggest cog). Adjust the L screw so that the centerline of the pulleys on the rear derailleur line up with the largest rear cog. Make sure you can't push the derailleur past that point otherwise you will drop the chain inbetween the spokes and largest cog and bad things happen.

For the front, its pretty much the same except that H and L are reversed. H is the biggest cog and L is the smallest cog.
bobotech is offline  
Reply
Old 02-18-12 | 06:38 AM
  #6  
pat5319's Avatar
Senior Member
20 Anniversary
 
Joined: Sep 2000
Posts: 1,148
Likes: 1
From: Spokane WA

Bikes: Seven Axiom Ti, Trek 620, Masi cylocross (steel). Masi Souleville 8spd, Fat Chance Mtn. (steel), Schwinn Triple Bar cruiser, Mazi Speciale Fix/single, Schwinn Typhoon

try: https://www.youtube.com/results?searc...3.4.1.0.1l11l0 ...... (open in new window) gives several video demo choices on how to do
pat5319 is offline  
Reply
Old 02-18-12 | 11:50 AM
  #7  
Retro Grouch's Avatar
Senior Member
Titanium Club Membership
20 Anniversary
 
Joined: Feb 2004
Posts: 30,225
Likes: 649
From: St Peters, Missouri

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Originally Posted by bobotech
Make sure your rear derailleur isn't bent at an odd angle respective to the rear cogs.

You have a rear derailleur. It has 2 screws. H and L-High and Low. The low is the BIG gear/cog. The high is the LITTLE gear cog. I would put the chain on the middle wheel in the front. SHift the rear so its all the way in the highest gear (littlest cog). Adjust the H screw so that the centerline of the pulleys on the derailleur line up with the smallest rear cog. Now shift all the way to the lowest gear (biggest cog). Adjust the L screw so that the centerline of the pulleys on the rear derailleur line up with the largest rear cog. Make sure you can't push the derailleur past that point otherwise you will drop the chain inbetween the spokes and largest cog and bad things happen.

For the front, its pretty much the same except that H and L are reversed. H is the biggest cog and L is the smallest cog.
While that's correct, I think that it's still bad advice.

Assuming the limit screws were correctly set when the bike was new, messing with the limit screw adjustment is almost always a bad idea.
Retro Grouch is offline  
Reply
Old 02-18-12 | 01:55 PM
  #8  
Senior Member
Titanium Club Membership
15 Anniversary
 
Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Originally Posted by Retro Grouch

Assuming the limit screws were correctly set when the bike was new, messing with the limit screw adjustment is almost always a bad idea.
While I agree with you that messing around with limit screws can cause problems, the converse is also true -- not checking limit screws every time you adjust rear derailleurs is equally if not more dangerous.

Most derailleurs today hold adjustment very well. If a derailleur that used to trim correctly no longer does, there's a reason. It could be as simple as cable stretch (descriptive of effect not cause) and a tweak of the barrel adjuster is all that's needed.

But that's a dangerous assumption because a major cause of loss of trim is the hanger being bent inward (they rarely if ever bend outward). That changes the trim, but also the inner and outer limits, correcting only the trim leaves the bike vulnerable to overshifting beyond the low gear sprocket into the wheel.

My rule --- Every time I adjust trim, especially if trimming the RD outward, I confirm the low gear limit by pulling the cable away from the downtube like a bow string (or pushing the lower body manually in manually) and making sure I cannot overshift into the spokes.

BTW- if low gear limit and trim moved, then so did the high gear limit, and if they moved a lot or slightly a few times, then it's to square up the hanger.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Reply
Old 02-18-12 | 02:05 PM
  #9  
Homebrew01's Avatar
Super Moderator
20 Anniversary
 
Joined: Jul 2004
Posts: 21,979
Likes: 1,154
From: Ffld Cnty Connecticut

Bikes: Old Steelies I made, Old Cannondales

Since the OP hasn't explained the problem, it's a bit pointless to offer good or bad advice.
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.

FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
Homebrew01 is offline  
Reply
Old 02-18-12 | 02:07 PM
  #10  
Senior Member
Titanium Club Membership
15 Anniversary
 
Joined: Apr 2009
Posts: 39,897
Likes: 3,865
From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Originally Posted by Homebrew01
Since the OP hasn't explained the problem, it's a bit pointless to offer good or bad advice.
he got good advice ---- read the available tutorials. the rest is apropos after he's done so.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline  
Reply
Old 02-24-12 | 12:12 PM
  #11  
sen2two's Avatar
Thread Starter
ROOKIE!!!
 
Joined: Apr 2011
Posts: 86
Likes: 0
Sorry I didnt respond. It's correct that I posted prematurely without doing my research. I also asked a vauge question. Thanks for the helpful hints even though I didnt ask the right question...

I have been reading up and wathcing videos. I want to gain a little more knowledge before I start adjusting anything. I come from the car world where I have built high HP street/drag cars and I have forgotten what it's like to be the rookie. I am not use to having to ask questions.

Thanks for the replys.
sen2two is offline  
Reply
Old 02-24-12 | 12:36 PM
  #12  
RubberLegs's Avatar
Senior Member
 
Joined: Mar 2011
Posts: 1,698
Likes: 6
From: Tampa Bay, Florida

Bikes: 87 Bridgestone 550 (Shocking Electric Metallic Pink)

I have Sora on my newest road bike, it may be lower end on the food chain, but once dialed in, it works fairly well. Describe set-up, symptoms, and we will see what we can do to help.
RubberLegs is offline  
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
teachme
Bicycle Mechanics
9
06-25-19 11:39 AM
virtuosity
Mountain Biking
10
08-22-12 04:37 PM
celloyd
Bicycle Mechanics
6
06-25-12 08:39 AM
BLACK KNIGHT
Mountain Biking
1
04-23-11 10:05 PM
Snicklefritz
Bicycle Mechanics
10
01-11-10 04:53 AM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



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

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.