Giant TCR composite 06 frame size S

[lmk30]

You seem keen to buy a new frame (nothing wrong with that, BTW) ...
If you can make your GIANT "fit" then you really have to consider changing frames to be a cosmetic issue (nothing wrong with that, either).

FWIW. A similar suggestion could be made with regard to crank arm length -- that is, using a formula is actually an arbitrary method for deteriming the best crank arm length for any particular rider & one probably has to question how ANY of the formulas were determined. While the formulas are interesting, they are too dogmatic because a person's leg is comprised of levers of varying proportions which engage another lever; and, the maximum efficiency for one set of levers may-or-may-not be different for another. So, while a taller rider (than you are) might be using a 165mm crank arm on his/her TRACK bike, the reason is because the pedal MUST clear the banking ... and, if the mathematician who came up with any of the formulas used that paradigm in association with a particular (group of) rider(s) OR any other where the presumption is the higher ultimate speed must mean greater efficiency, then the reasoning is (IMO) flawed ...

Similarly, if a riding style (e.g., "KOPS") is the status quo, then it is probably a miracle that anyone can pedal a recumbent with any efficiency (to use an extreme illustration).

THAT's a really long way of saying that you should probably try to make the current frame fit comfortably, first ... then, consider riding it for a season to ensure it is the right fit for you AND the way you ride ... then, decide if you want a smaller frame (for whatever reason). Having a second frame/bike is not uncommon, particularly if you want to ride through the Winter months or during inclement weather.

BTW. Back to the ORIGINAL question regarding the USED value of your GIANT frame -- if you & the RIGHT buyer cross paths, you might be able to expect to get between £530-to-£600 for the frame/fork/headset PRESUMING that the frame/fork/headset would cost ~£1000 (retail) from you LBS if they could order one for you sans components if the original retail cost for the bike would have been about £2000+ ... but, then again, £530 may be too optimistic OR impossible if you don't find another cycling enthusiast who is looking for a "small" frame. If the bike's retail was less, then (as a rule of thumb) figure on about 1/4th the retail price for the complete bike (i.e., allow half the cost to have been the frame & half the cost the components/wheels).

Cheers again for a comprehensive and interesting answer! Have just got the bike back from my LBS with a shorter (70mm) stem and compact handlebars and actually, it fits quite well. Those changes have managed to shave off almost 4cm in reach. My position is significantly more compact and there's no more excessive stretching to sit on the hoods. I'm thus planning on keeping it this season and riding it for what it's worth.

However, the reason for wanting to get a new frame next season is that I'd like one that fits really well. My ideal riding position is v agressive with a big seat to bar drop and my current frame has a much to tall a head tube to allow this however I tweak the stem. Also, in an ideal world, I'd like to get a bit more compact than I am at the mo.
Crank lengths seem like a nightmare to determine, but seeing as I'm more of a high cadence rider, I'd like to at least try shorter cranks to see if I like it better. However, I've never been that bothered by 170s I currently have and have had in the past.

The frame alone cost new around $2500. I'd hope I'd be able to get 700-800 bucks for the frameset, so best start saving up for the rest!

 

[Solanog]

Cheers again for a comprehensive and interesting answer! Have just got the bike back from my LBS with a shorter (70mm) stem and compact handlebars and actually, it fits quite well. Those changes have managed to shave off almost 4cm in reach. My position is significantly more compact and there's no more excessive stretching to sit on the hoods. I'm thus planning on keeping it this season and riding it for what it's worth.

However, the reason for wanting to get a new frame next season is that I'd like one that fits really well. My ideal riding position is v agressive with a big seat to bar drop and my current frame has a much to tall a head tube to allow this however I tweak the stem. Also, in an ideal world, I'd like to get a bit more compact than I am at the mo.
Crank lengths seem like a nightmare to determine, but seeing as I'm more of a high cadence rider, I'd like to at least try shorter cranks to see if I like it better. However, I've never been that bothered by 170s I currently have and have had in the past.

The frame alone cost new around $2500. I'd hope I'd be able to get 700-800 bucks for the frameset, so best start saving up for the rest!

I read on a bicycling magazine that for checking if the lenght of your frame or frame plus stem plus handlebars was close to good for your size was: when riding on the saddle and with you hands on the hoods the handlebar would be blocking the vision of the front wheel axle. I checked that and it is true for my two road bikes and I feel comfortable on both eventhough they have slightly different geometries. I'm 5'10" and ride 54cm - 56 frames, one with a 172.5mm crank arm and the other with a 175mm, I think I can't tell the difference between those two. My MB has a 175mm one.
Good you save a lot of money with those changes.