I've got a Giant CadexII mountain bike. It's old, but it's carbon.
I am trying to replace the pedals that came with it with clipless pedals.
Unfortunately, the pedals do not want to loosen.
First, I wonder is it possible that I can accidentally apply enough pressure trying to loosen the pedals to do any damage, and secondly, is there anything designed to loosen pedals.
I know there are lubricant like things that supposedly will loosen tight nuts, but I've never used them and I have no idea whether they might also dissolve the carbon fiber frame if I accidentaly got some on it.
Thanks for any help anyone can offer.
WD40 wont hurt a carbon frame and you should be able to apply it precisely to the crank threads.
To remove a stuck pedal you need a lot of torque so use the longest wrench you can find or fit an extension. Bike shops usually have a special one for this purpose.
I use carefully applied foot power thus:
Put the bike in lowest gear and aply brakes.
Point the relevant crank foward and up.
Place the wrench on the pedal pointing rear and up.
Place foot on end of wrench and take up the tension.
Carefully apply more force until all your weight is on the wrench. Beware of the wrench slipping.
To prevent sticking, smear grease over the threads.
I'm letting the WD 40 work, and then I'll be getting a bigger wrench so I'll have more leverage. The only wrench I have that fits is too short.
I appreciate the advice.
Slip a length of steel pipe or tubing over the end of a short wrench to extend the lever arm. A cut out piece of old bike frame works well for this. If the inside diameter is a bit too small, flatten the pipe with a hammer or in a bench vise to get a better fit. It is possible to get too much leverage on a small wrench and cause a drastic failure of the tool.
Pouring boiling water over the cranks, as you unscrew the pedals, will also help as the aluminum crank will expand more than the steel pedal shaft.