Big Brother Posted October 8, 2005 Share Posted October 8, 2005 First of all... Yes, I know it will weaken it! Before I get flamed, this is just a general question. By how much (in % terms) will drilling a single 2mm hole into the diagonal part of an FIA roll bar weaken the bar overall? (the hole would be round and therefore will not introduce any obvious stress points) Just interested Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
martinwhitcher Posted October 9, 2005 Share Posted October 9, 2005 Got to ask why? I would imagine that if you were to put a screw into it no strength would be lost? Martin MW 51 CAT Superlight No.171 now known as:Superlight DVA 207 Link to comment Share on other sites More sharing options...
Normans_Ghost Posted October 9, 2005 Share Posted October 9, 2005 Steve, Can you not weld a small bracket to take whatever it is you're planning. Use MIG as it's cooler. Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here Link to comment Share on other sites More sharing options...
PaulD Posted October 9, 2005 Share Posted October 9, 2005 I suspect that it wouldn’t make any noticeable difference. You may have problems persuading a scrutineer of this. I wouldn’t weld anything to it. The lowest impact would be to bond a bracket on. Paul Link to comment Share on other sites More sharing options...
Tony Whitley Posted October 9, 2005 Share Posted October 9, 2005 I did the calculations and came up with an answer of a reduction in bending strength of the bar of 0.0273%, in compression 0.0182%, tensile strength 0.0302% and shear strength in the region near the hole 1.257% HTH Fatalism means never having to wonder if it's safe to overtake Link to comment Share on other sites More sharing options...
Tony Whitley Posted October 9, 2005 Share Posted October 9, 2005 Of course all facts you read on the Internet should be taken with a pinch of salt. About 3.428 grams is usually enough. Link to comment Share on other sites More sharing options...
stevefoster Posted October 9, 2005 Share Posted October 9, 2005 0.29996745% Steve 😬 Forgot to say, you don't wanna trust Tony's calculations... Hants (north) / Berkshire club here Area meeting pics here My Racing here Edited by - stevefoster on 9 Oct 2005 11:16:25 Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 Thanks all for sharing your knowledge so generously 😬 I am thinking of fitting a high level brakelight to the 7. The unit itself would be bonded to the bar but I would like to run the wiring through the inside of the rollbar. (just like they do in American Chopper - que the string of chopper jokes from Tony ) The wiring needed would be of a very small diameter so I would only need a small hole. To be honest I can't see a 2-3mm hole would make a huge difference to the integrity and strength of an FIA roll bar, especially as it would be drilled into the diagonal bar. Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 Hmmmm, just spotted the fatal flaw in my plan.......the diagonal bar is welded into the middle of the hoop section- with no way of getting any wiring down to the boot. Bu99er! Plan B, I guess will to stick the wiring onto the outside of the bar and have it looking like a dogs breakfast Plan C, Would be to drill a hole in the top hoop - probably not a good idea ☹️ Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
wag Posted October 9, 2005 Share Posted October 9, 2005 Id do it, if it was my roll bar. I wonder, though, if there is a super neat way of fixing the wire to the outside. Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 I'm thinking along the lines that if a 2mm hole drilled in the rollbar becomes a problem (structurally), then I'd probably already be in a huge amount of trouble!!! Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Chris Eccles Posted October 9, 2005 Share Posted October 9, 2005 Isn`t there a wireless brake light available 🤔 i thought i had read about these somwhere Ho Hum Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 http://www.webbikeworld.com/r2/riderlight/ Not sure how bright it is though Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
stevefoster Posted October 9, 2005 Share Posted October 9, 2005 Steve, You could run it down some rollbar padding like I do. It depends if you think it looks a dogs breakfast or not I guess My first 7 was done with a hole in the top of the hoop. The wire ran down and out at the base. It worked with the non FIA bar of the time. Never tested the strength of the bar... Hants (north) / Berkshire club here Area meeting pics here My Racing here Edited by - stevefoster on 9 Oct 2005 12:29:59 Link to comment Share on other sites More sharing options...
