To the bike gurus... problem with my derailleur ? - Update

[UnatcoAgent]

I have a problem with my mountain bike, which is fairly new. It's a 21 speed Hardrock Specialized, 19.5", about a month old.

Problem: Today when I took it out for a ride, I notice that no matter what gear I'm on, the chain is making a rattling noise. I think that it is rubbing against the metal brace that surrounds it near the front gears. Also, when in either a very low or high gear, it will sometimes drop into the next gear if I apply a lot of power.

This is very un-nerving, as the pedals basically give way under your feat when the chain shifts on it's own. Does anyone know what could be the problem ? I believe that the Shimano gears are still under warranty, so I will talk to the store I bought it from.

I'd like to be able to fix this myself though, any advice is appreciated.

Update - When the chain enters the derailleur, the teeth on the first derailleur cog are not biting it and it's sliding along next to it. It's on the rear derailleur, the very bottom cog. It only catches the chain a little bit, and the chain slides against the metal bracket. Any ideas how to fix this specifically?

 

[vshah]

you should be able to adjust the alignment of the derailleurs front and rear, adjusting them so that there is no contact with the chain should fix your problem.

-Vivan

 

[UnatcoAgent]

How do I do that ?

 

[notfred]

If the chain slipping off the chainring when you put a lot of pressure on it, maybe something in the crank is lose and flexing when you put a lot of pressure on it.

 

[vshah]

i havn't done it in a while...i'm not at home right now but when i get back i'll take a look at my bike and see if i can give you instructions...its usually different for diff types of shifters, but i have shimanos too. maybe someone will come along before then though.

-Vivan

 

[notfred]

Originally posted by: Sabot
How do I do that ?

Link

 

[vshah]

Originally posted by: notfred

Originally posted by: Sabot
How do I do that ?

Link

well there you have it. check out "adjusting front/rear derailleurs" on that site :beer:

-Vivan

 

[Fausto]

Here ya go.

Adjusting your front derailleur.

Adjusting the rear derailleur.


Have fun.

 

[boyRacer]

... and some more...

Front Derailleurs

Rear Derailleurs

 

[UnatcoAgent]

Great, thanks a lot guys.

I tried messing around with them, but it hasn't helped that much, at one point the chain fell off the front gear cog when switching from the 2nd front to 3rd front gear :brokenheart:

I think I'll take it into the store and ask to go through it with their bike mechanic

 

[UnatcoAgent]

Updated

 

[SoyBoy004]

can you take it back to where you bought it? most shops should offer first month or year (or lifetime like the one I bought mine at) free adjustments to all of those sorts of components.

 

[sygyzy]

Adjust the High Low screws on your front derailleur.

 

[UnatcoAgent]

Originally posted by: SoyBoy004
can you take it back to where you bought it? most shops should offer first month or year (or lifetime like the one I bought mine at) free adjustments to all of those sorts of components.

I know that I have 2 years of free tune-ups, so I'm hoping that entails fixing this as well. We'll see I suppose.

 

[UnatcoAgent]

Originally posted by: sygyzy
Adjust the High Low screws on your front derailleur.

And that will alter how the chain is fed into the rear derailleur ?

 

[UnatcoAgent]

This is terrible, nearly every gear is skipping now

 

[dman]

Originally posted by: Sabot
This is terrible, nearly every gear is skipping now

Adjusting Derailers is an art. You can do it, but, you need to be making small adjustments and spinning the crank to check the shifting after each.

There are also barrel screws on the shifter itself (where the cable connects) that you can use to make minor adjustments.

The problem is the cable(s) and chains stretch with use, so, it very often needs tweaking. The barrel screws on the shifters help tighten the cable some between derailer adjustments.

Lastly, on some ranges, there will be chain rub... it seems that way anyway.

/edit: and the shop should do it for free if you just bought the bike, and if they include free adjustments for 2yrs it's likely that's part of the deal.