Single front disc conversion?

[Windblown]

12 hours ago, Ray Ride4life said:

I have a single rotor kit with rear ABS delete form Stoltec on it's way, expect it here early next week (is at the customs).
I bought an EBC disk to go with it.

 

Pretty sure that's the same kit I used, or at least the same adapter by Motoswiss. It was nicely put together and I appreciated the lines having the rubber bushings in place to make the install straight forward.  I had to deepen the rotor groove slightly in the adapter to get clearance. The outer edge of the Galfer rotor was kissing it slightly.  Would have worn in eventually but it bugged me hearing it rub. 

 

As anticipated the braking with the stock MC is brick hard and lacks power.  Way too big a piston bore. Lot's of fluid, not enough leverage.  A YZF450 Master cylinder is in route. 

 

 

Edited January 13, 2023 by Windblown

[Ray Ride4life]

I will see what it does and look at options when i don't like it.

[blazoPL]

I'm just posting it here so it doesn't get lost. Great info (by our users) about Master cylinders and calipers piston ratio can be found on "What have you done for your T7 today? page (154): 

 

[JayD]

On 1/13/2023 at 6:18 PM, Windblown said:

 

Pretty sure that's the same kit I used, or at least the same adapter by Motoswiss. It was nicely put together and I appreciated the lines having the rubber bushings in place to make the install straight forward.  I had to deepen the rotor groove slightly in the adapter to get clearance. The outer edge of the Galfer rotor was kissing it slightly.  Would have worn in eventually but it bugged me hearing it rub. 

 

As anticipated the braking with the stock MC is brick hard and lacks power.  Way too big a piston bore. Lot's of fluid, not enough leverage.  A YZF450 Master cylinder is in route. 

 

 

Did you try the stock MC with a single disc? Piston too big, but was it absolutely terrible? I’ve heard some used it with okay results. Will eventually upgrade down the line though..

[Windblown]

1 hour ago, JayD said:

Did you try the stock MC with a single disc? Piston too big, but was it absolutely terrible? I’ve heard some used it with okay results. Will eventually upgrade down the line though..

 

I ran it with the Stock MC for a few days until I got my hands on a properly sized MC. It was usable, but it lacked both feel & power. Pretty dang craptastic. You can't halve the total piston area being used on the Brake caliper side and expect good results if you don't change the piston area on the Master Cylinder side. 

[BADDANDY]

The 1st MC I tried was a 14mm for an XT350, the 2nd for a wr450F unlisted mm.  Stock and these two felt wooden. 

Today I installed an 11mm MC for a WR125R.  MC sure seems a lot less wooden now. I haven't test ridden yet due to finishing late and bike is still on the lift for a new rear brake line. 

The MC I got wouldn't bleed and felt rough, so I removed the piston which did measure at 11mm.   The bore was filthy and dryish, maybe caused the bushes to roll?  Cleaned, reinstalled and she bled perfectly. Oh, and I also had to tap the threads for the mirror and mod switch wires.  A one hour job turned into 5!

The cool thing is this MC came with the same shortee lever but black as the WR450 had in red, so I was able to swap them out plus reuse the 450's red cap.

After I install the line, the test ride will be for the new MC, new pivot point on the rear brake pedal, and the rear line.

Edited March 11, 2023 by BADDANDY

[JayD]

Thanks a lot to both of you. So I have some questions left. With a new 11mm MC, will the ABS in front still work? And will the rear brake light flash when braking? I see there’s a few wires on the underside of the stock MC, and I’ve never done any brake work except bleeding

Edited March 11, 2023 by JayD

[Ray Ride4life]

I kept the standard MC with this conversion, want a bit more riding before i decide to change it or not.
The wires on the MC are for the switch that make it possible to start the engine when in gear and NO, it's not removable because somehow it's connected to the ECU.
ABS is regulated via the ABS ring on the wheel, the brake hose from the MC connects to the ABS pump and from there the hoses go to the caliper so ABS still be working like normal.
Rear brake light has a switch at the brake pedal which you don't need to touch with this kit.

[JayD]

Thanks a lot @Ray Ride4life.

 

Okay, so those that change out the MC for a smaller one they will have to start tye bike in neutral every time because of mentioned switch?

 

I assume those who do that also bypass the ABS completely and route new cable directly from MC to caliper?

 

Sorry I meant the brake light when using front brake I assume there’s a switch on the stock MC, but dont know if thats common on smaller, offroad oriented MCs. Thanks again.

[williestreet]

3 hours ago, JayD said:

Thanks a lot @Ray Ride4life.

 

Okay, so those that change out the MC for a smaller one they will have to start tye bike in neutral every time because of mentioned switch?

 

I assume those who do that also bypass the ABS completely and route new cable directly from MC to caliper?

 

Sorry I meant the brake light when using front brake I assume there’s a switch on the stock MC, but dont know if thats common on smaller, offroad oriented MCs. Thanks again.