Tony C Posted October 9, 2005 Share Posted October 9, 2005 I 'glued' the wire for mine underneath the diagonal with black silicone - works a treat and is not obvious unless you are REALLY short 😬 BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery) Link to comment Share on other sites More sharing options...
Drumster Posted October 9, 2005 Share Posted October 9, 2005 Steve, I pondered the same question when I fitted a high level brake light. Although I considered drilling a small hole in the same place as you, I discovered that on my rollbar the tube is 'closed' where it fits in the boot IYSWIM. I decided it was too much faffing around and ended up just taping the wire to the underside of the diagonal bar with colour coded tape. Not the perfect solution but it doesn't look too bad either. Chris Alston 1800 Supersprint here New, improved version! Drive it like you stole it! Link to comment Share on other sites More sharing options...
sugino Posted October 9, 2005 Share Posted October 9, 2005 Many sanctioning bodies requie a small hole in the roll bar main hoop to check wall thickness, so I assume it is not very detrimental Link to comment Share on other sites More sharing options...
Wight Skipper Posted October 9, 2005 Share Posted October 9, 2005 What about Caterham's own highish level brake light? Link to comment Share on other sites More sharing options...
Drumster Posted October 9, 2005 Share Posted October 9, 2005 think it fits to the spare wheel carrier.... Chris Alston 1800 Supersprint here New, improved version! Drive it like you stole it! Link to comment Share on other sites More sharing options...
JampJ Posted October 9, 2005 Share Posted October 9, 2005 You could drill another small hole in the bottom of the rear bar, just before the bolt hole bush. It would be a fiddly job getting the wire through, but not impossible. Cheers J&J JFDI (Just F*****g Do It) Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 That was my idea, I was planning to get the wire out via the flat plate the bar mounts to (its a LA bar) Getting the wire through shouldn't be a problem for me (I've had lots of practice ) Just need to find a suitable light. I really like the racing type LED clusters. (as used on single seaters) I know Maplin sell them but I don't think they are "e" marked for use on cars. Saying that, they are very bright so would be pretty effective. I guess a few resistors would do the trick if it turned out to be too bright. Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
Myles Posted October 9, 2005 Share Posted October 9, 2005 Steve - they would be too bright out of the box - at least as bright as a rear foglight I'd expect. I'm not well-known for cosmetic solutions - I make a bit of an effort, but direct most of my time into getting things to work in the first place. I just zip-tied the wire to the underside of the top-tube and to the forward-facing bit of the support that ends by the fuel-filler. The zip-ties are a bit conspicuous for polishers' cars though... I like the idea of the black silicone... Project Scope-Creep is live... Alcester Racing 7's Equipe - 🙆🏻™ Alcester-Racing-Sevens.com Link to comment Share on other sites More sharing options...
Big Brother Posted October 9, 2005 Author Share Posted October 9, 2005 "The zip-ties are a bit conspicuous for polishers' cars though" From your comment I take it you've never seen my car 😬 The black silicone does sound like a very good solution though. Tony, do you know if its possible to buy it in small quantities? Steve SE7EN-UP! Incorporating the Caterham Links Database Link to comment Share on other sites More sharing options...
martin b Posted October 9, 2005 Share Posted October 9, 2005 Steve I have several tubes of black silicone in the garage, left over from a job your more than welcome to one, could bring it along to next Surrey meet 🤔 Martin Edited by - Martin B on 9 Oct 2005 20:14:41 Link to comment Share on other sites More sharing options...
JampJ Posted October 9, 2005 Share Posted October 9, 2005 I've bought a stop & tail strip light from www.mandp.com motorcycle bits It's going under the top of the roll bar. Cheers J&J JFDI (Just F*****g Do It) Link to comment Share on other sites More sharing options...
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