CtrMint Posted January 24, 2019 Share Posted January 24, 2019 Guys,I've spent the afternoon trying to fit my replacement trackday rolbar, and guess what the same issue. No matter what I do it doesn't fit and is out by a similar margin. I can fit one of the two side bottom bolts, but it pushes the other out. I've tried every combination of bolt and angle on the bar too. it just doesn't help.I don't have a ratchet strap, but to be honest with the shape of the bar and X in the middle I'm not sure it will help. I'm not prepared to elongate the holes as I personally feel there is minimal surface area for the bolt head anyway, so reducing it further wouldn't be great and may be prone to operator error on my part during modification and thus compromising safety. I don't want screw up the chassis either.Any ideas please?I've attached some images to try an illustrate the distance which it's out by. Link to comment Share on other sites More sharing options...
Jim 123 Posted January 24, 2019 Share Posted January 24, 2019 As previously suggested measure the distance between chassis hole centers and ask Derek to send you a bar that he has pre matched to your car. Sometimes getting somebody to hold the bar loosely near the upper end of the chassis apertures and you getting both fixing bolts initially into their thread is a first step. Then screw the bar into position by working the bolts half a turn each side at a time. Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2019 Share Posted January 24, 2019 I would enlarge the holes in the chassis plates (and use a washer if necessary) but I do understand why you don't want to. I would argue that this bolt is not safety critical as in an accident the fastener will not be in tension but again, I understand why you don't want to mess with it.The only thing I can suggest without enlarging, is to try to put the two turrets on the bar only as far down the chassis as you need to engage the thread on the bolt. Do this on both sides to give you some movement in the bolt, before then tightening both. If you have tried that and it doesn't work they there is no other option.Whilst a ratchet strap can give you a tiny bit of movement, that is generally only going to help get the turrets into the holes. I have only ever fitted roll cages but with those, there is no wiggle room for the turret once they are in the chassis holes. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 Guys, the suggestion about the partial engagement of each thread on either side is basically what I've tried, I put about 1 turn on one side (offside), and got the wife to lift and hold it, while I worked on the other side. No joy, spent hours on it and finger are killing from trying to turn the edge of the bolt.I'm not enlarging the holes, I'll never trust the car period. It is my understanding these holes have been added to improve safety. Also you might change the behaviour of the bar in an accident if the retainers are unpredictably secured. That's without getting into a discussion regarding the high chance for such a mod just going wrong. Jim, I was guided by Derek on the replacement and he didn't mention this as an option. Requesting that will be my 4th bar, sure CC will be getting a bit frustrated at that. Link to comment Share on other sites More sharing options...
Tazio Posted January 24, 2019 Share Posted January 24, 2019 Its not clear from the pictures whether the problem is front to back or side to side. If it is in the front to back axis it was similar to mine, and I did two things, first was as Charles Elliot said, do not put the bar fully home, and secondly I roped in the wife to pull the top of the bar towards the rear, and this gave sufficient movement to start the bolts on a couple of threads, and I slowly bolted it up. Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2019 Share Posted January 24, 2019 When you tried to engage the bolt the other side, can you not get it to engage at all or something else? Why are your fingers involved, is it because you don’t want to use a socket in case of cross threading? In that case, I tend to use a socket on the end of an extension, but turn the extension by hand.If you won’t enlarge the holes and the turrets are tight in the chassis then the only solution would be a bar with turrets drilled in a different place. If there is some wiggle room with the turrets, then there might be some other options. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 Quick reply, I'll try and respond to everyone, as I really appreciate your help on this and certainly don't want to offend anyone. Apologizes if I miss one though. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 Tazio, I would describe the hole as being too far out, i.e. the hole in the bar has gone beyond the hole in the chassis and needs to be pulled back in. It appears to be horizontally aligned with the expected position. Not sure that makes sense, hope it does. I would not describe it forward or backward wrt the car.Charles, Tried for hours to get the other side engaged, just couldn't. You are correct, I don't want to cross thread the bolt, I got the initial bite on the other side with my fingers, so followed suit on the final side too. I tried various combinations of sockets, bars held by hand too, it just felt awkward. My fingers are better, just painful after a couple of hours. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 I'm not sure if this is the root of the issue, but if you look at the photograph above, the one which is the close-up. You will notice the hole in the chassis is not central in the turret. This can be seen by the amount of metal either side, you can also feel the difference with your finger.Obviously this is my first 7 so I'm not sure if that is normal, however, it occurs to me that if the hole was central, it would be significantly more aligned with the bolt hole in the bar as shown behind in the same image.I'm left with the conclusion some plonk drilled the hole cockeyed. Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2019 Share Posted January 24, 2019 I understand, it’s frustrating. I’ve built, crashed and re-built a few now so it sort of washes over me....As per Tazio, in what plane are the holes out? (Aft / rear, left / right?)Is there any wiggle room with the turrets in the chassis holes?One other suggestion - how long a bolt can go into the bar? From experience on roll cages, the thread is open so you have as long a bolt as you want. What I have also done in the past is used longer bolts to give me even more flexibility, e.g. engage the bolt when the turrets have not even gone into the chassis and then do up the bolts to draw it down. It works but it’s not very pretty from an engineering perspective either :-)Charles Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2019 Share Posted January 24, 2019 Just seen your latest post. I’ve never analysed it as I have just bodged it to make it work. But I agree, neither the holes in the chassis nor the holes in the turrets ever seem to be central <sigh>. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 Plane, I would say left/near side.To try and illustrate the plane, I've cropped the image, left side is the near side of the car, top of image is the car front. Link to comment Share on other sites More sharing options...
