Natural selection favors Smart people, so nature selects morons to be slow and dumb for tigers and stuff too eat. But in our modern world there just aren't enough tigers.
by no means am i an expert on this subject, but it appears to me the failure originated at the Y area, then once that area failed it put overwhelming stress on the frame spars and they finally broke. some clearer pics of the Y area would probly tell the whole story. ive seen alot of real skeptical / halfass home conversions, this might be one of them but without better pics its hard to say.
I agree, Y failed first then the spars under extreme force, he's a quick rider and big jumper. The bike was not SH, garage made though. He was not hurt, went on to ride another bike.
Welded properly it would have broken the down tube or the cradle (fat chance), not at the weld.
The welder wasn't paying attention to the penetration, it was a cold weld.
I treat my bikes as if they were aircraft, making a quick inspection of all key areas before riding.
Seems like it would have taken several landings to finally snap in two....you think iit might have felt rubbery at one point.
He wasn't hurt so that's what counts.
2nd gen SSS street hooligan
83 CR480
83 XL600
97 VFR750
Kawasaki H1-F
Suzuki Titan
HondaHarley
83 CB1100F
looks to me like if nothing else a poor design on that conversion... why the hell would their be a plug there on a gen-4. the Y is hallow and the down tube fits inside and the welding must have been crap as well. My gen-4 had some ugly mig welds from my harbor freight welder and I took some really nasty spills and sank the front wheel in some shit on that bike and never so much as a crack.
also where the frame spars snapped is the same spot I have seen crack on gen-3 bikes and I'm thinking of 1 gen-3 bike in particular that probably had some tension on the Y area that caused the crack.
'09 kx450f 4-Poke
Gen-4 trail bike --SOLD--
Gen-3 badass trail/mx bike --SOLD--
Gen-1 built dunes bike --SOLD--
'05 klx110 --SOLD--
'95 pw80