You don’t have to count the teeth, the size will be stamped on the sprocket
My bike has a 45T on and comparing the pics it’s clear yours is quite a bit smaller …
You would do well to take up JerryXT’s kind offer and borrow one (or 2) of his spares and give it a go. 14/45 is fairly widely accepted as being the “right” gearing for a 520/525 in supermoto trim and certainly gives a very different riding experience to 14/40 say. Of course you may very well decide you prefer the taller gearing but you really ought to try both. 14/45 will still give you a practical top speed in the mid 90s (perhaps 105 absolutely flat out with chin on the tank) which is more than enough for this kind of bike, imo.
…as long as they don’t come back infected with orangeness - worried about that chain
From memory, for track use, I’m up one on the front and running a 38 or 39 on the 'berg, just so that I’m not absolutely on the limiter on the straights. The motor tends to break in a bad way if you rev the tits off it for long periods…
Apart from that, it’s completely reliable. If you can get it started.
RFS engines also “tend to break in a bad way if you rev the tits off them for long periods” so you do have to be careful. If Dries does the sort of riding where he’s constantly running out of revs in top then higher gearing is the way to go. But tbh if that was the case, unless doing a lot of fast track riding, he’d be better off with a different bike.(I’ve found 14/45 spot on for faster kart tracks like Rowrah, the natural home of the supermoto imo, and fine on the shorter race tracks like Mallory and Brands Indy where you’re only maxed out in top for a few seconds on the straights. You’d need to gear up for faster tracks - I did a day at Lydden Hill last year, not a big track by any stretch, and found the back dog-leg straight a bit too long for comfort, really could have done with a couple less teeth on the rear for that one.)
I agree re the little tracks, but mines the 650 so it’s a little big for the smaller 'moto circuits. That’s why Chris sold it to me - the smaller motor allows the bike to turn more easily.With the gearing I’m on now, I’m within a thousand revs of the limiter halfway down the straight at Brands. With the higher corner speed, I can keep ahead of most things, but the faster bikes blast past on the straights then hold me up in the corners. I must go down one or two at the back for this year, but I don’t want to lose the corner exit speed…
And well spotted, it’s a 40. Not sure what the front one is though.
I may pick Jerry’s offer up and try bigger. Don’t worry, I’ll get a can of yellow spraypaint so I can give them back in your favourite colour.
I assume the chain will need lengthening if going up to 45?
I run a 14 on the front and dropped to a 42 rear… dont half notice the difference. Its good for those longer straights i get stuck on and with the fact most the people i ride with ride sportsbikes so dont stick entirely to tight twisties but i miss the tourque of the bigger sprocket. Gona go back up a couple of teeth i think or i may wait and see if its any better once ive fitted the 41mm carb and twin titanium FMF pipe and had it all set up on a dyno.
Hopefully you won’t need to lengthen the chain to go to 45. The spindle collars that butt up to the adjusters can be fitted in two positions (by rotating 180º) - one puts the wheel about 2cm (I’m guessing) further forward than the other. If you’re lucky it’ll be presently set with the wheel further back and you can reset the spindle collars to bring it forward. Also you should be able to shorten the adjusters by a few turns. I suppose there’s a possibility this could bring the tyre up against the swingarm but I don’t think that would be an issue - if it turns out to be then you’d just have to get a link added to the chain (you’d be able to go back to 40 without having to remove the link again). I’d measure the total amount of available movement on the collars and adjusters and see if there’s enough space - if not then you could get the chain lengthened before doing anything else.
^^^ Of course this will give you a shorter wheelbase, so while you’re at it you may as well shorten it further by dropping the yokes as far as they’ll go (reckon there’s a bit to go, looking at the pic). After this exercise you’ll have sharper handling and the bike willl be even easier to wheelie
BTW I’d put money on the front being 14 (you do have to count the teeth on that one btw).
Unless I’m a complete numpty, which is entirely possible, it was dark and early morning, I count just 13 teeth on the front. Does that make it equivalent of 14/42 or something? What’s the advantage/disadvantage of changing the front sprocket compared to the rear?
Good point. If you’re sure it’s a 13 then with the 40 rear you have the equivalent of 14/43 (1 tooth off/on the front = 3 teeth on/off the rear). You’d notice the difference if you changed to 13/42 to give you the magic 14/45 equivalent and well worth considering - especially as you wouldn’t have to think about lengthening the chain.
Going smaller on the front stresses the chain more and the sprocket wears out more quickly - doesn’t really matter that much but it’s why I don’t naturally consider reducing front sprocket size. Also a large rear sprocket looks cool :hehe:
That’s a supermoto riding style you don’t see every day. And yes, a beauty of these bikes is they do crash extremely well - even better with can protector, axle sliders and brush guards - how was your front brake lever and swingarm/rear wheel spindle after that off?
Been reading this with interest as my chain is coming to the end of it’s life and I’m considering changing my sprockets on the MT-03 for lower gearing (road riding).
The standard set up for my bike is 15 front 47 rear. I’m thinking of just getting a one tooth smaller front sprocket for a little more low down ommph. Do you guys think I would notice a difference or should I be upping the rear sprocket too? Also the speedo will be out I guess- since I’m lowering the gearing I suppose the speedo will read higher :doze:?
Soz to butt in like this but any info appreciated.
You would do well to take up JerryXT’s kind offer and borrow one (or 2) of his spares and give it a go. 14/45 is fairly widely accepted as being the “right” gearing for a 520/525 in supermoto trim and certainly gives a very different riding experience to 14/40 say. Of course you may very well decide you prefer the taller gearing but you really ought to try both. 14/45 will still give you a practical top speed in the mid 90s (perhaps 105 absolutely flat out with chin on the tank) which is more than enough for this kind of bike, imo.
