I have a road bike that I use mostly for touring (2-3 day trips) and my daily commute (~25km). It's loaded with the Shimano 2300 (2013) 3 X 10 groupset. I know it's not the most efficient or lightweight, but for my purposes it has served me well.

I just broke the rear derailleur. My policy is to always replace parts with ones of the same or better quality.

My problem is that 8-speed parts are becoming less and less common for road bikes, so buying better or equivalent parts for the 2300 is becoming difficult (I live in Singapore).

Is it worth it to upgrade to a complete higher tier groupset like the current Tiagra? My hope is that with this change I can access the market of 10 X 3 speed components and have room to upgrade part by part later if I want to.

Would I need to change more parts than the ones included (derailleurs, shifters, cassette, crankset, BB) other than the chain if my bicycle already handles 2300?

  • If you have a 2300 group set, I'm not sure your rear wheel will take a 10 speed cassette. But you can use any 8 or 9 speed rear derailleur from shimano without issue (they're still very common).
    – Batman
    Commented Aug 25, 2015 at 11:50
  • @Batman, you are incorrect. 8/9/10 is the same spline.
    – Noise
    Commented Nov 15, 2021 at 22:16

2 Answers 2


As usual Sheldon has the answer. However you can also find a great range of second hand parts such as derailleurs from your local bicycle shed.

There's little point replacing the entire groupset, however if you want to move up to 9-speed then there's no problem replacing the rear derailleur, cassette and shifters. If you're replacing your cassette, replace your chain.

Sheldon writes:

In general, all Shimano Cassette Freehubs will work with all Shimano cassettes, any number of speeds.

Your crankset, front derailleur and bottom bracket can remain as they are (matched groupsets are a lie sold to everyone by Shimano). If you do decide for a lighter crankset, you can still leave the front derailleur alone so long as it suits your chainring choice. Similarly you can reuse the bottom bracket if it has the right interface and spindle length.

  • The statement about freehubs is no longer strictly true for Hyperglide road freehubs. 10s and older Hyperglide freehubs won't support 11s cassettes (save for the HG 800 and 700 cassettes, which are 11-34 only, or unless you physically modify the cassette or freehub). 11s HG freehubs will definitely take 10s or lower speed cassettes with a spacer. Also, as of 2021, 12s Dura Ace freehubs don't take older cassettes (but 12s cassettes can go on 11s HG freehubs; it's a long story).
    – Weiwen Ng
    Commented Nov 16, 2021 at 15:41

(2021 update: the below is not true for 11 speeds and above or 10-speed Tiagra)

All Shimano rear derailleurs have same actuation ratio (except for 10-speed MTB), so you can just swap in a Tiagra one.

For the second question, a higher quality groupset will be slightly lighter and work better. The shifter levers on Tiagra and upwards are a different design, allowing more comfortable shifting from the drops. Changing the entire groupset will require some special tools and be expensive; if you aren't looking for a DIY learning project it's probably best to sell the current bike and buy a new one.

  • Thanks. Does this mean that if I get the 10 speed tiagra cassette and derrailleur, the 2300 shifters would work? Commented Jul 25, 2015 at 10:59
  • 3
    No, cassette and shifters need to have same number of speeds. The number printed on rear derailleur does not matter as long as the actuation ratio is same.
    – ojs
    Commented Jul 25, 2015 at 11:01
  • So the Tiagra derrailleur would work in an 8-speed system? Commented Jul 26, 2015 at 5:31
  • Can it handle the width of the 8-speed chain? Commented Jul 26, 2015 at 5:32
  • I would except so, but can't easily find a reference. It's not uncommon for manufacturers to install a derailleur from upper tier group and use that for marketing, even if the number of speeds doesn't match.
    – ojs
    Commented Jul 26, 2015 at 10:15

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