I have been considering making a foray into road bikes and ended up picking up a pretty pristine Giant TCR advanced 2016 bike for a bargain. I bought a size M and ended up figuring out that I actually needed a size M/L.

https://bikeinsights.com/compare?geometries=5d1434e58f568e0017f135bc,5d1434e58f568e0017f135bd, (scroll down to see comparison)

I couldn't figure out as I am used to steel tourers and more into commuting until now. I have the seatpost set to almost the cutoff height. I still feel that it should be 15~20mm larger for me to be at my most efficient.

I looked up the seatpost, it seems like a proprietary product.


The standard length seems to be 375mm. I figured out that if I get a 400mm seatpost, it'd be good enough for me, and I should be able to ride just fine. However, I am not able to find the seatpost, they seem to be out of stock, since the newer version has a different seatpost.

Are there any aftermarket brands (even from aliexpress) which would be a suitable replacement? Is there anything else that I can do to increase the height,like a different saddle for example. Or is this a lost cause?

Is there anything else that I can do such as changing the stem, to make the bike fit me better ?

  • I looked on the 'bay to see if there were anything that would work there but came up empty (a few 375-380 mm offerings, but nothing longer). As the owner of the 2015 TCR Advanced, I would complement you on your taste in bike (love my TCR), but as Criggie answered, you are probably out of luck getting your size M to fit. A bike that does not fit is not one you would want to ride, and could be a safety concern as well. I wish it could have been a fit for you, but the best deal in the world is only good if it fits, and you feel comfortable riding it.
    – Ted Hohl
    Aug 28, 2022 at 3:30

1 Answer 1


Sadly if you need a longer seatpost, there's not a lot of other options.

It is possible to get longer crank-arms, but that's not cheap and you also increase the risk of pedal strike on the ground when turning/leaning. Additionally this lifts your other leg higher at the same time, which may feel odd.

Riding with the seatpost near, at, or above the minimum insertion line is a recipe for frame damage - I've killed multiple frames from doing this.

Your best fix is a much longer seatpost, or bite the bullet and sell/return the bike, to buy the size you really need. Do try and test-ride any replacement bike before you commit.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.