break the chain

The chain and sprocket set was old and mismatched. it was time for a replacement but off the shelf was just not going to cut it.

The stock VFR750 FG chain is a 530 pitch which is great for racking up miles with the odd lube when you get the chance to but I was racing and that chain was going to be bulky to lug about.
Finding a replacement chain at a more suitable weight would be tricky enough but I was now running a CBR600 F3 rear wheel  which ran a 525 pitch chain to add a little complication.
I wanted to run a 520 gauge chain (the RC30 ran one so it will be plenty strong enough for the RC24)  which is a lot lighter weight and would offer less rolling resistance over stock. This has been done by other people by buying kits that featured "special made to measure" sprockets and came with an associated price tag.
Now I knew that the splines on the output shaft of my engine and the bolt spacing on the rear sprocket would be common to other machines and many o them run a 520 chain so it was just a case of getting researching.
JT sprockets have a great website which will show you every machine that a sprocket will fit. It was simple then to find the sprocket for my VFR then compare all the other bikes said sprocket would fit.
Armed with this information I then searched for sprockets for these machines in 520 pitch and it wasn't long before I had a 15T CBR900 front sprocket on its way to me.
Next up was the rear: I went through the same process again but ended up circling back to the CBR600 F3 for which I found a JTA1403 45T aluminium sprocket well priced.
Finally I found the cheapest gold X ring DiD chain I could find with 120 links (most are about this length and I was hoping my bike wouldn't need more) which ended up being for an Aprilia SXV 550.

The ratio choice was ball park guessing one tooth off the front and the correct 45 teeth on the rear that should give a small hike in acceleration along side the drop from a 18" to 17" rear wheel. The ratio changes are going to be somewhat less with the 520 pitch over the 530 so the bigger change caused by a tooth down on the front sprocket shouldn't be as big as it might have been with the old chain pitch.

Once everything had turned up and a rivet link was ordered (the chain came with a split link which wouldn't be suitable here) I fitted the lot and was pleased to find all fitted the bike perfectly.

You might not be able to buy a 520 pitch kit for a VFR750 FH but you can sure make one!


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