CRF250L Sprocket mod. Is it worth it?

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Blouberg, Cape Town
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There are a few performance mods you can make on a Honda CRF250L. I never considered the sprocket mod as one - it will only up the revs and slow down the bike, or will it?

I recently took the plunge and bought a 2014 CRF250L with 27000km as secondish bike, and was immediately impressed. I can use it as a moderate fun bike on the farm and as general suburban runaround. For a 250L it really goes well: 153km/on the speedo down a highway hill☺

So impressed I was that I bought another one (2014) with less k's (5000km) on the clock (with the intention of selling the other one), but first some comparisons had to be done. I just got the impression that no 2 did not go as well as no 1 - it is just not as spunky. It was confirmed on a farther and son shootout. Hein on no 1 pulled away from me at top speed and I could just not catch it, despite slipstreaming and ducking the wind like mad.

Immediately I was disappointed. Maybe I should keep the higher mileage no 1 and sell the lower mileage no 2 - or maybe at 5000 km no 2 was just not run in yet?

While doing the rear suspension mod on no 2 I asked Hein to check the front sprocket size on no 2 - and to my surprize we discovered that it had a 13t front sprocket fitted instead of a 14t. It made sense as no 1 registered a higher speedo reading at the same speed as no 1 (7km/h "faster" - speed is read off the output shaft rather than on the front wheel). On a 150km outride over tar and gravel no 1 used 500ml more petrol than no 2, which I thought strange but attributed it to "better performance" (before I knew of the sprocket difference).

This boggled my mind - a smaller front sprocket should make a bike slower, shouldn't it? As luck had it I had a 13t in stock - to fit on no. 1 for farm work - and we immediately fitted it on no. 2 to compare - I had to know!

The time for rematch came when we returned from a wet railway to Darling ride this Saturday. I took no 1 (I am heavier than Hein, but no 1 is faster!) and we had a " get there first" match on the R27 back home. Don't worry anyone - you will not really break the law on a CRF250L.

So what happened? I had the faster bike and should easily win!
I gave Hein on the newer no 2 headway and sat in his slip. Surely I gained on him, but when I left his slip to pass I could get next to him before slowly falling back again. Hein is lighter (80kg odd vs 102kg), but suddenly no. 2 had the benefit - it was faster!

So, at the expense of slightly higher fuel consumption and a speedo overreading with another 7km/h, downgrading the CRF250L front sprocket from 14T to 13T in front really makes the difference. Instead of 6th gear being a relative overdrive and wind getting the overhand over horsepower, the CRF250L's engine rpm is better matched to top speed/ terminal velocity with a 13T sprocket than with a 14T. It also makes the bike feel more alive through the rev range.

There you have it. The most affordable performance mod you can do on a CRF250L.

PS. I am awaiting a EJK kit to up engine output a bit, but for now these bikes really go well for a 250...
 

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