I need a new chainset for my CX bike – the Tiagra 4500 that was on there has been fine and I’d happily enough replace it with the same but I’ve spotted a Sora HT2 chainset for £30 which looks pretty much identical. I suspect that the rings will be cheaper but I can live with that but wondering if anyone knows if they’re the same otherwise (a la Campag where several models have the same cranks with different rings)

Sora FC3450

Tiagra FC4550

i’ve got both.

the answer is:

colour.

(as far as i can tell)

Ah, thanks for that – what colour is the Sora as Tiagra is just aluminium

Aha! Shimano says that sora is ‘painted’. How’s that holding up?

http://www.shimano.com/publish/content/global_cycle/en/us/index/products/road/sora/product.-code-FC-3450.-type-..html

not bad at all, it’s a little scuffed, but i have done 2000km on it (commuter, covered in filth)

(black sora cranks on a genesis cdf)

Nothing ultimately. I bought a 2010 sora equipped bike in the sales in early 2011. I pondered over spending another few hundred quid on a tiagra equipped bike, but then I was informed that the 2011 sora was the 2010 tiagra flowed down the range and re-branded, and sure enough when you compared the 2011 tiagra with 2010 sora they looked identical visually save for a couple of very minor aesthetic details. The sora works fine, shifts smoothly and quickly, is reliable, does what it says on the tin. i doubt you’d notice any difference with tiagra, or even 105. I really couldn’t justify spending more on the groupset. Buy your bike based on frame and wheels.

Be interested in the rings – 50t particularly if you’re selling them. My Tiagra 50t on the winter road bike is essentially a bash ring now 😕

£27 for the rings? 🙂

Hopefully it’ll be here today anyway.

It’s here and just to confirm, it looks identical to the Tiagra/4500 other than the painted silver finish.

njee – the rings look alright tbh so I think I’m going to keep them .

just bought a set as the bb on my chedder cheese made fsa chainset is fubared after not a lot of miles and they want £30 for a fsa bb

quite noticeable difference in weight and stiffness, if you care about that kind of thing

got sora in 1 x 10 on my commuting bike

got tiagra in 2 x 10 on my road bike

the sora are not true “Hollowtech” cranks in that they do not have the forged hollow 2-piece construction used on tiagra and above.

The Sora are just a single lump of forged alloy with the rear of the arms scopped out

the Tiagra are proper Hollowtech with the hollow arms which reduces weight and improves crank stiffness

whether that is worth the money? for a commuting bike perhaps not? for a sports bike then yes?

esher – true or not true depending on which Tiagra…

My 4500 Tiagra (as per my original post 😉 ) aren’t ‘true’ hollowtech in that they’re just like the Sora – just ‘scooped’ out rather than actually hollow.

4600 Tiagra isn’t Hollowtech either, they are solid arms.

installed mine weighed exactly the same as my old fsa chainset and the shifting from small to big ring is crisper than the fsa
so a good buy 🙂

I stuck the Sora chainset on my bike at the weekend.

The BB cups were really tough to get in. Much harder than normal & the thread quality looked rubbish. But, they went in.

The Sora chainset was just over 1/2lb lighter than the one that came with the bike; not massively surprising, given the original is sq taper.
But a nice weight saving all the same for £36 (incl. a new 14mm socket I had to buy) and it looks better than the old one.

Will probably get most of that back once I stick the original on ebay; pretty sure there’ll be a sq taper fan who will snap it up.