83 GS1100E Front Master Cylinder Options

[snoobler]

Spent about 30 minutes searching - nothing definitive.

2X 83 GS1100ED - one with an aftermarket I'm not happy with, and the other with a stock master cylinder that needs a quick pump or two to perform. Yes. I have bled the living crap out of it. I spoke with Steve at Brake Crafters, and he concluded it sounded like the master cylinder was the issue.

Have already been down the rabbit holes in this thread before hitting a brick wall:

https://www.thegsresources.com/_forum/forum/technical-forums/tires-suspension-brakes/1709480-83-gs1100e-brake-system-rebuild-kits

At Steve's (Brake Crafters) recommendation, I tried the universal 14mm piston EMGO master cylinders:

32-37281

https://emgo.com/wp-content/uploads/2021/08/2019general_IN-2967-1.pdf

Got them from CyclesRUs since Brake Crafters doesn't offer them.

Unfortunately, their quality was COMPLETE garbage. There was paint INSIDE the reservoir, and the threads were so boogered, I couldn't start a bolt let alone the mirror post. Worst of all, it wouldn't build any pressure except during the last 10% of the pull after every form of bleeding known to man (bench, banjo, gravity, vacuum, pressure, manual).

I bought TWO, and they were both the same. They also behaved oddly - when the lever was pulled, a large jet of fluid exited the ports. When the lever was released, little to no fluid jetted back into the reservoir. I mucked with these things for about 4 hours - went through nearly 32 oz of DOT 4.

Videos/pictures: https://photos.app.goo.gl/rsSX6TEuBSZuCEMFA

Fortunately CyclesRUs gave me a full credit with evidence they had been rendered unusable.

I had the stock one re-installed, bled and fully operational in 15 minutes. I noticed the amount of fluid injected into the reservoir during pull was minimal with a large amount on the release. This suggests to me an issue with the port placing/spacing on the EMGO master cylinders.

Here's a link to the video of the stock master cylinder operation:

https://photos.app.goo.gl/NRfU54fTghU7qYAq6

If you compare the EMGO to the stock, it's notable the EMGO ports are notably closer together.

At this point I'm pretty desperate. Appreciate any help.

rphillips - I'm tagging you because I see that you have one in your sig and hope you've been down this road...

[rphillips]

First of all WELCOME. Luckily I've not had the problems you've got, a rebuild of my orig. usually fixed my troubles, though the after mkt. kits are quite iffy. I do remember (I think, though I can't find it now), a front master from a Kawa. EX500 was recommended as a good replacement for our GS's, thinking needed to be from an early EX500 to get the threaded well for the mirror. Pretty dang confident somebody here will be along with a reasonable solution.

[Nessism]

You need a 5/8" bore master (or 16mm). Don't buy 14mm, or the lever will feel very soft and spongy.

I like the rectangular bore EX650 master. It has a proper threaded mirror post, with the same threads as common GS mirrors. And consider removing the anti dive junk, or at least disabling it. If you remove it, you need a block off plate, with a passage between the holes. Easy to make in your garage with a hunk of 1/4" aluminum plate, and a drill motor.

P1010741 by nessism, on Flickr

[KiwiAlfa156]

If you really want to improve your braking
performance with stock calipers, fit one of these.



It's made in China (like Brembo is) and the quality is superb. Cue the misguided comments on "Chineseium". Ordered on Aliexpress they land at my New Zealand doorstep for about NZD $90.00. Which is about USD $55.00, although with the tariff that 'somebody' pays.. it might cost you more. Lever feel is awesome and is fully adjustable. It allows confidence inspiring control. The radial master cylinder seems to convert more of the lever pressure to caliper squeeze. The one in the pic that I took 10 minutes ago is five years old and when I resurrected the Katana 750 a year or two ago, the choice to fit one to that bike was a no-brainer. The brand is Adelin.

[snoobler]

You need a 5/8" bore master (or 16mm). Don't buy 14mm, or the lever will feel very soft and spongy.

