after just one jump

pumpkin · 04-27-2007, 09:16 AM

i would call it more of a hop. the road i was on has like a whoop in it and i forgot to slow down and here's what happened.

and from the other side

just in case you can't see i sheered an engine mount bolt. i'm going today to try and find one local before i have one ordered thought i'd share with you all first

pumpkin · 04-27-2007, 09:17 AM

that turned out better than i thought

molypod · 04-27-2007, 12:48 PM

wow,

that sure didn't take much to shear off..

TeamCheap · 04-27-2007, 04:21 PM

yeah both mine were shot, the lower and upper rear bolts thats why I changed the upper rear mount and put in different bolts but I worry now about cracking the case so I may just add in some tubing near the skid plate on the bottom of mine.

The engine itself completes the lower front part of the frame.The frame itself is pretty thin (2 small tubes) on the top so I keep thinking of completing the frame on the bottom so the force goes around the engine a bit more, rather than thru it.
If I do close the frame up it will need to allow for engine removal still.[UGH]

Jdcooper · 04-27-2007, 04:35 PM

Look at the welds on that frame ! I could do a better job in my garage. They're terrible !

John22j · 04-27-2007, 09:16 PM

that's what to expect for $.02 / hr :roll:

TeamCheap · 04-27-2007, 09:55 PM

yep the welds are rough, especially mine

but I see one of the biggest problems as being the weak frame design.

Those engine bolts are going to give people headaches.
They have a loose fit and allow to much flexing.I'm not sure if they did it that way because it was easier to assemble(most likely) or because without the flex it breaks the weak engine case which wouldnt make sense in the long run. (I'll find out soon)
I have grade 8 bolts in mine so something else will have to give or it will end up being just alright.

I think any heavy jumping on these bikes with people of my size

and these bikes could fold in half.

4xflyer · 04-28-2007, 08:13 AM

Over torquing a grade 5 bolt and engine vibration combined with a shock that acts like a hard tail could have contributed to the failure. The loose fitting bolt as was mentioned could also contribute to failure for sure. The effective g-loads resulting from high tire pressure and zero suspension travel is very hard on a bike frame.

Using the engine as a frame member is a common practice but only works with a properly engineered and strong frame.

??Was your shock the near zero travel hardtail like stock/linkage set up or had you modified it??

The skid plate doesn't really seem to help the frame strength and we need to address this problem before someone destroys their engine or worse yet, gets hurt!

TeamCheap · 04-28-2007, 08:24 PM

My bike was in stock form and we were just doing some mellow trail riding but then again I am biggie sized.

I agree about the skid plate, no structural value there, it's just a rock deflector.
I really have been thinking of just adding some sort of tubing down there.
Not sure if I can weld someting in and still get the engine out or would have to make a removeable frame support.I'd still want the rock guard to fit on also.

liverchip · 04-29-2007, 08:52 PM

Extending the frame below the motor is a very interesting idea. As my jumping has been becoming a bit more aggressive, I think I will be looking into it as well. It should be noted however as has been stated many times within these forums, these bikes were never designed for how some of us have been abusing them....heck it's a copy of a Honda XR frame, which was also never known for its jumping survivability either from what I understand. I think we can improve this. We have the technology. We can make the world's first highly jumpable Chinabike!

liverchip · 04-29-2007, 08:54 PM

Yes I know mine is a dirt bike, and not a DS, but the only differences are the height of the frame and a spongier rear suspension with a bit different linkage.

liverchip · 04-29-2007, 08:55 PM

Oh yes and no lights.

Jim · 04-29-2007, 08:56 PM

We have the technology, we can rebuild him

pumpkin · 04-29-2007, 09:30 PM

i didn't mean to jump becuase i knew something would break i forgot about the whoops worst part is i wasn't ready for the landing and stoved up my back a little all better now .
i called napa they said they have a bolt that might be long enugh(spell) to fit going there tomarrow

TeamCheap · 04-29-2007, 09:50 PM

seen the long upper-rear bolt on Hooper Imports site tonight, atleast I believe it to be that bolt.

The frame needs to be beefed up even for modest offroad riding.
I think I can come up with a way to stiffen the stock frame and still get the engine out if needed and just have the rock guard part of it or bolted to it.
Some of the other bikes I've seen seem to have better frame designs.

I wasnt even jumping mine, just riding thru the trails and it actually broke when riding down a short section of pavement but it must have been stressed already.

I got mine fired up today but still have 2 things that have to be done.(clutch cable and exhaust bearing-

)

04-27-2007, 09:16 AM	#1
pumpkin Join Date: Jan 2007 Location: Westover wv Posts: 443	after just one jump i would call it more of a hop. the road i was on has like a whoop in it and i forgot to slow down and here's what happened. and from the other side just in case you can't see i sheered an engine mount bolt. i'm going today to try and find one local before i have one ordered thought i'd share with you all first __________________ 06 american lifan 200 gy-5
	0

04-27-2007, 09:17 AM	#2
pumpkin Join Date: Jan 2007 Location: Westover wv Posts: 443	that turned out better than i thought __________________ 06 american lifan 200 gy-5
	0

04-27-2007, 09:16 PM	#6
John22j Join Date: Oct 2006 Location: Central Ohio Posts: 289	that's what to expect for $.02 / hr :roll: __________________ '20 RPS Magician 250 '06 Hensim (Tierra) DB150-2 '06 X-Treme 70cc pitbike '02 Kawasaki KX125
	0

