Drilling Your Own Gyro Tabs

words and photos by travis anteau

October ‘20

Whether you throw sick barspins and tailwhips or you’re just looking for a clean and tangle free front-end, a gyro is probably what you are looking for if you aren’t a brakeless rider. Gyros have even found their way on to mountain bikes (read: dirt jumpers) under the feet of many of today’s top athletes. Despite decades of use in BMX and a number of years on mountain bikes, not all modern frames come drilled for gyro tabs. If you want to use a gyro, but you’re frame doesn’t have the tabs, then keep reading…

Yes, there are options out there that can save you from drilling and tapping the headtube on your precious frame. In the case of BMX, the older style lower cable hanger/plate will only work with non-integrated headsets that require a bearing cup to be pressed into the frame. Most modern frames use integrated headsets, so these won’t work. In the case of mountain bikes (dirt jumpers and slope-style bikes), most modern frames have an oversized headtube that works with a tapered fork steerer, which requires a special (and hard to find, at least at the time of writing) lower plate that will fit under a press fit bearing cup. Many MTB frames use integrated bearings similar to modern BMX bikes, so these special plates won’t work either. So, if you are like me, the only option is to drill and tap your own holes for removable gyro tabs.

First, you need to make sure that you have a long enough steer tube to run a gyro. If you run your stem slammed and don’t have any steerer sticking out of the top, then you probably won’t have enough room to install the gyro. The total length of steerer needed will depend on the length of your headtube. It might be time for a new fork! Next you will need to determine whether you feel comfortable drilling straight, perpendicular holes into a round, hardened steel (or sometimes aluminum) tube. If you believe in yourself, check out the material list below before you start to disassemble your bike.

Materials you will need:

• fork with a long enough steer tube

• removable gyro tabs

• drill

• 1/8 inch drill bit for metal

• m4 x 0.7 tap

• tap handle

• punch

• tape measure

• masking tape

• sharpie/pencil

• calipers (optional)

• cutting fluid/oil/chain lube (optional)

• upper gyro plate

• gyro

• upper and lower gyro cables

Gather The Goods

Go to your local bike shop or favorite online retailer and purchase the parts listed above. If you don’t have all of the tools, they can be found at your local hardware store. Choose whichever gyro and upper gyro plate you like the looks of. The length of the upper cable will depend on the stem and handlebar you use. The easiest way to determine the proper length is to run a length of flexible, static (not stretchy) material from where it enters the brake lever to where it will connect to the gyro plate (the base of the stem on the opposite side from your lever). Measure that material and add 12mm to be sure the cable is long enough. An old piece of brake housing or cable works great for this. You may have to convert your measurement to millimeters to know which cable to purchase. The lower cable should be long enough to reach the rear brake on most BMX and MTB frames.

You will need approximately 35-40mm between the top tube and bottom of the upper gyro plate for the gyro to function properly. If you don’t have enough clearance, you will need a fork with a longer steer tube. You will also need to make sure you have enough headset spacers or a tall enough headset cover.

Prep Your Frame

Remove your stem/bars, fork, and headset bearings. Using either a tape measure or calipers, determine half of the circumference of your head tube at a distance of 22mm and 31mm from the top edge. The circumference needs to be the same at both locations. Depending on the shape of your headtube, you may have to adjust this height slightly. For a tape measure, measure the circumference at an open area of equal size and divide by two [Figure 1]. With calipers, measure the diameter and then use the formula Circumference = Pi times Diameter divided by Two (C=3.14 x measured diameter/2) [Figure 2]. On a piece of masking tape that is slightly longer than your half circumference, mark a parallel line 31mm from the edge. Mark two perpendicular lines at a distance equal to your half circumference measurement, with a third perpendicular line half way between those two [Figure 3]. NOTE: If you don’t have a metric tape measure, multiply your measurement in inches by 25.4 to determine the distance in millimeters.

Using your eyeballs’ finest judgment, line up the center mark with the center of the front of your headtube and the top edge of the tape at the top edge of the headtube. Carefully wrap the tape around, trying to keep it as level as possible. It may be helpful to make a slight tear near the top of the tape to allow it to wrap the headtube more easily [Figure 4]. Using a punch, make a small punch mark at the intersection of the horizontal and outside vertical lines where the gyro tab will mount [Figure 5]. Carefully drill a 1/8 inch hole at this location [Figure 6].

Place the gyro tab upside down in the hole that you just drilled, so that the small post fits inside of it. Line up the hole where the screw goes with the vertical mark on your tape. Mark the center of the hole and remove the gyro tab [Figure 7]. Carefully drill a 1/8 inch hole at this location [Figure 8]. Place the gyro tab in the holes right side up to confirm that the post and the screw hole line up properly [Figure 9].

Insert the M4x0.7 tap into the tap handle. Apply a small amount of cutting fluid, oil, or chain lube to your tap and insert it into the lower hole. Take extra care to ensure that it is perfectly straight as you begin to create the threads. Make a half turn in, followed by a quarter turn out, until you have tapped the entire hole and the tap turns easily [Figure 10]. Turning the handle out as you go allows metal shavings to clear the threads and makes the process easier. Install the gyro tab [Figure 11]. Repeat this process on the other side, starting at Figure 5.

Enjoy!

Reinstall your headset, fork, and stem/bars along with the gyro you selected and enjoy your newfound ability to whip AND brake-brake like never before! If you are installing your gyro tabs on a mountain bike, all of these same steps apply. You’ll just need to make sure your gyro is big enough to fit around the top of your headtube/headset. Any preparation/installation instructions omitted from this article are intentionally left out, as I assume that by attempting this, you already have the knowledge/skills/tools to complete the installation. If you have any questions about the process, just hit the contact button in the navigation at the top and send them my way. There are no stupid questions and I’d be happy to help! Also, please note that these instructions work for standard gyro tabs, not any of the less common styles such as Fly Bikes Guiri tabs.