I like the rectangular bore EX650 master. It has a proper threaded mirror post, with the same threads as common GS mirrors. And consider removing the anti dive junk, or at least disabling it. If you remove it, you need a block off plate, with a passage between the holes. Easy to make in your garage with a hunk of 1/4" aluminum plate, and a drill motor.

Any specific years? Does it have the brake switch as well? Both my GS anti-dive systems work pretty well, so I'm inclined to keep them as long as they do.

[snoobler]

If you really want to improve your braking
performance with stock calipers, fit one of these.

It's made in China (like Brembo is) and the quality is superb. Cue the misguided comments on "Chineseium". Ordered on Aliexpress they land at my New Zealand doorstep for about NZD $90.00. Which is about USD $55.00, although with the tariff that 'somebody' pays.. it might cost you more. Lever feel is awesome and is fully adjustable. It allows confidence inspiring control. The radial master cylinder seems to convert more of the lever pressure to caliper squeeze. The one in the pic that I took 10 minutes ago is five years old and when I resurrected the Katana 750 a year or two ago, the choice to fit one to that bike was a no-brainer. The brand is Adelin.

I've had very mixed results on Aliexpress. I have found it's a fantastic way to get ripped off or at a minimum get your funds tied up and require you to dispute charges UNLESS you're dealing with a reputable seller. Can you supply the specific seller you used?

Thanks,

Steve

[Griffin]

The nice thing about Ed's solution is that it works fine, and appears to be a stock (unless one is truly a GS1100 expert) master cylinder.

And yeah, the anti-dive. I have block off plates on two of my anti-dive equipped bikes, and still functional anti-dive on the other. Oddly enough, I've gotten the mushiness out of the bike with the functional anti-dive units to the point it feels just as tight as the blocked off units do. By switching to stainless brake lines, and following the bleeding procedure outlined in the factory service manual to the Nth degree, you can get good results, if you want to keep the stock appearance.

[snoobler]

The nice thing about Ed's solution is that it works fine, and appears to be a stock (unless one is truly a GS1100 expert) master cylinder.

And yeah, the anti-dive. I have block off plates on two of my anti-dive equipped bikes, and still functional anti-dive on the other. Oddly enough, I've gotten the mushiness out of the bike with the functional anti-dive units to the point it feels just as tight as the blocked off units do. By switching to stainless brake lines, and following the bleeding procedure outlined in the factory service manual to the Nth degree, you can get good results, if you want to keep the stock appearance.

Thanks. I hear you.

I didn't mention it, but I've had stainless lines on this bike (GS1) for 15+ years, and I have followed the Suzuki shop manual bleeding procedures multiple times. GS2 recently had stainless lines installed and an ebay aftermarket master cylinder that looks almost identical to the EX650 one pictured above, but it's performance is pretty mediocre. I'm hoping to find a better solution for both.

[KiwiAlfa156]

I've had very mixed results on Aliexpress. I have found it's a fantastic way to get ripped off or at a minimum get your funds tied up and require you to dispute charges UNLESS you're dealing with a reputable seller. Can you supply the specific seller you used?

Thanks,

Steve

Here you go Steve.

Letgoing Co., Ltd.(CHN.)


Just search for "PX1 16mm"

The only other thing to be aware of, is the banjo bolt (which it ships with) is 1.25mm pitch (stock Suzuki is 1.0mm) This is only important if fitting a switch type banjo for the brake light.

[snoobler]

Here you go Steve.

Letgoing Co., Ltd.(CHN.)


Just search for "PX1 16mm"

The only other thing to be aware of, is the banjo bolt (which it ships with) is 1.25mm pitch (stock Suzuki is 1.0mm) This is only important if fitting a switch type banjo for the brake light.

Thank you sir. It looks like they have several options that include a banjo bolt pressure switch with the master cylinder and one that has a brake switch with the same connectors as stock. Gotta weigh my options.

Still have a preference for a Japanese option where rebuild is an option in the future, but this is a very close second.

