I need advice on how to fit the rollbar. I bought a pre drilled roll bar from MK and have had it powder coated.
I have marked and drilled the two inside holes through the box section and fitted M8 size bolts, however the two outside holes dissapear down the
chassis tubing when drilled.
What bolts should be used for the two outside holes?
Thanks,
Rivnuts seem to be a popular option for this.
Cheers
mark
I'd be suprised if rivnuts would be strong enough?
A rollbar should be able to cope with the car be rolled over funnily enough, I would expect arivnut couldn't cope with the forces involved
surely?
I welded my rollbar on, but bolting is fine, though I wouldn't use rivnuts, unless I've got it completely wrong and you're talking
about an anti-roll bar?!
Ned.
[Edited on 7/4/05 by ned]
i want to use bolts for strength but just can't see how to use bolts for the outer two holes.
Hi Ned,
I went through the same thought process with my first roll over bar.
MK suggested I use rivnuts and even introduced me to a guy who had rolled his Indy with a bar fixed in this way and it had held up ok apparently!
For competion use I relpaced it with a welded one with diagonals and a removable stay into the passenger footwell to RAC standards.
The standard MK roll over hoop has no diagonals or back stays so it is mainly decorative anyway IMHO.
For the record, when the bolt on hoop was removed It was a hell of a job to get it off as I had stuck it with sikaflex and I got the impression that
it would have held up with no bolts at all!
Cheers
mark
Provided it has the two rear braces, I would have no problem with using rivnuts again. Like Mark, we used PU Adhesive to fasten the rollbar as well as
rivnuts and bolts through the chassis. When we came to remove the rollbar, the PU adhesive stripped the chrome off the underside of the plates
I don't have the rear brace on my roll bar. I used bolts through the chassis tube on the inner side with large washers to prevent tube collapse when tightening. On the outside, i used rivnuts. on the inside I have washers between the rollbar and the chassis to bring everything to the same hight as the rivnuts.
I'd never use rivnuts for a roll bar! I used 4 bolts on each side. For the bolts where there is a chassis tube, I drilled it larger andput a piece of tube in to stop it from crushing when tightened up.
We had the same problem, wat we did was on the outside edge of the bar jus drill 2 holes, close together, so the bolts go thru these and the chassis
(not very good at explaining)
Description
[Edited on 7/4/05 by Crazy Jay]
Thanks for the pic
Seems a good solution, its just that i got mine pre drilled fropm MK and I have had it powder coated now
ah unlucky, how bout tryin to patch up the holes wit round bits of metal?? 
I jus found out that the only chroming place in, pretty much ireland, doesnt do rollbars!! So does anyone know of any places that i cud post too, and
that wont have a waiting time of a month??
Cheers
We went with the Two bolts all the way through on the inside, and just 1 all the way through on the outside ( like the pic that had 2 on the outside)
and it passed the SVA fine.
You said the holes were already drilled, could you go for a pattern of 6 bolts?.
Drill another all the way through on the inside in the centre of the other 2 bolts and put two into chassis (effectively fake)
on the outside as well as the 1 in the middle on the outside all the way through
Making a pattern like a number 6 on a dice
Thanks mate. Gonna have a go at it this weekend. Will let you know what I do in the end.
I see your in Leeds, i live in Barnsley but work in Leeds. Do you know any other MK owners in yorkshire?
Yep, theres quite a few of us 
I did like Crazy Jay with 4 M10 bolts. Donīt know what you call them in UK, but translated from swedish it would be wagonbolt 
Hereīs a pic where you can see some of it
they look like coach bolts.
i did it with 3 as well, but M10. surely a pair of M10 HT bolts per side would suffice, then just cut bolt heads off to dummy the other 2 with a bit
of sikaflex to hold the bolt head on.
as for the MK back bracing on yours hellfire, i cant see how it is any better than a standard bar, as there is no real support down to the chassis, as
it is not a straight run to the base of the back panel. it should be more like the luego one to be of significant structural strength. IMO of
course
and i'm in dewsbury and with indy.
tom
just about addressed everyone i think
i,m a yorkshire lad.
do you other yorkshire lads ever meet up?
I dont think coach bolts are rated to any standard...they are only designed to hold shed doors on and wooden panels together really.
Remember the fixing of the rollbar is entirely up to you. The SVA man cant criticise it (except for edges) as roll bars arent required for
SVA!...Though the fixing needs to be good if your belts are attached to them!
David
quote:
Originally posted by colmaccoll
They are coach bolts, do they have a square section under the domed head? like this
quote:
Originally posted by tim windmill
i,m a yorkshire lad.
do you other yorkshire lads ever meet up?
quote:
Originally posted by indykid
as for the MK back bracing on yours hellfire, i cant see how it is any better than a standard bar, as there is no real support down to the chassis, as it is not a straight run to the base of the back panel.
Its fitted. Thanks for all the advice.
In the end we tapped the rollbar and the outside holes and fitted M10 bolts, with M8 bolys straight through the box section on the inside holes. I
know the bolts are different sizes but its matches on both sides and is as solid as a rock.