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nautaflcl 09-27-10 11:31 AM

A nightmare
 
So i posted a few days ago that i had a nishiki with a really stubborn derailleur issue.
So i have done everything possible to make sure the derailleur is right.
There is no way the derailleur is going to not work right or at least not as bad as it is simply for being 1/2 of a millimeter off.
Basically, i came across a discovery today in my journey to being a good Bike mechanic.
I realized that the chain is having a hard time actually getting onto the big ring in the front.
It shifts beautifully onto the smaller one, but it just seems like the big ring, well is too big.
I looked at my Raleigh marathon and notice the large ring has only about the space of the height of the chain between the smaller one to the larger one. It is definitely not as much of a jump as the nishiki chain ring. Even at the most precise alignments on the spirt, it still has trouble shifting onto the large chainring.
I did also notice that the inner plate on the FD on the nishiki isn't straight in terms of being parallel with the chain. However i've seen no mention of this being important. I only see everyone mentioning the outer plate being parallel with the chain, in which case it is, for sure.
So with these conclusions I'd like to know if the chain ring is the problem.
Is it possible for a large chainring to be too large that it would create difficulty for my chain to shift up properly?
it seems just as worn as the small one, so i dk wtf is up.
Maybe someone changed them? I dk, but i'd like to find an effing solution b/c i'm starting to lose it.
I had no problems at all on my last bike, it aligned easily, and had no shifting problems when i aligned to procedure.
Some help please?

gt35built 09-27-10 11:50 AM

Possibly the derailleur is mounted too high or low on the seat tube? If this is the case, its most likely too high because if it was too low it would rub/hit the top chainring.

Also you do usually look at the outer plate for alignment issues, but the inside one should also be pretty "straight" with the chain line. Its possible that it has been bent out of shape. You can always try to bend the inside plate outwards more to help with pushing the chain up.

nautaflcl 09-27-10 12:08 PM

I've done everything in terms of it's position. I've put it to where it's 'supposed' to be, according to procedure, and i've even moved it up more and down more just to see what happens. I thought moving it up would help, but nothing really came out of that.
here are some pics for you to check out and everyone else. Theyre not amazing, it's hard to get a perfect picture in there.
And im thinking maybe i could bend it in a bit. i'll try it out in a bit.
you can see in the pic the inner plate on the derailleur is not parallel like the outer one.

http://i66.photobucket.com/albums/h2...f/DSC02051.jpg

http://i66.photobucket.com/albums/h2...f/DSC02047.jpg

http://i66.photobucket.com/albums/h2...f/DSC02048.jpg

http://i66.photobucket.com/albums/h2...f/DSC02043.jpg

gt35built 09-27-10 12:39 PM

I would bend It outwards a little. Grab it by the pin at the bottom/end of the derailleur, and pull from there.

due ruote 09-27-10 06:28 PM

Well, you asked if your big ring is too big, only you didn't say how big it is, ie. how many teeth does it have? Still, my answer is no.

It's hard to see whether you have room, but if you can, I'd lower the front derailleur so it just clears the large ring. That's usually worked for me.


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