Xebra Front Wheel Change
Click on any image to see an enlarged version.
Before I begin, here is the requisite disclaimer:
I don't claim any particular automotive expertise. The information here
pertains to MY VEHICLE. If it happens that you can make use of this information you do so at your own risk!
I am not telling you to do this to your vehicle. I am telling you what I did to mine!
The Xebra trike is overloaded on the stock front tire (mine was overloaded by 25% of the load rating), and it also rides really rough.
While changing the front tire will not make it ride the way it should (the shocks and springs are TOTALLY wrong)
it will help the ride somewhat, and it should certainly be safer. In addition, if you have put a set of 13" mags on the
back, you probably noticed that the nose sits noticeably lower. Putting a larger tire on the front makes it sit level
again.
The best tire I have found is a 155/80R12. It has a load rating of 908 lbs, and it fits on the stock rim. I
tried a 155/80R13 on the rim from a Geo Metro space saver spare, but it rubs on the rear downtube at the back of
the front tire compartment. 13" tires smaller than the 155/80 are not available in North America. The best
solution I can find is the 12 inch 155/80 tire. It has lots of sidewall
for a good ride, a high load rating, and is readily available. The downside is that it MAY rub on the front
bumper rail inside the nose of the PK. If it does, you can use the method below to space the bumper rail away
from the tire to increase clearance. I hope you can make use of my research to make your Xebra safer.
This modification can easily be done in a single morning. It took under an hour here in my shop and I didn't need to use any
exotic tools. Here are the before and after pictures:
 |
 |
| Before |
After |
Tools Required:
- 2 x 13mm wrenches
- 2 x 1/2" wrenches
- 1 x Wheel wrench (17MM)
- Saw capable of cutting UHMW plastic (I use 4" bandsaw).
- Hand drill or drill press.
- 3/8" drill bit.
Material Required:
- Small qty of 1/2" thick UHMW plastic (in sheet form available from hardware stores - $5) approx. 6" x 4".
- 155/80R12 Merit tire (available from Les Schwab part #03101002 - ~$29).
- Qty 8 Bolts - 5/16" x 1 1/2" with 8 flat washers and 8 nylon locking nuts (Home Depot - $8).
Step-By-Step:
Step 1: Take the stock spare over to Les Schwab (or some other dealer) and have them
mount a 155/80R12 tire. By the way this is the ONLY TIRE SIZE I could find that has a load rating over 900 lbs
that does not rub on the shock spring - which MUST NOT HAPPEN - and is available in North America.
The Merit 155/80R12 has a load rating of 908 lbs. Here is how the replacement tire compares to the stock
tire:
| Stock Tire |
Replacement Tire |
|
Size:
|
145/70R12
|
|
Load Rating:
|
716 lbs
|
|
Sidewall:
|
4.0 inches
|
|
Diameter:
|
20.0 inches
|
|
Circumference:
|
62.8 inches
|
|
|
Size:
|
155/80R12
|
|
Load Rating:
|
908 lbs
|
|
Sidewall:
|
4.9 inches
|
|
Diameter:
|
21.8 inches
|
|
Circumference:
|
68.4 inches
|
|
Jack up the vehicle and mount the new tire and wheel. If the tire clears the front inner bumper rail, great - you are done. Skip to the bottom of the page. If it rubs
on the bumper rail, continue on...
Step 2: Using the two 13mm wrenches, remove the inner bumper rail underneath the hood. There are two mounting plates, each with 4 bolts.
One mounting plate at each end of the inner bumper rail. Remove the 8 bolts that hold it in place and remove the rail from the vehicle:
 |
 |
| This is the bumper rail. |
One of the two mount points. |
Step 3: Take the bumper rail and mark out the outline of the mount plate on the UHMW as shown and then cut it out with the saw:
 |
 |
| Mark the outline and holes. |
Cut it with a saw. |
Step 4: Drill the holes where you marked them on the templates. Although we will be using 5/16" bolts, drill the holes 3/8".
There is no need for the holes to be a tight fit, and the extra size will allow easy alignment of the bolts, and be more forgiving of
small errors in the templates:
 |
 |
| Plates cut. |
Ready to drill. |
Step 5: Check the alignment of the holes against the bumper rail, then prepare to bolt it back into the trike. By the way, I did not change these to
SAE bolts because I hate metric. I did it because nylon locking nuts were not available at Home Depot for 8mm bolts. If you
prefer to use metric feel free - substitute 8mm x 125 x 40mm bolts, with flat washers and nylon locking nuts. It is however, very important that you use
nylon lock nuts so that the bumper rail does not become loose over time. Other than that substitution the rest of these instructions are the same for metric bolts - even
drilling the 3/8" holes:
 |
 |
| Check the plate. |
Ready to install. |
Step 6: Here is the new hardware that will be used to re-install the bumper rail. Because of the compressibility of UHMW, we are using
nylon locking nuts instead of flat washers and lock washers, which would eventually work loose. Mount the rail and put a bolt
through each mount hole from front to back, and on the back side of the mount plate for each bolt install one flat washer and one nylon
locking nut:
 |
 |
| Old bolt - new bolt if you go metric. |
New SAE hardware beside old. |
Step 7: Here is the mounted bumper rail:
 |
 |
| Right side mounted. |
Left side mounted. |
 |
 |
| New clearance on the bumper rail. |
Finished product. |
Once you complete this change you need to be aware that your speedometer AND your odometer will read 8.9%
lower than they did before you changed the wheel. If you are one of the many whose speedometers were not accurate
and gave a reading higher than true ground speed then it may be more accurate after this change. If you are one of
the people who removed a magnet from the sensor on your front wheel to make it read more accurately, you probably
want to put it back now.