Tech Tips

Lost Love and Sparks

Written by  November 30, 2003

Tires and Height
Q: I have a 2000 ZX-XR that came stock with Dunlop D207 Sportmax tires, size 120/65-17. When the time came to replace the tires, I went with D207 120/60-17’s to quicken up the steering and because they were on sale about a third off the OE rubber. Once again it is time to replace my tires, and I wish to try Michelin Pilot Sports in the correct size (120/65-17). I know that there is a slight difference between the two brands, which leads to my question. Is there a way or place I can find the actual, true circumference of the different brand of tires so I can either raise the rear, or drop the front to get back to the Dunlop 120/60-17 height and the quickness I love?
Scott M. - Leawood, KS.

A: Wow, I had to layout a matrix to understand your dilemma! Part of the change in feel will come from the slightly different profiles. I’m not sure where you could find that information, unless you take a tape measure to your shop and measure the tires. You could also note the radius from the axle to the ground and adjust the fork tubes to compensate. But as a rule of thumb, if the steering feels slower than you like, try raising the fork tubes through the triple clamps in 5mm increments, or raising the rear ride height to accomplish the same effect; or vice-versa if the steering is too quick.

This is the challenge most of us face when we switch to different tires, profile widths, lowering the back end or extending the front. The bike comes from the OEM in its most balanced state, to work with the estimated rider weight and braking system. When we make changes, expect a different feel in handling and braking distance. So Scott, once you feel you have it right, put on your safety gear, have a friend tag well behind and safely put it through it’s paces, making sure it is still the one you love!

Electrical Short
Q: I need a simple solution to what seems a simple problem. After riding in the American Royal Parade my hand brake will no longer activate the brake light. This is the second time this has happened on my '01 Fat Boy. Fortunately the foot brake still activates the brake light. Apparently the little switch at the hand brake is easily damaged when the brake handle is used with a little too much pressure. Is there an easy fix or do I just bite the bullet and replace the switch again and again?
Steve - KC North

A: I’m glad to hear you rode in the parade, as it is a great opportunity to help create awareness of the number of bikes in the KC area. Non-riders seem to grasp the “share the road” concept a little better after seeing a large group of riders, but back to your question. No, the switch is not damaged by applying too much pressure. Any pressure on the switch is actually released when you apply the hand brake lever. When you use your brake, the button is let out completing the circuit and lights the brake light. Now for the fix.

It could be either the switch has gone bad again, or you have a short in the wiring of the right handlebar control housing. I would buy a new brake light switch, as it may be damaged; the OEM part number is 71590-96, J&P Cycles part number is 27-683. If you buy it from the dealer, it may be close to $40, if you order it from J&P Cycles, it would cost $21.99 plus shipping; but check with the dealer first. If you have a maintenance manual, all the better, as it is always nice to see how things are suppose to go back together. The first task is to split the control housing. Put a heavy blanket over and around your fuel tank and headlight in case the housing slips and drops down, as it is heavier then it looks. First pull the fuse that protects the housing area and remove the mirror so it is easier to work on. Undue the housing screws and open it just enough to slide off the handle bar without scratching it. Split it open a bit but watch the throttle cables and lay it on your covered tank. If you have a magnifying glass, look closely at the wiring leading from the switch out of the housing area. This is where you will usually find the pinched wire, which in time, may have shorted out due to vibration.

You will have to use an electric soldering gun (get a small one from a hobby shop as you will need it again) and unsolder the old switch, then solder in the replacement, using electrical solder and assembly in reverse order. Make sure all wires are in their proper channels and taped with a small amount of electrical tape, as they will pinch easily and you will be doing this again. Check your throttle and make sure it rotates well, put your fuse back in and check out your fine handy work. This may seem like a challenge, but with the right tools, a warm well-lit dry area, and patience, you can easily accomplish this repair. If you are using high pressure water or air drying devices on your bike, this too, can lead to shorts in electrical parts of a bike. Let me know how it turns out!

Sounds like both of you are in need of Christmas gifts: tires, maintenance manuals, and soldering gun. I have started your list for you, now look through the rest of this magazine and you’ll find many more recommendations!

Merry Christmas!

Bart

'Ride Free'