changing the chainrings on a tiagra 4700 chainset………. possible?

chainset came with 50/34 rings.   I want 42/30.

is it possible?

I think the smallest you can get on the inner 110 bcd is 33 teeth.

If it’s the four arm spider then you’re probably stuck with a 34 on the inside.

I have just found a xt 28/38 crankset.  gonna swap it for that and a smaller cassette.

cheers

If it’s on a road frame then you might need BB spacers and chainline might not be perfect but it should work

As an alternative, I had an old set of octalink LX cranks, and (I believe with a 5mm shorter axle – this was just based on the parts bin, I reckon it would work with the specified axle length) which I used as my Tiagra 4700 cranks clashed with a new commuter frame.

I had to do some filing and use spacers to get the chainring sleeves in (as they were going through the “wrong” side of an outer position chainring single ring sleeves and bolts were a bit short) but I’ve now got myself a 44/28 double that works with a Tiagra front shifter by using granny and middle ring positions.

I did search online for 44/28 doubles but not easy to find at all, this solution cost me about a tenner (though took all morning from initially discovering the cranks clashed with the chainstays) as I didn’t have the inner but have a couple of surplus outers from buying cranks for the middle/inner rings only.

Spa Cycles do low-range doubles, and alpine doubles.  Worth having a look at what they have, and generally with a square taper BB so are indestructible…

https://spacycles.co.uk/m2b0s109p3383/SPA-CYCLES-Super-Compact-Chainset-with-Zicral-Rings

for example…

Oh sorry didn’t notice your XT chainset post until after! That’s your best bet I reckon. If possible I’d avoid the proprietary odd arm spacing, it makes getting a replacement a total PITA – I took a ring from a 105 chainset that fitted but dropped the chain between inner and outer rings on my Tiagra as couldn’t find any Tiagra in stock…

MTB chainsets might be a bit easier to find replacements for.