Saturday, February 22

DIY Studded Fat Tires

Using the #8 x 3/8" self-drilling pan head sheet metal screws that I used last time, I studded up a pair of retired fat tires.  These screws are made out of 410 stainless steel, which is harder than (but not as corrosion resistant as) standard 18-8 stainless.  The self-drilling screws also have a nice multi-edge tip on them.  The 410 resists wear significantly better than the 18-8 screws I've used in the past, and hasn't shown any rust so far.  I think using 410 stainless really makes it worth the effort required, and brings DIY studded tires closer to the durability of production studded tires.  You'll still want to limit the amount of time these studs spend on pavement.  

I found these online for about $6 per 100 screws.  While they won't be as durable as a production studded tire or Grip Studs, they are significantly less expensive.  Grip Studs are $1 per stud!  The biggest disadvantages are the reduced wear resistance, and the added weight of the larger stud and the silicone.

I put 150 screws in both a Larry (front) and Endomorph (rear), and the added grip on ice is impressive.  The picture of the Endo above only shows 100 studs.  I ended up adding 2 more studs (inboard of the studs shown) to every other row of knobs for a total of 150 per tire.  Same pattern on the Larry.  150 is more than enough for great traction, even on glare ice.  I can skid to a stop on an ice rink with these suckers.  

The Process:  If it is dirty or dusty, clean the inside of the tire.  After laying out the pattern, I poke a hole through the knob from the outside of the tire so I know where to install the stud.  I used an old spoke that I sharpened.  From the inside of the tire, I screw in the stud by hand using a screwdriver.  I thought about using an electric screwdriver, but I wanted to have a feel for when the screw was tight.  This is a tedious process, but not difficult.  After all the studs are in place, I apply a dollop of silicone sealant to cover the heads of the screws (to prevent them from puncturing the tube).  I give the silicone a few days to set up, then install the tube with an abundance of talc.

Here is a shot of the track left by the tires… you can even see the holes in the snow from the studs.

4 comments:

Death Rider said...

Glad to see you back on Blogger, your contributions to the twin cities bike scene have been missed.....DR

FTMN said...

Thanks DR!

kurtbredeson said...

Nice job. I made mine out of steel screws last year, but the center section has worn significantly. I could do a wheelie on ice rinks when they were new, but now skid out on glare ice (although it's controlled). Still, better than no studs, which I tried a couple weeks ago on a friend's bike. Dangerous!
Post an update in a year about the durability of the SST studs, I'd like to know if it's worth it.

FTMN said...

Thanks! Not sure how the durability will compare to regular, zinc-coated steel screws… my guess is that the hardness of regular steel is somewhere between standard 18-8 stainless and 410 stainless. But that's just a guess.

I've been running these same studs in 2.3 mtb tires for over a year now (since last January), and they are holding up better than expected. At least compared to other DIY studded tires I've made in the past.

Unless you are putting in carbide studs, it all really comes down to how many miles of pavement they see...