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Clubroom => Tech Talk => Topic started by: eric318 on December 16, 2012, 08:49:58 am

Title: These small rim studs that grip the tire
Post by: eric318 on December 16, 2012, 08:49:58 am
Hello all,

I am about to take a nice old Hallman Sun rim to be re-anodized (gold).
I had to remove the little pointy steel stud that were pressed at regular intervals on the inside of the rim edge. See photo.
Some of them are quite damaged and I wonder where to get a full set of them.
I don't even know what they would normally be called, so wasted some time on Google.com.
Any pointers?

Thank you,

E

(https://lh4.googleusercontent.com/-ki_5Bj0QfXo/UJcmohwi1WI/AAAAAAAAadY/VMjUi801DPU/s800/IMG_20121104_183649.jpg)
Title: Re: These small rim studs that grip the tire
Post by: maico police on December 16, 2012, 09:19:14 am
Gary Bailey talks about them in his book "How to win motocross". I've always been intruiged by them as they'd make for a more balanced wheel than one with rim-locks.
He just used to used some big self-tappers just long enough to not penetrate the inside wall of the tyre.

Going to give it a go myself soon.  :)
Title: Re: These small rim studs that grip the tire
Post by: Canam370 on December 16, 2012, 09:57:16 am
I've always known them as rim pins. Sen a few rims where the pins are removed from one side to make tyre removal quicker on the trail.
Title: Re: These small rim studs that grip the tire
Post by: NSR on December 16, 2012, 10:34:01 am
I used to use self tappers only on one side.  I would think you would still be able to buy Rim Pins.  Contact Ballards. 

Just a thought do they use these when they run Bib Mousses?   
Title: Re: These small rim studs that grip the tire
Post by: huskibul on December 16, 2012, 10:56:08 am
   Imo the pins can be a pain when in a hurry trying to set the bead right ! bultaco/akront used screw's on most mudless rims and were easy ,cant remember seeing any problems with them ! maybe bully got the idea off bailey when he rode  them or vice-versa  :) 
Title: Re: These small rim studs that grip the tire
Post by: John Orchard on December 16, 2012, 11:20:30 am
Yeh I had a bike in the 80's with 'rim pins'; never had a tyre slip.  I've been thinking about using self-tappers in all my dirtbikes; just getting up the courage to drill the rims lol
Title: Re: These small rim studs that grip the tire
Post by: TeeBone on December 16, 2012, 12:18:45 pm
With a Mousse, there is NO need to prevent the tyre from slipping (not that they do) as there is NO valve to rip out. I have always known them as RIM PINS too.
Title: Re: These small rim studs that grip the tire
Post by: KB171 on December 16, 2012, 12:40:07 pm
Peter Shone -  Bultaco Parts in Vic sells them about $20 per set, you need a 4.5mm x .75 tap to suit the threads.
Cheers KB
That size was for the front rim, rear pins are a bit bigger,
Title: Re: These small rim studs that grip the tire
Post by: David Lahey on December 16, 2012, 02:12:25 pm
The Bultaco screws are OK but I wouldn't recommend using standard self-tappers because they are too pointy and sharp and rip the bead to shreds within seconds of getting a flat. Concurrently, the steel wire from the bead winds up around the axle/sprocket and things come to a stop.
My advice comes from first hand experience in 1977 or 78. It was somewhere near the Glasshouse mountains. After getting the remains of the tyre off and unwinding all the wire, I rode to the next checkpoint very carefully on the rim. I remember the day well also because Phil Eldridge stopped and asked did I need any help and I was quite impressed to see someone racing with a prosthetic leg.
Title: Re: These small rim studs that grip the tire
Post by: John Orchard on December 16, 2012, 03:46:55 pm
The Bultaco screws are OK but I wouldn't recommend using standard self-tappers because they are too pointy and sharp and rip the bead to shreds within seconds of getting a flat. Concurrently, the steel wire from the bead winds up around the axle/sprocket and things come to a stop.
My advice comes from first hand experience in 1977 or 78. It was somewhere near the Glasshouse mountains. After getting the remains of the tyre off and unwinding all the wire, I rode to the next checkpoint very carefully on the rim. I remember the day well also because Phil Eldridge stopped and asked did I need any help and I was quite impressed to see someone racing with a prosthetic leg.


That's handy to know; thanks.  I will grind/round-off the self-tappers.
Title: Re: These small rim studs that grip the tire
Post by: eric318 on December 17, 2012, 04:07:05 pm
Thank you all,

I found them where I looked for them without knowing what they were called:

http://www.buchananspokes.net/categories/miscellaneous_tools.asp