Dirtbike Help!!!!

So the other day I went on a little dirtbike trip with mmy great aunts and uncles and my nan, and when we stopped one I was looking at my bike and noticed that there is paint rubbed off on the inside of my muffler? so I was like wtf? so I told my uncle to sit on it, and sure enough when he started jumping on it, the muffler went pretty well down to my tire, so I took her for a ride and got her muddy so I could see if the tire rubbed over the fresh paint to see if it happened recently, so I the muffler muddy and hit a few jumps and sure enough thats what was happening,
So my main question
Im pretty sure I can just twist my shock to stiffen the suspension right? if so do I need any tools? and will it raise my bike any?
thanks

So my main question
Im pretty sure I can just twist my shock to stiffen the suspension right? if so do I need any tools? and will it raise my bike any?
thanks[/QUOTE]

first look to see if the silencer is bent, second did you change the rear tire to something wider, and lastly, if you insist on setting the suspension stiffer, your prob gonna need a new spring designed for your weight, turning the rings wont add much height at all and only result in the back end kicking out on every little bump and possibly bouncing up when landing a jump. dirtbike suspension is precise for rider weight and can be dangerous if not set up properly. read your book, you need to set static height, and race sag and everything else

kevinsranger said:

first look to see if the silencer is bent, second did you change the rear tire to something wider, and lastly, if you insist on setting the suspension stiffer, your prob gonna need a new spring designed for your weight, turning the rings wont add much height at all and only result in the back end kicking out on every little bump and possibly bouncing up when landing a jump. dirtbike suspension is precise for rider weight and can be dangerous if not set up properly. read your book, you need to set static height, and race sag and everything else

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thanks,
no the muffler isnt bent, and its the original tire, but I know alot of people that just twist the spring and stiffens up there shock, theres a place there to twist it, But what is race sag? but I dont know if it makes a difference but I dont do like motocross or anything, I hit jumps that only give me about 4-5 feet of air
thanks

Boggin-B-Series said:

thanks,
no the muffler isnt bent, and its the original tire, but I know alot of people that just twist the spring and stiffens up there shock, theres a place there to twist it, But what is race sag? but I dont know if it makes a difference but I dont do like motocross or anything, I hit jumps that only give me about 4-5 feet of air
thanks

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race sag it the amount the swingarm drops after the rear tire is lifted off the ground to where it sits level without anyone on it with the tire on the ground, you dont have to race motocross to have suspension setup get you in trouble, it effects the way the rear stays straight when hitting ruts, tree roots, whoops, ruts from other dirt bikes in the turns and mud, so if you turn the collars down to stiffen it up and your too heavy for that spring then when you are on the throttle and hitting rough terrain like bumps or tree stumps the back of the bike is gonna kick side to side really bad as opposed to just staying straight under you and soaking the ruts up.

are the knobs on the side of the tire rubbing on it or just more than the knobs. You could try spacing it out more with a few washers and longer bolts and see if the solves the problem. I would try that before fawking with the suspension

kevinsranger said:

race sag it the amount the swingarm drops after the rear tire is lifted off the ground to where it sits level without anyone on it with the tire on the ground, you dont have to race motocross to have suspension setup get you in trouble, it effects the way the rear stays straight when hitting ruts, tree roots, whoops, ruts from other dirt bikes in the turns and mud, so if you turn the collars down to stiffen it up and your too heavy for that spring then when you are on the throttle and hitting rough terrain like bumps or tree stumps the back of the bike is gonna kick side to side really bad as opposed to just staying straight under you and soaking the ruts up.

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I dont think I'm too heavy, im only like 110lbs..but is that too heavy?

Boggin-B-Series said:

I dont think I'm too heavy, im only like 110lbs..but is that too heavy?

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depends on the bike, most 125cc 2stroke or 250cc four stroke motocross bikes are only set up for a 150-160lbs rider, so if your bike is smaller you can bet the suspension is set up for even lighter.

kevinsranger said:

depends on the bike, most 125cc 2stroke or 250cc four stroke motocross bikes are only set up for a 150-160lbs rider, so if your bike is smaller you can bet the suspension is set up for even lighter.

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its a honda crf150f 4 stroke

dude just raise your shock(s). there's no way in hell that you're too heavy for it, and it shouldn't be doing it. If that doesn't help then you may wanna go and get it checked out by a shop, they may have to redo them.

kevinsranger said:

race sag it the amount the swingarm drops after the rear tire is lifted off the ground to where it sits level without anyone on it with the tire on the ground, you dont have to race motocross to have suspension setup get you in trouble, it effects the way the rear stays straight when hitting ruts, tree roots, whoops, ruts from other dirt bikes in the turns and mud, so if you turn the collars down to stiffen it up and your too heavy for that spring then when you are on the throttle and hitting rough terrain like bumps or tree stumps the back of the bike is gonna kick side to side really bad as opposed to just staying straight under you and soaking the ruts up.

