14 replies to this topic

[dklawson]

Having used the search feature, I got some of the answers I wanted from previous threads but I have some additional questions about brace bars.

This weekend I visited a new Mini owner in my area. His project car has a fiberglass front end installed by a previous owner. They left the inner wings but provided no additional bracing. The following questions are technical, not legal, so please comment but don't remind me what's necessary for MOT since it doesn't apply in this case.

1) Is this car at risk without brace bars? Do they significantly improve the front end stiffness?
2) The round-nose brace bars I've seen pictures of have a bend in them. I haven't studied the front end of this car in detail... but why is a bend necessary? Couldn't subframe mounting/attachment tabs be made longer so the bend in the square tubing can be omitted?
3) If anyone has made their own bars, did you keep any sketches or drawings you could share? I can make my own but would prefer to learn from the experiences of those who've dealt with this before.

I know the bars can be bought and the current price at Mini Spares is only about 23 GBP. However, after shipping/carriage charges that will be rather a lot of money... especially since it's not my car. (I can buy them over here from Mini Mania but they sell them for about $86... roughly twice what you guys pay... plus I'd have to ship them across country, probably another $20)

[fikus01]

i've read that that dont actually add any strength, jsut keep the triangulation there for what wuld be a flimsy rubber mount if u had it all standard. i think is only the mot man that kicks up a fuss about them. hence the name mot bars.

[dklawson]

Thanks for the reply. I wasn't sure how effective bent 1" square tubing was at reinforcing a flip front. Since inspectors over here won't know anything about these things I may not pursue this further unless the car's owner has strong feelings about it.

[Grimmy@JHE]

im just about to fit one my self. i have read alot about these and it came back the the man himself again. david vizzard. he says that the two main bolts (above rubber dough nuts) and the ones below are more than ample to hold the subframe.
also if you did make your own bars have you got any drawings that you could share with me. i would prefere to make my own too. just to say i did
many thanks in advance Robert.

[GraemeC]

In the newer shells (single bolt subframe) there is a common(ish) problem with the toe board cracking round the lower subframe mounts when solid mounts are used. I personally believe that there will be enough movement in the tower mounts to exagerate the flexing at the toe board if the front of the subframe is not braced.

However if I was making my own I would make them out of straight round tube with a rose joint at each end. Especially at the rear side of the engine where it would make clutch work even simpler as two nuts and the brace bar could be removed for improved access. Where a front mounted rad is used in the miglias they run the bracing from the bulkhead cross member rather than the outside of the inner wings.

If you use straight box section (ie no kink) there may be an issue with the wheels catching on full lock? Especially with big rims or lowered cars. Also they may look odd being far away from the subframe corners.

[Tomf]

I dont know if you would be interested but iv got a brace bar making guide from somewhere, if you send me you email ill send you a copy of it

[Woody]

The lads doing their own cars at my workshop have made their own on a couple of occasions , we have used inch square tube and 3mm plate , the bend is achieved by cutting a wedge out of 3 sides of the tube and welding up , make your bar, cut in wedge ,bolt to both ends , weld up cut, job done !
one time in a rush to get an MOT(on my own car) i used inch by inch angle , it bolted on easier and was well up to the job , not as pretty though .

[Guess-Works.com]

As Graeme has pointed out... the more important thing is that the subframe is solid mounted ( ie the top and bottom mounts are replaced with metal - steel or alloy ). This induces the issue of cracking round the floor ( as it's advised to strengthen this mount with a plate )

The front support bar provide support and control over the front of the subframe ( basically providing the same fuction as the valance and inner/outer wings.

As for the kink, I would believe that it's mainly for esthetic reasons but you may also experience clearance problems on the front end panels when fitted.

[annodomini2]

When I had my pickup, it was flip fronted, yes the subframe was solid mounted, but I used some 2.5" 16 gauge tube which bolted to the front of the tower points and the front of the subframe and then reinforced the back of the bulkhead with some more tube which was welded into the weld in roll cage.

[Ethel]

Ran an unbraced pre 76 frame for years with no problems including passing MoT's.

I'd be inclined to put the front end of the brace a little higher and cut 'n shut it to give a vertical section at the front in an attempt to dissipate any head on impact loads better.

[dklawson]

This is quite a flurry of posts on a thread that ran its course in January.

My question was posted for another local Mini owner who has no money but owns a Mini with a fiberglass front end.

TomF, is your brace bar guide in a format that can be emailed? If so, let me know and I'll send you my address also. My friend has even less money to spend on this now but when he can get the material together I'm sure he's still interested in stiffening his car's front end.

[pato280884]

Hi Tomf I would be interested in a guide if possible might be doing mine this weekend steels here I'm just worried about the clearance on rad wheels ect if I guess my email is [email protected]

[bmcecosse]

I ran a road car many years ago with FG front and no brace bars.....and no problems with MOT or cracking. But I guess for competition use brace bars would be a really good idea - but 'bent' tube is a useless thing. Keep it straight!

[miniman24]

I put the bends in my brace bars to keep the actual bar as close to the subby as possible, reducing the length of the tabs needed on the bottom of the bars. This photo shows it quite well:



It the bar didnt have a bend in it, the tab would be a good 6 or 7 inches longer than it needs to be, reducing the stiffness of the bar. It would also be very close to the wheels on full lock without the bend.

Also, it had to be done

[pato280884]

Thanks for the pic miniman didn't get round to it this weekend but will do them during the week I'd like it to be strong and while I agree bent bar is weaker it's all extra from not having any I suppose thanks all