MV Agusta Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
9,955 Posts
Discussion Starter #1 (Edited)
On the My 10 F4s and B4 Brutales there is a single bolt on each fork bottom clamp to hold the axle in place.

Just a heads up to owners who may be thinking of changing their surface corroded bolts for stainless to be very careful with the thread type as it may not be a standard metric thread.?

The 09s used a thread which is 7 x 1mm. I can't see from the manuals what the MY 10 thread is, but it warrants more than a little care.

The last thing owners want is to strip out the female thread on the fork bottoms. Of course it may be a standard thread but it needs clarification before proceeding with replacement bolts


If anybody out there has the bolt size it would be useful for the record.

For myself I wouldn't change that bolt for stainless anyway due to the different specifications of generic stainless bolts and the important task that bolt performs.

joe
 

·
Registered
Joined
·
9,955 Posts
Discussion Starter #3
Hahaha, I saw someone else here on the forum putting stainless steel bolts in his brake calipers the other day, brave move.
I wouldn't do it down there on the MY 10 fork bottom clamp. There is only one bolt per clamp and they cost more than 13 times the price...There may be a quality reason for that ?

Hope you are getting better Donsy :)

joe
 

·
Registered
Joined
·
14,420 Posts
if you guys knew anything about bolts you wouldn't make such comments;

stainless bolts are usually more ductile and of lower strength than alloy steel bolts

the small axle pinch bolts only take the clearance up on the axle, nut fork leg connection.....to cut down on stiction

Donsy, my radial fork bottoms have the early style hinged clamps with aluminum studs and nuts......the fit either 310 or 320mm discs

stainless Allen bolts hold the discs on my R1150GS

M7 X 1.0 is almost a bastard thread......nobody used it until fork manufacturers started using it..... OK for 50 years the only places it was used .....VW transmission noses and Yamaha alternator bolts

Joe, its not English.....

a Rolls Royce Merlin has 72 screw thread pitches
a Packard Merlin 7

which would you want to work on?????


:drummer:
 

·
Super Moderator
Joined
·
22,070 Posts
Huh ?

if you guys knew anything about bolts you wouldn't make such comments;

stainless bolts are usually more ductile and of lower strength than alloy steel bolts

the small axle pinch bolts only take the clearance up on the axle, nut fork leg connection.....to cut down on stiction

Donsy, my radial fork bottoms have the early style hinged clamps with aluminum studs and nuts......the fit either 310 or 320mm discs

stainless Allen bolts hold the discs on my R1150GS

M7 X 1.0 is almost a bastard thread......nobody used it until fork manufacturers started using it..... OK for 50 years the only places it was used .....VW transmission noses and Yamaha alternator bolts

Joe, its not English.....

a Rolls Royce Merlin has 72 screw thread pitches
a Packard Merlin 7

which would you want to work on?????


:drummer:
Are you struggling to read again Noel, I meant exactly that, stainless is much softer than the HT bolts used on the OEM Calipers, I was not talking about axle clamps.
 

·
Registered
Joined
·
14,420 Posts
really?

Are you struggling to read again Noel, I meant exactly that, stainless is much softer than the HT bolts used on the OEM Calipers, I was not talking about axle clamps.
guess I should read between the lines, to divine what you meant?

you said quote"Hahaha, I saw someone else here on the forum putting stainless steel bolts in his brake calipers the other day, brave move."


well Donsy BMW bikes come with axial 8mm caliper bolts.....that scare you???

if the brake loads on those is OK why would they need 10 mm bolts on radial Brembos?????

since 8mm bolts are only 64% as strong as 10mm bolts in shear

here's the table for metric bolts......you may notice they don't even bother with core hardness on grade 8.8, 16mm or less

http://en.wikipedia.org/wiki/ASTM_F568M

PSST......8.8 bolts are NOT High Tensile bolts, they are generic bolts

Donsy;
read post 1 its about fork pinch bolts.....

Joe alleged that stainless is more brittle
 

·
Super Moderator
Joined
·
22,070 Posts
You know Noel, sometimes it's just too friggin hard to understand you. My apologies, fwiw, I won't be using stainless bolts in my calipers. ��
 

·
Registered
Joined
·
9,955 Posts
Discussion Starter #10 (Edited)
guess I should read between the lines, to divine what you meant?

you said quote"Hahaha, I saw someone else here on the forum putting stainless steel bolts in his brake calipers the other day, brave move."


well Donsy BMW bikes come with axial 8mm caliper bolts.....that scare you???

if the brake loads on those is OK why would they need 10 mm bolts on radial Brembos?????

since 8mm bolts are only 64% as strong as 10mm bolts in shear

here's the table for metric bolts......you may notice they don't even bother with core hardness on grade 8.8, 16mm or less

http://en.wikipedia.org/wiki/ASTM_F568M

PSST......8.8 bolts are NOT High Tensile bolts, they are generic bolts

Donsy;
read post 1 its about fork pinch bolts.....

Joe alleged that stainless is more brittle

You becoming a lawyer Noel ha ha !

Case for the defence..There is only one bolt per fork on the MY2010.....I ( personally ) would stick with OE unless I knew what I was putting in there...

I have modified my original post ..

Do we know what the thread is on these MY10 bolts yet ?

Joe
 

·
Registered
Joined
·
14,420 Posts
Donsy & Joe;
we raced 100,000's of miles on 6, 8mm sprocket bolts on a 100mm pattern....we ran on JPX Nylon rear sprockets too, they were 15mm thick except at the edge where they were narrowed for 530 chain, the cush drive was built into the sprocket.....6, 30mm chunks of Urethane pressed into 29mm holes with 12mm steel bushings pressed into the Urethane....

the entire sprocket/cush drive couldn't weigh less or be any more forgiving to transmissions

all our caliper bolts were M8 x 1.25.......just like every old car using Lockheed or Girling calipers (OK, most cars were 5/16"-18)

Joe;
fork manufacturers seem to like to use M7 x 1.0 for some crazy reason. what the '10 bikes are ???? have only played with the stupid fuel pump plate
:banghead::banghead:
 

·
Super Moderator
Joined
·
22,070 Posts
Noel, Joe's not referring to the M7 bolt, he's talking about the non radial style clamp bolt (M8 ?), which is the same as what they use in the >10 bikes.
I have a set of those fork leg bottoms up in my roof space , I'll get Theo to hop up and get them for me , pretty sure that bolt had some sort of retainer on it so it doesn't just drop out, I might be wrong Joe, but I'll let you know.
Cheers for that
 
1 - 13 of 13 Posts
Top