frame questions

simmo_24 · Dec 18, 2007

yes definately better than CHINUMLIUM

orion125proseries06 · Dec 18, 2007

hey seduce was that u in the green van???? and the guy i saw i thought he snapped his peg but yeah

SEDUCE · Dec 19, 2007

YES GOING THE MOTORVERT EXPERT FRAME
YEAH orionproseries06 i was the guy in the green ute with the green/black bike, i snapped the peg mount off and the frame where the shock bolted to

Cactus Jack · Dec 19, 2007

SEDUCE said:
ha. i ask so many people lately and i have people say they are **** and break(not sure if they think they are the **** AGB29 frames) but then i speak to people like yamoto who sponsor QLD #2 and he uses one and they say they are strong as.
so i dont know who to believe but i had somone on here who sells the standard type frame(like i got now) and he said the BBR replica frame is ****,
and then another member on here who sells both frames said they are great and strong...so who do i believe

Believe your own brain !!!!!!! ....

Sellers are the LAST people you should believe ....... didn't everyone who has has ever been ripped off in this world get thoroughly reassured they were in good hands by the very person who ultimately ripped them off ......... LOL ......

Ask the fabulous Mr Yamoto or any other seller if they're willing to give you a written full free replacement or money back guarantee that their alloy frame won't fail under jumping use for as long as you own it ..... then see if they'll put their money where their mouth is .......

I'm a 1st class welder fabricator (30 years experience) and I can assure you that those frames simply don't have the required cross section to be fail safe . IF the twin spars are hollow RHS ..... they're DEFINITELY ..... Sh*t !!!!!!

Think about it for 1 minute .... forward mount shock swingarms require a 1000 lbs + shock so the rotational force on the spars just in front of the top engine mount is subjected to the leverage force of a minimum of 1000 lbs on the end of a lever ..... the friggers had better be solid heat treated aluminium to safely withstand the cyclic loading fatigue forces ....

When you land from a big jump the load can exceed 1200 lbs plus any additional impact from bottoming out ......

Aluminium is weaker than steel , therefore to attain an equivalent strength it NEEDS to be either solid OR well over twice the cross sectional width and thickness . Aside from that , most of all the pit bike frames are designed totally the wrong way around . You want the thickest section to be right in the middle just before the top engine mount where the max stress is concentrated . Question : Why do people think the Sydney Harbour bridge is bigger in the centre than on either end ??? Answer : Because it would have collapsed years ago if it wasn't !!!!!!!

Check out these Vinco chromo frames .... they're built the right way !!!!! The Motovert Pro frame is fairly well designed ....... the expert twin pipe copy alloy frame ........

SEDUCE · Dec 19, 2007

Cactus Jack said:
Believe your own brain !!!!!!! .... Sellers are the LAST people you should believe ....... didn't everyone who has has ever been ripped off in this world get thoroughly reassured they were in good hands by the very person who ultimately ripped them off ......... LOL ......

Ask the fabulous Mr Yamoto or any other seller if they're willing to give you a written full free replacement or money back guarantee that their alloy frame won't fail under jumping use for as long as you own it ..... then see if they'll put their money where their mouth is .......

I'm a 1st class welder fabricator (30 years experience) and I can assure you that those frames simply don't have the required cross section to be fail safe . IF the twin spars are hollow RHS ..... they're DEFINITELY ..... Sh*t !!!!!!

Think about it for 1 minute .... forward mount shock swingarms require a 1000 lbs + shock so the rotational force on the spars just in front of the top engine mount is subjected to the leverage force of a minimum of 1000 lbs on the end of a lever ..... the friggers had better be solid heat treated aluminium to safely withstand the cyclic loading fatigue forces ....

When you land from a big jump the load can exceed 1200 lbs plus any additional impact from bottoming out ......

Aluminium is weaker than steel , therefore to attain an equivalent strength it NEEDS to be either solid OR well over twice the cross sectional width and thickness . Aside from that , most of all the pit bike frames are designed totally the wrong way around . You want the thickest section to be right in the middle just before the top engine mount where the max stress is concentrated . Question : Why do people think the Sydney Harbour bridge is bigger in the centre than on either end ??? Answer : Because it would have collapsed years ago if it wasn't !!!!!!!

Check out these Vinco chromo frames .... they're built the right way !!!!! The Motovert Pro frame is fairly well designed ....... the expert twin pipe copy alloy frame ........

