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View Full Version : Front Derailleur replacment?



Jsnyd
06-08-2011, 07:41 PM
My front derailleur has an issue. excuse my explanation if it gets hairy, Iím not familiar with biking jargon just yet or correct part names for that matter :p when changing gears on my front sprockets, I canít go from 1 through 3. I try and adjust the derailleur and cable but only get 2 and 3 or 1 and 2. There seems to be a lack in the amount of travel I need. is it possibly bent or just crappy? I've messed with it so much that my gear indicator doesnt even know what gear im in anymore.

RESTONTODC
06-08-2011, 09:43 PM
I'm not an expert but my guess is the limit screw. I need to adjust them.

Good luck

CCrew
06-09-2011, 03:55 AM
Based on that picture the derailleur is installed waaaaay too high. Usually only want 1-2mm to clear the tips of the chainring teeth and you've got what looks to be 3/8"

After that jump on someplace like Park Tools site or You Tube for a tutorial on FD adjustments. They can be little buggers, I'll tell you that.
http://www.parktool.com/blog/repair-help/front-derailleur-adjustments should get you started

Jsnyd
06-09-2011, 04:52 AM
Awesome! Thanks!

PrintError
06-09-2011, 05:09 AM
+1 to CCrew, looks like an easy adjustment. Your local bike shop can tweak it if you can't get it to work.

Jsnyd
06-09-2011, 07:30 AM
Thanks everyone. First I'll try and drop the whole thing a bit but im afraid that it may be bent. The front of the derailleur looks high while the back of it is right on top of the lower gear. I might swing over to CityBikes Inc. and have them look at it.

CCrew
06-09-2011, 07:38 AM
Thanks everyone. First I'll try and drop the whole thing a bit but im afraid that it may be bent. The front of the derailleur looks high while the back of it is right on top of the lower gear. I might swing over to CityBikes Inc. and have them look at it.

Is that the original derailleur for the bike? It's not unusual that the curvature doesn't match perfectly, it's more about clearance and function. I'd at least give it a shot.

Jsnyd
06-09-2011, 07:52 AM
Is that the original derailleur for the bike? It's not unusual that the curvature doesn't match perfectly, it's more about clearance and function. I'd at least give it a shot.
I believe so, I found a site that lists a 95 Arriba to have almost all Shimano STX parts which is the same as I have.

Dirt
06-09-2011, 07:56 AM
There are many things that make a front derailleur work properly, as people have identified.

The height of the derailleur;
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)
Limit screws (both low and high)
Cable tension
Shifters functioning correctly.
Chain length
Age/amount of wear on the chainrings; and
age/wear on cable housing.


It helps if the planets are aligned too. :D

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
06-09-2011, 07:59 AM
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
06-09-2011, 08:01 AM
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
06-09-2011, 08:05 AM
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
06-09-2011, 08:38 AM
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
06-09-2011, 08:42 AM
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
06-09-2011, 11:04 AM
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
06-15-2011, 07:13 AM
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.