MV Agusta Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
967 Posts
Discussion Starter #1 (Edited)
After searching evolution bike and star twin it looks like the steering tube and bearings come as an assembly and expensive. Can anyone confirm if this is true or can I just replace the bearings. Thanks Guys. On a 2010 1078RR Brutale.
 

·
Registered
Joined
·
967 Posts
Discussion Starter #7
“F06” is all I can find so far Mate, that’s on the plastic cage. Haven’t been able to get the cups out of the steering stem yet.
 

·
Vendor
Joined
·
5,335 Posts
OK,can anyone help with the bearing numbers please.
Do we convert the original bearings to tapered rollers?
 

·
Registered
Joined
·
338 Posts

·
Registered
Joined
·
967 Posts
Discussion Starter #10
Thanks Tony, absolute champion. Hey Mitchy, I might as well try and get them here if the tapered rollers are easier to find than exotic ball bearings rather than take up your time. I’ll let you know how I go. Thanks very much for your help Mate, gotta love this forum
 

·
Registered
Joined
·
967 Posts
Discussion Starter #11
At the risk of asking a stupid question why are ball bearings fitted rather than the usual roller bearings ?
 

·
Administrator
Joined
·
19,829 Posts
Ball bearings have less friction and weigh less......mainly the less friction part.
 

·
Registered
Joined
·
967 Posts
Discussion Starter #13
Thanks for that,they are light and given the water damage to my lower bearings surprisingly little drag.
 

·
Administrator
Joined
·
19,829 Posts
If you knock the races out you should find numbers on them.... The balls themselves can be purchased lots of places, just measure diameter. Nothing special there.

With races and caliper in hand you can probably find replacements at any Japanese bike shop. Pretty generic stuff. Dust seals, on the other hand, may be harder to find.
 

·
Vendor
Joined
·
5,335 Posts
Thanks Tony, absolute champion. Hey Mitchy, I might as well try and get them here if the tapered rollers are easier to find than exotic ball bearings rather than take up your time. I’ll let you know how I go. Thanks very much for your help Mate, gotta love this forum
OK Mark,see how you go.I will try if you can't get them in Tassie.
 

·
Registered
Joined
·
14,499 Posts
?

From the mouth of MV's Chief Engineer........

"But we may have just been had: Our friend Brian Gillen, MV Agusta’s head engineer, tells us using ball bearings in the steering head does offer advantages regarding packaging, since they take up less space and also weigh less. But in most cases, he says, the choice is primarily cost; tapered roller bearings can cost over twice as much as ball bearings."

A little thinking might help......
It isn't about friction......there are steering dampers, you know
The balls aren't loose, they're caged just like on bicycles, so they won't get lost....mechanics would spend too much time
looking for dropped balls
The seals will be the same if the races are ......the ID and OD they work on is the same:grin2:
MV worried about weight?????
Nice try, weigh a pair of the original star wheels......effing boat anchors and that's rotating unsprung weight, the worst

>:)
 

·
Administrator
Joined
·
19,829 Posts
The balls aren't loose, they're caged just like on bicycles, so they won't get lost....mechanics would spend too much time
looking for dropped balls
The seals will be the same if the races are ......the ID and OD they work on is the same:grin2
Actually, most motorcycles (every one I have worked on over the past 40+ years) have loose balls in the steering head. No cages like bicycles.

The seals are generally larger than the OD of the bearing to seal over the edges of the space the steering stem is going through. Some top seals are like caps.

Even though there are steering dampers, the balls provide less stiction and therefore better steering feel. Most factory race bikes have ball bearings.

But you are right...there is a cost advantage.

Suzuki originally had tapered bearings in their big VL1500 cruiser introduced in 1998 but changed to balls for cost reduction in 2005. Customers then began complaining about handlebar shake under decel (with their hands off the bars !!).
The remedy was to install the tapered bearings from the original model. Suzuki went back to the tapered as standard a few years later.

The stiction is just enough to quell the handlebar shake....of course, if you keep one hand on the bars there is no shake either.

The original Honda CB750 suffered the same "hands off handlebar decel shake". Their remedy was to tell the customer "you are not supposed to ride without gripping the handlebars". :loser:
 

·
Registered
Joined
·
14,499 Posts
Stiction.....?

You sure about that Ed?
https://www.amroll.com/friction-frequency-factors.html

Go down to Friction Table lll

Here I'll help...
Angular contact (what ball bearing steering heads are) 0.0020
Tapered roller 0.0020
The same....there goes that tenet of motorcycle design BS

When something is wrong in the front end the problem is usually the back
end and the other way around too.....
Stock my R1150GS ate the left side of the front tire.....the rear wheel is offset to one side, parallel but offset:wink2:

1st picture page B03 of the Brutale parts book .... looks caged to me
2nd picture Timkin 07100L tapered roller bearing with mounted seal
 

Attachments

·
Administrator
Joined
·
19,829 Posts
Well...I stand corrected, having never had to look at my MV's steering heads. Caged balls...nice. Must be another reason why an MV costs more than a Honda.

In 40+ years of working on Jap bikes I have never seen caged balls in the steering head. You use a heavy grease to hold the balls in place while assembling.

Thanks for educating me Noel.

Do Ducatis and other Euro bikes use caged balls, too? I know they didn't back in the 70's.
 

·
Super Moderator
Joined
·
22,329 Posts
I am trying to recall if my Ducati Monster S4Rs had caged balls...

I believe it did. If I can find the race on my "workbench" I'll let you know.
 
1 - 20 of 29 Posts
Top