Giant CRX2 Single speed Conversion

My brother got a new drop bar road bike and wanted to convert his old flat bar GIANT 2009 CRX2 into a single speed that he can ride along the beach in Melbourne Australia.

The goal was to have a single speed bike requiring little maintenance over time. Just to note the GIANT CRX2 is a beautiful bike, lightweight with carbon forks.

This Blog summarises how I converted a 2009 Giant CRX2 into a single speed bike.

Parts List:

1/8" Chain
TA Chainring Track 1/8 48T-130 PCD
1 x Surly Singleator Chain Tensioner Silver
1 x Gusset 1-ER Single Speed Conversion Kit Black

(Approximate price from the usual online sellers AUD $140)


So to start things off I undid the derailleur cables followed by removing the front/rear derailleurs off the bike by undoing a few bolts using hex keys.

I then removed the handlebar grips and proceeded to remove the gear shifters (again by undoing some bolts)

Whilst I had the the grips off I cut 2.5cm off each side of the flat bar using a pipe cutter. I repositioned the brake levers and put back on the grips. This effectively reduced the handlebars from 60cm to 55cm. Whilst I was there I decided to shorten the front wheel brake cable to remove the unnecessary slack!

I then proceeded to remove the old chainrings. To remove the chainrings I had to completely remove the crankset from the bottom bracket. Whilst I had the crankset off I cleaned and re-greased the bottom bracket. I replaced the chainring with a 1/8" track chainring as it is more robust and doesn't have the "notches" that makes the chain want to jump off and change gears. I bolted on my new chainring to the middle chainring position. I used the middle chainring as it lines up better with the conversion kit (The CRX2 is a triple chainring crankset).

I then removed the old 3/32" chain using a chain breaker.

Next thing I did was remove the rear wheel and took off the rear cassette. I proceeded to put on the conversion kit with wide spacer (19mm) first followed by 16T cog then 14mm spacer. I tightened the locking ring and put the wheel back on. 48T Chainring combined with 16T rear cog gave me a nice 3:1 ratio.

I then put on the new 1/8" chain ensuring it was as short as possible, rejoined, wiggled chain as much as possible to loosen up and then I put the Surly Singulator tensioner on in an upward push position to ensure maximum wrap around cogs.

I checked the chainline - looked pretty straight so I was happy, ensured and double checked all the bolts on the bike were tight  and voila there was the Giant CRX2 in single speed mode! Took it for a spin at 12:30am and was happy with the result!

Optional extras:

Might need shorter chainring bolts
Might want to replace bottom bracket depending on how worn your old one is.


Would like to thank plenty of videos posted on youtube.com (ie removing cranks, bottom brackets, installing Surly singulator) as reference points and the fantastic single speed conversion information from Sheldon Brown. Hegsy also gets a mention.

Tools used:

Hex Keys

Tacx Sprocket Remover (Whip)

Park Chainwheel Bolt Peg Spanner

Park HG Cassette Lockring Remover

Park Tools Hollowtech II BB And Crank Arm Tool Silver

Tacx Rivet Extractor

Multi-Pupose Greese

Delivered to my Brother by pedal power tonight, he seemed pretty happy and was going to SMS me the result tommorow morning.

Disclaimer: I'm not a bike mechanic so don't take my advise in regards to anything bicycle related. Enjoy the read.

Update 5/4/2011

Have finally done the upgrade and added a RaceFace XC Ride Seatpost and Headstem and put on a Ginat Road bike seat. The bike is now complete check out these new photos.