Quote: (Whenever feasible to obtain a specific ratio, avoid using a smaller than stock front sprocket. The smaller sprocket requires the links of the chain to turn a tighter radius, which increases friction and decreases the life expectancy of the chain) (by decreasing the life-expectancy of the o-ring seals of the chain).

Anybody experienced any excessive wear when they changed to a 13T front sprocket.

Also, i have done 2100 klms with the current sprocket and chain set up.

Is it ok to change just the front or am I going to have to replace everything

 

I finally changed my front sprocket to a 13th today.

Tried about 50 times in the last couple of months to remove the nut with-out any luck...... Broke two ratchets (cheapies), tried a couple of small rattle guns, tried breaker bars (one was bigger than me and i am six foot) and still no movement on the nut (and yes I had flattened out the retaining washer)

This morning I put my pride on the line and took it to my brother’s mechanic. He had a hardcore rattle gun which took it off (still took a few goes though).

We went straight out to the forest and......... WOW what a difference on hill climbs, wish id taken it to the work shop earlier. I think ill go to a 45 tooth on the back once I get a chance, although I might wear this chain out a little more first.

 

For what it's worth:

The bigger the diameter of the sprockets the less the wear on both the chain and sprockets. The load is distributed over more teeth decreasing load, and thus wear, and the chain doesn't have to wrap as far around cutting some rotational wear on the pins, the biggest and worst wear point on the chain that causes what riders call "stretch" in length. The chain really actually gets longer because the pins wear, that wear causes the links to slightly lengthen and wear the sprockets into a hook pattern in the direction of load. That combination of wear is why both chain and sprockets should be replaced at the same time.

Race teams use rear sprockets probably because they usually have multiple rear wheels doing fresh tires too, so swapping sprockets is no big deal - and they have the money/parts. Plus they will be so dialed in when they hit a track they will only need to change the ratio by a tooth or two on the rear sprocket rather than the huge jump with a tooth on the front. They keep notes and the variance will be due to maybe slightly slicker or stickier track conditions on a given day.

All else has pretty much been covered, except to say if possible when you buy new chain and sprockets, if you know the ratio of front teeth/rear teeth that you want to use, figure out what rear sprocket will allow you to run one tooth smaller than max on the front. That would allow for one tooth bigger and possibly three smaller as options, while having the biggest possible front and rear sprockets to minimize wear and tear on sprocket and chain.

 

I didn't notice much wear on my setup when I changed to a 13T, however I did go with a bigger rear sprocket and got a nice new chain with it. After 2 years of some decent riding I didn't notice anything.

Well worth changing the front.

 

So....
Having only done 2100 klms on the current stock set up will it be ok to change only the front sprocket or am I going to have to replace everything with new stuff. Trying to save a few bucks you see.

 

You should be fine changing out only the front, unless the original shows severe hooking. Change it and see if you like it first, then if you buy new stuff you might want to change your rear sprocket tooth count and go with a 14 or 15 after figuring the tooth count needed to get the ratio you want. You might find that the 13 is too much and you could cut the change in half by working with a larger rear. Do the math and find what you'd have. Rear/front = ratio, find what it is with the stock set up then what is with 13. Knowing that, if you want to split the difference do the math with a few teeth difference on the rear with the stock front.

Since front sprockets are relatively cheap if your chain and sprockets are just slightly worn just do the front one and run them till worn out.

 

pardon my irritation, but...


I get so sick of people busting out math on a damn dirtbike. "This sprocket is going to have less teeth and more force wearing it out quicker...blah blah blah."


We're not talking going from a 14 tooth to a ........... 3 tooth. Its a 14 to a 13. There will be more wear based on the individual than anything. How well do they care for their machine? What kind and quality of chain and sprockets do they have? Do they ride in mud/sand? Do they keep their chain adjusted propoerly? Will they be riding on or off road?

This stuff plays 20 times more difference than someone sitting here debating a 13 vs a 14. And another thing, look at this way. Fronts are A LOT cheaper and A LOT easier to change, so even if they did wear out quicker. A few bucks from your wallet and litereally a few minutes of your time in the garage later and your good to go. Versus changing the back one which is A LOT more money and A LOT bigger pain in the *** to change.

You guys are squabbling over a few bucks and a few minutes its not even worth wasting the breathe from your mouth or energy from your fingers to ask such a question.

 

Wooooh... calm down dude.

I asked a question and frankly KLX678 has given me the answer I wanted regarding the front sprocket and just replacing it at this stage.

Thanks for your interest but your comments are not helpful.

 

I guess I have to excuse myself for having some racing, riding, and work experience here along with a little engineering experience... sorry.

But after going through several sets of chains and sprockets on bikes, both on and off road, along with working in a shop and seeing a few hundred other drivelines in varying states, I do know a bit about wear. And rider style has so little to do with chain wear unless, as you pointed out, that style is to not lubricate, clean, or adjust chains on reasonable interval... or worse yet - a rider that pressure washes the O-ring chain. Now that will promote wear significantly after the water displaces the lubricant when it blows past the O-ring.

I will tell you one tooth on a front sprocket doesn't sound like much, but it's a significant difference in load area on the sprocket, especially should someone drop 2 teeth, say 15 to 13. On the rear it is less significant. It's all about contact area. Just look at the sprockets and the chain wrapped around them and think. I apologize if it hurts, but think. Look at how the load is distributed. Nothing wrong with knowing that. Nothing wrong with understanding how to increase life in a part when replacing parts. The sprocket costs if replacing the whole driveline is going to be the same for the slightly larger front and rear, so why not do the math and get slightly larger sprocket tooth counts that might add miles to the driveline? It also will make it easier to go to even lower gearing. There's a benefit that may come in handy in tight woods offroading. In addition if you actually read what I wrote you would notice I said if the chain and rear sprocket is in decent shape doing a 13 to see if it works makes sense... but maybe you were too irritated to see that, and for that I apologize. Sorry to make your brain work overtime.

All that was ever pointed out along with the original question about front and rear changes, were the advantages and disadvantages - along with the math and knowledge to decide what approach to use. Apparently you're irritated at learning something?

P.S.
I remember when I was 18 and riding my first off roader - that Bultaco listed in my signature, I still have it. I had 13, 14, and 15 tooth front sprockets for it. If someone had filled me in a bit on this whole thing back then I would have saved a lot of swapping between the 13 and 14 by simply going to a 54 tooth rear sprocket over the stock 52 at one point to split the numeric difference. It seems petty, but the 13 was too low in first and the 14 too high in third. By your views that's not a big deal on a "dirtbike", but you see I was riding a trials bike and it made a difference in approach to various uphill sections, going over logs, through stream beds, and over rocks.

Based on personal experience and 38 years later I see the value of someone learning something here. You see some of us will be doing more than riding "a dirtbike". We will be riding or racing at a level above that where you are at. Unless, like me, you get more serious in riding motorcycles, maybe getting into racing. That's when this information becomes relevant. Knowledge helps.

 

Hey guys this 13T front sprocket everyone talks about, is there a genuine Kawasaki item or only aftermarket?