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observations on switching an old CB900 to radials

Discussion in 'Technical and Troubleshooting Torque' started by bikeboy, Dec 15, 2009.

  1. I managed to find radial tyres that would fit my 1980s cb900, so I thought I'd replace the BT45s with a pair of BT021s and see what all the fuss was about. First thing that struck me was the price! Boy, they're proud of these radials aren't they? They'd better last twice as long!

    I've put a few Kms on these now, and I wonder about the veracity of comparing radial/conventional when the most recent impressions of my BT45s were of worn tyres, just before I replaced them??

    Regardless of that, here's a couple of observations.

    1. Tyres seem to be able to soak up more shock. Maybe the construction? They seem to have taken the sharp edge off a lot of the bumps on the way to work.

    2. There seems to be more road 'noise' from the tread pattern than before. I know it happens with car tyres, but these do seem a touch noisier.

    3. Handling is 'way' different. I'm still trying to determine what the change is, but I have to make a more determined effort to tip the bike over. Maybe it's 30-odd years of cornering on conventional technology, and having to adapt to radial construction? Time will tell I guess.

    4. An unexpected nuance to date. I haven't had the pegs down yet because I'm still feeling my way to a large extent. However. I tend to use my foot as a bit of an early-warning system, and the indications are that I'm still a few Ks away from that at the moment-me being the nervous type and all. What slightly alarmed me is the (relatively) narrow chicken-strip already presenting itself:


    Not an empirical measure by any means :wink:

    On the BT45s, I could scrape the pegs and still have more than this left on the outer edge of the tyre (no pics :( ), but judging by my foot-ometer, I'm gonna be close to the edge of this puppy by the time sparks start to fly?

    So there you go. A quick and dirty first impression of what I'm sure will turn out to be a wonderful tyre.

  2. Is that chicken strip front or rear? You're probably already aware that if you're going to run out of tread, it's preferable to do it at the back first.

    It's an interesting experiment. I've never put radials on an old-tech bike, but I've known a couple of folk who have and have avoided coming too badly unstuck. The main comment was always about the seemingly unlimited grip.

    My old (87) K100 lists Pirelli radials, as an alternative fitment, on its tyre placard but I'd be surprised if sufficiently narrow ones were still available. Come to that, I'm a bit surprised you managed to find anything for the CB.
  3. It's the rear. For some odd reason, this pattern is reversed on the front. The old front ran right to the edge (lip), but the new one has almost twice the amount of the rear still untouched

    well I have cheated *a bit*. I have latter model wheels fitted, which increases my options a tad ;-)