Help with high gear slipping to lower gears.

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Help with high gear slipping to lower gears.

Postby bradley.j » Thu Feb 25, 2010 7:15 pm

Hi everyone!

I've been wanting a bike for over a year now and finally had the cash to get one which I thought was pretty decent. I've had it for a week now and am totally enjoying it but I have a bit of a problem whilst riding up my hill.

When I put the front gear to the lowest (smallest) gear and the rear gear to the highest (biggest) gear, so that I can get up a hill, when I start pedalling with a bit of effort, the rear gear will slip off one or two gears ever 10 seconds and then will get pushed back on. This causes my legs to move quickly forwards and feels really bad. Not like the smooth ride I was expecting.

Anyways, I don't know if I'm shifting gears correctly (really new at this) and that may be why, or if it is just a problem with the gears, or even the way it's been set up? I got the guys at the shop to set it up for me so I hope it's not that.

It's an Avanti Montari '09 model.

Any help as to why this would be happening and how I can fix it, or if I just ned to go back to the shop and let them know what is going on, would be greatly appreciated.

Thanks lots.
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by BNA » Thu Feb 25, 2010 7:20 pm

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Re: Help with high gear slipping to lower gears.

Postby Mulger bill » Thu Feb 25, 2010 7:20 pm

G'Day Bradley, welcome outside. :D

If I read you right, it sounds like the shift cable has stretched a little in the first week, perfectly normal on a new bike.

I'll move this thread over to the shed so the resident wrenches can mull it over and give you their wild guesses.... umm sorry, learned opinions that's what I mean :wink:

Cheers
Shaun
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Re: Help with high gear slipping to lower gears.

Postby bradley.j » Thu Feb 25, 2010 7:29 pm

Thanks for the prompt reply. The joint I bought it from have told me to come back in 6 weeks to get a service so that makes sense now.

Basically you have made me a lot less worried. Heh.
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Re: Help with high gear slipping to lower gears.

Postby clack3rz » Fri Feb 26, 2010 6:03 am

As MB stated - the cable has stretched a little and needs a minor adjustment to correct it.
If you're not comfortable with doing the adjustment yourself, don't wait the 6 wks out to get it fixed in the service, take it down there and get the cables done.
You don't want to be continually riding like that - you could put unwanted strain on the chain and damage the cluster/derailleur - or worse still have the chain ride up and over the rear cluster when shifting gears and into your spokes. Which is no good for the rider :(
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Re: Help with high gear slipping to lower gears.

Postby jules21 » Fri Feb 26, 2010 9:12 am

make sure it's (the chain is) lubed properly as well. i reckon the granny cog often gets little use and can get pretty dry, which can cause it to skip.

at the Alpine Ride in Jan, i cleaned my drivetrain and only lubed the chain on the morning of the ride. bad mistake, the lube didn't have time to soak in (at least that's the usual advice - do it the night before). 1st gear slipped and chattered all the way up Tawonga Gap, until i pulled into my motel in Mt Beauty and gave it another squirt.
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Re: Help with high gear slipping to lower gears.

Postby Stovepipe » Mon Jul 14, 2014 5:30 pm

thread dig....

I get this too. I get out of the saddle and it drops a couple of cogs over - major pain in the ass.

how exactly do you adjust the cable to fix this? happy to have a go at it, just not sure how....
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Re: Help with high gear slipping to lower gears.

Postby reefer » Mon Jul 14, 2014 6:01 pm

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Re: Help with high gear slipping to lower gears.

Postby Stovepipe » Wed Jul 16, 2014 5:14 pm

yep yep cheers good video, BUT...
what exactly is the mechanical process that is happening when the gear is slipping? and hence how do you prevent it (im not sure exactly but it's somewhere around the 4-6 gears of an 8speed campy cassette)

ie. if it's a result of the cable stretching, does that mean my indexing is misaligned now? do i basically have to go through the whole calibration process again as per the video? or is it a matter of adjusting shift cable tension or something?

soz, new to tinkering with gears. tbh im pretty PO'd since I paid my LBS $120 to set this up
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Re: Help with high gear slipping to lower gears.

Postby reefer » Wed Jul 16, 2014 5:38 pm

If your cable tension is out just a little bit, it will affect your tune. It could also be that your RD is not quite set correctly (vertically aligned).
I had gears slipping and after I learn’t how to re tune, my gears have been perfect with no slip or noise. I also run from either extremity (39/11 or 53/28) with no issue at all. Something that a few of my local LBS struggle with.

I doubt its a problem with your brifters and assume your RD hanger is not bent, so:

This is how I would attack your issue. As you have no idea what is where with respect to the tune.
I would now assume the cables have stretched (though they may stretch more :P )
I would disconnect the cable from the derailers and wind in the adjusters (to allow for stretch / fine tuning down the road).
I would complete a whole retune. The first night it took me 45 minutes, watching video, pausing and doing to achieve a perfect noiseless tune.
After that process, You will have a good understanding of how and what to adjust. Its a 5 minute job now.
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Re: Help with high gear slipping to lower gears.

Postby tez001 » Thu Jul 17, 2014 5:38 pm

Is it a new bike? Also go to the Shimano site and follow the instructions there in the tech documents.
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Re: Help with high gear slipping to lower gears.

Postby Stovepipe » Thu Jul 17, 2014 11:14 pm

nah old bike i put together. i got a 2nd hand campy veloce groupset but put it on a 8spd campy hubbed shamal, and sent it to the LBS to install the cables etc and tune it all in. figured i'd learn to adjust gears eventually, but for the first build leave it to someone who knows what theyre doing

but it would drop gears under strain from the first ride since they put it together. i never took it up with them though...
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Re: Help with high gear slipping to lower gears.

Postby Duck! » Thu Jul 17, 2014 11:31 pm

Campag shifters have a tendency to wear out their ratchets as they age*, which manifests itself two ways: one is that the indexing feel becomes very vague, and two, the shifter loses its ability to hold the cable in position, resulting in slipping gears.

*Contrary to the mantra popular among Campag devotees "Campag wears in, Shimano wears out", I can assure you that Campag gear does wear out.

Just another thought.... Are the shifters 8-sp as well? If they're not, your indexing will be whoopsed 'cos 8, 9, 10 & 11-sp. all have different sprocket spacing (more gears = closer spacing), and the appropriate shifters are calibrated so they pull the right amount of cable to move the derailleur over a particular spacing. Using a shifter/cassette combo that's not matched for the number of gears is never going to work.
I had a thought, but it got run over as it crossed my mind.
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Re: Help with high gear slipping to lower gears.

Postby duds2u » Sat Jul 19, 2014 11:26 am

Stovepipe wrote:nah old bike i put together. i got a 2nd hand campy veloce groupset but put it on a 8spd campy hubbed shamal, and sent it to the LBS to install the cables etc and tune it all in. figured i'd learn to adjust gears eventually, but for the first build leave it to someone who knows what theyre doing

but it would drop gears under strain from the first ride since they put it together. i never took it up with them though...


If it's dropping gears under load you may need to look at the age of the chain and cassette. A mate had the same problem with a new chain and old cassette not marrying. The chain skipped badly under heavy load up a hill and it put him on the tarmac. Scary as hell as there was a 4WD following close behind that just stopped in time.
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Re: Help with high gear slipping to lower gears.

Postby Stovepipe » Sat Jul 19, 2014 12:22 pm

it's all in pretty good nick as far as I can tell. cog teeth are all in good health. the chain was new. groupo is about 1995 as far as i can tell. it's one of these,
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yep it's definitely the worst time to drop a gear. makes you look heaps unco to the casual passerby too.
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