Friday, March 7, 2008

Fixing A Cog Without Tools? The ROTAFIXA Method

So you're changing your bike's gearing and want to secure a new cog but don't have a proper chainwhip tool, what to do?

Well, first of all, a chainwhip will not really even help you to get your cog on tight enought and secondly, there is a better and better yet complely free method of doing this.

It's usually called The ROTAFIX or ROTAFIXA method due to the Milanese riders' club who've made it famous in the web by showing how it's done but as they say, it's originally invented (or at least used by) the track Legend Giovanni Petella.

Basically it "...enables the secure assembly of a track sprocket without having to use the traditional lock ring too. This is very handy as it enables you to use hubs that don't have space for the lockring, and inverting the rotational directions shown it is possible to remove the sprocket without having to use special tools."

It's really quite simple, click here and just follow these instructions. Or download the PDF directly from here.

You won't even need a lockring, although using one, just in case, is always recommended if you ride outside of a velodrome, like you most likely do. Also, you might want to be careful because by using this method you can - at least in theory - over-tighten the cog so much that you will f**k-up the treading on your hub. Your cog is (should be) made of hardened steel but the hub and the delicate threads on it are made of much softer alloy (aluminium, or something, I'm not a metallurgist) and rotafixing creates really a lot of torque... Anyway, the cog needs to be really tight, but just do not put your full weight on the wheel when you are turning it to tighten the cog, ok?

FYI the Dura-Ace combined chainwhip and lockring tool in the pic above is really the best money can buy, but obviously it also costs some. Even the chain on it is genuine Izumi chain, made in Japan and used my those Keirin racers...

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