Yamaha forks on a BMW F650GS Dakar

[jbfbouchard]

Long time lurker, first time poster

I feel like I have combed over this forum forever trying to find this answer to this question, lots and lots of google-ing

Would it be possible to use the yz brake caliper with the BMW ABS unit, I know I could just not run ABS but I feel as though my ass was saved because of the ABS a few times. also I like the idea of using the yz front wheel because it makes for a more off road capable machine and I can just bolt everything on and has a good chance of being easier/cheaper/more upgradeable.

Different options

1.YZ caliper with larger SM rotor using the existing BMW master cylinder and abs unit. This option concerns me cause the volume of the master cylinder and the caliper are dissimilar but possibly the abs unit could be adjusted to produce something workable.

2.YZ Caliper with larger SM rotor, YZ master cylinder, BMW ABS unit. I feel like this is a better option cause the master/caliper volumes would be correct and when the wheel locks the abs unit will act like a pulsar to "Anti-lock"

3.Aftermarket supermoto caliper, larger SM rotor, BMW master Cylinder, BMW ABS unit. The idea behind this is that the larger aftermarket caliper would have a similar volume to the BMW caliper and the brake pressure could be similar.

4. buy the brake adapter ($500) Hawk Engineering


Does anybody have any experience with any of this, does any of this make sense?

[Lupin 3rd]

Originally Posted by jbfbouchard

Long time lurker, first time poster

I feel like I have combed over this forum forever trying to find this answer to this question, lots and lots of google-ing

Would it be possible to use the yz brake caliper with the BMW ABS unit, I know I could just not run ABS but I feel as though my ass was saved because of the ABS a few times. also I like the idea of using the yz front wheel because it makes for a more off road capable machine and I can just bolt everything on and has a good chance of being easier/cheaper/more upgradeable.

[....]

Does anybody have any experience with any of this, does any of this make sense?

The BMW master is sized to fit a single "twin piston" caliper, so it "should" work well with any similar setup. I think it would not work if you put two front disks (and two calipers) or if you used a four piston caliper (eg Brembo Gold series), because these would require moving a larger volume of brake fluid.

I'm looking into doing this conversion as well, and fitting the ABS is my main obstacle. I have the forks and a caliper from a WR250X (Sumo version) that comes with a bracket to fit a 298mm rotor. Now I need to either find a way to fit the BMW wheel on a 20mm axle or fit the ABS ring on the Yamaha wheel...

Hope this helps!

[GSBS]

Originally Posted by jbfbouchard

Long time lurker, first time poster

I feel like I have combed over this forum forever trying to find this answer to this question, lots and lots of google-ing

Would it be possible to use the yz brake caliper with the BMW ABS unit, I know I could just not run ABS but I feel as though my ass was saved because of the ABS a few times. also I like the idea of using the yz front wheel because it makes for a more off road capable machine and I can just bolt everything on and has a good chance of being easier/cheaper/more upgradeable.

Different options

1.YZ caliper with larger SM rotor using the existing BMW master cylinder and abs unit. This option concerns me cause the volume of the master cylinder and the caliper are dissimilar but possibly the abs unit could be adjusted to produce something workable.

2.YZ Caliper with larger SM rotor, YZ master cylinder, BMW ABS unit. I feel like this is a better option cause the master/caliper volumes would be correct and when the wheel locks the abs unit will act like a pulsar to "Anti-lock"

3.Aftermarket supermoto caliper, larger SM rotor, BMW master Cylinder, BMW ABS unit. The idea behind this is that the larger aftermarket caliper would have a similar volume to the BMW caliper and the brake pressure could be similar.

4. buy the brake adapter ($500) Hawk Engineering


Does anybody have any experience with any of this, does any of this make sense?

If you use the YZ wheel and fork you've still got to fab a way to mount the ABS ring to the hub and the sensor to the fork leg, regardless of the caliper you use.

You say you feel like the ABS on this bike has saved your ass a few times? That's hard for me to imagine because my feeling was just the opposite... Since removing the ABS I feel like taking it off has saved my ass more than once. IMO the ABS system on these bikes is worse than bad... it's downright dangerous!

But to each his own.

[swamp]

guys, i would like to change the front suspension on my bike using the easiest way possible. i dont want to measure cut, glue or pray for rain. i see this thread has a bazillion pages so.. can one ye' with infinitesimal knowledge please:

1. give me a shopping list of parts i need to gather in order to get this done.
2. i do not want the ABS
3. if anything needs to be sent off for machining it would be nice to know where to send the stuff to.

grassyass

[GSBS]

Originally Posted by swamp

guys, i would like to change the front suspension on my bike using the easiest way possible. i dont want to measure cut, glue or pray for rain. i see this thread has a bazillion pages so.. can one ye' with infinitesimal knowledge please:

1. give me a shopping list of parts i need to gather in order to get this done.
2. i do not want the ABS
3. if anything needs to be sent off for machining it would be nice to know where to send the stuff to.

grassyass

I just did my 03 Dakar last year and removed the ABS stuff at the same time. I'm 30 miles north of Bham in Blount Springs if you want to look at what I did.

