Frame bolts breaking Need Help

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chainednitromaxx

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To date I have broke two left side forward crash bars. They are shearing on the upper mounting area and have sheared three 12 millimeter bolt nuts that bolt the lower part of crash guards. I also just notice the right side crash bar is ready to break at upper mounting area with cracks. I know I need frame braces and plan to purchase some but will it also stop the bolts and crash bars breaking. ??
 
What is causing your bolts to get sheared ?
DID you lay the bike down ?
If so I'd be happy the bolts shear as long as the guards protect your engine cases like they should.

I have had the crash guards on my 2000 since I bought it in 2001 and have never had that issue.
I bought it after my brother laid it down in 2000 and the left guard was bent.
All I did was pull it an bend it back into shape then sand and paint them and they have saved my cases at least 3 times since then.
Every time I just bent them back and re-installed them and they still look and work great.
See the pictures below of the let crash guard after my accident 2 years ago.
 

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PS
Here's a picture of my Vmax now after I added Some weld-on RMS frame braces.
They have nothing to do with the crash guards working as designed.
 

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Did you purchase all the fasteners from the same source? Could be the bolt material is too soft, regardless of the grade markings. Apparently there are lots of bogus fasteners flooding into the market, including the aircraft industry, which is really scary.
Or too much torque is being used at installation. If a torque wrench is not available, use a flat washer AND a lock washer. Torque only enough to fully compress the l.washer, and you should be good to go.
As for the cracking on the guard itself, make sure there is no interference between the bolt and hole. If I remember correctly, I had to file one or two of the fastener holes "oblong", in order to match up with the tapped holes of the framework. The bolts should screw into the frame with no interference from the guard, until contact takes place with the head/washers.
One other possibility - The guards themselves are slightly warped, and not contacting the frame evenly. For instance, if the bottom bolts are tightened first, and then a gap is noticed at the top mounting location, between the guard and frame, requiring excessive torque on the fastener to close the gap. Shims (flat washers) between the guard and frame would solve this issue.
Cheers!
 
I imagine the extra hp and torque your engine is making is flexing all that stuff around.

I'd use grade 8 bolts through the frame cross brace and the other mounting locations. You'll find it as metric 12.12
Then weld up the cracked guard and add a welded washer over top. Should give the extra strength needed to hold up.
 
Ok more details. They are not breaking from dropping the bike. It seems from motor moving around like one2dmax mentioned. They are fitted dead on as far as Miles long covered. The damn left side guard is gone. It freakin fell off I can only assume when I was accelerating onto hwy 25 sat since it was there on hwy 14. Did not even know it till I went to rest foot on it miles later. It's making 180 at tire on motor and 227 on bottle @ 150 ft lb. I do not use the bottl a lot the bike is running gp race tires front and bike which at the lengthy I have it set will drive your back bone thru your helmet. It really really hooks insane. It is set up dead on to hook !!! The hardware I keep using is Yamaha factor bolts no cheap stuff. I gues try better hardware as one2dmax mention and maybe the frame braces will stop it moving so much. If any other advice I appreciate all inputs
 
Ok more details. They are not breaking from dropping the bike. It seems from motor moving around like one2dmax mentioned. They are fitted dead on as far as Miles long covered. The damn left side guard is gone. It freakin fell off I can only assume when I was accelerating onto hwy 25 sat since it was there on hwy 14. Did not even know it till I went to rest foot on it miles later. It's making 180 at tire on motor and 227 on bottle @ 150 ft lb. I do not use the bottl a lot the bike is running gp race tires front and bike which at the lengthy I have it set will drive your back bone thru your helmet. It really really hooks insane. It is set up dead on to hook !!! The hardware I keep using is Yamaha factor bolts no cheap stuff. I gues try better hardware as one2dmax mention and maybe the frame braces will stop it moving so much. If any other advice I appreciate all inputs

Do you still have the stock motor mounts? Have you thought about Delrin or aluminum? I think Sean sells both. With the mounts the engine wouldnt move any more.
 
His chain drive requires the solid mounts. The frame is flexing even with that and engine is simply trying to twist in the frame. Get the good bolts and you can also upsize one partial size to an ASE size and get a standard grade 8. That should resolve the shearing issue. Getting the frame braces will help launch as well since chassis flex will be reduced even more.
 
Or, I can take an order too lol (though might be more cost)
 
His chain drive requires the solid mounts. The frame is flexing even with that and engine is simply trying to twist in the frame. Get the good bolts and you can also upsize one partial size to an ASE size and get a standard grade 8. That should resolve the shearing issue. Getting the frame braces will help launch as well since chassis flex will be reduced even more.

Wow...thats a helluva bike.
 
Hey sucks your having problems but glad to see you never sold your bike! You put alot of hard work into that thing!
 
Donnelly, glad it didn't sell myself. It's really working well now with the changes (rims and gearing . A lot faster than use to be.mdidnt start all this tell the changes. Really works well on the street launching. Let ya know when I get it corrected
 

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