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


Mysterious Chain Jumping
#1
The derailleurs are perfectly tuned, brand new chain, cassette, and chain rings. New rear wheel, still same problem.
Whenever i stand up to pedal hard up hills or even on flat trail, my bike makes this disgusting noise and the chain skips or something. Sometimes the chain even falls off from the chain slip. (like in the video)
http://www.youtube.com/watch?v=wU_fdH-AOV8
All components are properly lubed with the appropriate lubricants... WTF. All i can guess is something with the bottom bracket?
I am so thankful for any insight anyone has, two shops have already tried to fix it and failed.

  Reply
#2
chain too long?

  Reply
#3
yo thepinto201 i am having same difficulties w/ 2 mongoose XR 250 mountain bikes. properly calibrated & lubed by professional bike enthusist . have contacted http://www.pacificcycle.com manufactures of mongoose bikes & warranty. they just keep blowing us off. my children can't ride across flat surfaces 40 feet without chain not climbing into rear spokes . need to accumate a class action against http://www.pacificcycle.com and Shimano...

  Reply
#4
Tough one!<br />
Looks like the chain is falling off the front chain rings. True? Does the same thing happen on all of the front chainrings or only on the inner? It could be flex in the BB or crank causing the chain line to get so bad the chain slips off. But that's pretty weird.
Can you get it to slip at a slow enough speed someone can jog next to you and try to spot where the chain is jumping? That might help. You've changed all the parts that would normally cause this. So either you have a mismatch (incompatible) part or something quite odd going on. Sadly, you may just need to keep trying shops until you find someone willing to spend the time to isolate it.
@billy_anders - something on your bikes need adjustment or replacement. I'm not defending Pacific Cycle, but I don't think this is a 'class action' issue. You need a good mechanic to figure out what is wrong and if there is a warranty issue, have them take it up with Mongoose directly.

  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
26" Thruster® Street Style BMX | July 20...
Yesterday 10:58 PM
Post a photo for aeroe Spider Rear Rack
Yesterday 10:47 PM
FD cable pull on opposite side of frame
Yesterday 06:54 PM
Creaky crank with play and loosening
Yesterday 06:36 PM
60s Viner Repainted..?
Yesterday 06:23 PM
budget speedometer
Yesterday 10:44 AM
2020 road cycling season
Yesterday 08:53 AM
Pinging noise fixed
Yesterday 08:08 AM
Need advice on Bike Rack
Yesterday 02:07 AM
RE: Merida Matts 6.5 Bicycle | June 2020...
07-07-2020 11:25 PM

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