My 11 year old has been beating on his dirt bike lately and now the front shocks don't seem to be near as stiff as before...as if they're not holding compression(bottoming out) and making a clunking noise. I really haven't had a chance to look at it other than there isn't any fluid leaking out. He's jumping 3-4' high but luckily he's landing it on the rear tire. What is inside the fork tubes and what is probably wrong with it?

He's wanting a bike that can handle what he's doing but I can't see trading right now since his is like new. Can you upgrade this one so it'll be more of a jumper than a trail bike?

 

Sounds like they need rebuilt. Are they leaking around the fork seals?

Sounds like he needs a CR 85 or better yet a KTM 105 sx....

 

Do some searching you might be able to bolt up a Cr85 front fork setup........either way yer looking at spending some coin. Honestly though the CRF100 is more of a trail/backyard cruiser and not built for that. He guna eventually break the frame. Just my .02

 

I pulled the boot up and didn't see any so I don't think he's lost any fluid. What's inside those tubes?

 

Basically springs and oil. Larger springs work most likely solve the problem, along with a good old rebuild of the shocks themselves. But that will be costly for sure.
When a fork seal is bad the oil usually leaks out and causes the fork to "bottom" more than usual. keeping the correct oil capacity is critical.

If I had to guess I would say your son has blown the seals long ago and pretty much all the oil is gone.
As mentioned earlier, this CRF 100 is basically a trail bike and it sounds like your sons skill level has surpassed a CRF 100.. I would also check out the CRF 150R ( with the key being the "R" model) Those little bikes RIP and will totally handle anything your son can throw at it.

 

I'll check them out. Thanks.

 

Yeah, they also totally cost close to 4 grand too..........LOL Thats why my kids runnin an RM85L

 

You're right. I never said they were cheap. I have been racing harescrambles and GNCC's for over 20 yrs and one thing is for sure, It is NOT cheap. But if you wanna play you gotta pay...

 

There's a lot of companies out there that will rebuild forks and shocks specific to your needs. They usually ask for rider weight, ability and what kind of riding you'll be doing...Most arnt all that expensive either....Look up RACE TECH Motorcycle Suspensions. I believe they also rebuild rear shocks too.
There's also a place called XR's Only thats sells rebuild kits. the only problem with a rebuild kit is that you'll be in the same boat as you are with your son over riding the suspension.
The weak frame thing that the other guy mentioned could also become an issue. Your best bet there is to find out where the weak points are on that frame and have some guessets welded in those areas.

 

A CRF 100 wouldn't be worth adding killer amounts of $$$ to. If he likes to jump alot, he may need something like an 80cc 2 stroke or the 150R. I had a CRF 230F and loved it for its low end torque, but it just wasn't designed for jumping big, so I ended up with a brand new 04 Yamaha WR250F (so I can jump at night too LOL!!!)

 

Problem is I'm going to have to fix this one so I can sell it. I'll give RaceTech a call and see what the cheapest option will be. Thanks.

 

True, but 800 bucks in suspension work and another 100 bucks to strengthen the frame Vs. a new(used) bike at say 2000.. take that extra money and blow it on your truck! hahah
I agree with you though... a new bike is the way to go, but not always an option... specially a 2 stroke! mmmm


you'd be amazed at what good suspension can do for a bike....
I have a banshee..and althought i love it to death, it lacks in the suspension dept... if i had to do it all over again, i would have started with the suspension instead of the engine...

 

if your going to sell it, just buy for a rebuild kit from XR only (or whoever) their kits were only 75 bucks... i dont know what they all included, but its gonna be the cheaper way to go to fix it and get rid of it...

 

Thats my gripe with them. Not any faster than an 85 just more money. So it's not really an if you wanna play you gotta pay situation. Really not worth it for what you are getting. Guess im getting off subject here.......

 

http://www.pro-action.com/ This is who does my suspension work. Turn around time is pretty quick, price is good and my suspension is always smooth as butter on thr gnarliest of sections...

Sounds to me like the boy just needs a different bike. One that is designed to take the punishment. If you are gonna sell this bike I also vote for just a rebuild kit. Selling bikes always sucks, you never get anywhere close to what you have in them... I usually have around $2k in bells and whistles on my race bikes and then I end up selling them for about $1500-$2000 less than retail...