shimano sora upgrade

hobbit1021

I have a kona zing with a 50/34T 9 speed chainset and I was wondering if is possible at all to get a 53/39T or 52/36T chainset and where would I get one?

happytramp

You've got a compact chianset, 53-39 is a standard chainset and may require a new rear derailleur to function perfectly. You can certainly buy a 36t inner chainring that will work with your current set-up.

hobbit1021

thanks for the tip.

rab!dmonkey

Why should he need a new rear derailer?

happytramp

rab!dmonkey wrote: »

Why should he need a new rear derailer?

He probably won't but it's worth investigating. I know going from a standard to a compact often doesn't work because the short cage rear mech can't pick up the extra chain slack. But going from compact to standard should be okay.

rab!dmonkey

Surely that's a case for a shorter chain, rather than a new derailer?

hobbit1021

so if I don't need a need rear derailleur, next question is would a tiagra 53/39 double work?

ford2600

hobbit1021 wrote: »

so if I don't need a need rear derailleur, next question is would a tiagra 53/39 double work?

Can't see why you should need a new rd.

The bcd of your compact will be different than anew sstandard chainrings. You'll therefore probably need a new complete crankset.

is the old one worn?

Sora to Tiagra is an upgrade but compact to standard isn't necessarily.

If not worn, why not just change to a cassette with a bigger range? Cheap and cheerful.

If changing crankset try rose, bike discount, 4thebike, merlincycles etc for a good price.

ZiabR

rab!dmonkey wrote: »

Surely that's a case for a shorter chain, rather than a new derailer?

That's what I would have thought too. New chain should sort it.

hobbit1021

thanks ford2600. found this website which will give me what I want. http://www.spacycles.co.uk/products.php?plid=m2b0s149p0.
As long as I stick to 110 bcd.

smacl

rab!dmonkey wrote: »

Surely that's a case for a shorter chain, rather than a new derailer?

Longer I would have thought. On the same cassette a 53t is larger radius than 50t and hence takes three more links to surround for the same rear derailleur position. Some discussion on calculating rear derailleur capacity here.