Problem with bark busters & renthals

I just put a new Renthal on my son's CRF150r. I don't know why they don't come with it! Anyway, I also got him a set of bark busters. The problem is, there's some kind of plug or something inside the throttle tube side. It seems like it's in there good. Looks like a red plastic something. I'm new at this stuff and before I do something dumb, I though I should ask the experts! Any takers?


Oh, I forgot to mention, the PROBLEM is that I can't insert the hardware for the bark busters with that stuff in there!


if its not the throttle tube then its probably a vibration damping plug in the bar... drill it out so your insert fits...

What is it, some kind of caulk?

Do you think it DOES anything? I mean, should I consider squirting some caulk in behind the hardware?


I think its supposed to make the bars not vibrate as much, but I have some renthals on my 230 I drilled out seems the same but Im not a mx racer just a woods rider... Me personally I feel a bigger difference with the grips I choose

sorry for the slow reply, but honestly if your going to do the bark busters you have no

Regarding your reply time, no prob! I've been at work for the last 24hr and away from my computer.

My main issue is, I've been reading Renthal's stuff and they are pretty clear that tampering with the product can lead to failure. My judgement tells me it's fine, but I want to make sure I'm not gonna hurt my kid.

I'm a woods rider too. I bought these bikes to get my boys into the sport while they're young. I wound up with the CRF R/X for the performance and we've been winding up at the tracks for convenience sake. There isn't much woods around anymore. I live for a couple of trips to ME where there are miles free marked legal trails.

I've been told MA is OK too, but this is another thead! (sorry, I'm in New York)

Thanks Again,


I think as long as you dont drill out anything structural (metal) youll be fine... those anti vibration plugs are plastic or some other inert material... Just dont drill out steel and it wont fail structurally

I’d say the reason motorcycle manufacturers don’t put solid metal hand guards on bikes is for liability reasons. I saw a kids about 12 years old on an 85 crash a bike with solid metal hand guards. His hands slipped off the grips, down into the openings of the guards. He then flipped over the handle bars. You can imagine what happened. Both his arms broken midway between wrist and elbow, a total of four bones there, breaking threw the flesh, spraying blood all over the place. It was almost the worse accident I have ever seen. The worse I saw resulted in death.

Problem solved. After all that, I touched a drill bit to the plug and it yeilded like butter. I was surprised because I was poking at it with a long screw and it seemed pretty firm. Anyway, it sunk further in and is out of my way.

As for the BBs, I'm returning them. The attachment hardware in the center of the bars sucks. There's no adjustment. There's no way they'll make up with the hoop part of the BB. These were from Motorcycle Superstore. I'm gonna get the Tusk ones from Rocky Mtn. ATV. I have these on my son's bike and they seem fine.

Thanks for all the help,


the insert that goes into the bar expands when you tighten it, sometimes they come with a piece of rubber that goes around the insert taking up space so it will the grip the inside of the bar, im surprised they wont fit ...

I wouldnt be scared off by mikes story although Im sure its possible to get hurt with hand guards its possible that people get caught under water trapped in a seat belt too...

happens but so rare the bark busters do more saving your hands than any risk they represent. Ask the thousands and thousands of riders with hand guards how many levers they have saved, how many times they saved knuckles... and grips...

just my .02

Hey Wanawakeboard,

The "prob" was not with the dia of the bar, but a plug inside the bar. I was able to push the plug further in and out of the way. Prob solved.



I agree with wakeboard, the risk of you flipping over and getting your hands wedged is small, i've never even had anything remotely close to that happen (although i've never flipped over lol) I would think that's more of a risk to riders doing jumps. If you're just cruising the woods with your son he should be fine. Will save a lot of busted knuckles and broken levers.

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