chain hitting sandman guard with 14t sprocket

I have been experimenting with gearing so recently bought a sandman guard and a 14t Renthal sprocket. All was well on my urban commute for a few weeks.

I went dirt riding with friends over the weekend and spend most of the day hunting for a drive train noise that turned out to be the chain hitting the sandman guard (the metal the separates the engine from the chain, not the vented cover).

I use this this bike like a plated dirt bike: whoops, small jumps, water crossings etc. I keep the chain on the loose side to compensate for using the entire suspension travel regularly.

Can someone confirm that this is common? I struggle to believe tightening the chain is a viable option but short of going back to a 13t sprocket or running without the guard that seems like my best option. Thoughts?

thanks,

-morgan

13 tooth on front dude.

Don't know why you'd want 14t on front if you're running bike more like a dirt bike.

I'd only want a 14t front if doing a shit load of super-slab droning.


What's your rear sprocket size?

motokid wrote:

13 tooth on front dude.

Don't know why you'd want 14t on front if you're running bike more like a dirt bike.

I'd only want a 14t front if doing a shit load of super-slab droning.


What's your rear sprocket size?

I have a 51 on the rear. In the haze of reading gearing threads I ordered a larger sprocket that I had intended. 13/51 is *awesome* in the woods but too short for riding to/from the woods and commuting. So rather than buying a smaller rear I figured I'd try a 14 front with the positive side effect of allowing an easy change if I found 14/51 was too tall for the woods. Chain hitting the guard aside, 14/51 it turns out is a pretty good compromise gearing. I'll go 13/48-ish next time.

Suffice to say this is my first true dual sport (I came from a KTM 300exc) so I'm experimenting with gearing that will allow me to use it in the woods as well as on the street.

thanks,

-morgan

You had a 300exc?????????

motokid wrote:

You had a 300exc?????????

I was looking for a DRZ400 when the KTM popped up locally for a reasonable price. It was even plated which is necessary around here as our riding is almost all some percentage public roads. It turned out it really didn't like to be ridden on the road, in fact it didn't like to be ridden anywhere below half throttle which as you might imagine on a 300 2-stroke was tough for a non-expert rider. I used to carry spark plugs with me and replace at least one on a long day. I could also never get it to idle properly. I finally listed it with the idle problem and when it sold in a few weeks for blue book retail value I took that as a sign and began the search for the WR.

-morgan

morgan9283 wrote:

Can someone confirm that this is common?

To actually answer your question;
yes i think its normal, i had this same situation when i was running a 14t front - except myne only rubbed on decel.
I didnt really worry about it, eventually the chain wore grooves in the case saver and it didnt rub any more.

The sandman guard wasnt meant to be used with a 14 tooth sprocket but its a easy fix.

Take the guard off and grind down where the chains rubbing on it.

When you say you run the chain "loose" is it possible that it is too loose? One suggestion, if you have not done so already, would be align your front sprocket, swingarm pivot, and rear sprocket centres to find the point of maximun chain tightness. Give yourself some extra looseness from that point and make a reference to some distance. That should take care of the full swingarm motion concerns that you have, and the chain might end up being a bit tighter than it currently is. I am running 14/50 (BigDogAdventures, and others recommendation) as well as the Sandman case protector and am having no issues. Then again, I ride in a somewhat tamer manner than you are. Good luck in finding out what works for you. You just need to experiment a bit.

Biglake/xy500--I had considered this option, thanks for validating. I am more inclined to run without the guard until the 14t sprocket wears out and then go to 13/48 gearing. Or perhaps just tightening the chain a little will take care of it.

saddletramp--it is indeed possible tightening the chain would help. I firmly believe in running the chain a little loose on a dirt bike is better than a little tight so I may be at least in part the cause of this problem. I will check for tight spots as you suggest and see if that helps.

Thanks for the feedback everyone. The net-net is I'll probably go back to a 13t once this set of sprockets wears.

-morgan

My 14t front would just rub in a very small area on the sandman C/S..... What i found is that if you loosen all the C/S mounting bolts you will see that you will be able to move the C/S "away" from the sprocket enough to give full clearance. This is because you will find that the diameter of the mounting bolts is much smaller than the "thru" holes in the C/S, so this allows quite a lot of "off centre" travel to be able to "offset" the C/S closer to the engine case & away from the sprocket. You will see what i mean if you just slightly loosen all the bolts & then push the C/S away. ( Push quite hard to compress the foam tape that is stuck onto the back of the C/S ).

I too will be going back to a 13t front, as my experimenting with gear ratio's for the best compromise will see me with settle with 13/45. I do use the bike primarily as a daily work commuter on the road, but hoping to start getting off road alot more in the future. Obviously the 14t front makes 1st gear way to tall for good dirt use, and to be honest i have also found that the 14t front is even a little to tall for 6th gear as well, even with the 45t rear.

In any case i will be glad to re-gain the bigger clearance on the front sprocket when i go back down to the 13t, as even though i have no rub with the 14 at present there is absolutely no clearance for any type of foriegn material at all. Proberly get away with it no worries when only using on the black top, but off road i would worry a little with the total lack of clearance with the 14.

Cheers guys.

morgan9283 wrote:

I am more inclined to run without the guard until the 14t sprocket wears out

You do realize the risk of running without a case saver right?

Somewhere around this forum is a picture of a wr250 case with a hole in it. One of the bolts that holds the seat down vibrated loose and fell onto the chain.
The chain travel carried the bolt around until the bolt fell between the chain and case and had nowhere else to go - but into the case.

I would imagine any smallish rock could do the same kind of damage....

A 14t sprocket is not an expensive item.

It's a hell of a lot cheaper than a new case.

It's a gamble and a risk to be off-roading without a case saver of any kind.