Thanks again,

Steve

[limeex2]

I used a Triumph Speed triple Master. Love Triumph brakes. When i was member on the ZRX forum, many were using EX500 masters. They never had any issues with them on ZRX's. Not sure if the Anti-dive makes them feel spongey. Most brakes use a 9/16" bore size. The EX's use a 1/2".

[KiwiAlfa156]

Thank you sir. It looks like they have several options that include a banjo bolt pressure switch with the master cylinder and one that has a brake switch with the same connectors as stock. Gotta weigh my options.

Still have a preference for a Japanese option where rebuild is an option in the future, but this is a very close second.

Thanks again,

Steve

No problem, mate. I wouldn't recommending something I don't use myself and am completely satisfied with. "Made in ..." means less these days than ever before. My parents generation referred to Made in Japan as "Jap-crap" back in the day.

The way I see it, China produces about one third of the global vehicle production each year, more than the US, Japan, India, South Korea, Mexico, combined. Surely they don't all come with sh-hit brakes? There's no apparent tsunami of fatalities from Chinese vehicles is there? Last week I inspected a BYD electric pick up that colleague had purchased. Not 'my cup of tea' but the build quality and features were impressive. No wonder BYD now outsells Tesla in Europe.

The world moves on.

[salty_monk]

The EX650 Master cylinder is my favorite of the cheap Ebay options too. You can usually find one for $30 or so.... I have a MC on my shelf you can look at if you want. PM me a cell number & I'll send you a picture of it if you're interested. Not 100% sure what it's off but it does have remote reservoir & is 5/8".

[snoobler]

I used a Triumph Speed triple Master. Love Triumph brakes. When i was member on the ZRX forum, many were using EX500 masters. They never had any issues with them on ZRX's. Not sure if the Anti-dive makes them feel spongey. Most brakes use a 9/16" bore size. The EX's use a 1/2".

That's pretty tempting... I have an '02 Daytona 955i, and I have high confidence in those brakes.

[snoobler]

No problem, mate. I wouldn't recommending something I don't use myself and am completely satisfied with. "Made in ..." means less these days than ever before. My parents generation referred to Made in Japan as "Jap-crap" back in the day.

The way I see it, China produces about one third of the global vehicle production each year, more than the US, Japan, India, South Korea, Mexico, combined. Surely they don't all come with sh-hit brakes? There's no apparent tsunami of fatalities from Chinese vehicles is there? Last week I inspected a BYD electric pick up that colleague had purchased. Not 'my cup of tea' but the build quality and features were impressive. No wonder BYD now outsells Tesla in Europe.

The world moves on.

I get what you're saying. The issue is that Chinese manufacturers can't be trusted by default. A good friend of mine was reliant on a Chinese supplier for a major component of his product (literally no other supplier on the planet). He had to test it extensively. He would regularly discover that 5-10% of the product wasn't even close to meeting spec. Eventually, they quit doing it, so he quit testing to increase throughput - the cost and time required with the level of testing was quite burdensome. His warranty rates were very very low - about 2%.

About a year later, they started doing it again, but at a rate of about 20%. About 6 months later, his warranty rate shot up to... 20%. It almost put him out of business.

I firmly believe that even if you locate the Chinese supplier for Brembo and buy direct, you're very likely to get the quality cast-offs that would be rejected by Brembo.

I personally use Victron products for my off-grid power system, all of which are made in India or China. The only reason I trust them is because they have Victron scrutinizing their suppliers and standing behind their equipment.

There is also a price correlation. $15-20 aftermarket m/c on Amazon aren't confidence inspiring, but ~$50-70 suggests they're not just scraping the bottom of the barrel. It also helps that your supplier has been on Ali since 2016. With that and your testimony, I'm not running scared, but I'm going to be paying very close attention if I go that route.

EDIT: Unfortunately, it looks like 16mm is very popular and out of stock. I'm not seeing anything that works in 16mm. I'd have to go with 15 or 17.5.