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Aftermarket Brake Rotor

Started by TJ, December 07, 2019, 05:13:45 AM

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TJ

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)
1992 FJ1200A (3YA)

ribbert

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
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"

TJ

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 :morning1:
1992 FJ1200A (3YA)

balky1

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....


FJ 1100, 1985, sold
FJR 1300, 2009

Motofun

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.   :good2:
'69 Honda Trail 90
'75 Honda CB400F
'85 Yamaha RZ350
'85 Yamaha FJ1100
'89 Yamaha FJ1200
'09 Yamaha 125 Zuma
'09 Kawasaki KZ110 (grand kids)
'13 Suzuki GSXR 750 (track)
'14 Yamaha FZ-09
'18 Suzuki GSXR 1000R (track)
'23 Yamaha Tenere 7
SOLD: CBX,RZ500,Ninja 650,CB400F,V45 Sabre,CB700SC,R1

balky1

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.   :good2:

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.


FJ 1100, 1985, sold
FJR 1300, 2009

Motofun

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.   :good2:

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.... :good2:
'69 Honda Trail 90
'75 Honda CB400F
'85 Yamaha RZ350
'85 Yamaha FJ1100
'89 Yamaha FJ1200
'09 Yamaha 125 Zuma
'09 Kawasaki KZ110 (grand kids)
'13 Suzuki GSXR 750 (track)
'14 Yamaha FZ-09
'18 Suzuki GSXR 1000R (track)
'23 Yamaha Tenere 7
SOLD: CBX,RZ500,Ninja 650,CB400F,V45 Sabre,CB700SC,R1

balky1

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.   :good2:

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.... :good2:

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


FJ 1100, 1985, sold
FJR 1300, 2009

RPM - Robert

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

EBC brake rotor for Yamaha FJ1100/1200






Pat Conlon

Robert, What's the weight on those?

Aren't they something crazy like 20 lbs each?
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

RPM - Robert

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

Pat Conlon

Thanks Robert!

Those are some beefy tostadas...
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

CutterBill

Never Slow Down, Never Grow Old.

Current Stable:                                                     
FJ1100                                              
FJ1200 (4)
1999 Yamaha WR400 (street-legal)
2015 Super Tenere
2002 Honda Goldwing

Pat Conlon

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.....
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

TJ

Hi again,

finally managed to install the new rotor.
No, not one of these beefy tostadas, the lighter aftermarket one :i_am_so_happy:
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 :dance2:
Thanks alot for your advices!

1992 FJ1200A (3YA)