Categories: all aviation Building a Biplane bicycle gadgets misc motorcycle theater
I haven't really been riding the motorcycle too much lately. It comes in very handy when I have late nights at the theater, but apart from this very utilitarian duty, it mostly sits as I ride my bicycle for my daily transportational tasks.
Even so, I still manage to rack up the miles, and the old Bridgestone BT45 tires I've been running forever were finally bad enough that I had to replace them. Feeling in a daring mood, I decided to look into the other options available in good tires for a Ninja 250. That more or less boils down to the Pirelli Sport Demons. There are other tires that will fit, but they're either good tires that require modifications to the bike (mostly raising the front fender) or cheap tires that I don't trust very well.
So, I decided to take the plunge, and get the Sport Demons. The one thing I knew, that rang in my memory like a bell, is that they don't cup as they wear. This is what happens when adjoining blocks of tread wear unevenly, resulting in a series of diagonal blocks, instead of a continuous surface. The practical upshot is that the bike starts to feel very uncertain when going around corners. It's not, and the grip is fine, but the feedback from the tire is unsettling, at best. The BT45s will forever live in infamy in my mind, for they do this typically with about half the tread left. So I get half the life out of those tires that I theoretically could, which irritates my frugal soul to no end.
As I had suspected would be the case, I ordered the tires, and they arrived, and it took almost two months before I had the right confluence of time and energy to tackle the re-shoe job. It's not terribly difficult, but it does take a few hours, and it's also not simple. Changing motorcycle tires is something I started doing years ago, and I still like doing it, in a sort of abstract, "I'm more independent this way!" sort of way. I finally got them levered onto the rims in early December.
When riding on brand new tires, one must be gentle. Tires come out of the mold with a release compound, which you may safely think of as being grease. It's not actually, but it's more lubricant than anything else, and that's great for getting them out of their mold. Not so great, though, for actually riding on. So the first 50-100 miles are ridden gingerly, as if your tires are coated with lubricant.
Within seconds of starting out on my new tires, I noticed a huge difference from the BT45s: the Sport Demons are a very triangular profile! I guess this is common knowledge, but I hadn't been conscious of it before. They tracked very nicely in a straight line, with a slight tendency to wobble. But in doing some very shallow swoops as I rode along, they clearly wanted to lean into the corner, and stay there. It was disconcerting.
Apparently also common knowledge is that the BT45s are a very round profile, so they have very neutral handling. I was not best impressed. I don't want the bike to suggest anything. If I'm going into a turn, I want to tell the bike that's happening. It shouldn't urge me along -- that's what the cupped tires do, sort of, and it's what I was hoping to get away from. The Sport Demons are much more controlled about their urging than the cupped BT45s, and there's no feeling of being out of control, like there is with the cupped tires. But still, it's a bit unsettling.
There's another choice, of course. On my race Ninja 250, I had fitted Pirelli MT75 tires, which are unique in being the smaller 120/80-16 profile rear tire and 100/80-16 front. The BT45s and Sport Demons are 130/90-16, which theoretically slightly pinches the tire into a more-triangular shape than they're strictly designed for, due to the slightly narrow rear wheel. With the MT75s, there's no pinching, thus the shape is truer to what Pirelli intends. There's also about a 2 pound weight savings per tire, which is pretty significant.
The MT75s, however, did not favorably impress me as rain tires. On one of my few outings aboard the race Ninja, I had a damp track, and noticed a very distinct sense of losing grip, more than the BT45s had. They're probably fine for normal riding, but that little niggling sense of losing traction was enough to turn me off them. I don't want to have tires I can outride, although granted, I was outriding them in far more strenuous conditions than I ever allow myself into on the street.
So, for the moment, I'll live with the Sport Demons, and see if I can get used to the bike falling into corners a bit more than I want. If not, I may swap over the MT75s, and see if they treat me a bit better. I already know they have a lovely profile, it's just a matter of wet grip. And if I love the MT75s, a new set costs less than $150, vs. the nearly $220 of the Sport Demons. There's that frugal soul again...
Posted at 21:04 permanent link category: /motorcycle
Categories: all aviation Building a Biplane bicycle gadgets misc motorcycle theater