Chain Rings Cannondale Synapse

[bondirob]

Hi, I've got a Synapse carbon 105 2016.
Its got compact FSA chainrings.
Is it possible to change them for a different size?
I've seen a few for sale that say compatible with shimano but my cranks are Cannondale SI

 

[Sharky]

As long as they are the same BCD, they should be ok, but curious as to why you want to change the sizes.

 

[bondirob]

As long as they are the same BCD, they should be ok, but curious as to why you want to change the sizes.

Thanks for the advice I'll measure them
I want to have lower gearing and wondered if it would be cheaper to swap chainrings than get a larger cassette and a lindaret Road link in order for the derailleur to accommodate it

 

[Sharky]

I suspect that a 33t inner ring is the smallest you can get for a 110 bcd (compact chainset), so a larger cassette might be the only option, unless you explore alternative cranks.

Good luck with the hills

 

[Ajax Bay]

I want to have lower gearing and wondered if it would be cheaper to swap chainrings than get a larger cassette and a lindaret Road link in order for the derailleur to accommodate it

(I have added in a link)
Your FSA compact will not really support an inner chainring any smaller (BCD limitation). So for lower gearing you need to go to change the rear sprocket set up as changing to a triple in front would be much more expensive. The Lindarets Roadlink is circa £23 - £25 all up.
You don't say what 11sp cassette you have on now. Several on this forum have successfully fitted a 11-32 and operated it with a GS RD (don't know if you have SS or GS) with B screw fully in. With a compact, the 11-32 driven by a 50-34 is close to the RD capacity (wrapping) limit. This is the cheapest option. If you can't get up the hills you need to on a 34/32 (ie 29" gear) then a triple is the way to go, or reconsider whether the bike you have is the right one for you and your riding style (ie avoid steep steep hills).

 

[bondirob]

Thanks for the advice Ajax. I have a 32 cassette
Tbh I'm not bad on the hills, fair enough I'm never going to be at the top of strava but I'm comfortably top 30% on most climbs.
I just think the 50/11 combo is a waste of time, I'm never going to be able to spin that out (i don't think there's many who can) so my theory is to use those 11 gears at the lower end of the scale hence the chain ring question.
I like to keep my cadence well above 80rpm and there are only the odd hills I can't achieve that with my 32 but it would be nice to have gears in reserve for those times.

 

[Ajax Bay]

I just think the 50/11 combo is a waste of time

I agree that for the vast majority of people, an 11t sprocket is a complete waste and you're better off with a 12t smallest and an additional intermediate sprocket (eg 15t or whichever one would fill the first two tooth jump to keep the ratios closer at that point). Manufacturers seem to drop to 11 at the same time as extending the cassette to 32, which means the gears are not as close mid-cassette (a disadvantage) and the RD needs to wrap that bit more chain.
You might find this gear calculator useful - all the variables are just that.

 

[bondirob]

Thanks Ajax I've been using a gear calculator app hence why I want to lower the whole range a bit.