[perihelion_soul]

Hi Guys

Quick question.

On my initial post, someone commented that i would need to tweak my new bike after around 10 hours of riding. I have found this to be true!

It appears that my gears seem to 'slip' somewhat, eg just after i have changed into a gear and i get ready to put more power into pedalling the gears seem to slip again. Naturally this is worrying because i feel its adding more pressure onto the cogs, and also damages my trust in the actual bike! For example, sat morning i was buidling up some speed for a jump and the gears seemed to slip on me and go into another gear.

What can i do to remedy this problem? I hope i havent bought a duffer!

Thanks for the help

Ben

 

[jacksonpt]

I suspect that your cables have stretched... normal for a new bike (and new cables on an old bike). As the stretch, they don't keep the same tension... thus the slipping. You can do one of 2 things. Take it to an LBS and have them tune it up for you. The shop you bought it from may do it for free - give em call and see what the deal is. Most other shops will do it for fairly cheap - $25 or so. Your other option is to do it yourself. It'll be a lot of trial and error at first. The shifter pod on your handlebars should have a small barrel adjuster where the cable comes out. Give it 1 full rotation and see what happens. If it makes things better (but not good), then give it another turn. If it makes it worse, turn it the other direction. Make sense?

I think... don't quote me on this... that you'll want to turn the adjuster clockwise, threading it INTO the shifter pod. That should increase the tension on the cable.

Good luck - let us know how it goes.

 

[binary visions]

Jackson, actually that's reversed. Increasing cable tension means turning the adjuster counterclockwise.

It's easy to see why if you think about it for a second, you're unthreading the little cable stop, which minutely increases the length of the housing/cable needed, thus increasing tension.

p_s, as jackson said, if you bought the bike from an LBS, take it back and ask for an adjustment. It'd be a pretty poor shop that didn't provide this minor service for free after you bought a bike from them.

If you didn't buy the bike there, they'll probably charge you a fee for a tuneup, which should include brake and drivetrain adjustment, lubing your chain, and checking other things like spoke tension, headset tightness and such. All good stuff, so just pay 'em the fee and have no worries!

Good luck.

 

[jacksonpt]

Jackson, actually that's reversed. Increasing cable tension means turning the adjuster counterclockwise.

It's easy to see why if you think about it for a second, you're unthreading the little cable stop, which minutely increases the length of the housing/cable needed, thus increasing tension.

p_s, as jackson said, if you bought the bike from an LBS, take it back and ask for an adjustment. It'd be a pretty poor shop that didn't provide this minor service for free after you bought a bike from them.

If you didn't buy the bike there, they'll probably charge you a fee for a tuneup, which should include brake and drivetrain adjustment, lubing your chain, and checking other things like spoke tension, headset tightness and such. All good stuff, so just pay 'em the fee and have no worries!

Good luck.

Listen to this dude... he knows his stuff. I no longer have to take my bike in for regular tune-ups... I do it all myself thanks to the advice I've gottom from him.

Thanks BV.

 

[binary visions]

Listen to this dude... he knows his stuff. I no longer have to take my bike in for regular tune-ups... I do it all myself thanks to the advice I've gottom from him.

Thanks BV.

Wow, thanks Jackson - that's awesome.

Drivetrains are suprisingly simple and rely on a lot of common sense if someone just takes the time to explain why things work the way they do.

For anyone starting out (or anyone at all, actually), I would highly recommend a copy of Zinn and the Art of Mountain Bike Maintenance. It's a thorougly straightforward, easy-to-understand, and totally comprehensive book on maintaining your bike.

Zinn has this great knack for breaking down mechanical processes into instructions that everyone can understand.

I just noticed Amazon.com has it on sale for $15, and it looks like free shipping! Best fifteen bucks you'll spend in your riding career, without a doubt.

Click!

 

[jacksonpt]

Wow, thanks Jackson - that's awesome.

No, thank you. There have been a few occasions where I've thought about sending my $25 (that's what my LBS charges for a tuneup) every time you help me with something that I otherwise would have had the LBS do.

Obviously, I've never followed through on it - sorry.

 

[trailblazer]

just to be a dick>>the cables do not streatch. Like changing guitar strings they need to be pulled hard after installing and then re-tightened. This is usually skipped.
This is why you need to retighten the cables not adjust the barrels. Adjusting at the barrels is an on the trail fix and should be corrected.
ALSO>pins wear out on chains>>they do not streach.
Missconception # 3>>semi slicks being faster.NOT. gimme big air and small to medium knobbies any day.

 

[jacksonpt]

just to be a dick>>the cables do not streatch. Like changing guitar strings they need to be pulled hard after installing and then re-tightened. This is usually skipped.

If they don't stretch, why does this need to be done... what does "pulling hard" do?

 

[HenryTheHammer]

Cables stretch and housings wear. Facts of life.

 

[sanjuro]

just to be a dick>>the cables do not streatch. Like changing guitar strings they need to be pulled hard after installing and then re-tightened. This is usually skipped.
This is why you need to retighten the cables not adjust the barrels. Adjusting at the barrels is an on the trail fix and should be corrected.
ALSO>pins wear out on chains>>they do not streach.
Missconception # 3>>semi slicks being faster.NOT. gimme big air and small to medium knobbies any day.

Thanks for the 411 about the myth about cable stretch. You better tell this author of this site about it as well, because he has it wrong too.

http://www.sheldonbrown.com/derailer-adjustment.html

 

[sanjuro]

And a more useful tip my boss showed me:

The outer cable housing (made of plastic) will sometimes pull back from the inner housing (made of metal), which will cause flex in the housing system, particularily with derailleur housing.

My boss makes us pull the ferrules off to check the ends of the housing. I have seen 2mm of inner housing sticking out. You have to clip it off or sometimes replace that piece.

 

[binary visions]

just to be a dick>>the cables do not streatch. Like changing guitar strings they need to be pulled hard after installing and then re-tightened. This is usually skipped.

Well, you're incorrect. Sorry.

 

[MtnbikeMike]

Missconception # 3>>semi slicks being faster.NOT. gimme big air and small to medium knobbies any day.

It depends on what you mean by faster. Faster rolling? You bet they're faster. Over the course of an XC race? That depends on the course.

 

[sanjuro]

just to be a dick>>the cables do not streatch. Like changing guitar strings they need to be pulled hard after installing and then re-tightened. This is usually skipped.

I should also point out that pre-stretching cables during bike assembly is a bike shop mantra. Every shop likes to say "we do this, our competitors don't", but the only places who skip this are big box sporting goods departments.

This is why you need to retighten the cables not adjust the barrels. Adjusting at the barrels is an on the trail fix and should be corrected.

Adjusting at the barrels should only be done on the trails?

I do agree you should retighten the cables after prestretching them. It allows you to use the entire length of the barrel adjuster later. However, a turn of adjuster during installation is normal, particularily with the rear derailleur.

 

[SkaredShtles]

Well, you're incorrect. Sorry.

He should've simply left his statement as:

Originally Posted by trailblazer
just to be a dick

-S.S.-

 

[Wumpus]

Is cable stretch for real? Maybe not

I'm sure some cables in some applications stretch. I'm just not sure that there is enough force on a shifting cable to cause it to stretch.