F800GS front brake rotors.

Discussion in 'Parallel Universe' started by The Griz, Feb 25, 2009.

  1. Singletrack_mind

    Singletrack_mind Cave Man

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    I'm not too keen on being a guinea pig when it comes to cut-rate Chinese brake parts. It's also not clear to me that you get the set of 2 for that price, and if I was paying $218 Australian for each rotor, plus $60 AUS for shipping from China . . . that'd be $396 USD as of today. Still a raging deal if they are any good, but the "Bike Master" rotors from Bike Bandit are way cheaper and alleged to be made by a major brake manufacturer in Spain. Might be a better bet for those inclined to gamble. I am leaning towards the Braking Batfly rotors, since I like to have complete faith in my front brakes and tend to ask a lot of them. (Also, see my edit above; EBC does not have a rotor for the GS800 yet)

    So Loutre: IF indeed you did just order some of these Chinese rotors, let us know how you like them.
    #61
  2. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    [​IMG]
    these are the ones I bought...



    [​IMG]

    this is the chinese stuff.

    looks close but not the same minimum thickness: 4.5 vs 4mm

    The Brand is chinese: Arashi. Someone I met in england recommended them to me about two years ago on a trip. He ran them on his boxer and said he didn't have any problems. Mine didn't come from china but from germany but I'm happy to make a feedback on them, might even start a separate thread if there is enough interest.
    #62
  3. sarathmenon

    sarathmenon Armchair Adventurer

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    I got a pair of braking's cheaper rotors. WL101L and WL101R from my mailbox. They cost ~300 USD shipped for the pair. They have been on the bike for two years now, and I am still alive and braking just fine.
    #63
  4. Singletrack_mind

    Singletrack_mind Cave Man

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    Well, I am going to have to change my tune: I've been informed the company I work for will close at the end of the summer, so suddenly cost became a paramount virtue and I ordered a pair of the Bike Master brand rotors at something like $220 with free shipping. I'll report back once I've received, installed and ridden with them.
    #64
  5. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    those are the one's I wanted. then they weren't available when I needed new rotors. plus had a screaming discount on my new rotors meaning that I got both of them from 120!!!!!!!!! bucks plus shipping; If I'm still alive at the end of the summer it was worth it. Otherwise you guys will finally have your peace of mind in the //u :lol3
    #65
  6. Singletrack_mind

    Singletrack_mind Cave Man

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    Well, I received the Bike Master rotors and they weren't even remotely correct for the application. Bike Bandit's website is wrong, they verified the error with me on the phone and say they will correct it. They do not offer a rotor for the front of our GS800s.
    #66
  7. sarathmenon

    sarathmenon Armchair Adventurer

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    Do they offer one for the 650 single? Its the same rotor, you have to get two of them for the parallel twins

    Sent from my XT1575 using Tapatalk
    #67
  8. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    installed rotors, broke them in, didn't die.
    #68
  9. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    IMG_20160702_195048.jpg
    #69
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  10. Singletrack_mind

    Singletrack_mind Cave Man

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    Loutre, can you tell me exactly where you got these? I am having a lot of trouble finding ANY aftermarket front rotors for the F800GS that are actually correct and/or in stock.

    Thanks!
    #70
  11. Lost-n-Lovin-It

    Lost-n-Lovin-It Lurker

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    I hope they work as nice as they look.

    :raabia

    Please keep us up to date.
    #71
  12. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    Ebay :)
    #72
  13. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    after their break in they feel reallly good, but like after all use part you compare them to used up, not-fit-to-purpose parts =) but atm they work =). will test them mor once I've figured out how to remow that old flywheel.. stil can't get my head around how it is fixed . can't pull it off.
    #73
  14. Singletrack_mind

