Aftermarket Brake Rotor

TJ · December 07, 2019, 05:13:45 AM

Sooo it's time for Tüv (german MOT) again... and currently my FJ would not pass.
The rear brake rotor finally worn away and went out of spec.
Just to be clear, official spec seems to be 7-7.5mm for the original vented rotor.
Mine averages to 6.4mm

I already ordered an aftermarket replacement.
However, the new part has an original thickness of 5mm and I got confused...

Is the 7mm limit just for the structural integrity of the vented rotor?
Is it okay to just "bolt on replace" the old rotor with the new, thinner one?
Can the original brake calliper handle these thicknesses, or may a piston pop out?!

Optional
Little background: in germany you are allowed to mount any parts that are kinda "certified" for you specific motorcycle.
Alternatively you can mount any other part, but someone has to inspect whether this combination of parts is safe to use ($$$).
Thats why I chose one of the certified parts (ABM Peak SF14 brake rotor)

ribbert · December 07, 2019, 06:08:02 PM

Quote from: TJ on December 07, 2019, 05:13:45 AM

Sooo it's time for Tüv (german MOT) again...

The use of non vented (and thinner) rotors as replacements is the norm and will cause no issue with the caliper. For the purpose of the examiner, there will be a "min thickness...." stamped on the rotor. There is an assumption also that the tester is qualified and understands what he's looking at and that common sense prevails.

I was a Licensed Tester for many years and the wear indicators on such a part would override any other reference material, assuming of course, the part was suitable for the application.

I'm unfamiliar with German practice but I'd be very surprised if non genuine parts needed to be inspected before installing when referring to brake components. That sort of requirement in most places refers to modified parts, not replacement
parts or consumables.

Noel

TJ · December 08, 2019, 03:16:15 AM

Thanks alot!
I was basically just concerned that the 7mm limit is not only for the rotor itself, but also for other parts of the braking system...
But yeah, if its really just the rotor itself, i'll bolt on the new one.

Regarding the upcoming "checkup", I guess it'll be fine

balky1 · December 08, 2019, 04:41:08 AM

Quote from: ribbert on December 07, 2019, 06:08:02 PM
Quote from: TJ on December 07, 2019, 05:13:45 AM

Sooo it's time for Tüv (german MOT) again...

The use of non vented (and thinner) rotors as replacements is the norm and will cause no issue with the caliper. For the purpose of the examiner, there will be a "min thickness...." stamped on the rotor. There is an assumption also that the tester is qualified and understands what he's looking at and that common sense prevails.

I was a Licensed Tester for many years and the wear indicators on such a part would override any other reference material, assuming of course, the part was suitable for the application.

I'm unfamiliar with German practice but I'd be very surprised if non genuine parts needed to be inspected before installing when referring to brake components. That sort of requirement in most places refers to modified parts, not replacement
parts or consumables.

Noel

Exactly such parts and emission related parts (like axhaust systems) need to be ECE approved and often written up in the Traffic license. If not, you are not allowed to mount them. It is like that in the whole EU. Other pair of boots is the fact that the testers usually don't bother you with it, at least in Croatia. And what I find shitty in Croatia is that if you change exhaust on a car no one will ask you anything. Same for the discs for example. But if you changed your blinkers on a motorcycle, let alone the exhaust, 'OH MY GOD, NO, NO, YOU CAN NOT PASS THE MOT LIKE THAT!'
For example, that's the reason why we can't mount RPM's exhaust....

Motofun · December 08, 2019, 12:40:19 PM

Not that I'd ever suggest doing something "shady" but what's to stop you from temporarily mounting the stock exhaust to pass the inspection. After you have the proper sticker just swap back.
In so may ways I'm happy to not deal with so many regulations. My FJs are antiques (over 25 years) so they don't even get inspected, no yearly fees (one time fee of about $100) and fancy purple antique plates.

balky1 · December 08, 2019, 02:36:51 PM

Quote from: Motofun on December 08, 2019, 12:40:19 PM
Not that I'd ever suggest doing something "shady" but what's to stop you from temporarily mounting the stock exhaust to pass the inspection. After you have the proper sticker just swap back.
In so may ways I'm happy to not deal with so many regulations. My FJs are antiques (over 25 years) so they don't even get inspected, no yearly fees (one time fee of about $100) and fancy purple antique plates.

Then police stops you, sees you don't have the exhaust written up in your Traffic license and off you go to an early MOT together with a fine.

Motofun · December 08, 2019, 06:01:58 PM

Quote from: balky1 on December 08, 2019, 02:36:51 PM
Quote from: Motofun on December 08, 2019, 12:40:19 PM
Not that I'd ever suggest doing something "shady" but what's to stop you from temporarily mounting the stock exhaust to pass the inspection. After you have the proper sticker just swap back.
In so may ways I'm happy to not deal with so many regulations. My FJs are antiques (over 25 years) so they don't even get inspected, no yearly fees (one time fee of about $100) and fancy purple antique plates.

Then police stops you, sees you don't have the exhaust written up in your Traffic license and off you go to an early MOT together with a fine.

WOW, your "license" details the construction of the bike? Geezzz, my registration card just shows the make, model and VIN #. I could have ape hangers and shoot flames out the exhaust....

balky1 · December 09, 2019, 12:51:52 AM

Quote from: Motofun on December 08, 2019, 06:01:58 PM
Quote from: balky1 on December 08, 2019, 02:36:51 PM
Quote from: Motofun on December 08, 2019, 12:40:19 PM
Not that I'd ever suggest doing something "shady" but what's to stop you from temporarily mounting the stock exhaust to pass the inspection. After you have the proper sticker just swap back.
In so may ways I'm happy to not deal with so many regulations. My FJs are antiques (over 25 years) so they don't even get inspected, no yearly fees (one time fee of about $100) and fancy purple antique plates.

Then police stops you, sees you don't have the exhaust written up in your Traffic license and off you go to an early MOT together with a fine.
WOW, your "license" details the construction of the bike? Geezzz, my registration card just shows the make, model and VIN #. I could have ape hangers and shoot flames out the exhaust....

Everything from VIN to max load capacity, measurements of the vehicle, tyre sizes and added stuff (and much more).

RPM - Robert · December 09, 2019, 11:34:57 AM

There are the proper 7.5mm thickness non-vented rotors available.

EBC brake rotor for Yamaha FJ1100/1200

Pat Conlon · December 16, 2019, 05:30:26 PM

Robert, What's the weight on those?

Aren't they something crazy like 20 lbs each?

RPM - Robert · December 16, 2019, 05:37:18 PM

If you added all 3 up they are a bit more than 14 lbs. Individually weighed in at 4 lbs 12 oz

Pat Conlon · December 16, 2019, 11:48:32 PM

Thanks Robert!

Those are some beefy tostadas...

CutterBill · December 17, 2019, 12:05:39 PM

Quote from: Pat Conlon on December 16, 2019, 11:48:32 PMThose are some beefy tostadas...

Drill more holes in 'em.

Pat Conlon · December 17, 2019, 01:17:00 PM

With 2 of those beefy tostadas on your front wheel, that's a bit under 10 full pounds of unsprung weight....
....gonna need more than holes.....

TJ · January 01, 2020, 11:06:52 AM

Hi again,

finally managed to install the new rotor.
No, not one of these beefy tostadas, the lighter aftermarket one

And to be honest, it not just fulfils the specs again, it also looks way better (at least to my eyes).

Ah and I got the FJ checked by the Tüv. Everthing's fine

Thanks alot for your advices!

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Aftermarket Brake Rotor