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

Thread Tools Search this Thread
Old 09-26-12, 08:06 PM   #1
Senior Member
Thread Starter
PatrickGSR94's Avatar
Join Date: Apr 2012
Location: Memphis TN area
Bikes: 2011 Felt Z85 (road/commuter), 2006 Marin Pine Mountain (utility/commuter E-bike), 1995 KHS Alite 1000 (gravel grinder)
Posts: 7,316
Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 613 Post(s)
Rear derailer position at rest with no cable tension

Most RD's I've seen default to the smallest cog when there is no tension (or lowest tension) on the RD shifter cable. Increase tension on the cable (and stretch the RD spring) by pressing the largest lever on trigger-shifters, or moving the brake lever on brifters, usually down-shifts to the larger cogs. Releasing the tension up-shifts to smaller cogs.

This seems backwards to me. It's not backwards from how the FD works, but it's backwards in terms of upshifting (lower cadence, faster speed), or downshifting (higher cadence, lower speed). Indeed after riding for months I still get my rear shifting backwards by hitting one lever when I meant to hit the other from time to time.

But it seems like I saw a video once showing how to adjust an RD that had its default position under the largest cog on the cassette, and increasing cable tension moved the chain to smaller cogs. This would make both levers on both shifters operate the same - large lever (or brake lever) for up shifting, small lever for down shifting. Is there a name or term for each type of RD, one that normally sits closer to the wheel, and one that sits farther away? Have searched Sheldon's site but didn't see anything relating to RD positioning.
PatrickGSR94 is offline   Reply With Quote
Old 09-26-12, 08:12 PM   #2
well biked 
biked well
well biked's Avatar
Join Date: Jul 2005
Posts: 7,185
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Shimano's Rapid Rise mountain bike RD's use spring tension to move the derailleur towards larger cogs, cable tension is used to move it towards smaller cogs. So the "default" position (no cable tension) is at the largest cog, opposite of conventional RD's.
well biked is offline   Reply With Quote
Old 09-26-12, 08:15 PM   #3
Senior Member
dsbrantjr's Avatar
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 5,412
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 365 Post(s)
The most common derailleur type, which defaults to the smallest cog is a "high normal" one. The other is called "low normal" , trademarked by Shimano as "Rapid Rise". Here is the Sheldon Brown article you were looking for:
dsbrantjr is offline   Reply With Quote
Old 09-26-12, 08:16 PM   #4
cowboy, steel horse, etc
LesterOfPuppets's Avatar
Join Date: Sep 2008
Location: Rock Springs, WY
Bikes: everywhere
Posts: 29,395
Mentioned: 32 Post(s)
Tagged: 1 Thread(s)
Quoted: 1885 Post(s)
Semi-related, I have a backwards thumbshifter made by SR Sakae. Nice shifter but sure threw me off. It has a powershifter style ratchet to it. Seems like it was of a vintage prior to the Rapid Rise stuff...
LesterOfPuppets is online now   Reply With Quote
Old 09-27-12, 11:50 AM   #5
Certified Bike Brat
Burton's Avatar
Join Date: Jan 2011
Location: Montreal, Quebec
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Shimano marketed several rear derailleurs in both versions. My hybrid and mtb bike rear derailleurs are all XT low normal derailleurs.
Burton is offline   Reply With Quote
Old 09-27-12, 12:40 PM   #6
Senior Member
bud16415's Avatar
Join Date: Jul 2011
Location: Erie Penna.
Posts: 1,141
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Not sure if this will help but when I got my first modern bike with STI shifting I was racking my brain trying to remember what I was doing and mixing up shifts etc.

I read a lot of stuff about shifting and nothing seemed to help me with getting it straight in my head.

I started thinking about it and this is how I reconciled it in my mind and it became second nature instantly. If you are looking at the gears on the rear cassette the smallest is to the right and the largest the left. In the front it’s opposite with the chain rings the smallest is the left the largest the right. My shift thought is not about what gear I’m in but that it takes force to push the chain up hill to the bigger gear front and back. The rear gears are controlled by the right hand so pushing the big lever (more power) always moves the chain up the hill of cogs. The left big lever pushes the chain up hill to the bigger chain ring. The small lever (less force) lets the drop down (easy force). Not that I have trouble remembering the rear gears are on the right hand brifter but knowing I’m pushing them to go up makes it an instinct feeling.

With the mental picture of the cone of gears going opposite directions front and back made the way the levers work seem quite correct.
bud16415 is offline   Reply With Quote

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 09:04 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.
  • Ask a Question
    get answers from real people!
Click to start entering your question.