Part Five

From Ninja250Wiki
Jump to: navigation, search

Okay, got out early today for my ride. Need to get it in before it heats up; it's that time of year here in coastal Virginia. Also, less traffic early, before the day trippers are heading to the Outer Banks of NC.

Let's review wheels, tires and brakes today. At 95,441 miles I installed both wheels and tires from the 1,700 mile '01 bike, because both tires on the '88 needed replacement. But everything about the wheel bearings and true running of the '88 wheels was still perfect. No looseness or roughness in the bearings, and no attention ever needed. I did replace the rubber damper in the real wheel once somewhere along the line, even though slack there probably makes no significant different, just a bit more lash in the driveline, which has considerable built into it. The gearbox has racing-style dogs in it with plenty of backlash for instant gearchanging. Plus, the design of the rear fork pivot in relation to the gearbox sprocket center means that quite a bit of slack has to be allowed in the rear chain to keep from being over-tight during the swing of the fork.

I must say the design of the standard wheels is a splendid piece of engineering. Light wheels and front fork give the best possible handling, but they must also have sufficient rigidity and beef to give an infinite service life going over the bumps on the road. The front fork and wheel on these bikes is a perfect compromise for my money. You can feel the front wheel going over all manner of irregularities but its lightness combined with the fork design keep it free from the tendency to wobble shown by many bikes.

The single front disc help that effect, and as I found out a couple of months ago in an Interstate braking emergency, there is still more braking power than you ever need.

I might mention that Roland's notes show that at only 3100 miles he installed a new front brake disc. I am guessing that he observed an annoying amount of wibble-wobble runout in the brake, and thought the disc was defective(he saved it, though, Brits were taught at home never to throw anything away that might be needed later. And too, he came along during the Depression; which affected Brits as much as Americans).

At the same time he installed EBC front brake pads, as evidently he didn't like the stock sintered metal ones. The EBC pads lasted up to 95441 miles when they started to scrape audibly on the front disc, because the inner pad had completely worn away. I replaced them with the original sintered metal ones which Roland had saved(in the box of spares and special tools he gave me with the bike. These squealed curiously for awhile until they apparently bedded in to the disc, after which that noise stopped.

Anyway, a couple months ago I found out after 14 years riding what these brakes can do, to save your skin. I was gliding down the Interstate with the rest of the traffic at 75(which seems to be legal here, despite the posted 55). Presently I noticed with alarm that not far up ahead all the traffic had slowed to 20 or so, with no brake lights, and NO hazard flashers(the public seems very stupid about the use of these, hardly ever seen but they DO have a valuable role to play in sudden traffic jams to protect your tail)!

I realized instantly that I had just a chance to save my skin and keep from eating the back of the rearmost car in the jam ahead. So I instinctively pulled on the front brake lever harder than I ever had before, and LOCKED the front wheel instantly with a HOWL. Great retarding effect, 75 to 50 or so almost instantly. But just as instantly, from a lifetime knowledge that a locked front wheel can slide in any direction and drop you in the road like lightning, I let off the brake. Then in the next split second, put it on hard again so it howled again! Let off it again then howled it again. But by now I saw I was going to clear the rear car ahead with a slight margin of safety.

That's all fine, but the surprising thing I learned was that I had a strong feeling that even with the wheel locked, I could have rode the little pony down to a standstill safely! I NEVER expected that! Even with a howling front tire, it still felt under control; evidently due to some favorable combination of light weight, general good handling, and CG.

But don't test this theory of mine except with great care of a Sunday morning in some huge, deserted shopping mall parking lot, where you can find out for yourself how much braking power you have, and how the bike behaves under a maximum stress situation.

The bottom line here is that THIS is one of the safest bikes you can ride, all the way around!

Okay, let me note that I never yet have added any fluid to the front master cylinder(yes, really), but I did add a little to the rear one, which today still has the original sintered metal stock brake pads in it. I will tell you that the rear brake is a bugger when you are replacing the rear wheel, since the pads always tend to fall out of place when are struggling to get the wheel in with your fingertips.

There has always been a little bit of wibble-wobble runout of both brake discs, and the ones on the '01 wheels are no different. But this is merely a perceptible trivial annoyance in use, and not serious, nor, do I think, does it have any adverse effect on the brake performance.

Roland(being an old T.T. racer) apparently was a much harder rider than I am, as he had already replaced his tires at 8,400 miles. I have found, using the oem stock tires(which some on this forum hate with a passion, can't imagine why) which I get from Dennis Kirk, that fronts last 22K miles, and rears 11K. The Tsubaki Omega chain that I prefer also lasts 22K miles, as does the 14t front sprocket. So every 22K miles I got into the habit of replacing both tires, chain and front sprocket(which is found somewhat hooked at that mileage). Dennis Kirk sells all these for what seem reasonable prices. I favor the rivet master link, after having the spring clip disappear from a master link once(but the pressed-on sideplate still did not come off, before I noticed the missing clip. A replacement clip stayed on for the remainder of the normal chain life).

A less expensive DID o-ring chain was tried once, but only lasted a third of the mileage.

I lube these chains with 90wt gear oil applied with a brush once in a while when they look dry and adjust them once in a blue moon. The lube only gets into the rollers anyway, the o-rings are designed to keep dirt and foreign matter out of the grease installed during manufacture. It also keeps out any lube you attempt to apply externally. I suggest you forget the expensive spray bomb chain lube. I doubt it can do anything more for you than this cheap gear oil that Kaw recommends as well.

I got a bead breaker from Dennis Kirk to change my own tires at home, the job is virtually impossible otherwise, unless you make up some other special tool of your own to do the same job. You will need a small home shop air compressor too, but you need that anyway to check and blow your tires up every couple of weeks when you will find they have lost a pound or two of air.

You need to use the utmost care to avoid scratching your wheels when mounting and dismounting tires(with proper tire irons only) because scratches will increase your air leakage. You MAY be able to seal such leaks with Bead Sealer from NAPA.

Since the standard air pressures of 28/32 apply to the full 340 pound bike load rating, and I weigh 200 and ride solo only, I took the liberty of running 27/25 pounds with an accurate gauge. Overly hard tires feel like riding on wooden wheels to me. I suggest, as above, that you stay with official pressures until you have several decades of experience.

I guess that's about it for wheels, tires, brakes and chains. Oh yeah, the rear sprocket lasts much longer than the front, so change it sometime when you see it becoming noticeably hooked. Mine has only been changed once.

End of Part Five.