Well,
That's the "kicker" here. They aren't the same material (at least not
mine). I believe Chris is right in that tubes are reportedly stronger than
bars. I think the rule states chrome moly which is what I got. Mine were
47" long, 1.25" OD, .25" wall thickness, opposing keyways on each side, and
C-clips on the ends. $67 from American Powersports.
dg
----- Original Message -----
From: "Phil Green" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, January 31, 2007 5:52 PM
Subject: RE: [F500] Bent Axle
Don't see how a tube could be stronger than a solid if the materials are
the same. I would suspect if you have seen a difference, it was also
due to a material difference. It will be lighter, of course.
But, a larger diameter tube will be stronger than a thicker wall.
Imagine trying to bend a 2" fencepost tube or conduit compared to a 3/8"
solid.
On the subject of bent / breaking axles.... Had an axle break on me at
Grattan in May during a test day. It was something that we were trying
with Don Handley, using a larger axle with the ends turned down to the
normal 1.25". There wasn't a good radius on the transition which
created a huge stress riser. This decided to snap at the apex of the
last turn going on to the straight at Grattan. Somehow I didn't hit the
wall. However, the flailing axle broke both carbs, of which pieces went
completely through the engine.
So, the bill included: axle (of course), carb bodies, bearings,
complete engine tear down, Gates drive belt ($$$), and an assload of
work. Now have a continuous diameter axle. It may bend, but it
shouldn't snap. In fact, the drive belt tension causes a little bit of
a bow in the axle. Look down the hollow tube and see for yourself, I
bet I'm not the only one with a little bit of rear toe-out!
Phil
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Chris
Reinhardt
Sent: Wednesday, January 31, 2007 5:28 PM
To: [email protected]
Subject: Re: [F500] Bent Axle
Ain't no engineer here, but a hollow axle will resist bending better
than a solid one. I believe it has to do with #1 the flexibility, #2
the surface area both inside and out... Plus the missing 3/4" bar,
assuming you're using .25 wall axles, is equal to about 5.5lbs.
CR
Dave Phaneuf <[EMAIL PROTECTED]> wrote:
John
The axle ( 1.125 dia. solid ) that came with my car was slightly bent so
following a recommendation from Don at Red Devil I made one up out of a
steel he suggested, ETD150, it's 150ksi tensile and yield is about
125 ksi.
It bent, no crash just bumps, at that point I redid the whole rear
suspension
and used a piece of 4340M also called 300M ....it's has held up fine. I
seem to remember the certs that came with it showed a tensile of about
280ksi and a rockwell of about 52-53 on the c scale. Maybe overkill but
I haven't had to mess with it since. Dave Phaneuf
---------------------------------
8:00? 8:25? 8:40? Find a flick in no time
with theYahoo! Search movie showtime shortcut.
________________________________
FormulaCar Magazine - A Proud Supporter of Formula 500
The Official Publication of Junior Formula Car Racing
Subscribe Today! www.formulacarmag.com or 519-624-2003
_________________________________
_______________________________________________
F500 mailing list - [email protected]
To unsubscribe or change options please visit:
http://f500.org/mailman/listinfo/f500
*** Please, DO NOT send unsubscribe requests to the mailing list! ***
