|
rbent Forum
https://rbentonline.org/YaBB.pl General Category >> Technical >> Chain jumping aftr shifting gears https://rbentonline.org/YaBB.pl?num=1313835414 Message started by Tom Nuchols on Aug 20th, 2011, 5:16am |
|
Title: Chain jumping aftr shifting gears Post by Tom Nuchols on Aug 20th, 2011, 5:16am I am havine a problem with the chain jumping after shifting gears. This normally happens on the down shift and normally i can shift up one gear and make it stop. Does anyone know why this is occurring? Thanks Tom |
|
Title: Re: Chain jumping aftr shifting gears Post by power_bent on Aug 20th, 2011, 4:30pm Tom Nuchols wrote:
Does it have bar end shifter?? If so that what the prob is , same what it was doing on my trike... |
|
Title: Re: Chain jumping aftr shifting gears Post by Bud_Bent on Aug 20th, 2011, 4:41pm If you've been running this chain for a while, be sure to check it for wear. They will do that when they get too worn. A loose nut on the cassette can cause this, too. |
|
Title: Re: Chain jumping aftr shifting gears Post by Tiger_Mike on Aug 20th, 2011, 9:52pm I had this problem once. I did some reading on it, and found that the shifter cable tension regulates the sensitivity and speed of the shifting. There on the handle bar where the shifter cable enter the shifter housing, there is a nut around the cable that makes small adjustments to the tension. I found that I could adjust this easily while I was riding - I found the sweet spot and my bike stopped shifting gears by itself. It's hard to climb a hill when your bike keeps shifting gears, isn't it! Oh yeah, the adjuster screws on the rear derailluer are for setting how high and low the chain will go, they don't affect how it shifts on the cogs in between. As long as your bike will shift onto the biggest and smallest cogs without throwing the chain off, leave these screws alone. Good luck! |
|
Title: Re: Chain jumping aftr shifting gears Post by Tom Nuchols on Aug 21st, 2011, 5:25pm Thanks for the information. I checked the chain and to my surprise it exceeds the 1.0 mark on the chain gauge. This chain has not got more than 2000 miles on it if that much. It is a Sram 971 chain. I thought this was a good chain when I installed it. I had replaced the cassette at the same time. I will check with the Lonview Bike shop to see if they have any three chains in stock tomorrow. Thank you Tom Nuchols |
|
Title: Re: Chain jumping aftr shifting gears Post by power_bent on Aug 21st, 2011, 7:26pm Tom Nuchols wrote:
You will prob still have the same prob because what you describe is indexing wasn't right .A loose chain will jump up not change gears . |
|
Title: Re: Chain jumping aftr shifting gears Post by rmillay on Aug 21st, 2011, 7:55pm Also, I doubt a worn chain would wear out a cassette in 2000 miles. Replace the chain and adjust the tension on the shift wire and see if you've fixed it. The cassette can go on your spare wheel. (You do have a spare wheel, don't you?) [smiley=laugh.gif] |
|
Title: Re: Chain jumping aftr shifting gears Post by Patti on Aug 24th, 2011, 11:39am I had a similar problem on my trike. It made climbing a real adventure. I couldn't find an adjustment to consistently correct it it but Mike (Easy Street) finally fixed it by adding an extra spacer to my cassette. |
|
Title: Re: Chain jumping aftr shifting gears Post by Opus the Poet on Aug 24th, 2011, 8:26pm Check the low limit screw on your derailler, it sounds like it might have backed out a touch. |
|
Title: Re: Chain jumping aftr shifting gears Post by Tom Nuchols on Aug 25th, 2011, 6:22am Thanks for every one inforumatgion. The chain was definitely worn out. The gauge fell in the 1.o slot like it had molasses on it. The Cassette nut was definitely tight. The new 951 chain is installed, and now for the adjustments. I am having a hard time understanding why the old 971 chain wore out so fast. I t did not have many miles on it. I had changed the chain on the Home built bike at the same time an it has a lot more hard miles on it than the Bacchetta did. 5/8 inch of rain last nite and the air sure is cool and nice. Thanks again. Tom Nuchols |
|
rbent Forum » Powered by YaBB 2.1! YaBB © 2000-2005. All Rights Reserved. |