Front Derailleur replacment?

[Dirt]

There are many things that make a front derailleur work properly, as people have identified.

1. The height of the derailleur;
2. How it is aligned in relation to the large chainring (the outer cage should be parallel to the large ring when looking down on it)
3. Limit screws (both low and high)
4. Cable tension
5. Shifters functioning correctly.
6. Chain length
7. Age/amount of wear on the chainrings; and
8. age/wear on cable housing.

It helps if the planets are aligned too.

The most honorable Sheldon Brown (may he rest in peace) has a good article about it (and anything else bicycle related… though his list of pick-up lines for dating while cycling is a bit dated) http://www.sheldonbrown.com/derailer-adjustment.html

Hope that helps a little.

Pete

[DismalScientist]

I can’t tell for sure from this picture, but it looks like someone tried to take a bite out of the large chainring. Is it true or bent? If bent, it may need to be replaced.
If the derailleur needs to be changed, it is probably OK to use non-STX parts.

[DismalScientist]

I can’t tell for sure from this picture, but it looks like someone tried to take a bite out of the large chainring. Is it true or bent? If bent, it may need to be replaced.
If the derailleur needs to be changed, it is probably OK to use non-STX parts.

[CCrew]

Obviously your bike, your call as to what to do with it. We’re working from pictures

To me the alignment looks way off. If it’s never been replaced I find it odd it’s that way. So I’ll give you that it could be bent, out of whack, etc. Seriously though, I’d try to see if you can align it using the instruction link I sent, and you can certainly search You Tube for more – theres a lot of tutorials . If ya can’t get it then take it to a shop. Not like none of us here haven’t whimpered “uncle” before and gone to a shop – certainly no shame in it. Good luck with whatever you choose.

[CCrew]

Obviously your bike, your call as to what to do with it. We’re working from pictures

To me the alignment looks way off. If it’s never been replaced I find it odd it’s that way. So I’ll give you that it could be bent, out of whack, etc. Seriously though, I’d try to see if you can align it using the instruction link I sent, and you can certainly search You Tube for more – theres a lot of tutorials . If ya can’t get it then take it to a shop. Not like none of us here haven’t whimpered “uncle” before and gone to a shop – certainly no shame in it. Good luck with whatever you choose.

[CCrew]

@DismalScientist 4440 wrote:

I can’t tell for sure from this picture, but it looks like someone tried to take a bite out of the large chainring. Is it true or bent?

Looks to me to be a lower end stamped steel chainring, and that’s the way they engineer shift ramps… But I’ve been wrong before too

Do look like they have a reputation for crappy shifting and bending though:
http://www.mtbr.com/cat/older-categories-bikes/oldercranks/shimano/stx-crank/prd_350986_1519crx.aspx

[CCrew]

@DismalScientist 4440 wrote:

I can’t tell for sure from this picture, but it looks like someone tried to take a bite out of the large chainring. Is it true or bent?

Looks to me to be a lower end stamped steel chainring, and that’s the way they engineer shift ramps… But I’ve been wrong before too

Do look like they have a reputation for crappy shifting and bending though:
http://www.mtbr.com/cat/older-categories-bikes/oldercranks/shimano/stx-crank/prd_350986_1519crx.aspx

[Jsnyd]

Pete thanks for the link. Reading that helped me wrap my head around how it works, Thanks!

DismalScientist – I took a close look at the chainrings and they are in bad shape. Unless they are supposed to look like someone has been chewing on them, but the teeth seem to catch or realease the chain just fine.

[Jsnyd]

Pete thanks for the link. Reading that helped me wrap my head around how it works, Thanks!

DismalScientist – I took a close look at the chainrings and they are in bad shape. Unless they are supposed to look like someone has been chewing on them, but the teeth seem to catch or realease the chain just fine.

[Jsnyd]

@CCrew 4441 wrote:

To me the alignment looks way off. If it’s never been replaced I find it odd it’s that way. So I’ll give you that it could be bent, out of whack, etc. Seriously though, I’d try to see if you can align it using the instruction link I sent, and you can certainly search You Tube for more – theres a lot of tutorials.

Thanks for the info CCrew, I took a second look at it after reading a few article and it looks way off. The height AND angle need to be addressed. It is odd to me as well that it hasnt been replaced but it so far off.

[Jsnyd]

@CCrew 4441 wrote:

To me the alignment looks way off. If it’s never been replaced I find it odd it’s that way. So I’ll give you that it could be bent, out of whack, etc. Seriously though, I’d try to see if you can align it using the instruction link I sent, and you can certainly search You Tube for more – theres a lot of tutorials.

Thanks for the info CCrew, I took a second look at it after reading a few article and it looks way off. The height AND angle need to be addressed. It is odd to me as well that it hasnt been replaced but it so far off.

[Jsnyd]

Well during my lunch break I went at it for a good 45 min. Something has got to be wrong with it. I’ve read article’s, watched a couple YouTube how to vid’s and seem to have a good grasp on what it entails. I’m going to bring it buy a shop in the next few days and see what’s up with it. Thanks again for all the help, I haven’t fixed my bike but I sure did learn a lot about derailleur’s, great references and bikes in general!

[Jsnyd]

Well during my lunch break I went at it for a good 45 min. Something has got to be wrong with it. I’ve read article’s, watched a couple YouTube how to vid’s and seem to have a good grasp on what it entails. I’m going to bring it buy a shop in the next few days and see what’s up with it. Thanks again for all the help, I haven’t fixed my bike but I sure did learn a lot about derailleur’s, great references and bikes in general!

[Jsnyd]

Just for an update and a close out type reply. I took it to the guys at Capitol Hill Bikes and told me the shifter was shot. The other was in bad shape too. Maybe I got ripped off on CL. Guess thats the price to pay when you buy something you dont know anything about. You learn something new everyday! haha.

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