Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take part in the July Giveaway for a brand new 26" Thruster® Street Style BMX Cruiser Bicycle

New product launch: WIN an innovative aeroe Spider Rear Rack


Gear changes under load
#1
trek hardtail 3900 shifts under load uphill, got this in nov 09 new, rode it a couple of times, no problems,the first day above 40 I had it out and rode it long and hard. Going uphill with weight on pedals only, it shifted and I almost had my first crash of the year. Its happened quite a few times since then, any ideas? Thnx.
  Reply
#2
First of all check out the info here, especially Alex's video. Than print the instructions and go through the tune up process. Park Tool site has a good process for setting up the dérailleur. Basically start by setting the hi/low positions so the rear dérailleur is straight down in both top and bottom position, the front so it just clears the inside and outside than start tune up on the center front sprocket using the cable barrels a 1/2 turn at a time.

Not enough info given is it the front or rear??

If you do not have a bike stand use rope to hang your bike from rafters, bike hooks or whatever you can so you can pedal by hand and see what the problem is.
Never Give Up!!!
  Reply
#3
(04-12-2010, 01:44 PM)GeorgeET Wrote:  First of all check out the info here, especially Alex's video. Than print the instructions and go through the tune up process. Park Tool site has a good process for setting up the dérailleur. Basically start by setting the hi/low positions so the rear dérailleur is straight down in both top and bottom position, the front so it just clears the inside and outside than start tune up on the center front sprocket using the cable barrels a 1/2 turn at a time.

Not enough info given is it the front or rear??

If you do not have a bike stand use rope to hang your bike from rafters, bike hooks or whatever you can so you can pedal by hand and see what the problem is.

PS you say its a fairly new bike , so its likely that the cable stretched in which case try turning the adjustment barrel at the rear derailleur counter clockwise 1/2 turn at a time and test. If its the front turn the handlebar out counterclockwise and test.
Never Give Up!!!
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Dork disc - remove it or keep it?
Today 12:59 PM
Creaky crank with play and loosening
Today 11:21 AM
Post a photo for aeroe Spider Rear Rack
Today 10:45 AM
26" Thruster® Street Style BMX | July 20...
Today 08:23 AM
2020 road cycling season
Today 07:18 AM
FD cable pull on opposite side of frame
Today 04:18 AM
60s Viner Repainted..?
Yesterday 06:23 PM
budget speedometer
Yesterday 10:44 AM
Pinging noise fixed
Yesterday 08:08 AM
Need advice on Bike Rack
Yesterday 02:07 AM

[-]
Top 5 Posters This Month
no avatar 1. Jesper
73 posts
no avatar 2. CharleyFarley
21 posts
no avatar 3. Painkiller
15 posts
no avatar 4. Papa Dom
10 posts
no avatar 5. G_M
8 posts