Rear Master Cylinder - GS1000 Anyone used anything more modern?

[greg78gs750]

lulz I think saltymonk has a pretty good idea about the workings of this forum......

[salty_monk]

So I said I'd report back...

I bought a Ninja 300 (EX300) master cylinder & caliper - full set from a 2015 low mileage bike for the grand sum of $31 to my door. Here's what I learnt.

1. The Ninja master cylinder is the same 14mm bore as the stocker. That's a decent start.
2. The pushrod is 8mm threaded so easy to extend with a coupling nut.
3. The mount bolts are 50mm centres. That's just close enough to allow the drilling & tapping of the existing Suzuki mount.
4. It took me about 15mins to adapt this to fit the Suzuki, grind a couple of mm off the mounts (I want a mm extra & used a penny washer for better stability as the mount is overdrilled with a weld nut mounted at the back), Drill out the mount holes to 8mm clear (rather than 8mm threaded) - 5 mins to drill & tap the frame - 8mm x1.25 & another 5 mins to touch up the frame.
5. The Ninja caliper is the same as the KLR caliper with the bleed nipple tapped at the front instead of the back as it's mounted in front of the axle not behind it on the Ninja. Neither are particularly good candidates for the Suzuki (although anything can be made to work I guess).

So what did I get for my $35 - A master cylinder that give a pedal that feels as good if not better than any GS I've ridden (I think I've ridden about 15 different GS's) and a very good source of spares for my KLR.

Caveat - you do have to grind a mm or two off the mount bosses to get it to line up with the pedal bracket. You do need to "relieve" a very small part of the cylinder where it hits the exiting mount (I also broke the corner on the mount in that area to save creating a stress line).

The master cylinder res hose from the KAWI works. You have to cut it done & use the SUZI clip if you want to use the stock res. The Kawi Res would work but would be very slightly angled.
I am not worried about the bends in the hose, my KLR has more acute bends than this.

The pictures should be self explanatory from here.

EX300 by salty_monk, on Flickr

IMG_2081 by salty_monk, on Flickr

IMG_2082 by salty_monk, on Flickr

IMG_2082 by salty_monk, on Flickr

IMG_2080 by salty_monk, on Flickr

IMG_2092 by salty_monk, on Flickr

IMG_2086 by salty_monk, on Flickr

IMG_2087 by salty_monk, on Flickr

and the finished piece....

IMG_2093 by salty_monk, on Flickr

[80GS850GBob]

Well done! Can you use the caliper too?!
Maybe it's me, but there seems to be a tad of forward deflection in the push rod assembly up from the foot lever pivot point. That's one of the retrofit issues I'd worry about- new subject piece rod stroke, MC bore, frame point configuration/orientation, foot lever leverage throw point and brake line exit angle.

Looks like you nailed everything in one shot!
Btw- man that's a tiny reservoir that came with it.....

[salty_monk]

IMG_2086 by salty_monk, on Flickr


Video linky Image above.

Nope it's in line. You have to be careful to line it up obviously

That video is without it being connected therefore the extreme range of the stroke. In reality it doesn't move even half this much when connected & bled.

[80GS850GBob]

LOl..."Adult content you must be signed in to view this content"....What, you got some barely bikini clad girl demonstrating the brake? {dang- now I really want to see it}

{I was gonna ask how flickr was treating you for hosting....}

[salty_monk]

Haha I changed it to "safe" viewing classification - hopefully that sorts it out...