Please help.

I am looking to change my chainset and want to fit an Ultegra sl double.
At the moment I have a 105 50/34 set up , running 11/25 on the back. I am strugling to find a 50/34 without busting the bank, but 53/39 are a plenty.

Question then, is there a massive difference when you change the chainrings on the front ? I do tend to spin out occasionally with the 50t, and hardly use the 34t chainring where I live.

Thanks.
(novice roadie)

Go 39/53 or 42/52 then.

Any reason for the “upgrade”?

If your a real roadie get the 53/39

If you mince along at walking pace get the compact

If you’re spinning out then a 53/39 will be fine but if you have steep climbs then yes 39 can be tough but I’ve been fine.

You could always change the cassette for 12-27 if you train on hills in the future.

Go for it.

I’m not an expert but you might want to check that your front mech is compatible with different chainring sizes.

And yes you are right that compact is a bit poofy.

I run a 50:39 (105) – my legs struggle to push a 53 round unless I’m going downhill or am at the big end of the cassette….it’s rare for me to spin out on the 50 though…

A standard chainset will be fine if you’re regularly spinning out a compact on a 12 sprocket (c.40 mph, I’d guess).

Oh, and if you are regularly doing 40mph on the flat, get a TT bike and break some records….