Why different screws?

Dann · Jan 17, 2017

On my 07 the clutch and brake reservoirs on the handlebars have different screws.

Brake screws: (Philips)
Countersunk M4X16
Stainless steel
PN 32 72 2 320
(4 screws)

Clutch Screws: (Torx)
Countersunk ISA M4X16
PN 32 72 7 681 032
( 4 screws)

Is there a reason? (Besides maybe saving money...)

I'm thinking of replacing my brake reservoir screws with the same screws that are used on the clutch reservoir.
I would like to get rid of those philips screws. They strip too easily (DAMHIK)

pglaves · Jan 17, 2017

Dann said:
On my 07 the clutch and brake reservoirs on the handlebars have different screws.

Brake screws: (Philips)
Countersunk M4X16
Stainless steel
PN 32 72 2 320
(4 screws)

Clutch Screws: (Torx)
Countersunk ISA M4X16
PN 32 72 7 681 032
( 4 screws)

Is there a reason? (Besides maybe saving money...)

I'm thinking of replacing my brake reservoir screws with the same screws that are used on the clutch reservoir.
I would like to get rid of those philips screws. They strip too easily (DAMHIK)

Of course there was a reason. The engineering intern was in charge that day. The rest were all at Oktoberfest!

henzilla · Jan 17, 2017

Pauls explanation is pretty good

...but my WAG is they were trying to keep most folks from mixing fluids by keeping the screwdriver only crowd from adding DOT4 to the mineral oil clutch...but as said my WAG

texasmule · Jan 18, 2017

Unless you're the original owner, I imagine the previous owner munged up the torx/phillips screws
and was too cheap to buy a full set of either.

lee · Jan 18, 2017

texasmule said:
Unless you're the original owner, I imagine the previous owner munged up the torx/phillips screws
and was too cheap to buy a full set of either.

The parts fiche shows Torx on one cover and Philips on the other.
I have no idea why.

lee · Jan 18, 2017

Dann said:
I would like to get rid of those philips screws. They strip too easily (DAMHIK)

You should be ok with philips because it takes very little effort when tightening the screws to make the cover seal.

pglaves · Jan 18, 2017

I suspect the real answer is that one supplier was responsible for the detail design and manufacture of the brake system and another for the clutch system. The responsible purchasing agent probably didn't know a Phillips from a Torx from a Whitworth and thus we have the result. I think two owners of these bikes ought to get together and trade: one owner gets 8 Phillips head screws and the other gets 8 Torx head screws, and they all lived happily ever after.

akbeemer · Jan 18, 2017

I wonder if the Phillips head screws are JIS?

dbrick · Jan 18, 2017

akbeemer said:
I wonder if the Phillips head screws are JIS?

Now that's funny!

alancoles · Jan 18, 2017

Probably never know if it was a bean-counter move, a mistake, or a deliberate design.

The typical reason to spec for a phillips head is to reduce the likelihood of over tightening and doing damage to what is being secured.

Henry Ford spec'd them for that very reason. They were also one of the items that lead most of us who had bikes in the 60's-70's to also have a manual impact driver in the toolchest. Also why kits to switch over from phillips screws to Allen head screws (aka Hex drive) were so popular then.

lkraus · Jan 18, 2017

akbeemer said:
I wonder if the Phillips head screws are JIS?

Probably not, I don't see the usual "dot", and it is not a Japanese component. But a #2 JIS driver does fit very nicely and the straight sides on the cross do not cam out or strip the screw heads.

lkchris · Jan 18, 2017

Perhaps it's to suggest you need to change your brake fluid fairly recently and that there's seldom need to mess with the clutch fluid.

henzilla · Jan 18, 2017

lkchris said:
Perhaps it's to suggest you need to change your brake fluid fairly recently and that there's seldom need to mess with the clutch fluid.

That was kinda my point

pglaves · Jan 18, 2017

lkchris said:
Perhaps it's to suggest you need to change your brake fluid fairly recently and that there's seldom need to mess with the clutch fluid.

Or perhaps it is for the same reason they use, on some bikes (Oilhead RTs come to mind) three different length body panel screws when all of the same length would have worked (and do work) just fine. Or, as on Voni's F800S the center panel over the "tank" that isn't a tank uses short screws and long screws but either length works fine in all eight locations. Sometimes all we can do is wonder.

I actually usually take my suggestions as to how often different fluids ought to be changed based on specifications in the repair manual and not by the type of the head of the fastener.

baronk · Jan 18, 2017

Torx and Phillips screws.

I have an '05 RT with the same screw difference and interestingly, at least to me, I have no sight window on the clutch reservoir to check the fluid level. Although it shows a sightglass present in my Haynes repair manual. My brake reservoir has a sightglass.

akbeemer · Jan 18, 2017

PGlaves said:
Or perhaps it is for the same reason they use, on some bikes (Oilhead RTs come to mind) three different length body panel screws when all of the same length would have worked (and do work) just fine. Or, as on Voni's F800S the center panel over the "tank" that isn't a tank uses short screws and long screws but either length works fine in all eight locations. Sometimes all we can do is wonder.

I actually usually take my suggestions as to how often different fluids ought to be changed based on specifications in the repair manual and not by the type of the head of the fastener.

The first time I took the fairing apart on my 07 RT I diligently kept track of which length screw went in which hole. Took awhile to realize that it makes no difference. I'm now incrementaly replacing the Allen head screws on my Yamahas with BMW torex screws.

lkchris · Jan 19, 2017

PGlaves said:
Or perhaps it is for the same reason they use, on some bikes (Oilhead RTs come to mind) three different length body panel screws when all of the same length would have worked (and do work) just fine. Or, as on Voni's F800S the center panel over the "tank" that isn't a tank uses short screws and long screws but either length works fine in all eight locations. Sometimes all we can do is wonder.

This was one of the updates for the "facelift" RTs, i.e. Camheads. All fairing screws are the same. They weren't for the Hexheads. (and, not counting the tankbag mount rail screws or the glove box lid screws.)

pglaves · Jan 19, 2017

lkchris said:
This was one of the updates for the "facelift" RTs, i.e. Camheads. All fairing screws are the same. They weren't for the Hexheads. (and, not counting the tankbag mount rail screws or the glove box lid screws.)

So it takes BMW two generational revisions to get right what they should have done on the R1100RT bikes. They have my congratulations. Some things they never get right.

Dann · Jan 20, 2017

henzilla said:
Pauls explanation is pretty good...but my WAG is they were trying to keep most folks from mixing fluids by keeping the screwdriver only crowd from adding DOT4 to the mineral oil clutch...but as said my WAG

That would make sense to me if this wasn't BMW. Their philosophy is more like : Only certified mechanics (Dealers) should work on their bikes.
Which would be one more reason to use torx screws
Maybe they don't trust their own "certified mechanics" to put the right fluids at right place. :dunno

kskraye · Jan 21, 2017

Just to make you go buy a metric Phillips head.

Why different screws?

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