WH-R550 has a Shimano freehub with 9 splines. The cassette is 9 speed, 11-25T, model CS-HG50-9.

The wheel itself is a little buckled, I could probably attempt to tighten some spokes to improve the situation but I think I'd sooner get a replacement.

I've tried to do some reading into what options I could have here, but I'm left confused.

As I see it I could:

  1. Buy a new wheel with the freehub on such that the freehub would be compatible with my CS-HG50-9 cassette. I'd remove the lockring and migrate the cassette.

  2. Buy a new wheel and migrate the freehub and cassette. I'm not sure if this is possible.

  3. Buy a new wheel which includes a newer freehub, and buy a newer 9-speed cassette that would fit the new freehub but also work with the rest of my 9 speed groupset.

Nuclear option: buy a new 105 R7000 groupset and use my existing frame, would rather not do this right now.

What is the best option for liquid second hand stuff on facebook marketplace or "cheap" new stuff below say $200 USD or so.

  • R7000 is discontinued, so get it while it's still available at a good price. It's a very good group.
    – Noise
    Commented May 27 at 19:53
  • Wow I'm so far behind the part I'm considering migrating to as a "nuclear option" has already been deco'd! lol, I'll pick this up cheap and run it another ten years!
    – bfitzg
    Commented May 28 at 1:41

2 Answers 2


I've been down this road a few times. You're in a good place because you're in the 8/9/10 speed sweet spot.

If you only would be comfortable with a new replacement wheel then buy the whole thing new. Shop around and see what you can find, and compare price.

It is possible to buy a new rim and move the hub over. That's a lot of work but can be done if you have the patience. The killer can be finding a new rim with similar numbers so you can reuse your spokes, because a whole new set of spokes can be stunningly expensive.

A wheel builder can also do this rebuilding work about 10 times faster than the home mechanic, but at a cost.

If you're accepting of a used wheel, explore various auction websites like ebay etc for wheels that may be "not new" and also not worn out.

Remember that an 8/9/10 speed cassette are all the same width, so will fit on the same size freehub.

Do make sure the new wheel has a compatible brake - whether that be a rim brake track or a rotor mount (unlikely)

Either way, you should be able to fit your existing 9 speed cassette+chain onto the new wheel. You have to check that the brakes are not rubbing and do close down on the brake track while clearing the tyre, and that the top/bottom limits on the rear derailler are okay. Perhaps some fine tuning of the derailleur cable tension too which is all simple stuff.

I got a 7 speed wheel brand new from auction website for $10 because it was 126mm OLD and I needed 135mm It was a simple matter of adding some thicker spacers and that wheel has done 8000 km mostly in the wet and rain now.


As previously mentioned, Option 2 is possible but is somewhat cost and time prohibitive. Option 1 was detailed out pretty good detail, and there is probably still an ample supply of used wheels out there. I wanted to expound on Option 3.

Buying a new wheel with a newer, 11-speed compatible freehub offers you some future upgrade options without negatives if the price is right. The same details of ensuring the wheel is compatible with your brakes, rim width, frame still apply, just like a wheel with an 8/9/10 speed freehub. However, a newer 11-speed freehub would accept your 9-speed cassette without issue by using a 1.85mm thick spacer and putting it on the freehub first (narrowing the width of the 11-speed freehub to that of an 8/9/10 speed freehub) before putting on the 9-speed cassette. A new wheel may actually come with this spacer, and if not, it is easily found at most any local bike shop. The benefit of a new wheel could be that if you choose to upgrade to the 11-speed 105 groupset in the future, the rear wheel would be ready for the 11-speed cassette (just remove the 1.85mm spacer).

  • 1
    Thanks that's a really interesting idea, I wasn't sure if I could use an 11 speed freehub with a 9 speed cassette. I'll explore this as I took the existing cassette off the other day to clean everything, I have the chain whip and lock ring tool so it sounds like I'm only missing the spacer, which should be very cheap.
    – bfitzg
    Commented May 28 at 1:37

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