# front derailleur not shifting when riding



## fantaxmon (Aug 18, 2006)

Ok, so just had the new bike for 2 weeks, and all last week I was out traveling on business... got back on saturday and had to make up for being out all week... finally, I got some time to ride a bit on sunday... well it didn't go very well :cryin: ... my front derailleur is not shifting right either to low or high when riding, it is stuck in the middle sprocket.... 

I go back to my car, and I hanged to bike in the rack to see if it needed some adjustment, and surprisingly :skep: , everything worked just fine, it was shifting in a snap! no issues... chain was not rubbing against the cage in any of the 3 gears, cage is properly aligned with tried all rear cog combinations with all 3 gears and it was shifting beautifully...

scratching my bald head, I wonder... was I shifting rigth? I rode again, even tried trimming a bit to the high gear, same issue... the derailleur was moving, but the chain staid in the middle, rubbing the cage, some hessitation to change to the smalles sprocket, but it just wont' shift to the largest one... :madman:

got it again in the rack, and there you have it, shifting at the first atempt every time... what conditions change when riding that make this problem surface, and works fine when not riding??

please do not crucify me, I'm in my baby steps here and any help would be great... I would go to the LBS in Mcallen, but just won't find the time this week, and want to try and fix it myself to learn something... I don't want to risk it taking it to Ciclomundo... a creepy little bike shop that mostly sells 'triciclos' for takeros, eloteros, and all those other goodies sold on the mexican streets...

I was close to move the low and high screws, but don't want to do that before I get some advise... 

by the way the bike has a Shimano Acera FD

Gracias por su ayuda...


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## arivas (Oct 11, 2005)

Sounds like either of two things:
a) Make sure you aren't appling too much power when shifting, FD is more sensitive to shifting technique, make sure you don't shift under load.
b) Check your cables are clean, sometimes gunk on them can create shifting problems.
for more info.: http://sheldonbrown.com/derailer-adjustment.html hope you get it sorted out!

El Rivas


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## fantaxmon (Aug 18, 2006)

arivas said:


> Sounds like either of two things:
> a) Make sure you aren't appling too much power when shifting, FD is more sensitive to shifting technique, make sure you don't shift under load.
> b) Check your cables are clean, sometimes gunk on them can create shifting problems.
> for more info.: http://sheldonbrown.com/derailer-adjustment.html hope you get it sorted out!
> ...


Thanks for your reply Rivas, by load do you mean, pedaling while going up? or could it be my 99 kilos? I'm a big and tall guy, would this be a reason for that failure??

jmg


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## arivas (Oct 11, 2005)

Pedaling while you are going up, if when shifting you feel resistance try to ease up a bit, then shift then smoothly start pedaling... well, that's what theory says! Weight matters as whenever you pedal you put a lot of power on the stroke, just try to be smooth.

El Rivas


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## Warp (May 24, 2004)

Yup... Arivas' theories are right...

Sounds like your cable is somewhat stuck. However, if you got to shift when not riding, then it can't be a stuck cable.

So, one possibility is for you to be shifting while pedalling hard (when the chain is loaded with tension). In that situation the chain acts like a beam that the FD can not distort.

Ease on the pedals and try shifting. It should shift by now.

If it doesn't, then you must probably have to go thru the whole FD PITA. Because the FD is a pain to adjust properly.

Check www.parktool.com for detailed instrictions. Also, download Shimano's FD Service Instructions from their site. Just follow the detailed instructions they give for tuning the drivetrain.

Oh... one last thing. Many if not all FD's can't simply work properly through all the shift range. Simply, it will rub on the side you choose it to do. If you can't get to the point whenre shifting is nice towards both end, just adjust it for the chainrign you use the most (in my case that's the granny, my FD simply makes a horrible noise and rub if I take it anywhere above 3-5).


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## fantaxmon (Aug 18, 2006)

Warp said:


> So, one possibility is for you to be shifting while pedalling hard (when the chain is loaded with tension). In that situation the chain acts like a beam that the FD can not distort.
> 
> Ease on the pedals and try shifting. It should shift by now.


Well you guys were right!! this forum is already paying off!!! he he he he 

I just did that the last two days and it has worked ok.., shifting and starting with smooth pedaling to engage the chain to the largest sprocket... it didn't need any adjustment, only learning the technique...

thanks for the tip... :thumbsup:


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