Brembo Stylema calipers on 1250 GS

[MAgnus.LPA]

Hello

After crashing my 60 000 miles GS and having left my clavicle heal, I bought another 1250 GS.

2021, 7500 miles, good price, but washed by the previous owner with an acid cleaner that left the wheels green and the front calipers pink.
(Didn't know that before I went 1000 miles away from home to get it, owner was a b*stard).

I changed the wheels, sold the green ones and bought used Stylema calipers. Since I had to change them, I though I might as well go for something better than the stock Hayes calipers. These Stylemas have already been fitted to a 1250 GS and have been neatly milled so as to fit the stock 1250 GS forks. No modification needed, simple one for one replacement.

And I can safely report that they work great and offer a night and day difference in feeling when braking. It's both softer and more powerful. They are also precisely half the weight of the Hayes, with 1150g for the Hayes and 600g for the Stylemas. Per unit. 1.2kg of unsuspended mass shaved off. Does make the front suspension feel very different, softer and faster.

So if at some point anybody thinks of changing their Hayes calipers for Brembos, don't buy M4s or M50s, get Stylemas!

PS: you don't HAVE to mill them, they can be fitted by simply removing the little ring in the forks. That was just OCD from the guy I bought them from.


Here are some pictures of the milling and a before-after comparison:

 

[Oldrat]

Thanks, useful report

 

[Bem]

Good comments.
Now here`s a good reason to keep my old bus for another year..........

 

[Spook1969]

They look great

 

[MAgnus.LPA]

Thanks @Spook1969

By the way, I answered to your post about handlebar bags, here https://www.ukgser.com/community/threads/handlebar-bag.476950/
This solution might suit you.

 

[B15ape1981]

Hi Magnus, its something ive been thinking about for a while to upgrade the calipers....Is it a simple swop over job without doing anything to the new Brembo calipers?? Wasnt sure what you meant by fork ring?? Thanks again Andy

 

[MAgnus.LPA]

Hi Magnus, its something ive been thinking about for a while to upgrade the calipers....Is it a simple swop over job without doing anything to the new Brembo calipers?? Wasnt sure what you meant by fork ring?? Thanks again Andy

Hi Andy

Glad to help! Let me know if it's clearer after what follows.

It is a simple swap, but you will need to modify either the forks of the GS, or the Stylemas themselves.

1. Modifying the forks:
Our forks have this little dowel here that is designed to center the caliper. The Stylemas have mounting holes that are smaller than that dowel. So you either need to remove the dowel, as shown here:

2. Or to mill the calipers:
as shown below, so that they have room for the little dowel.

Unless you have access to all the equipment needed to mill metal, I guess removing the dowel is easier!

I hope it all makes sense now

 

[MAgnus.LPA]

And by the way, I know someone who is selling his Stylema calipers. They are used, but good as new. I'm not receiving a fee or anything, again, just happy to help

PS: they are not milled. You will need to have it done or to remove the dowel.

 

[Bem]

And by the way, I know someone who is selling his Stylema calipers. They are used, but good as new. I'm not receiving a fee or anything, again, just happy to help

PS: they are not milled. You will need to have it done or to remove the dowel.

Oooh!
Will you post them up here for sale??

 

[M30SJM]

Is the dowel there to simply locate the caliper, or does it there to transmit some of the breaking force through to the fork leg, rather than it all going through the bolts?
Do the Stylema calipers not use a dowel at all? even on there original bike?

 

[TaskMule]

Is the dowel there to simply locate the caliper, or does it there to transmit some of the breaking force through to the fork leg, rather than it all going through the bolts?
Do the Stylema calipers not use a dowel at all? even on there original bike?

Dowels transmit all the braking force. do not mount without them

 

[MAgnus.LPA]

Is the dowel there to simply locate the caliper, or does it there to transmit some of the breaking force through to the fork leg, rather than it all going through the bolts?
Do the Stylema calipers not use a dowel at all? even on there original bike?

Short answer:
Your pads will fade looong before you break anything. That is my personal opinion.


Long answer:
I can’t answer that. I am no engineer. I know Triumph use those same calipers on the Speed Triple and don’t use any dowels on the forks. Neither do Suzuki on the Hayabusa, also equipped with Stylemas. Nor Ducati on the Panigale and the MS Pikes Peak.

I personally think there is no way four 10mm bolts can be sheared by the braking power x mass of a motorcycle. But again, I’m no an engineer.

What I do think is that BMW use the dowels to make assembling easier at the factory. I think it is part of the manufacturing chain, where the dowels keep the calipers in place for the next robot on the chain to bolt them in at the next stop. But I could be wrong.

