Montesa Cota 330 Sprocket

[steve]

Hi all,

I have a new front sprocket to fit on my Cota 330 but it doesn't have a keyway - only a taper. I haven't removed the old one yet but I am sure I can see a keyway.

Is the new one faulty or are do they rely on a taper only for the replacements. The new sprocket is a Talon.

Oh and the reason I haven't removed the old one yet is because I can't!!! Damn that thing is tight, It's been heated, prised and hit on the nut with a big hammer and still won't budge. I am going to have to make a puller to fit, unless anyone has any ideas?

[feetupfun]

Steve

The new Talon sprocket without keyway works fine on my 348 Cota provided the shaft is clean, undamaged and the nut is tightened correctly. I don't know if the 330 is the same arrangement but my 348 also had an old keyed sprocket on a taper which I recently replaced with the unkeyed Talon sprocket.

Options for removing the old sprocket are to make a special puller or cut the sprocket off with an angle grinder.

I have heard that the sprocket will loosen by riding the bike with the nut loose but would not recommend it in case the key shears and damages the shaft taper surface.

I have had great success using an 100mm angle grinder with the chain removed and the gearbox in gear. Take care not to grind too far. If you can see where the keyway in the sprocket is, grind there to reduce the risk to the shaft. It took about 2 minutes to get it off and no damage to anything.

David Lahey

Australia

[steve]

Cheers mate, I didn't want to grind the old sprocket off incase the new one didn't fit (cos there's no keyway!!) and it had to go back on. Now I know they don't have a keyway then I think I will grind it.