OzVMX Forum
Clubroom => Tech Talk => Topic started by: IT400C on March 09, 2012, 01:07:39 am
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Hi Guys,
Anyone had any experience with installing press studs onto helmets to use a Jofa Mouthguard?
They must have been drilled in back in the day, but I've never done it... Were they fitted with a short self tapper? Or with a treaded sleeve and machine screw? (i.e. like used on Sidi Crossfire Boots)
My open face helmets have some press studs from the factory, but they're not in the ideal location for the Jofa - too high and too far back...
(http://i374.photobucket.com/albums/oo184/IT400C/Helmets/HelmetFront3-4.jpg)
(http://i374.photobucket.com/albums/oo184/IT400C/Helmets/Helmet.jpg)
Have a look at the photo's - just the wrong position and angle etc..
What's the best method for fitting new studs? I know they must have been drilled in originally, but drilling into a new helmet just feels wrong!!! ::)
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I fitted press studs to secure a Koho face guard to my helmet. I used machine screws and nuts, trimmed to length fitted with a washer from the inside out. There isn't enough shell material to use self-tappers if the helmet shell is fibreglass. Tappers might be OK into poly though.
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We used short self tapping screws back in the good old days, for Jofa and Sinasalo mouth guards and Hallman 5 stud peaks. Just make sure the drill size is smaller rather than on the larger side for the screw so it does not flog out. Most likely a lot better way to do it these days but they hung in there for us in the late seventies..
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Two things here that I can see.
Modern helmets are larger over-all than in the old days-more padding and the shells have several more layers so they will be wider and give the effect as shown in ITs photo.
Also the modern helmets are not to be drilled, glued or even stickered in any way(supposedly) or they will/might/could fail.
I did scrutineer on a Swiss round of the World amature championships once and refused entry to a guy that had self tappers holding his guard on-though they were protruding an inch into the inside and would have made mince meat of his cheeks had he crashed!!!! ??? :D :D :o
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Thanks guys - my helmets are fibreglass, not polycarbonate... so drilling shouldn't be a major problem I suppose. Especially as I'd be doing it around the cheek area.
I thought they must have used self-tappers back in the day - I doubt any other options would have been available.
anyone else got thoughts/ideas?
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I would of thought that pop rivets (with a washer on the opposite side) would have been the preferred method. No sharp screws and quite safe to use I would of thought. No?
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I would of thought that pop rivets (with a washer on the opposite side) would have been the preferred method. No sharp screws and quite safe to use I would of thought. No?
I looked at that but couldn't find a washer that would fit into the eye and going the other way the riveter head wouldn't go down far enough into the eye to clamp it properly. :P
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I used the pop rivet method recently to attach a different peak to my helmet with great success.
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use a proper "solid" air frame rivet not a pop rivet.. or find a leather worker they use solid rivets n have the correct mandrels..
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We used short self tapping screws back in the good old days, for Jofa and Sinasalo mouth guards and Hallman 5 stud peaks. Just make sure the drill size is smaller rather than on the larger side for the screw so it does not flog out. Most likely a lot better way to do it these days but they hung in there for us in the late seventies..
Yep i did the same back in the day, the Hallman 5 stud peaks came with the extra studs and self tappers.