Vinco frames :

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-Ken Lamson.JPG

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-Ken Lamson 2.JPG

http://www.vincoracing.com/admin/pics/albums/userpics/normal_Miscellaneous 1 013.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_Miscellaneous 1 034.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC02506.JPG

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC02503.JPG

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC01654.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC01652.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC01651.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC01644.jpg

http://www.vincoracing.com/admin/pics/albums/userpics/normal_mini-DSC01362.JPG

http://www.vincoracing.com/admin/pics/albums/userpics/normal_Engine Shot 2.jpg

Vinco Racing ::

thanks man i am going the motovert expert 08 model frame chromemoly frame with alloy subframe
he said if i break it i will be the first person to and he will guarntee that.

Cactus Jack · Dec 19, 2007

Great to hear ..... as long as the bottom pipe is a REAL pipe and not fake pressed out crap .......

Take a really good look a those Vinco frames and you'll see that they've been extremely intelligently engineered . The lower brace bars are designed to connect in line with the subframe struts to form an upside down pyramid that has a centre bracing and stiffening bar .... the top of the subframe is designed to pull against the forward force of the rear shock . Everything on that frame is set up so that one force cancels out another ...... brilliant design .

themountain · Dec 19, 2007

well Cactus...but a Vinco frame cost almost the price of an complete Motovert....everybody got his limits to spend

Cactus Jack · Dec 19, 2007

themountain said:
well Cactus...but a Vinco frame cost almost the price of an complete Motovert....everybody got his limits to spend

Yes , I know that mountain ........ the main theme I was getting at is to show people that if they want a strong frame for jumping ...... then it needs to have a large braced cross section slam bam in the middle . Any frame that is the same thickness all the way along the back bone is doomed to failure unless it's so thick in section that the strength exceeds any possible impact force . That's just pure and simple common sense and well known fact to anyone who has ever built anything designed to take a load or impact .......

Have you ever seen an airplane with wings that were wider at the tips , then tapered in smaller in where they are attached to the fuselage ????? Well a frame that is wider at the steering head then tapers back is absolutely ridiculous as far as jumping goes ........ and it's too late to realise that when your leg bones or spine are all shattered from a frame collapse on landing .....

Chewy · Dec 20, 2007

I believe the BBR copys are solid alumium.
I have one, Ive pretty much broken everything on the bike except the frame.

themountain · Dec 20, 2007

Cactus Jack said:
Yes , I know that mountain ........ the main theme I was getting at is to show people that if they want a strong frame for jumping ...... then it needs to have a large braced cross section slam bam in the middle . Any frame that is the same thickness all the way along the back bone is doomed to failure unless it's so thick in section that the strength exceeds any possible impact force . That's just pure and simple common sense and well known fact to anyone who has ever built anything designed to take a load or impact .......

Have you ever seen an airplane with wings that were wider at the tips , then tapered in smaller in where they are attached to the fuselage ????? Well a frame that is wider at the steering head then tapers back is absolutely ridiculous as far as jumping goes ........ and it's too late to realise that when your leg bones or spine are all shattered from a frame collapse on landing .....

..you're the man!!

Cactus Jack · Dec 20, 2007

CRF50 type pit bike frames were never really designed to take a straight swingarm and 1000 lbs plus shock ..... the first SDG twin pipe frames had triangle swingarms that took up to a 350 lb shock to do the exact same job ..... and the 350 lbs force was designed to push mostly straight forward along the length of the upper tube ....... not try to snap it with downwards rotational force like straight swingarms do ....... either way ..... you have one swingarm system placing the frame under one 3rd of the strain of the other with the exact same rider weight on board .......

On top of that the original SDG frames WERE actually made of chromoly or at least a far superior type of metal ....... you need only to have several examples of both frames in front of you (bare) and tap over them with the plastic handle of a screw driver to hear the difference in sound ....... chromoly doesn't ring and sounds solid .... mild steel rings like hell and sounds tinny ........ you can also visually see and feel the different surface texture of the metal ........

There are also heaps of different grades of aluminium as well ........ I used to machine Duralumin blocks for Sandler's shoe moulds and that stuff was so tough that it wore into the high speed steel cutting tool of the planer on the light finishing cuts where excess heat caused it to work harden ...... necessitating frequent resharpening ........

Deeper cuts were no problem because the metal kept the cutting tool cool ....... Incidentally , aluminium frames need to be re heat treated AFTER welding ...... otherwise they'll just keep on breaking around the welds ..... Also make sure there is NO undercut at the edges of the welds .........

Incidentally , I had the thread below in mind when I typed this post :

http://www.miniriders.com.au/forum/mini-chat/15191-alloy-motovert-expert-frame-cracked.html

It's just ironic that Medina Motovert were the one's who experienced that embarrassing Motovert Expert frame snap incident ..... Looks like Bob was traumatised into looking for a stronger frame design so he stopped Vinco from giving up on production of their pit bike frames and is now promoting them .....

Defective · Aug 7, 2010

I know this is an old thread but it was a good read so worth a bump.

Cactus Jack you the man :coolthumb:

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