8th gear isn't catching?
03-13-10, 12:24 AM
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8th gear isn't catching?
Bought a GT ZuM 5.0 a while ago and got some awesome riding in during the spring/summers. Recently moved to cali from tennessee and didn't ride it at all until now. Whenever I'm in the top gear (8), it seems like the chain will just slip off one of the teeth for about half a pedal turn. This occurs both on a hard pedaling uphill and even level ground with hardly any resistance pedaling. Checked the cassette and I can't really see anything noticeably damaged but I'm pretty noob at bicycle maintenance.
I remember back when I was in shape, I never downshifted from 8th no matter how slow or how steep the hills were...could this extra tension have caused too much stress and damaged the cassette/chain? Anything I could do to fix it (it's really annoying to ride in 7th -_-...)? Thanks guys!
I remember back when I was in shape, I never downshifted from 8th no matter how slow or how steep the hills were...could this extra tension have caused too much stress and damaged the cassette/chain? Anything I could do to fix it (it's really annoying to ride in 7th -_-...)? Thanks guys!
03-13-10, 12:49 AM
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You're in 8th uphill? Either you're crossing your chain all the way (bad), or you're calling 1st gear 8th. Your second paragraph suggests the former.
Sounds to me like you shouldn't be using your granny ring in the first place, and your chain may be worn.
Measure 24 links under tension, and if it's more than 1/16" over 12", it could be time for a new cassette and chain.
Sounds to me like you shouldn't be using your granny ring in the first place, and your chain may be worn.
Measure 24 links under tension, and if it's more than 1/16" over 12", it could be time for a new cassette and chain.
03-13-10, 12:46 PM
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If you are cross-chaining, smallest chainring and smallest cassette cog, that could be causing the problem.
Don't cross-chain.
Good advice from Kimmo, above.
Don't cross-chain.
Good advice from Kimmo, above.
03-13-10, 12:52 PM
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Why do you feel you always have to stay in the smallest cog? Isn't it easier to go up hills with a larger one?
Especially if you are riding in the small chainring up front - shifting to small chainring says to me that you are going into an easier gear... the same gear can be found by using the middle chainring and one of the slightly larger cogs. THe advantage of staying middle/middle is that the chain is at a less severe angle which causes less drag and less drivetrain wear.
It is possible that the cross chaining is just making the chain hang up or get caught every now and then, and this is normal. The solution is to not cross chain. It is also possible that you have cause excessive wear on the small chainring by using it exclusively... but try not cross chaining first to see if that fixes the problem.
Especially if you are riding in the small chainring up front - shifting to small chainring says to me that you are going into an easier gear... the same gear can be found by using the middle chainring and one of the slightly larger cogs. THe advantage of staying middle/middle is that the chain is at a less severe angle which causes less drag and less drivetrain wear.
It is possible that the cross chaining is just making the chain hang up or get caught every now and then, and this is normal. The solution is to not cross chain. It is also possible that you have cause excessive wear on the small chainring by using it exclusively... but try not cross chaining first to see if that fixes the problem.
03-13-10, 06:51 PM
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What exactly is 'cross-chaining?' By the way, lardasse74, I do shift down to lower gears on uphills now, but the problem with 8th happens even on level ground (which I'm in 8th gear all the time on). Any recommendations for new cassettes/chains? Not even sure what will fit my bike? Thanks for any more help 
03-13-10, 07:05 PM
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Cross chaining is using the innermost chainring with the outermost cog and vice versa (also known as big chainring to biggest cog or smallest chainring with smallest cog, measured by number of teeth). Puts the chain at larger angles than ideal; depending on your setup you may also have chain sizing issues. Your using one cog a lot will put a lot of wear on that cog. While you might find a replacement cog for your cassette, typically you replace the whole cassette. Not familiar with your bike but an 8-speed chain and cassette should be easy to source, just start googling.
03-14-10, 01:58 AM
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Sorry...'chainring?'...'cog?'
Can anyone tell me a good company for a 8speed cassette/chain? performancebike.com reviews seem to say the SRAM cassette is better than the Forte (which tends to break).
Can anyone tell me a good company for a 8speed cassette/chain? performancebike.com reviews seem to say the SRAM cassette is better than the Forte (which tends to break).
03-14-10, 02:10 AM
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Chainrings are the sprockets up front attached to your crankset, the cassette is comprised of cogs...SRAM and Shimano are both good brands and easily found. Forte is a low end house brand from Performance/Nashbar, but useable. Depends on your budget.
03-14-10, 02:11 AM
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Rear Derailleur limiter needs to be adjusted most likely.