04-29-2007, 08:52 PM	#10
liverchip Join Date: Nov 2006 Location: Mystery Spot Posts: 1,223	Extending the frame below the motor is a very interesting idea. As my jumping has been becoming a bit more aggressive, I think I will be looking into it as well. It should be noted however as has been stated many times within these forums, these bikes were never designed for how some of us have been abusing them....heck it's a copy of a Honda XR frame, which was also never known for its jumping survivability either from what I understand. I think we can improve this. We have the technology. We can make the world's first highly jumpable Chinabike! __________________ 2009 XR650L Big Red Pig Tusk bar risers 2007 X-Moto(Jetmoto) GY250 --mods--- 15/40 sprockets UNI Pod Filter 2007 Shineray TMS 200XYi--Betsy Betsy Mods:______________________ Acerbis DHH headlight FMF Powercore pipe Uni Pod Filter
	0

04-29-2007, 08:54 PM	#11
liverchip Join Date: Nov 2006 Location: Mystery Spot Posts: 1,223	Yes I know mine is a dirt bike, and not a DS, but the only differences are the height of the frame and a spongier rear suspension with a bit different linkage. __________________ 2009 XR650L Big Red Pig Tusk bar risers 2007 X-Moto(Jetmoto) GY250 --mods--- 15/40 sprockets UNI Pod Filter 2007 Shineray TMS 200XYi--Betsy Betsy Mods:______________________ Acerbis DHH headlight FMF Powercore pipe Uni Pod Filter
	0

04-27-2007, 12:48 PM	#3
molypod Join Date: Oct 2006 Location: British Columbia, Canada Posts: 223	wow, that sure didn't take much to shear off..
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04-27-2007, 04:21 PM	#4
TeamCheap Join Date: Jun 2006 Location: directly under the earths sun............NOW Posts: 2,302	yeah both mine were shot, the lower and upper rear bolts thats why I changed the upper rear mount and put in different bolts but I worry now about cracking the case so I may just add in some tubing near the skid plate on the bottom of mine. The engine itself completes the lower front part of the frame.The frame itself is pretty thin (2 small tubes) on the top so I keep thinking of completing the frame on the bottom so the force goes around the engine a bit more, rather than thru it. If I do close the frame up it will need to allow for engine removal still.[UGH]
	0

04-27-2007, 04:35 PM	#5
Jdcooper Join Date: Dec 2006 Posts: 7	Look at the welds on that frame ! I could do a better job in my garage. They're terrible !
	0

04-27-2007, 09:55 PM	#7
TeamCheap Join Date: Jun 2006 Location: directly under the earths sun............NOW Posts: 2,302	yep the welds are rough, especially mine but I see one of the biggest problems as being the weak frame design. Those engine bolts are going to give people headaches. They have a loose fit and allow to much flexing.I'm not sure if they did it that way because it was easier to assemble(most likely) or because without the flex it breaks the weak engine case which wouldnt make sense in the long run. (I'll find out soon) I have grade 8 bolts in mine so something else will have to give or it will end up being just alright. I think any heavy jumping on these bikes with people of my size and these bikes could fold in half.
	0

04-28-2007, 08:13 AM	#8
4xflyer Join Date: Feb 2007 Location: W. Massachusetts USA Posts: 25	Over torquing a grade 5 bolt and engine vibration combined with a shock that acts like a hard tail could have contributed to the failure. The loose fitting bolt as was mentioned could also contribute to failure for sure. The effective g-loads resulting from high tire pressure and zero suspension travel is very hard on a bike frame. Using the engine as a frame member is a common practice but only works with a properly engineered and strong frame. ??Was your shock the near zero travel hardtail like stock/linkage set up or had you modified it?? The skid plate doesn't really seem to help the frame strength and we need to address this problem before someone destroys their engine or worse yet, gets hurt!
	0

04-28-2007, 08:24 PM	#9
TeamCheap Join Date: Jun 2006 Location: directly under the earths sun............NOW Posts: 2,302	My bike was in stock form and we were just doing some mellow trail riding but then again I am biggie sized. I agree about the skid plate, no structural value there, it's just a rock deflector. I really have been thinking of just adding some sort of tubing down there. Not sure if I can weld someting in and still get the engine out or would have to make a removeable frame support.I'd still want the rock guard to fit on also.
	0

04-29-2007, 08:55 PM	#12
liverchip Join Date: Nov 2006 Location: Mystery Spot Posts: 1,223	Oh yes and no lights. __________________ 2009 XR650L Big Red Pig Tusk bar risers 2007 X-Moto(Jetmoto) GY250 --mods--- 15/40 sprockets UNI Pod Filter 2007 Shineray TMS 200XYi--Betsy Betsy Mods:______________________ Acerbis DHH headlight FMF Powercore pipe Uni Pod Filter
	0

04-29-2007, 08:56 PM	#13
Jim Join Date: Mar 2007 Location: Abbotsford, BC, Canada Posts: 4,880	We have the technology, we can rebuild him
	0

04-29-2007, 09:30 PM	#14
pumpkin Join Date: Jan 2007 Location: Westover wv Posts: 443	i didn't mean to jump becuase i knew something would break i forgot about the whoops worst part is i wasn't ready for the landing and stoved up my back a little all better now . i called napa they said they have a bolt that might be long enugh(spell) to fit going there tomarrow __________________ 06 american lifan 200 gy-5
	0

04-29-2007, 09:50 PM	#15
TeamCheap Join Date: Jun 2006 Location: directly under the earths sun............NOW Posts: 2,302	seen the long upper-rear bolt on Hooper Imports site tonight, atleast I believe it to be that bolt. The frame needs to be beefed up even for modest offroad riding. I think I can come up with a way to stiffen the stock frame and still get the engine out if needed and just have the rock guard part of it or bolted to it. Some of the other bikes I've seen seem to have better frame designs. I wasnt even jumping mine, just riding thru the trails and it actually broke when riding down a short section of pavement but it must have been stressed already. I got mine fired up today but still have 2 things that have to be done.(clutch cable and exhaust bearing- )
	0