Bicycle Mechanics - hi to all what is the maximum back 'cog' a standard Shimano Ultegra ca

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droesen
04-23-05, 01:52 AM
My first time on ANY forum. But you guys delivered on my question so I an happy. I am Dutch live in paris, France. used to on cylce holidays when i was 18 or so. No I am almost double that and as traing for this summer's triathlon season i will be doing a cycling trip to te Pyrenees soon. bye for now. Bas

This was my question:

I plan 2 be climbing the col d'Aubisque and Tourmalet soon. problem is I have a standard road bike with 39 front and -I think- 25 in the back. That would mean heavy spinning if not walking for me.

I would like to change gearing in a cheap way what are the options? I am now planning on changing the back to 28 or even 30 but my friend was told 27 is the max generally a 'derailleur' can handle.

QUESTION: what is the maximum back gear a standard Shimano Ultegra (2003/4 model) can handle?


Retro Grouch
04-23-05, 06:04 AM
The issue is the point at which the upper derailleur pulley rubs the big cog. Shimano rates their road derailleurs for 27 teeth.

It's sometimes possible to make a larger cog work.
1. Dial in the B screw at the back of the derailleur as far as you can.
2. Substitute a longer B screw.
3. Reverse the B screw in the derailleur so that the head of the screw is what contacts the nub on the frame.

Bon chance!

sydney
04-23-05, 06:11 AM
The issue is the point at which the upper derailleur pulley rubs the big cog. Shimano rates their road derailleurs for 27 teeth.

It's sometimes possible to make a larger cog work.
A 30 almost always works and I have heard of getting away with a 32, but if I felt the need for more than a 30,I 'd just get a mtb RD


capsicum
04-23-05, 07:38 AM
Cross forum posting is bad juju.