Bicycle Mechanics - Initial Front Derailer Setting

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Initial Front Derailer Setting


grady
07-03-05, 08:39 PM
Taking my first swing at building a road bike. Everything is complete except for my front derailer. I seem to be having issues with the cable tension. I connect the cables, set the low stop, but when I get to set my high stop there is not enough cable tension to keep the inside of the derailer cage from rubbing. So I re-tension the cable so that the chain is clear of the cage. After I do this I have trouble getting the spring to pull the chain onto the middle chain ring.

Any tips? It just occurs to me, should I do my initial adjustments in a different gear, i.e. middle chain ring? Then set the low and high stops subsequently.


michaelnel
07-03-05, 08:44 PM
Follow the instructions here, exactly as written and in order:

http://www.parktool.com/repair_help/howfix_frontderailleur.shtml

Make sure your rear derailleur is properly adjusted first:

http://www.parktool.com/repair_help/FAQrindx.shtml

If you follow all those instructions, it should work great.

grady
07-04-05, 07:17 AM
Appreciate the help Michael. I will give it a try before I give in a take it to the shop.


sydney
07-04-05, 07:20 AM
Taking my first swing at building a road bike. Everything is complete except for my front derailer. I seem to be having issues with the cable tension. I connect the cables, set the low stop, but when I get to set my high stop there is not enough cable tension to keep the inside of the derailer cage from rubbing. So I re-tension the cable so that the chain is clear of the cage. After I do this I have trouble getting the spring to pull the chain onto the middle chain ring.

Any tips? It just occurs to me, should I do my initial adjustments in a different gear, i.e. middle chain ring? Then set the low and high stops subsequently.as per the park tool site, you start with the chain on the small ring,and big cog.shifters i small chainring position. Didn't the parts come with instructions?

seely
07-04-05, 09:20 AM
I always set my limits on a front der. without any cable tension.

1.Set the front derailleur paralell to the chainrings, 2. and then pull the cage out and verify that its 2-3mm above the big ring, 3. shift into your biggest cog in the rear and set the low limits so it almost/just barely rubs the front cage in this combination 4. pull the cage out and pedal and see if it jumps the chain into your big ring 5. if it does then go ahead and attach the cable and fine tune from there 6. if not adjust your high limit accordingly

I like this method for beginners on front derailleurs because it eliminates one at a time, instead of having a problem that is potentially a combination of limit screws and cable tension, you are limited to one or the other depending where you are in the process.

sydney
07-04-05, 09:26 AM
I always set my limits on a front der. without any cable tension.

3. shift into your biggest cog in the rear and set the low limits so it almost/just barely rubs the front cage in this combination 4.
It should be intuitively obvious that you start with a loose cable. As for #3, the chain has to be on the small ring/big cog, and the clearance is .5-1mm with respect to the chain and inner cage. Fine tune from there under actual riding conditions. FWIW, www.parktool.com has the whole correct drill.

dbg
07-04-05, 09:43 AM
And don't be discouraged. I personally think the front der is the hardest adjustment to get right of anything on a bike.

seely
07-04-05, 09:46 AM
True that, there have been a few that have led to the point that I was looking in the Yellow Pages under "voodoo priest".

operator
07-04-05, 09:53 AM
And don't be discouraged. I personally think the front der is the hardest adjustment to get right of anything on a bike.

Not really, especially if you have friction shifting. You'd better get the rear der shifter proper before the front, unless you like to buy new wheels.

michaelnel
07-04-05, 04:19 PM
And don't be discouraged. I personally think the front der is the hardest adjustment to get right of anything on a bike.

I've found that if you get the vertical position and rotation of the front derailleur's mounting correct, the rest of it is pretty easy.

If you don't, then the rest of it is pretty impossible.

Al1943
07-04-05, 04:36 PM
And like the instructions say, flip the small shift lever a few times and pull the slack out of cable before attaching, this is to get all of the cable out of the shifter.

Al