This might help....
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04-27-2013, 10:47 AM #11Junior Member
- Join Date
- Apr 2009
04-28-2013, 05:40 PM #12
No one here is going to tell you what you need to do. You are your own boss. Members will give you street names and suggest a path of travel but you will need to find your own way to your destination. The legal answer when the product you sell can hurt or kill a client or a third part is "I recommend you hire an engineer to calculate the stresses involved and recommend a suitable solution"
That said some times you have to have done the work first to know what questions to ask.
We all need more information before any real suggestions can be forwarded. First are the cracks in the same place on the chassis?
Is the cracking due to fatigue, catastrophic failure or temperature?
Have you got any photographs of the cracks to post so we can take a look?
I bike frames I have repaired have been dirt bike frames not street bikes. The loads transfer through the tyres up the shocks and into the frame from jumps and so forth. Damage usually occurs when flat landing off a jump, the shocks and forks bottom out leaving only the frame to flex. If the load is very high catastrophic failure is the end result, if the load is less, the resulting frame flexing will be added to the fatigue cycles. The other issue could be cold weather. If the bike was left outside on a freezing night the metal could shatter on the next pot hole.
Being a hard tail and a chopper the forces transfer in different vectors than a dirt bike. The tyres and frame make up the suspension for the frame. Frame flex can be solved by increasing the depth of chassis members not so much by wall thickness of tube. It can also be reduced by adding stiffening members like gusset plates or cross tubes. If you solve the cracking problem by increasing frame size the frame may be too stiff to ride with comfort as frame flex is required. There is no suspension as we know it in F1 cars. The engineers have worked out how much load it takes to flex the steering arms 25mm and that is the suspension. This saves weight but if they increased the steering arms to eliminate the flex the drivers would not be able to complete 60 laps.
JiGrip it and Rip it
04-28-2013, 08:12 PM #13
I know this info isn't for a bike or car frame per say but when i worked in the refinery some pipe had to be PWHT post weld heat treated. The pipes were already welded together 100's of feet long so a big oven is out. They had comapnies come in the specialized in heat treating. They brought in trailers of items. They wrapped the pipe with long firecracker looking things and wrapped with white insulation. Then everything was tied together to some welder looking machines where the temps were raised and lowered by computers. Heated so high then cooled slow taking 24 hours for some. Learned some watching but most of it was off limits. I did see the pipes glowing red hot during the high heat cycles...BobBob Wright, Grandson of Tee Nee Boat Trailer Founder
Metal Master Fab Salem, Oh 44460
Birthplace of the Silver & Deming Drill
1999 MM185 w/185 Spoolgun,1986 Thunderbolt AC/DC
04-28-2013, 08:28 PM #14Senior Member
- Join Date
- Feb 2012
jigantor, f1 cars do have suspension. Not that it has anything to do with the op's question . Not to be rude, just an f1 fanatic.
This is just ferrari's current set up. Has springs and dampers, like always, just in a new layout. http://www.formula1.com/news/technical/2012/0/937.html
Last edited by Cgotto6; 04-28-2013 at 09:20 PM.