Also, keep one thing in mind -> milling the caliper also weakens the assembly. It removes some metal mass from the caliper. And the OEM Hayes caliper is milled, and therefore structurally weaker. And I don’t think that removing an aluminium sheet dowel weakens the assembly any more than milling through a solid caliper. I think 4 big 10mm steel bolts will easily sustain anything a motorcycle can throw at them. But again, not an engineer!

 

[MAgnus.LPA]

Short answer:
Your pads will fade looong before you break anything. That is my personal opinion.


Long answer:
I can’t answer that. I am no engineer. I know Triumph use those same calipers on the Speed Triple and don’t use any dowels on the forks. Neither do Suzuki on the Hayabusa, also equipped with Stylemas.

I personally think there is no way four 10mm bolts can be sheared by the braking power x mass of a motorcycle. But again, I’m no an engineer.

What I do think is that BMW use the dowels to make assembling easier at the factory. I think it is part of the manufacturing chain, where the dowels keep the calipers in place for the next robot on the chain to bolt them in at the next stop. But I could be wrong.

Also, keep on thing in mind -> milling the caliper also weakens the assembly. It removes some metal mass from the caliper. And the OEM Hayes caliper is milled, and therefore structurally weaker. And I don’t think that removing a little aluminium dowel weakens the assembly any more than milling through a solid caliper. I think 4 big 10mm steel bolts will easily sustain anything a motorcycle can throw at them. But again, not an engineer!

PS: I forgot! Nope, the Stylemas are never used with a dowel. Not to my knowledge.

 

[MAgnus.LPA]

Oooh!
Will you post them up here for sale??

I can put you in touch with the guy, @Bem. I’m not the one selling them

He is from the Adventure Rider forum, where I’m also a member.

He had them mounted on a GSA with S1000 XR discs. He sold his bike and kept the Stylema calipers.

And by the way, his were not milled and were working bigger XR discs, and he never had a problem.

Let me know!

 

[Deleted account 260111001]

What I do think is that BMW use the dowels to make assembling easier at the factory. I think it is part of the manufacturing chain, where the dowels keep the calipers in place for the next robot on the chain to bolt them in at the next stop. But I could be wrong.

Here is a video of the robots in question

 

[MAgnus.LPA]

Here is a video of the robots in question

those robots are really super high tech! BMW never cease to amaze…

 

[Pukmeister]

The dowels have a pretty small wall thickness so will not add any real noticeable strength to mounting the calipers, they are there to aid location. The caliper mounting bolts will most likely be a 10.8 tensile application.

I would either mill out the calipers or counter bore in a drill press to accept the dowels, its a job you only need to do once. I would not wish to modify the fork lowers.

 

[B15ape1981]

Hi Andy

Glad to help! Let me know if it's clearer after what follows.

It is a simple swap, but you will need to modify either the forks of the GS, or the Stylemas themselves.

1. Modifying the forks:
Our forks have this little dowel here that is designed to center the caliper. The Stylemas have mounting holes that are smaller than that dowel. So you either need to remove the dowel, as shown here:

2. Or to mill the calipers:
as shown below, so that they have room for the little dowel.

Unless you have access to all the equipment needed to mill metal, I guess removing the dowel is easier!

I hope it all makes sense now

Yes completely.....Thankyou again for your clear instructions

 

[leadfarmer]

Here is a video of the robots in question

Not to be pedantic but that video is a half arsed mash up of some pre production assembly and prototypes that was released before the 1300 was released (factory workers don’t assemble bikes one at a time on their knees) and the rest is of the old 1200 and lord knows what else

Not particularly informative

 

[MAgnus.LPA]

The dowels have a pretty small wall thickness so will not add any real noticeable strength to mounting the calipers, they are there to aid location. The caliper mounting bolts will most likely be a 10.8 tensile application.

I would either mill out the calipers or counter bore in a drill press to accept the dowels, its a job you only need to do once. I would not wish to modify the fork lowers.

Thank you for that concise and more precise explanation.

I agree that keeping the forks in their original condition is better.

Which is why I was happy to find those Stylema calipers pre-milled by the previous owner and at a very good price. I probably wouldn’t have done the swap otherwise.

By the way, I am currently in the Stelvio area for a 5 days ride and I have had the opportunity to use them hard downhill and it is very, very pleasant compared to the Hayes. Everything is better. Touch, feeling, stopping power, even the noise they make. Smooth and powerful.

Very happy with the change!