17/43 tooth upgrade on 4th Gen?

Hey all,

It’s time to change my chain and sprockets in my 1996 4th Gen VFR 750.
By default the bike is wearing a 530 chain and a 16 front / 43 back sprocket.

I feel that the gearing is a little bit too short for my liking and I would like to go up to 17/43 and change to a 525 chain while I’m at it.

Is this a tall order or is it something doable?
I can’t find any front sprockets with 17 T specific to the VFR. The only available options are 14, 15 and 16.
Similarly at the back, I can’t go any lower than 43.

However, I did find that JT is doing a 520 conversion for Fireblades that is giving a 17 teeth option, matching the dimensions of the OEM VFR/CBR sprocket.

Here is the CBR and VFR OEM sprocket (they share the same code and sizes):



And here is the 520 conversion



What do you guys think?

 

As far as the 17T aspect, just make sure there is room for the chain to turn the corner and not contact anything. Typically Honda provides enough room to go up 1 tooth in front.

Up 1 on the c/s is the equivalent of going down about ~ 2.5 on the rear. It was 2.7 on the last combo I calculated a while ago.

As far as the 520 conversion, it looks correct.

 

Ideally I would want to go with a 525, but it seems that this is not an option at all, at least on the 4th gen. Lots more options on the later generations, but hey...

Another reason that I failed to mention about wanting this particular 17/43 combo is that I am running a 180/55 rear as opposed to the OEM 170/60, which I has a larger circumference. By upping to 17 front I’m getting back to stock gearing as per https://www.gearingcommander.com

 

Where are you getting the 520 rear sprocket?

I’d be keen to go to a 520. Modern 520 is more than sufficient for this bike.

 

Tagged for later follow up, if anyone finds these 520 sprockets.
But I;m not following the OP. If you have a larger diameter wheel, the gear inches go up. If you increase the front sprocket, the gear inches go up. If you go smaller rear sprocket the gear inches go up. In increase in gear inches is a taller final drive, or slower engine RPM for the same speed.
I would lover to find a 16/42 in a 520, but I can't find anything but 16/43. I also find it a bit short, especially for highway cruising.

 

https://sprocketspecialists.com/

 

I'm with you. His gearing would already be taller with the taller tire and changing the gearing to a taller ratio would make it very laggy in acceleration.

 

Well, looking at the rear sprocket, there is no room on the bolt circle to go smaller. So 43 will be smallest we will ever see. But a +1F and +0R would give a 4mph increase at observed 65mph, and a +1f and +1R would give a 2mph increase at 65mph. I think I may try the 17t front with the stock 530. So the CBR sprocket is supposed to fit?

 

No, he has a shorter tyre. 180/55 is about 1% smaller diameter/circumference than the original 170/60…in theory. Might not even be that if it is squeezed onto the OEM 5.00” rim.

Tyres shrink 2-3 times that as the tread wears, so it’s not something i’d worry about.

Back when these bikes were newer I had a Triumph Trophy with the 170/60 on the same 5.5” wide rim the Daytonas ran a 180/55. I ran quite a few 180s and apart from sweeter side-to-side roll, and more skittishness on gravel, they performed the same.

That Trophy I did shorten the gearing, going from 43 to 46 at the rear. Whilst fun, it was a bit unnecessary since it was making > 50% hp increase over standard. Made for too many gear changes.

Lots of bikes are geared too tall ex-factory, partly due to emissions, so i’d be extremely wary of gearing up any bike. IME OEM is best economy gearing (if that wasn’t obvious) and you’d only ever want to go shorter from there for better performance.