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Pros:Rollover protection, aggressive look
Cons:Hard to install, occupies windscreen mounting location
Cost:$700
HMS Rollbar

September 20, 1997
By: Robert Leidy

I had the pleasure of attending the 1997 Z3 Reunion. At this reunion I got to watch a video of Z3's being crash tested. I was very impressed with Z3's ability to protect the driver in an accident in all but one of the tests... the rollover.

I think my paranoia started there watching that video, but it was only a slight paranoia because I could tell myself "how would you ever roll a Z3". Later I remembered a story I heard about six months before the reunion. A Z3 owner was rear ended by a pickup truck going about 40mph. The pickup smacked into the back of the Z3 and crunched it pretty good, but the truck didn't stop when it hit the bumper. The truck's bumper hit the Z3 at about mid-trunk and basically jumped up onto the trunk and eventually stopped about a foot and a half behind the drivers head. If the truck had been going any faster it might have driven right into the back of the driver's head because there was nothing to stop it.

That was it, now my paranoia was real. I started noticing how many big pickups, and surburbans there were in Dallas and it was starting to really spook me every time one got behind me. Okay I'm exaggerating a little but my paranoia was real and it was taking away from the enjoyment of driving.

I have a 1997 Z3, starting with the 1998 models BMW added rollbars as a standard feature (well really they're roll-hoops not rollbars but basically the same thing PROTECTION). As a '97 owner I really only had one option and that was HMS Motorsport (Z3s built on or after 1/1/97 can get the rollhoops). The owner of HMS also owns a Z3, so he took the time and capital to design a rollbar specifically for the BMW Z3. The design is top notch with an emphasis on racing and safety.

Once I had the rollbar ordered and delivered I was left with the small task of installing it. Thankfully I had several friends who helped me do the installation (which really wasn't nearly as difficult as I thought it would be).

So now my Z3 has rollbar installed and I am extremely pleased with it. I think it adds an aggressive look to Z3 and more importantly protects Robert from that evil suburban. I like the appearance but it does change the Z3's looks quite a bit and some may not care for the more aggressive look.

Sold By:
HMS Motorsport
www.hms-motorsport.com
(888) HMS-3BMW

Specifications of the HMS Sportbar & Stylebar
HMS SportBar (includes an additional diagonal member for increased lateral rigidity)
HMS Stylebar (same construction as SportBar but without diagonal)
 
Design Features Main Hoop and Rear Braces
unobstructed operation of soft top all steel construction
e-z removal/re-installation in < 10mins 1.75' outside diameter
unrestricted movement of both seats .127" wall thickness
unobstructed access to storage areas TIG welded connections
torsional stiffness of chassis + 15% grade 5 hardware
 
Durable Powder Coat Finish SportBar Diagonal Member
satin textured black finish all steel, TIG welded
scratch, stain, and chip resistant 1.25" outside diameter
UV protected, fade resistant .095" wall thickness
 
Installation and Packaging Optional Accessories
4 - 5 hr. install by dealer or at home custom color, finish or material
e-z bolt-in, no welding harnessbar mounts
all hardware included wind screen deflector
plastic trim modification templates video camera mount
step by step install manual w/ pics. harnessbelts

Structural Rigidity Analysis of the HMS Sportbar & Stylebar
DYNAMIC RESONANCE
  Vibration Mode 1 Vibration Mode 2
SportBar 8,250 rpm 10,377 rpm
StyleBar 7,016 rpm 9,412 rpm
3,000lb. LATERAL FORCE
  Peak Local Displacement  Peak Local Stress 
SportBar 0.092 in 10,100 psi
StyleBar 0.189 in 2,370 psi
3,000LB. FORE/AFT FORCE
  Peak Local Displacement  Peak Local Stress 
SportBar 0.157 in 9,990 psi
StyleBar 0.148 in 9,960 psi
3,000lb. VERTICAL FORCE
  Peak Local Displacement  Peak Local Stress 
SportBar 0.035 in 4,210 psi
StyleBar 0.080 in 3,880 psi



Copyright © 1997-2003 by Robert Leidy and ///MZ3.Net. All rights reserved. This material is for individual use only and may not be copied, republished or redistributed without the prior written consent of ///MZ3.Net. ///MZ3.Net shall not be liable for any errors, inaccuracies, omissions or other defects in the information on ///MZ3.Net, or for any claims or losses arising therefrom.