Please Sir, Can I have a Big Ring :-)

[mickle]

I like my top gear to be a bit higher than you guys so I'm able to power through to circa 50mph @140rpm, but that maybe because I've not got any long descents around here so I have to take as much advantage as possible from the inclines I have.

And my penis is twelve inches long.

 

[ColinJ]

And my penis is twelve inches long.

But you don't use it, as a rule?

 

[mickle]

Ha!

 

[MartinC]

My Cannondale CAAD8 is a beast, however the biggest ring is just 50T, I love to sprint and dont feel that 50T cuts it when I open the taps, the bike is totally stock, I'm used to running a 53/39, but want to keep the Triple for the time as my knees are still feeling it on the hills, can you just change the big ring itsself ? or does the whole crank need to be changed ?

Thanks

Gaz

Gb155, to go back to the original question which has got a bit lost a bit in all the discussion. I'm assuming that you're running a Shimano (or pattern, 130mm BCD) 50/39/30 triple. You find the top end gearing a bit low compared to the 53/39 you're used to riding but would like to keep the 30 for hills.

Yes, you can just swop the big chainring to a 53. 130 BCD rings are easy to find (IIRC there were links posted). But, current specs for Shimano triple front mechs are for a 50 max chainring and 20 tooth capacity, so this would put your set up outside of this. This may not matter too much, I'd be willing to try it but I haven't done this with Shimano 10 speed stuff. The problem may be that the curvature of the outside plate is slightly too small and the mech will be mounted higher relative to the other chainrings than Shimano want (it will be as well 'cos of the 53 instead of 50). You may end up with the front change not being as smooth as it should - or it may cope fine. The quality of the new chainring (i.e. whether it's ramped and pinned) may affect this too. You can check that the cage is big enough for the new set up by looking at your current one. Put the chain on the small chainring and on the smallest sprocket you want to use with it - you'll need a gap of around 8mm between the bottom of the cage and the chain - slide allen keys in to measure it.

If you do this I'd be tempted to change the middle ring for a 42 as well. My reason would be that you don't need the low end of the 39 'cos you've got a 30 and you'll get a more usable set of gears on the middle ring. You'll also keep the 11 tooth gap outer to middle that the mech was designed for.

 

[GrasB]

And my penis is twelve inches long.

& very little idea about prevailing conditions it seems...

fyi: 190w is around about my maximum power at 140rpm