You can see a pix of my bike by clicking on my sig line for that bike.

[Kainic]

Originally Posted by swamp

guys, i would like to change the front suspension on my bike using the easiest way possible. i dont want to measure cut, glue or pray for rain. i see this thread has a bazillion pages so.. can one ye' with infinitesimal knowledge please:

1. give me a shopping list of parts i need to gather in order to get this done.
2. i do not want the ABS
3. if anything needs to be sent off for machining it would be nice to know where to send the stuff to.

grassyass

Supposidly House of Horsepower has a "kit" in the works. Still waiting on specifics myself. Not sure if anyone else have any new info on their setup?

http://www.houseofhorsepower.com/

[Aquatic]

This is the YZ yoke that I have









Is this standard? Or do I have something odd?

I have designed up a ignition block to hold the Dakar switch.
The yoke in this file merely a representation of a YZ yoke. I have only added the needed features hence no bar mounts.
https://www.dropbox.com/s/88z8onjxgs...YZ%20SETUP.PDF

Opinions please?

Hopefully I'll have one made up in 2 weeks

[GSBS]

This info was spot-on when I did mine last year:

http://www.f650gs.crossroadz.com.au/...orkNotesYZ.pdf

Originally Posted by Aquatic

This is the YZ yoke that I have









Is this standard? Or do I have something odd?

I have designed up a ignition block to hold the Dakar switch.
The yoke in this file merely a representation of a YZ yoke. I have only added the needed features hence no bar mounts.
https://www.dropbox.com/s/88z8onjxgs...YZ%20SETUP.PDF

Opinions please?

Hopefully I'll have one made up in 2 weeks

[Aquatic]

Originally Posted by GSBS

This info was spot-on when I did mine last year:

http://www.f650gs.crossroadz.com.au/...orkNotesYZ.pdf

Thanks for that.
So mine is different to the samples shown

[tomatoe333]

Originally Posted by Aquatic

Thanks for that.
So mine is different to the samples shown

Looks like the number-plate mount is a little different from the one I have, but a similar shape to the upper clamp. I built a similar ignition lock mount to the one in the PDF document, but I made the back side of it match the curvature of the front edge of the triple clamp. Looks like you might have to build an L-bracket of some sort to attach to your upper triple, mine had a single hole in the correct place. I'll post pictures tonight.

[GSBS]

Originally Posted by Aquatic

Thanks for that.
So mine is different to the samples shown

Mine was off an 02 YZ250F (at least that's what the seller told me and I have no reason to doubt it). It does appear a little different, especially on the leading edge. It has a recessed notch where the number plate mount had been and that's where I mounted the plate to adapt the ignition lockset.

Here's a photo of mine during the fabrication. We later cut it back closer (smaller by about 1/2") to allow for the steering lock pin to work and to give more clearance for cables, wires, etc.

[Aquatic]

Originally Posted by GSBS

Mine was off an 02 YZ250F (at least that's what the seller told me and I have no reason to doubt it). It does appear a little different, especially on the leading edge. It has a recessed notch where the number plate mount had been and that's where I mounted the plate to adapt the ignition lockset.

Here's a photo of mine during the fabrication. We later cut it back closer (smaller by about 1/2") to allow for the steering lock pin to work and to give more clearance for cables, wires, etc.

Thanks

I now think I might just go straight to making a whole new top yoke and include fat bars and a steering damper mounting holes

[jbfbouchard]

Originally Posted by Aquatic

But why are the front mudguard holes open and threaded thruogh to the top? Does something mount on the top face?



Thanks. It helps when you do it for a living

The frame is a solid file. And it is dimensionally correct

I cannot take credit for it. It is a shared file on a CAD design forum

Hey Aquatic, do have these as solidworks files? or a link to there origin?

They look pretty tight, do you know you know if the used a CMM to measure everything?

fellow solidworks-er



thanks
Jacob

[Aquatic]

Originally Posted by jbfbouchard

Hey Aquatic, do have these as solidworks files? or a link to there origin?

They look pretty tight, do you know you know if the used a CMM to measure everything?

fellow solidworks-er



thanks
Jacob

http://grabcad.com/library/bmw-moto-frame

I have no idea how the guy measured the frame, but the bits I have measured and compared are pretty accurate.

I have started on the rest of the bike but need the engine. Anyone got a laser scanner lying about???

My current progress on the bike model
https://www.dropbox.com/s/fdcdauplrx...-A-0001_3D.PDF

[tomatoe333]

Here's my mount. Made of 1/4" thick aluminum plate. Used a friend's bandsaw, belt sander, drill press, and milling machine.