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Old 09-26-2013, 09:13 AM   #4141
JDRadman
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Gangplank,

I too seem to remember some discussions on the YZ vs BMW brakes - hundreds of them actually over the years.

I think clamping force should be considered in these discussions. Consider the YZ caliper pistons, as I recall 2X27mm vs the BMW 1X30mm and 1X32mm? I am pretty sure about the BMW but calling from memory on the YZ diameter. Thats a pretty significant difference.

So the question is - does the mechanical advantage offered by the extra 20mm of rotor diameter overcome the limitations of the smaller pistons and the smaller pads (less clamping force and less swept area) ? That is more than I can calculate from here...but it doesnt look like it would.

The stock YZ brakes did not work for me on the highway in a big way - especially in the mountains. But when all is said and done, if its working for you - that is what matters.

Rad
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Old 09-26-2013, 09:25 AM   #4142
Gangplank
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Quote:
Originally Posted by JDRadman View Post
Gangplank,

I too seem to remember some discussions on the YZ vs BMW brakes - hundreds of them actually over the years.

I think clamping force should be considered in these discussions. Consider the YZ caliper pistons, as I recall 2X27mm vs the BMW 1X30mm and 1X32mm? I am pretty sure about the BMW but calling from memory on the YZ diameter. Thats a pretty significant difference.

So the question is - does the mechanical advantage offered by the extra 20mm of rotor diameter overcome the limitations of the smaller pistons and the smaller pads (less clamping force and less swept area) ? That is more than I can calculate from here...but it doesnt look like it would.

The stock YZ brakes did not work for me on the highway in a big way - especially in the mountains. But when all is said and done, if its working for you - that is what matters.

Rad
It is the full combination of factors.

Master Cyl. size at handle par
Piston size at caliper
Brake pad surface area
Rotor diameter & distance from hub
rotor heating/cooling capabilities
Brake pad brand & type
Brake Fluid used (I highly recommend RBF600 if you ride hard and use the brakes)
Proper bleeding of the brakes.

All these factors come into play. The Motul RBF600 is the best brake fluid out hands down. Majority of riders at the trackdays use it.

Riding style and brake pad choice factors into it.

I agree that the stock YZ disc and pads would be puny for the F650 in full dress. The 270, 300 or 320 kits can do the job.
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Old 09-26-2013, 06:30 PM   #4143
wiz.au
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Quote:
Originally Posted by Aquatic View Post
They fit the fork perfectly

So this is Yamaha Wheel, with BMW Caliper, and 320mm disc upgrade?

But the big question... $$$??
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Old 09-26-2013, 07:00 PM   #4144
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Quote:
Originally Posted by wiz.au View Post
So this is Yamaha Wheel, with BMW Caliper, and 320mm disc upgrade?

But the big question... $$$??
Nope

BMW wheel, 300 disc, Yamaha forks and BMW caliper.

$1000000's

Still working on the price as the axle is not done yet.
Unless you are just after the caliper hanger.


It could quite possibly work on a Yamaha wheel. Depends on the side to side position of the YAMAHA brake disc in relation to the BMW disc. If can get hold of a Yamaha wheel I can check the compatibility. I will see what I can do about borrowing a Sunshine Coast YZ wheel from some where.

Once this setup is finalised, I do actually have the design done for a caliper hanger to accomodate a 320 disc.
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Old 09-27-2013, 06:42 AM   #4145
wiz.au
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2001 WR/YZ426 Forks do?

Can those who know please confirm for me if 2001 WR/YZ426 forks will work for this upgrade? Or enlighten me to what is the critical thing to check for the forks that are required. I tried to work it out from reading everything, really, I did! .

Fork slider diameter? Steering head size/length?

These are what I'm looking at:
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Old 09-27-2013, 06:52 AM   #4146
kubiak
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Originally Posted by wiz.au View Post
Can those who know please confirm for me if 2001 WR/YZ426 forks will work for this upgrade? Or enlighten me to what is the critical thing to check for the forks that are required. I tried to work it out from reading everything, really, I did! .

Fork slider diameter? Steering head size/length?

These are what I'm looking at:
those should work. i put 2000 yz426 forks on my 02 dakar and all i needed was a few washers to take up a little slack in the stem.
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Old 09-27-2013, 06:54 AM   #4147
Gangplank
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Yamaha forks on a BMW F650GS Dakar

Quote:
Originally Posted by wiz.au View Post
Can those who know please confirm for me if 2001 WR/YZ426 forks will work for this upgrade? Or enlighten me to what is the critical thing to check for the forks that are required. I tried to work it out from reading everything, really, I did! .

Fork slider diameter? Steering head size/length?

These are what I'm looking at:
Here is what works: For the swap you can use Forks from Yamaha YZ or WR 125/250/426/450 +Fs all work depending on year. Some have a longer stem that will need a spacer or few washers to make it work. The 99 to 03 YZ250F have the same length stem & do not need a spacer for the stem. I used 01-03 YZ250F.

Here are some notes I made as I researched & started working on mine. No guarantee it works for you/not sure when I last updated it. WayneC1's website was helpful too.
https://docs.google.com/file/d/0B6Di...p=docslist_api
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Old 09-27-2013, 06:54 AM   #4148
wiz.au
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I'm blue, lah di dee...

Quote:
Originally Posted by Aquatic View Post
Finished
Blue will be fine thanks, matches my new Renthal handlebars, if I can ever get them!
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Old 09-27-2013, 06:56 AM   #4149
wiz.au
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WR426 Forks

Thanks guys, I don't mind a spacer, I can get one turned up custom if I need to.

Looks like I had better pony up the cash then....
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Old 09-27-2013, 12:37 PM   #4150
mattomoto
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Quote:
Originally Posted by wiz.au View Post
These are what I'm looking at:
Those will work. Same as what I have been running for a bunch of years. As Kubiak said, just need about 5mm worth of spacer under the stem nut. Grab a 1 1/8" bicycle headset spacer from a bike shop. Work perfect and very common.
Good luck!
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Old 09-27-2013, 05:16 PM   #4151
kubiak
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i have my old brake hose for sale in the for sale section. its the one i ran on my dakar with yz forks. 56 inches long. i took the hard plastic shell off though. good for project.
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Old 09-27-2013, 06:12 PM   #4152
Kainic
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I am finally getting around to doing my swap. To remove the ignition core (barrel) I assume I have to drill out the 2 safety bolts?



Also I assume I no longer need the tray?

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Old 09-27-2013, 06:57 PM   #4153
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Drill them bad boys out!

[QUOTE=Kainic;22429448]I am finally getting around to doing my swap. To remove the ignition core (barrel) I assume I have to drill out the 2 safety bolts?
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Old 09-28-2013, 07:16 AM   #4154
Gangplank
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Dril the bolts out. New bits work best & take your time. Start small & increase size as you go.

I kept the tray as a slash guard & trimmed & grinded it down
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Old 10-01-2013, 11:36 AM   #4155
creola
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actually, there is a hex in the center. I would try that first and use the drill as plan B
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