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


Go Back   > >

General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 07-20-10, 10:01 AM   #1
Bdude
Member
Thread Starter
 
Bdude's Avatar
 
Join Date: Jun 2010
Location: Santa Monica, Ca
Bikes: Diamondback Wildwood
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Changing gears by accident when bike is still

Why is it bad to change gears while the big isn't moving? When I carried my bike to my apartment, before the elevator got fixed, I had to carry it several flights of stairs. At times, I would accidentally bump into something and when I rode it, the bike gears were messed up leading me to have to take it to the shop to be repaired. If only there was some way to lock the gears while you were carrying it so you wouldn't have to take it to the shop again. But yeah, why is it bad to change the gears without having the bike in motion? Could that cause permanent damage when done frequently?
Bdude is offline   Reply With Quote
Old 07-20-10, 10:08 AM   #2
Velo Dog
Senior Member
 
Join Date: Jun 2004
Location: Northern Nevada
Bikes:
Posts: 3,802
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
When you shift the shifter while the bike is still (actually while the crank isn't turning; it doesn't matter if the bike is rolling or not), you force the derailleur against the chain as though it were going to shift. Since it has to be moving to guide onto the next chainring or cassette cog, though, the shift doesn't occur. In theory that can stress the derailleur, especially the rear, though I doubt it actually causes damage in real life. But the chain won't be squarely on the gear, so if you jump on the bike and start pedaling hard, it can jump toward the next gear and either spill you or tweak something. It's probably not as common as it used to be in the friction-shift days, and it's not a huge worry. From years of habit, though, I pick up the rear wheel and give the crank a spin before I get on the bike. If the chain is misaligned, that allows it to hop onto a gear.
Velo Dog is offline   Reply With Quote
Old 07-20-10, 10:11 AM   #3
Sixty Fiver
Bicycle Repair Man !!!
 
Sixty Fiver's Avatar
 
Join Date: Sep 2007
Location: YEG
Bikes: See my sig...
Posts: 27,262
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 9 Post(s)
Yep... before you ride give the crank a spin to make sure it is in gear and not somewhere in between.

Takes 2 seconds.

Saves grief.
Sixty Fiver is offline   Reply With Quote
Old 07-20-10, 10:15 AM   #4
Bdude
Member
Thread Starter
 
Bdude's Avatar
 
Join Date: Jun 2010
Location: Santa Monica, Ca
Bikes: Diamondback Wildwood
Posts: 38
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Velo Dog View Post
When you shift the shifter while the bike is still (actually while the crank isn't turning; it doesn't matter if the bike is rolling or not), you force the derailleur against the chain as though it were going to shift. Since it has to be moving to guide onto the next chainring or cassette cog, though, the shift doesn't occur. In theory that can stress the derailleur, especially the rear, though I doubt it actually causes damage in real life. But the chain won't be squarely on the gear, so if you jump on the bike and start pedaling hard, it can jump toward the next gear and either spill you or tweak something. It's probably not as common as it used to be in the friction-shift days, and it's not a huge worry. From years of habit, though, I pick up the rear wheel and give the crank a spin before I get on the bike. If the chain is misaligned, that allows it to hop onto a gear.
Sweet! Thanks a lot, dude!
Bdude is offline   Reply With Quote
Old 07-20-10, 11:31 AM   #5
Robert Foster
Banned.
 
Join Date: May 2008
Location: Southern california
Bikes: Lapierre CF Sensium 400. Jamis Ventura Sport. Trek 800. Giant Cypress.
Posts: 3,498
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If this is a big problem a visual check before you ride wouldn't hurt. Sometimes when stopped at a light on a group ride some friend will ride up next to you and tap the bifter two or three times just to be a joker. New riders panic and jump off the bike before the light changes and have to turn the crank to get into what ever gear the joker shifted them into. More seasoned riders simply look back at the cassette and see how many clicks it takes to get back in line.