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sorry but that is not true. its with the rider on it. teh bike its self does not weigh enough to be properly set, it requires the rider to be on it. Dirt bikes are designed that way seen as how a rider can weight half to 3/4 as much as the bike.

Boggin i would only add some "preload" as its called into the spring if when you get on it and the rearend drops a conciderable amount, the book will tell you. Should you have to put so much preload in that the spring is binding before you bottom out you will need a new spring or if your bike is handleing worse you may wnat to see if you bike has a compression knob on the shock resivor then i would increase that a few clicks (turn clockwise) then go out and ride it and see how it handles, you may have to mess with your rebound also assuming you have both of these on the bike. the rebound is a little flat head screw down by the bottom of your shock. you book will also tell you about this. if you need anyother help just PM me, i race a CRF 450R in the desert so i can help you dial that thing in

84projectFORD said:

sorry but that is not true. its with the rider on it. teh bike its self does not weigh enough to be properly set, it requires the rider to be on it. Dirt bikes are designed that way seen as how a rider can weight half to 3/4 as much as the bike.

Boggin i would only add some "preload" as its called into the spring if when you get on it and the rearend drops a conciderable amount, the book will tell you. Should you have to put so much preload in that the spring is binding before you bottom out you will need a new spring or if your bike is handleing worse you may wnat to see if you bike has a compression knob on the shock resivor then i would increase that a few clicks (turn clockwise) then go out and ride it and see how it handles, you may have to mess with your rebound also assuming you have both of these on the bike. the rebound is a little flat head screw down by the bottom of your shock. you book will also tell you about this. if you need anyother help just PM me, i race a CRF 450R in the desert so i can help you dial that thing in

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yea your right about the sag, i havent done it in a few years and forgot that part lol.

kevinsranger said:

yea your right about the sag, i havent done it in a few years and forgot that part lol.

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haha no prob. i didnt want to come off mean or nothin to ya either ya know

hey boggin dont worry about it too much take the bolt that connects the muffler to the subframe and shim it out a little but make sure you have plenty of thread left on the bolt then before you put it in throw a little loc tite on it. they sometimes will rattle out just from the engine vibration. its happened to me before and it sucks to look at your bike the morning of a race and see your muffler hanging there. i ride a 06 crf 250 with duel white bros alum. pro ex. and right before i mounted them up i took a nasty spill after caseing a tripple besides a broken colar bone and torn rotator cuff i was fine but i tweaked my subframe and within a week of ridding on the brand new exhaust my back tire ate through one of the 800$ ex cans. ordered a new can and shimmed it out and everything was great from then on. to adjust your rear shock you need to turn those preload rings. to do that you can buy a spanner wrench (about 15$) or use a hammer and a dull punch or screw driver. MAKE SURE YOU DONT BEND THE RINGS BECAUSE IF YOU DO YOULL NEED TO PULL THE WHOLE SHOCK OFF AND IT WILL BE A BIG PITA. but in your case you really dont have to adjust them if you dont want to because it wont make any diff. in the rubbing thats were the washers come in. and your not to heavy your just not ridding the bike for what honda designed it for. your ridding it more like you should ride a 85 2 smoke. and dont worry about the reabound because im pritty sure youre bike doesnt have a reboung dampening adjuster. this adjustment on the bigger bikes helps to keep the rearend from kicking back at you but if you adjust it to much it will make the shock feel dead and sometimes wadd up on you going through woops

Static sag is the amount the bike sags without a rider on it, should be in a certain range (see your book for exact numbers) race sag is with the rider on the bike. If you're race sag is set right but you can't get the static in the correct range you need a spring change. But that is all beside the point. Your tire should never rub on your silencer.... especially not if it's stock, the suspension is meant to bottom out sometime. If I were you I'd be looking more towards a bent sub-frame.... have you had any gnarly crashes on it?

I would have to say that it should not be rubbing on the pipe, and that something in there is bent..
Especially considering you are only 110lbs.

I work at a motorcyle place (we do alot of race parts) (BBR Motorsports) and the CRF150 is one of the more common bikes we do stuff for, so I'll see if there are any in the bike build area when I sweep up, and I'll ask my boss what he thinks. That is if he is still here when I sweep.

If you were alot heavier than you are, that would expline why the tire is up further, but I still don't think it should be up THAT far, and even if it is, it shouldn't be rubbing on the pipe.
If you have crashed on it, and it was a hard crash, I guess the swing arm could be bent slightly too. But that would have to be a damn hard crash, I think.