Flex

dms70

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Ok so on my v3 Kraton I run the m2c chassis. I also have the m2c motor mount. I’ve recently noticed a lot of flex coming from somewhere in the center of the chassis. Meaning if I push down or pull up on the back of the motor can something is flexing. I should add I’m only using my finger strength to do this, and obviously know if you put enough pressure somethings gonna give. My question is has anyone else noticed this? My motor is a 4082 size can, so it not ridiculously long. I haven’t been able to pin point the cause of flex yet, but I’m looking into now. Just curious if any of you guys have seen this. Or if you have the same set up, could you see if the flex is there on yours, I’d appreciate it. Oh, and I’ve checked for the obvious loose hardware, and it’s all tight.
 

bicketybam

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Ok so on my v3 Kraton I run the m2c chassis. I also have the m2c motor mount. I’ve recently noticed a lot of flex coming from somewhere in the center of the chassis. Meaning if I push down or pull up on the back of the motor can something is flexing. I should add I’m only using my finger strength to do this, and obviously know if you put enough pressure somethings gonna give. My question is has anyone else noticed this? My motor is a 4082 size can, so it not ridiculously long. I haven’t been able to pin point the cause of flex yet, but I’m looking into now. Just curious if any of you guys have seen this. Or if you have the same set up, could you see if the flex is there on yours, I’d appreciate it. Oh, and I’ve checked for the obvious loose hardware, and it’s all tight.
M2C chassis, V4 motor mount, 4092 can. It doesn't really flex using finger strength and I don't want to try using any more force. How much does yours move?
 

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That is strange...cant even see that much flex on my v4 Kraton. With standard chassis, HR front/rear braces, and the 2019 chassis red brace/rod in place.
That M2C chassis is stiff as hell from what others say. No chassis brace is even needed using that. Have no experience with it however.
 

dms70

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Ok so first to answer some questions. First and fore most I am a huge M2c Racing fan and customer, so absolutely no bashing or blame going to them. 2nd if you think even an M2c chassis doesn’t flex that’s just flat out wrong. Yes it’s 100x better than stock, but any aluminum chassis will flex, and as it should. 3rd absolutely would expect flex from heavy force, but I was not doing that at all. 4th and final, I found the problem. Motor mount top section had cracked. Once I got it apart I could see the crack and subsequent flex. With a light push from my finger it broke clean off. Hey poop happens right? When you think about 14 plus pounds flying through the air and then landing, the force has to go somewhere. I’ll contact Mitch and see if he’s heard of this or it’s an isolated incident. Thanks for everyone’s help, and thanks Bickety for checking yours. By the way this most likely happened at the BMX track :rolleyes:
I can put the stock one back in for now.
 

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That’s good news. Glad they resolved it. I wasn’t getting much flex in mine. So it was the delren piece that was cracked?
 

olds97_lss

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I was thinking that was normal until I saw you mention it was an M2C chassis deck. Even with HR front/rear braces on my outcast stock chassis, I can easily see flex in the center if I push down on it with my thumb in the center with the front/rear in the air.
 

dms70

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That’s good news. Glad they resolved it. I wasn’t getting much flex in mine. So it was the delren piece that was cracked?
No it was the top of the slide section of the aluminum motor mount.
I was thinking that was normal until I saw you mention it was an M2C chassis deck. Even with HR front/rear braces on my outcast stock chassis, I can easily see flex in the center if I push down on it with my thumb in the center with the front/rear in the air.
Personally, and this is my opinion, I believe what is happening is during a hard landing the chassis is either flexing up, or the motor is flexing down. After a few big jumps at the bmx track I noticed a gouge in my chassis under the rear of the motor can. There’s a few button head screws in the motor can towards the rear. One of them is directly on the bottom of the can. So it would be the first to make contact. My only concern is that transfer of energy could have caused the mount to crack. I’m no structural engineer, so I’m not sure what’s going on. But I do know when you land flat from a big jump like that, the energy has to go somewhere. I’ve added some foam under the back of the motor, which is only a 4082 can. Also currently I’m trying out my 4070 tp motor which is considerably longer. That I’m using a motor brace I found from an RC boat seller. But even still, nothing is going to stop the energy from transferring through.
 

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slick2500

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The design of these motor mounts has always dumbfounded me, yes let's attach the front of this giant can to a plate and let the rest of the can just hang there. The bigger the motor can the more this design shows it's weaknesses.
 

olds97_lss

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The design of these motor mounts has always dumbfounded me, yes let's attach the front of this giant can to a plate and let the rest of the can just hang there. The bigger the motor can the more this design shows it's weaknesses.
While it makes it easier to set mesh and use alternate motors... it's not a great way to mount one of the heaviest pieces on these things.

The savage flux used collars around the motor on a chassis plate. So the motor doesn't float, it's bolted in on the front and rear of the can. Their motor clamps could have used a re-think to make them adaptable to other motor's, but the strength/support it gives is far better.



I'm surprised more don't do it this way. To adjust mesh, it's like a nitro engine. You loosen bolts under the chassis and slide the motor.
 
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