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Roll Hoop Fitting On Locost Chassis (cobra style hoops)
mclnh04 - 15/7/04 at 12:19 PM

Hi,

I have a 95% completed locost chassis, that is about to be finished by a professional welder (with a de-dion axle - from GTS).

I have opted for a pair of cobra style hoops (from Luego), instead of the 'standard' roll bar. I was wondering if anyone had any plansspecslinkspics showing me the best way to fit them.

Any help would be appreciated.

Thanks,

mclnh04


locoboy - 15/7/04 at 12:58 PM

my chassis which is a second hand triton built chassis has 2 roll hoops, they are butt welded onto 3mm plate sections which are in turn welded onto the chassis member that forms the upper limit of the panel behind the seats and another chassis rail that is about 2 inches further back.

maybe this diagram will explain it a bit better.
hoops
hoops


MikeRJ - 15/7/04 at 06:55 PM

Col,

How is the second tube supported? Is it simply welded to the two diagonals via short pieces of tube?


kiwirex - 15/7/04 at 10:46 PM

What about longitudinal support?

After the photo posted here the other day with the flattened rollcage I'd say that would be a necessity (even if you use thick walled tube).

- Greg H


locost_bryan - 16/7/04 at 12:23 AM

I've been thinking of going down the twin roll hoop route too.

I was thinking of extending the hoops down to the floor, along K3/4 and the rear H tubes, and using forward braces along K1/2 (and possibly at the same angle to the trans tunnel).

Could I replace the 25x25 tubes with larger round roll hoop tubes (say 50mm rather than 40mm)? ... or does the roll hoop structure need to be seperate for comp use (track days, hill climbs)?

Would I still need a rear brace? Is there any risk in a rear impact of a rear-facing brace pushing the top of the roll hoop forward?


mackie - 16/7/04 at 01:35 PM

AFAIK there is no requirement to have a roll bar/hoop for road use so it's basically up to you. Ofcourse if you use the rollbar structure to fit harnesses then they will have to be strong enough to make Mr SVA happy.


locoboy - 19/7/04 at 07:48 PM

quote:
Originally posted by MikeRJ
Col,

How is the second tube supported? Is it simply welded to the two diagonals via short pieces of tube?


Yes MikeRJ it is, i am not keeping the hoops but if i was going to i would brace them to the rear anyway.


wjggregg - 22/7/04 at 04:13 PM

On the McSorley site, he details a nice solution. I have used it and it works well!

I can send some pics if you like.

Here's the link :

http://mcsorley.net/locost

(Page 11 of the assembly section)

Hope this helps!!

Gary

[Edited on 23/7/04 by wjggregg]


mclnh04 - 16/8/04 at 02:15 PM

Many thanks for all the info. The mcsorley link was very useful.

Cheers,

mclnh04