I'm planning to buy a TCX Advanced SX, this one: https://www.giant-bicycles.com/us/tcx-advanced-sx-2017

All is cool, I simply would like a 10/42 instead of the stock SRAM 11/42. What is the less expensive way to get about it? Can I simply swap the 11t for a 10t?


  • Common advise is "buy the bike you want" and not plan on making significant changes immediately. See if the bike shop will take off the unused parts and adjust your price accordingly. – Criggie Apr 27 '19 at 14:27
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    Probably more cost effective to go 11-46 and increase the size of the chain ring. – mattnz Apr 27 '19 at 20:10

Changing the front chain ring to a 40t is easy and requires only to swap out one SRAM part for another.

A 10t sprocket is too small for a regular freehub. A special hub body that is compatible with SRAM XD cassettes is needed.

There are many hubs that allow you to swap the driver body. For example, the DT 350 hubs on my bike can be converted to XD standard with a part that costs about €40.

That may or may not be the case for the hubs in Giant's PX wheels. AFAIK these are, or were, available for mountain bikes with XD hubs as well. I couldn't find anything in a brief search on the web however. Perhaps I simply confused something.

If you plan to replace the stock PX wheelset, which isn't all that great anyway, it will be an easy conversion to a XD driver. Then you could mount any SRAM XG 11 speed cassette. A 10-42 XG-1150, for instance.


As Criggie remarked, you may consider buying a bike that fits your specs better. A similar Canyon Inflite has a 40t chainring, and DT380 hubs. For these a switch to a XD driver is easy. Otherwise the specs and geometry are very similar.

If you get a 44t chain ring at the front, you will have the same transmition ratio to a 11t sprocket as with a 40t to a 10t. (A Focus Mares, for example, comes with 44t and has nearly the same frame geometry.) You might then simply choose an humongous last cog. For example, up to a 11-42 cassette instead of the 11-32 that comes with the TCX (which is geared for cyclo-cross where you carry and run up slopes when it is too steep for 32/42).

A 10t cog is by principle inefficient (chord losses). In a nutshell the chain doesn't wrap properly around a circle when the radius is small compared to a link's length. Thus 40/10 is less desirable than 44/11.

  • Fitting new chainrings is hardly a big deal. Since the shop is building the bike anyway, they'll probably be happy to fit a different part to the standard one and may well charge little more than the cost difference between the parts. – David Richerby Apr 27 '19 at 20:36
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    Thanks to all for the valuable advise. The bike is like new but actually second hand.It's a private sale so I'd have to tweak whatever I find! And I know the stock TCX wheels are quite basic....!!! Difference Canyon (which I quite like) vs Giant: Giant gives a lifetime warranty on their frames..Isn't it something to consider?? – huckfinn Apr 29 '19 at 19:37
  • It's an absolutely fantastic bike! I love it. I wish I bought the aluminium TCX instead of a Merida two years ago. The changes to your drive train aren't all that extensive, and you may do it as you replace worn components or upgrade anyway. – gschenk Apr 29 '19 at 20:07
  • I've just noticed your TCX comes with a 11-42 cassette and bit with a 11-32 I thought. Going to a larger cassette with road SRAM isn't possible. However you may easily take a MTB cassette. Sun race and Shimano as well. As long as you take care of XD and regular 11 speed drivers 11 speed cassettes are interchangeable. You need to lengthen your chain then. The 114 links a KMC X11EL usually comes is just enough for 40:42. – gschenk Apr 29 '19 at 20:21

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