Tazio Posted January 24, 2019 Share Posted January 24, 2019 If thats left to right, I'd ratchet strap it to its opposite number to pull it in. Link to comment Share on other sites More sharing options...
Wrightpayne Posted January 24, 2019 Share Posted January 24, 2019 I dont think adding a washer is feasible as the bolt head is already thinned so it doesnt touch the shock absorber.Ian Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 Just back in from the garage, 10:35pm, in my dressing gown (too much of this car has been done late at night like this :-) ).Anyhow the wife and I have finally beaten it into submission, had to get the first bolt on probably less than a single turn, then hold both sides at their maximum height out of the recess just managed to get the second bolt thread hooked in with my fingers. Then pulled them down gradually, did think the first wasn't going to pull down it was so offset, but it did.Sorted finally. That was incredibly stressful, hopefully, I can finally finish the rear of the car now.Thanks all for your support. Link to comment Share on other sites More sharing options...
Jim 123 Posted January 24, 2019 Share Posted January 24, 2019 Mark re #4, you've probably tried it, but when you try to get both under bolts loosely in place on each side are you ensuring that the rear facing bar diagonals are free from their fixing brackets? Link to comment Share on other sites More sharing options...
Jim 123 Posted January 24, 2019 Share Posted January 24, 2019 Well done ignore my last message. Link to comment Share on other sites More sharing options...
CtrMint Posted January 24, 2019 Author Share Posted January 24, 2019 thanks Jim,Quick question, the rearmost brackets/mounts, are they designed to bend around the rear bars? The assembly guide say 47nm, but from the factory the brackets are wider than the bars, so I'm assuming I'm supposed to let the load pull the brackets inwards? Link to comment Share on other sites More sharing options...
Wrightpayne Posted January 25, 2019 Share Posted January 25, 2019 With the single diagonal bar you cannot fit one of the harness bolts nor drill the boot cover fixings once the bar is on.Hopefully, you’ve done both of these! Ian Link to comment Share on other sites More sharing options...
SM25T Posted January 25, 2019 Share Posted January 25, 2019 Looking at that last photo .... that isn't a crack in something metal is it ... 10 o'clock position. Hopefully just sealant ? Link to comment Share on other sites More sharing options...
TomB Posted January 25, 2019 Share Posted January 25, 2019 I thought it was considered these bolts from the underside of the RB were semi-optional. I've had them on my car, but plenty of folk have said they've not fitted them. Bit late now and doubt you want to revisit it, but given the shallow head of the bolts, they can be tricky to remove if exposed to years of grot and corrosion and fitting with copper grease on the thread to aid future disassembly might be worthwhile. When I took my RB off a few weeks ago, I was terrified of rounding these off, fortunately all was OK, but Ill be fitting new bolts with copper grease when it all goes back together Link to comment Share on other sites More sharing options...
Wrightpayne Posted January 25, 2019 Share Posted January 25, 2019 Tom,the earlier bars also have a big plate on the foot with 2 or 3 bolts in from above incl one of the harness bolts. I dont think the later ones have this.Ian Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 25, 2019 Share Posted January 25, 2019 I don't think they are safety critical (and turning down the head would somewhat diminish that!On the latest chassis, I think the brackets are cupped so a turned down head is no longer required? Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted January 25, 2019 Leadership Team Share Posted January 25, 2019 I've had 2 Caterhams, one bought with an FIA bar, the other with a full cage. Neither had these bolts fitted when I bought them. I suspect the bolts not fitted is more common than you may think.Stu. Link to comment Share on other sites More sharing options...
Jim 123 Posted January 25, 2019 Share Posted January 25, 2019 Mark, re #18 you are correct. The rear brackets simply get pulled against the sides of the rear diagonals by the fixings. Link to comment Share on other sites More sharing options...
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