Have Twinwalls? Please Read!!!

[grass-digger]

i dont believe that i will ever go withought my pro-tapers, i have a set on my cr250 and there 3 years old still as strait as when i got them, that is after bending my triple clamp bolts about 30degrees :ohmy: , My tag bars on the other hand bent my first crash and i had to get a new set of pro-tapers for my crf450

 

[will pattison]

Will,
I am just over 6', but I am tall in the torso. I have the Button 7/8" Renthal on my KX310 and nothing feels better on any bike I have ridden and the cross bar just clears my GPR steering stabilizer. Here is the goon like specs:

A - 807
B - 110
C - 85
D - 205
E - 67

well, we can get close. the new se bar has a kx high model that is 813 wide, 108 tall, but has more sweep - 78mm. i don't know if the extra sweep would be an issue or not, because bend is such a personal thing. let me know if you have more questions!

wp.

 

[sampson]

yes it was the triple clamp that broke

 

[BlazinBoy]

Fellas I work at a cycle shop here in Cinci which supports alot of motocross/offroad racers and I NEVER recommend the twinwalls to anybody. The problem is they are TOO stiff! Instead of flexing when needed they simply snap or crack. Regular Renthals are a great bar (for you crossbar types) and the Renthal Fatbar is excellent also. Stay away from the twinwalls! They suck and are not worth the rediculous price they are. Pro Tapers are the best fatbars out there. Tags are good but I always recommend the Pro-Tapers. I personally use the Renthal Fatbar (sponsorship and preferred bend) and love it but have a set of Pro Tapers on my 97 KX. Nice to see Pro-Taper is making a high KX bend. That is what my Fatbar is. Awesome!

 

[Daisycutter]

I've got a set of Twinwall's on my CR500. They've been on there for a year now and been in contact with the ground a few times. Including my collarbone breaking 65mph wheelie into a mesquite tree incident that buried the throttle side of my handlebars 6" deep into the dirt 5 weeks ago.

I have yet to see any cracks. What's the failure mode? Low cycle fatigue?Catastrophic failure implies that the bars completely separated causing much added damage or injury.

 

[SND]

Hey guys,
I just wanted to warn all of you Renthal Twinwall users to check your bars as soon as possible. The Twinwalls seem to be cracking on the larger bar, right at the bend above the crossbar clamp, it will most likely on the side facing the rider. I have seen lots of these bars coming in over the last two months, and most of the cracks are very small hairline cracks that you wouldn't notice right away, you have to really examine the bar. If you find that your bar is cracking please send it to Renthal America as soon as possible for a replacement.
Jeff

Hey guys, Shawn Norfolk from Renthal here. I got wind of this thread, so I came right over.

Here's the skinny on the Twinwalls. The Twinwall came out in 1998. The bars that were produced PRIOR to 2002, had the problem of which you speak. Having said that, let me explain. It is a very simple problem and a very simple solution. Understand that even the bars that developed cracks were not deemed 'unsafe'. I know, I know...that sounds ridiculous, but allow me to explain further. The strenght of the Twinwall comes from the inner wall (a standard Renthal bar) that is surrounded (like a suit of armour) by the outter tube. The outter tube developed a crack because the balls that we used in the peening process were too large. As they put the compressive load on the outter surface, they thinned the material and the cracks would develop. Now, it didn't happen to all of the bars...just a few (probably 130-150 bars total out of the more than 100,000 that have been produced. Also, it only occurs in the area between the crossbrace clamp and the end of the outter tube. Why? This is where the material steps down from 1 1/8" to 1". That particular part of the handlebar is the thinnest part of the outter tube. NOT of the bar itself (as a whole) just of the otter wall. Now...You may ask yourself...How can a cracked bar be safe?

Here you go. On the Twinwall, the outter tube acts as an exoskeleton. It is made to take all of the abuse from the clamps, rocks, tie downs etc. All of these things abuse aluminum. The Twinwall is not going to have a fatigue failure (the number 1 cause of broken bars...with #2 being crashes). This simple fact makes it the safest bar in the world. The outter wall can be cut, cracked, notched etc...all the while the inner tube remains 100% perfect and as strong as it ever was. This is why no recall was done. The bar was not a safety issue. Had it been...we would have recalled them. We would NEVER put our customers at risk.

Now, How can you tell if your Twinwall was made prior to 2002?

simple. On the bars, between the clamps, there is a series of numbers. If it is not between the barmount/clamp area...it is out on the left grip end of the bar. The numbers look as follows:

918 59401801.

the FIFTH number (the 9 in this case) is the number that you need to look for. Your bar will either have a 9 or a 6. 6 was made before 2002, and 9 was made after 2002. Please understand again that just because you don't have a (9) bar...doesn't mean that your bar will crack. Again, only 1% of the bars developed cracks. However, if you crack your bar, send it to us and we will replace it.

The TwinWall is the strongest and the safest bar that is available. THAT is why all of our team riders use this bar. It is stronger, safer, less likely to bend, and more likely to make it through a crash. I hope that this makes it easier to understand for you guys/gals.

 

[Jeff Howe]

In this instance I will withdraw my comment of not ever buying Renthal TwinWall bars again. Although I had 3 of them crack I never had a problem with them beyond that. I didn't know that the crack was no big deal, but I can say that after noticing the crack on my 3rd bar I rode most of the rest of the season with it as it was.

I felt I would never be able to destroy my Azonic DoubleCross bars. I did it last Thursday at Cooperland though :). I need to order new bars now and after riding a 04 KX 250 I seem to really like that stock KX bend. What I need to know is if KX bend bars are the same as 04 spec??

 

[SND]

In this instance I will withdraw my comment of not ever buying Renthal TwinWall bars again. Although I had 3 of them crack I never had a problem with them beyond that. I didn't know that the crack was no big deal, but I can say that after noticing the crack on my 3rd bar I rode most of the rest of the season with it as it was.

I felt I would never be able to destroy my Azonic DoubleCross bars. I did it last Thursday at Cooperland though :). I need to order new bars now and after riding a 04 KX 250 I seem to really like that stock KX bend. What I need to know is if KX bend bars are the same as 04 spec??

The stock KX bend is actually a bend that they borrowed from us. It is our standard 983 bend...which is a 996 TWINWALL bend. It is the old Emig/Bradshaw bend!

 

[Jeff Howe]

Thank you for that info Mr Norfolk. I think that bend with some slightly higher mounts will suit me well.

 

[KawieKX125]

Thanks for clearing that up! I had one of the early sets of twinwalls and they cracked and you [renthal] replaced them no questions asked with a bend of my choice. Thanks again!

 

[BlazinBoy]

Shawn thanks for the info and I will definately inform my customers. Sorry to be so hard on the twinwalls......all of your other porducts are excellent!

 

[cernicsRM125rider]

DO they replace them if they were made before 02 and there bent really badly???

 

[Jeff Howe]

Only if they came that way from the factory.