OK, now I understand a lot more. I didn’t read what you’d said before about riding the CPI and since I haven’t
rode that motorcycle, I don’t even know the basics of it. If the front caliper is really small like that, I would
change it if I felt it didn’t have the braking power that I think the motorcycle could handle. From what I
remember, the tires on the CPI are kind of small for a motorcycle of it’s size, so I’d be careful of getting a
caliper that’s too strong. You don’t want to find out the hard way if your motorcycle will pull an endo, or
if the front tire will slide if you brake too hard and lock the front tire. On my Grand Dink 250, my front tire
will slide because I have a 12" rim and my scooter is really heavy. As for changing the o-rings, I don’t think
you’ll find a shop that will do that for you. They’d rather sell you a new master brake cylinder or caliper.
One thing you should do anyways, because you don’t know when it’s been done, is to have the brake oil
changed on the front brake. If you watch them do the job, look in where they add the oil for the master
cylinder. If you see anything other than oil in there, like small bits of junk in there, it’s probable that the
master cylinder is slowly failing. I’ve seen that in my master cylinders for both brakes. The master cylinders
still work, but I know they don’t as well as they should.
So here’s the thing, what to change. If your master cylinder is OK, then you’re caliper should be OK too.
If you are unhappy with the braking power, then change the caliper. You mentioned you didn’t know if
your caliper has one or two pistons. If it only has one, it’s weak and get a better one. If you get a caliper
with 2 pistons, it should be fine. If you get one with 4 pistons, you’ll really have more braking power.
You don’t need one with 8 pistons, that’s overkill.
Everything I mentioned before is so you understand what could be the problem, and what you’d need to fix
it. With the master brake cylinder, if it doesn’t push the caliper hard enough (you could find that out by
comparing your motorcycle with another that’s the same), then replace it. If your caliper is leaking oil
behind the brake pads, replace it. Otherwise, they should be fine.
Now, as for your steering shaking when cornering at any speed, I don’t think that normal and it needs to be
fixed. You’ll need to have your steering column opened up and have the bearings looked at. The bearings
in the steering column are what I’ll say is an “open” bearing. As in you can access the steel balls in the
bearing, as opposed to a “sealed” bearing where you can’t. So you have your steering column opened up
and look as see if there are enough steel balls in both the top and bottom bearings. If it looks like an extra
ball or 2 or 3 could fit in there, then the bearing needs those extra balls. But don’t stop there, have the steel
balls removed, the grease cleaned up, and look at the bearing race. The bearing race is the metal that holds
the bearings in place. There are 2 bearing races at the bottom of the steering column and 2 at the top. You
look for any damage or wear marks in them. If there is, then the bearing race will need to be replaced.
This should fix your steering column shaking issues. I can’t say for sure, but my gut feeling is that you’re
missing a steel ball or 2, and that’s why you have shaking issues when cornering. My thinking is that when
your cornering and putting more stress on the steering column, there aren’t enough steel balls to hold it
steady. If you had a problem with your bearing race, you’d feel it when you turn the steering as it feels like
you hit a “notch”, or doesn’t turn as smoothly in one direction as it does the other, when turning your
steering, as in the steering doesn’t feel completely smooth going right to left or left to right.
Sorry for the long post, but I hope it gives you a better idea of what to do with your motorcycle.
and still had his knee down.
and still had his knee down.