Observations at 24,000 miles

[Greg Field]

I just pulled the rear wheel to change out the tire and dug deeper, just because.

 

There's a little weeping at the trans rear seal, so it needed replacing. That meant taking off the swingarm and rear drive. That's all easy enough and gave opportunity for detailed examination of the driveshaft and swingarm bearings. The swingarm bearings are notchy and really rough. There were no handling symptoms. Even so, they have to go.

 

Same for the driveshaft. No symptoms, but the failure mode is typical—meaning no play in the bearings but definite stiffness in one set of caps up front and one set in the back. That's kinda disturbing, since I was pretty methodical in lubing the u-joints. I'm half thinking of running this shaft until they show symptoms, and half thinking of replacing it with another used one I have. What to do?

 

Also up is a radial master cylinder for the front brakes and who knows what else?

[docc]

...who knows what else?

 

Throttle body shaft bushings/seals and a valve job?

 

No . . . that's not til 58,000 miles . . .

[Steve G.]

I've always thought that universal joint life had alot to do with clutch and throttle application smoothness. Agressiveness means short life. Of course, that can be said for anything mechanical.

Steve

[jcbooghs]

I have recently changed those swingarm bearings. Damn, those are expensive things!! Not to mention the work! They were rusted in the swingarm, was a hell of a job to get them removed.

Before the job I felt no play in the swingarm but when I dismantled the wheel, driveshaft and rearshock I could set the swingarm in any position. And it stayed there!!

No wonder I crashed two (yes, 2) times on a same day. The rearshock couldn't do the job anymore and the tire melted like snow in the sun.

[Dan M]

I just pulled the rear wheel to change out the tire and dug deeper, just because.

 

There's a little weeping at the trans rear seal, so it needed replacing. That meant taking off the swingarm and rear drive. That's all easy enough and gave opportunity for detailed examination of the driveshaft and swingarm bearings. The swingarm bearings are notchy and really rough. There were no handling symptoms. Even so, they have to go.

 

Same for the driveshaft. No symptoms, but the failure mode is typical—meaning no play in the bearings but definite stiffness in one set of caps up front and one set in the back. That's kinda disturbing, since I was pretty methodical in lubing the u-joints. I'm half thinking of running this shaft until they show symptoms, and half thinking of replacing it with another used one I have. What to do?

 

I's swap the shaft. I'll bet the bike is smoother at speed with joints that have fluid motion

[Greg Field]

Pulled out the spare shaft. I got it from a bike with 6,000 miles. It also has one set of caps at each end that're stiff. It's actually stiffer than my 24,000-mile shaft. Perhaps this is normal? In any case, I'm going to run it and see how long it lasts.

[gstallons]

I just pulled the rear wheel to change out the tire and dug deeper, just because.

 

There's a little weeping at the trans rear seal, so it needed replacing. That meant taking off the swingarm and rear drive. That's all easy enough and gave opportunity for detailed examination of the driveshaft and swingarm bearings. The swingarm bearings are notchy and really rough. There were no handling symptoms. Even so, they have to go.

 

Same for the driveshaft. No symptoms, but the failure mode is typical—meaning no play in the bearings but definite stiffness in one set of caps up front and one set in the back. That's kinda disturbing, since I was pretty methodical in lubing the u-joints. I'm half thinking of running this shaft until they show symptoms, and half thinking of replacing it with another used one I have. What to do?

 

Also up is a radial master cylinder for the front brakes and who knows what else?

What is a "radial master cylinder" ?

[raz]

What is a "radial master cylinder" ?

http://motorcyclebloggers.com/tech-talk-ar...ster-cylinders/

 

Probably just bling bling, just like "radial calipers". Sure, theoretically there may be an advantage, but real world? I'm not convinced. If I had much more money I would probably say something else

[Greg Field]

We shall see. I'll report it if it's shit. I just like to experiment.

[BrianG]

I put a Brembo 18 X20 radial MC on mine. Definitely a lighter pull. Not certain if it's the "radial" part or if it's a new mechanical advantage via a new hydraulic ratio...

[dlaing]

http://motorcyclebloggers.com/tech-talk-ar...ster-cylinders/

A brake engineer named 'AngryBob'...do you think he might post on this forum.

It was a good post, but he did not cover the interesting stuff, like efficiency, etc. He seems to have some misconceptions about common conceptions and his solution to brake fade is moving the lever out, rather than different rotors or pads.

I think our V11s have about the perfect ratio, so in my opinion, any improvement from a radial master cylinder would come from the small gains in efficiency that comes from the slightly superior design and superior materials, assuming the radial master cylinders are forged alloy.

My question for a brake engineer is, how much efficiency is gained with radial master cylinders?

Obviously it would vary model to model, and our Brembo gear is already pretty good stuff.

Still I fall into the camp of, if I had a few more dollars and the skills to accurately calculate the ratios, so that I don't ruin my already near perfect ratio, I would switch to radial master cylinders in a heart beat.

IMHO, the best bang for your buck is to maintain the brakes properly. Good pads, clean fluid with minimized air, and a clean greased lever pivot will keep your braking happy.

[dlaing]

I put a Brembo 18 X20 radial MC on mine. Definitely a lighter pull. Not certain if it's the "radial" part or if it's a new mechanical advantage via a new hydraulic ratio...

Do you find the lever gets closer to your grip, or less close?

Is your reach fo the lever about the same?

[Greg Field]

I got the new RCS m/c with a switchable pivot for 18 or 20. I'll try both out and see which works best for my tastes. It's a lovely piece that I just fell in love with it at Brembo tech training and had to try out. How else does one learn what works and what doesn't? Plus, I can't let hte 'prilier and duc boys have all the fun.

[pete roper]

I got the new RCS m/c with a switchable pivot for 18 or 20. I'll try both out and see which works best for my tastes. It's a lovely piece that I just fell in love with it at Brembo tech training and had to try out. How else does one learn what works and what doesn't? Plus, I can't let hte 'prilier and duc boys have all the fun.

 

Of course 20 or so years ago it was essential for every high-bling tosser, (Like me ) to have a Lockheed variable ratio master cylinder on their Guzzi. Poxy thing actually worked quite well but like most of this stuff once set to where you want it you never look at it again .

 

Rally thogh Greg I'll be interested to hear what you think as at the moment the one thing that is leaving me a bit peeved with the 1200G is the performance of the front brakes. Its not like they're spongy or anything, they just don't seem to have either the bite or the stopping power I would of expected. I know you love the petal rotors, (I'm still waiting to hear the cool whistling noise! ) but to me, or at least for me, there is something lacking. I'll try pads first, (They made a big difference on the 1100.) but if that doesn't work I'll spring for a whizz-bang M/C.

 

Oh, and the new tyres worked wonders. I dunno what was up with the OE Metzlers but they went off in a flash.

 

Pete

[raz]

We shall see. I'll report it if it's shit. I just like to experiment.

Sorry, I just intended to answer the "what is" question and I had no intention to bash Greg for trying. On the contrary, of course we're interested in how it works out.

 

The key seems to be that a radial m/c will have its plunger moving in the same direction as the lever is pulled, while a conventional one will have the plunger moving perpendicular to it. I'm not sure why that would matter much but even if it doesn't, a new m/c can be better for numerous other reasons.