    Singletrack_mind Cave Man

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    This is a good idea, but will only work with non-directional designs. Many floating rotor designs are specific to the right or left side either due to asymetric rotor or carrier design. The same Braking Batfly Enduro rotor is specified for the right side of our F800GS and the 650 for example, but then you need a different part # for the left side on the 800. There are some more basic simple round rotors that are not directional though like those from Wunderlich and Brembo, and with those this should work.
    #74
  15. sarathmenon

    sarathmenon Armchair Adventurer

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    Not necessarily. A floating rotor is just that. The rivets give the steel braking surface some play from the solid mounting surface so that it can better align with the brake pads. This allows for better tolerances when the rotor and the pads start wearing. Unless there is a offset to the rotors, there is nothing preventing cross use from another model. BMW lists the same part # for the stock brembo rotors for all the parallel GS and the singles. The aftermaket rotors have to follow the same 0 offset (I measured this separately for another experiment) to ensure compatibility. My guess for the different L/R part numbers on the aftermarket rotors is that the colors and the lettering show up in the opposite places for these L/R part numbers. Either that, or they want to give the impression of better engineering.
    #75
  16. Singletrack_mind

    Singletrack_mind Cave Man

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    While it's physically possible to reverse any rotor that fits the right side of our wheels and bolt it up with correct alignment in the caliper on the left side, there ARE at least two things you are overlooking that make it a bad idea on anything other than a 'conventional' round rotor with a symmetrical carrier:

    Rotor design: Particularly in the design of venting grooves or slots, these are made to pass between the pads traveling in a particular direction in order to work most efficiently scavenging gasses and heat, also clearing mud and water. Mounting them backwards wouldn't be a big deal on a commuter bike or other low-speed use, but certainly the venting won't work as designed and in a high stress situation like track use (on a different bike), they could suffer from much higher temperatures.

    Carrier design: Many carriers are optimized structurally in one rotational direction. The load-bearing arms from hub to disk can be aligned with braking force, the angle of the button seating area can be rotated so the buttons are in compression rather than in shear, and some carriers even have tabs that interface with the rotor directly to transmit load. Mounting them backwards could actually be pretty dangerous.

    The OEM rotors on our bikes are of what I am terming a "conventional" round symmetrical design. That is why they are not specific to right or left side fitment.
    #76
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  17. Singletrack_mind

    Singletrack_mind Cave Man

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    It took about 4 weeks, but I finally have received and mounted a set of the Braking Batfly rotors, sourced through F800GS Depot/ADV Depot/Twalcom/SP LM Cycle Supplies. It really was kind of hard to tell who I was dealing with, and my credit card company blocked the transaction at first wondering why I was suddenly spending $620 with a European clothing supplier . . . but the people were nice, and the order arrived on time and correct. I had to wait for a new shipment from Italy, which explains why my local shop couldn't get them through their national parts distributor, and why it took 4 weeks.

    Here's a picture of what they look like mounted up. You can see why this design wouldn't work if mounted backward as suggested above. Note that the pads aren't bedded in yet, you can see they aren't making full contact so it's too early to asses performance. At this early stage I'll say they feel normal at speed, but at the very end of stops when you are moving at walking speed, those ventilation channels DO set up a vibration kind of like riding a brand new knobby on the street. I expect that to go away once the pads are bedded in. I'll report back after a few hundred miles.

    [​IMG]
    #77
  18. sarathmenon

    sarathmenon Armchair Adventurer

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    Nice. What are those black lines on the rotor surface area?
    #78
  19. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    they are for the cooling / heat evacuation. they are deeper than the actual braking surface area, you kind find the same kinda principle on sport cars.
    #79
  20. Loutre

    Loutre Cosmopolitan Adv Super Moderator Supporter

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    well I did 600kms with my new chinese discs. Still alive. They brake hard and work as expected. only thing that I notice is at lower speeds they are kinda noisy at the wave "nipples" or whatever those round things are called on wavy brakes. I cleaned them but that didn't seem to help. oh well I can live with it and just increase the volume of my MP3. leaving for a 6k kms trip next week, by the end of it I expect to know how they hold up.
    #80