Don't ask me how many times I jumped off the bike.
Robert Foster is offline   Reply With Quote
Old 07-20-10, 11:57 AM   #6
black_box
Fax Transport Specialist
 
black_box's Avatar
 
Join Date: May 2008
Location: chicago burbs
Bikes: '17 giant propel, '07 fuji cross pro, '10 gary fisher x-caliber
Posts: 898
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
would it matter if the derailleur spring was pushing against the chain vs. the next limit stop? I wouldnt think so. Just avoid spinning the cranks backwards and when possible, spin them forward to let the chain catch up to the shifter.
black_box is offline   Reply With Quote
Old 07-20-10, 04:46 PM   #7
AdamDZ 
Bike addict, dreamer
 
AdamDZ's Avatar
 
Join Date: Nov 2009
Location: Queens, New York
Bikes:
Posts: 5,165
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You won't damage the derailleur, it's designed to take a lot more tension than that. The worst that will happen, if you push hard, the chain will not engage any sprocket and will slip (jumping over the sprocket teeth) causing the pedals to spin nearly freely and your feet might slip off the pedals causing you to fall or hit the crank or outright fall if you're clipped in. If this happens often you may risk damage to the sprocket teeth.

Either do what Sixty Fiver suggested or start gently and allow the shift to complete before pushing hard. If you're facing uphill you have to do what Sixty Fiver said.

Or, if you know how many clicks you shifted, just shift back to undo.

Shift happens.
AdamDZ is offline   Reply With Quote
Old 07-20-10, 05:27 PM   #8
Mr. Beanz
Banned.
 
Mr. Beanz's Avatar
 
Join Date: Dec 2005
Location: Upland Ca
Bikes: Lemond Chambery/Cannondale R-900/Trek 8000 MTB/Burley Duet tandem
Posts: 20,030
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Why not pop it in the small chainring before you start lugging? Chance are if you bump the derailleur, it might spin the pedal too into a nice clean shift! I do this with my stuff.
Mr. Beanz is offline   Reply With Quote
Old 07-20-10, 05:36 PM   #9
AdamDZ 
Bike addict, dreamer
 
AdamDZ's Avatar
 
Join Date: Nov 2009
Location: Queens, New York
Bikes:
Posts: 5,165
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Mr. Beanz View Post
Why not pop it in the small chainring before you start lugging? Chance are if you bump the derailleur, it might spin the pedal too into a nice clean shift! I do this with my stuff.
This happens to me very, very rarely and I usually just start slowly to let it complete the shift the shift back once I'm moving or I click back to undo. I don't like to shift chainrings unless I really need to, shifting chainrings takes too long IMHO. Also, I usually ride with panniers so lifting the rear wheel isn't a viable option either for me, but that may work well for light bikes. There are few options to deal with this so one needs to chose what shifts... umm suits them best
AdamDZ is offline   Reply With Quote
Old 07-20-10, 06:10 PM   #10
Mr. Beanz
Banned.
 
Mr. Beanz's Avatar
 
Join Date: Dec 2005
Location: Upland Ca
Bikes: Lemond Chambery/Cannondale R-900/Trek 8000 MTB/Burley Duet tandem
Posts: 20,030
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by AdamDZ View Post
This happens to me very, very rarely and I usually just start slowly to let it complete the shift the shift back once I'm moving or I click back to undo. I don't like to shift chainrings unless I really need to, shifting chainrings takes too long IMHO. Also, I usually ride with panniers so lifting the rear wheel isn't a viable option either for me, but that may work well for light bikes. There are few options to deal with this so one needs to chose what shifts... umm suits them best
True! I don' use my bikes for commute, strictly sport fun fitness. So if I'm heading to a mtn road where we'll be climbing 5,000 ft, I have no problem shifting my bike into the smalll gear beforehand!

As far as our tandem, barend shifters so they rarely get bumped in transport.
Mr. Beanz 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 12:56 PM.