Ok team...For your reading pleasure:
Materials needed:
- Black runner mat from Lowes, 1 foot (
Item #: 115764)
- Razor blade
- Compass
- Marker
- Straight edge
- Adhesive
Step 1
Put bike on a secure lift where the rear tire is off the ground about 3 or so inches. My rig lets me get a little creative as the bike is pretty secure. If you don't have this secure of a set up, be careful and don't drop the bike!
Step 2
If your belt runs fairly centered, before removing anything from the rear axle you first need to put a piece of tape on the lock nuts of both the left and right axle alignment brackets. What this does is keep the spot saved where your pulley is relatively centered. After you put it back together you will be fairly close to where you want to be without starting from scratch (
you will likely still have to readjust a little once it's all back together). After you have taped both nuts, turn the adjustment bolt counterclockwise to loosen. By nature of loosening, the nut will loosen and turn with the bolt which is what you want. Also, loosening both of these adjusters a little makes the axle easier to slide out as it is under less tension.
Step 3
Unscrew the rear brake adjustment nut and take the brake cable completely loose. Careful not to lose the cylindrical spacer inside.
Step 4
Put the spacer on the cable and screw the nut on to keep from losing the parts.
Step 5
Start removing the axle nut, and once loose start working the axle out. It may come out easier if you have a piece of wood under the rear wheel where it is not dangling freely, but is as neutral as you can get it. This helps take the pressure off of the axle. You may have to tap the axle with something to get it started sliding out, just be careful not to damage the threads on the end. Use a small punch, piece of wood, or leave the nut screwed on just a few turns and use the nut as a tap. Pay attention to the order that things come off. Here is the order they go in, left to right. Note the larger of the two spacers goes on the left. Also note that there is a top and bottom to the adjusters. The top of the adjuster has the little indention in it.
Step 6
Take the wheel off. I personally find it easier to first take off the brake drum on the right side (
you have to angle the wheel to the left some and wiggle the brake drum out), then I have room to angle the tire to the right and it gives me room to wiggle the pulley out and then roll the tire out. The higher your rear wheel is off the ground the easier this is.
Step 7
Now that you have the wheel off, use the compass (
that you probably stole from your kid's school supplies) to measure the radius from the center to the outer edge of the inside of the hub, which should be about 3.5”, which makes a diameter of 7”.
Step 8
Transfer this measurement to the mat and mark a circle about 7” diameter.
Step 9
Use the compass to measure the radius from the center to inside of the hub, which should be about 1.75”, which makes a diameter of 3.5”. Note that you don’t go all the way to the inside edge of the hub as the ‘turn up’ in the spline you see under the pencil doesn’t need to be fully covered. You will see a better example of this in subsequent images.
Step 10
Transfer this measurement to the mat and mark a circle about 3.5” diameter.
Step 11
Cut out the circles. (
This is not a 45rpm record. Do not try to play it on your parent's or grandparent's record player.)
Step 12
There are many ways to do this, but what I did is place the cut out circle over the pulley with the splines pointing up. I made sure it was centered and then took a silver marker and marked the edges of the splines just to get a reasonable location. This may be easier if you sit a 1 gallon paint can on it to hold it in one place...I didn't need to. I then turned the marked mat over and using a straight edge I cut the lines from the outer edge of the circle
down to about 1/4” from the center hole. You don’t want to cut all the way down as this little center piece will help you keep things aligned and together later. You'll understand this better a few pictures down the road...
Step 13
This should be your finished product. Depending on how good you are with a razor blade, you may need to do some fitting and trimming once you place it on your hub. Just make sure nothing appears to be binding on the hub's outer edge…it doesn’t have to fit exact and you don’t want it so perfect that the edges of the mat get stuck between the pulley and hub when you put them together. They should slide together smoothly.
Step 14
Verifying fitment
Side view of pulley in the hub for a test fit, and you can see that they meet up near perfect. This is what you want to end up with. A little more or less isn’t a crisis.
Step 15
Dab a little silicone (
or similar adhesive) on the hub, then put the new shim (
mat) on the glued hub and then sit the pulley back on it to both ensure it is centered properly and as well to hold a little pressure on it to help it stick. You just need enough to help hold it in place while you wiggle the pulley and wheel back onto the bike. Otherwise, it would keep falling out and make you say bad words.
Step 16
Reverse the take off order and put the wheel back on. Use your own method of alignment, but personally my rig lets me securely run the bike in 1st gear with the rear wheel off the ground
, and I can center the pulley quite accurately. If you don’t have a rig that lets you do this safely, just put things back together back to the spot they were at when you took them off (
remember the tape on the adjusters!) and you should be close..and just adjust as needed.
Remember to not over tighten your belt tension! The belt should be flexible enough where you can grab it on the bottom and with your thumb and forefinger twist the belt 90 degrees. Can’t do it and it’s too tight. Twist it to more than 90 degrees easily and it’s too loose.
Lastly,
Since I am such a nice guy and wanted to spread the holiday cheer a little early (
and because I bought 3 feet of mat) I went ahead and cut out a handful of shims until I ran out of material. If you want one, PM me and I'll see what shipping is. I imagine for a few bucks I can slide it in a small envelope and get it to you. Just please understand that I am not "selling" these and not advertising them as some precision cut laser etched cutout...my tired, sore hands cut them out tonight after grouting kitchen tile until midnight Friday night and working in the yard, shop, and on the bike all day today...so my precision cutting may be a little off, but they will still do the trick.
PM me if interested...just be patient as sometimes my job and/or life gets busy and I may not be on here for a day or so.