The lack of a clutch switch will require starting in neutral.  The brake switch or lack of one has no effect on starting the bike so do not worry about that.

Absolutely no need to remove or bypass the ABS unless you want to.  As mentioned before ABS looks at wheel speed front and rear to determine if it needs to actuate.  It doesn't know or care what type of master cylinder or how many brake discs you have on the bike.

 

If you install a dirt bike master cylinder with no integrated brake switch you can purchase an aftermarket hydraulic brake switch.

Basically it is a replacement banjo bolt that has a built in pressure switch that activates when you pull the lever and build brake pressure in the lines.

 

These are commonly installed on the rear but can also be installed on the front.  Remove stock banjo bolt, install brake switch banjo and connect wires to stock brake switch wires.  Just make sure you get one with correct size bolt and thread pitch.  Most Japanese bike are the same , but some Italian and others use different size/pitch.

 

Here is a link to a video.  Sorry it's not in English but around the 4 minute mark it shows how easy the install is.

 

Amazon.ca Something Went Wrong / Quelque chose s'est mal passé

 

Edited March 11, 2023 by williestreet

[Windblown]

3 hours ago, JayD said:

Thanks a lot @Ray Ride4life.

 

Okay, so those that change out the MC for a smaller one they will have to start tye bike in neutral every time because of mentioned switch?

 

I assume those who do that also bypass the ABS completely and route new cable directly from MC to caliper?

 

Sorry I meant the brake light when using front brake I assume there’s a switch on the stock MC, but dont know if thats common on smaller, offroad oriented MCs. Thanks again.

 

The switch on the brake side won't impact starting the bike. It's there to operate your brake light. I installed a hydraulic brake switch since the new MC I used didn't come with one.  Hydraulic switches are easy to get, inexpensive, and work great. If you don't install a switch your brake light will not come on when you apply the front brake., that would be bad.  

 

As to the line routing - Yes, if one is ditching the ABS the brake line would then be run directly between the MC & BC. 

 

I'd suggest to keep on reading up on the subject from several sources before diving in. It's important to feel pretty comfortable with what you're looking at and know how each part plays with the others before diving in too far.  Unless you're like me, in which case you occasionally have to learn the hard and sometimes painful  way in order to remember why it's a bad idea. Ha. 

Edited March 11, 2023 by Windblown

[JayD]

Thanks a lot @williestreet, very useful information!

 

@WindblownHehe I’ve been there many times, bitten over more than I can chew, but I’ve learned a lot that way. This operation doesn’t sound too advanced, I just didn’t know as I’ve never touch brakes besides replacing brake lines and bleeding them.

 

Sounds like the ‘biggest’ challenge is getting the brake light to activate when using the front brake. I’ll have to read a bit more about those hydraulic switches.

 

Thanks again guys, you’re the best

[BADDANDY]

The MC I bought has a brake light switch although I had to change the connectors to spades to go into stock wiring. I run steel braided lines; MC to ABS, ABS to caliper.  I made the "NEWB" mod to shut off ABS when offroad.  I have a few extra kits if any Wetsiders want one. 

 

 

Edited March 11, 2023 by BADDANDY

[Ray Ride4life]

5 hours ago, JayD said:

Thanks a lot @williestreet, very useful information!

 

@WindblownHehe I’ve been there many times, bitten over more than I can chew, but I’ve learned a lot that way. This operation doesn’t sound too advanced, I just didn’t know as I’ve never touch brakes besides replacing brake lines and bleeding them.

 

Sounds like the ‘biggest’ challenge is getting the brake light to activate when using the front brake. I’ll have to read a bit more about those hydraulic switches.

 

Thanks again guys, you’re the best

Just curious since you're not seem very technical (not any form of accusation or otherwise negative), why do you want a single rotor?
I mean, it's a pure offroad mod and most people having use for this mod are out of necessity somewhat technical.

[JayD]

@Ray Ride4lifeHehe, I know the basic stuff, but I’m not too good with the electrics, hence the questions about the switches etc.

 

Appreciate your concern though, I’m doing this to shed unsprung weight to make it as offroad capable as possible.

Edited March 11, 2023 by JayD

[Ray Ride4life]

I mostly encourage doing the work on the bike yourself but a few things i'm always thinking it might be better to get a bit more experienced.

[BADDANDY]

Holy cow! My BRAKES ARE AWESOME NOW!  

Front single disc: 11mm MC w/shortee lever, 318MM rotor, Motoswiss bracket, semi-metallic pads, and steel-braided brake lines.

Rear: Stock MC, disc, pads, and lines. Relocated actuator pivot point and offset link.

Nerb 1 ABS shutoff switch mod.

I'm done!

Edited March 11, 2023 by BADDANDY

[blazoPL]

On 3/11/2023 at 10:07 PM, BADDANDY said:

Holy cow! My BRAKES ARE AWESOME NOW!  

Front single disc: 11mm MC w/shortee lever, 318MM rotor, Motoswiss bracket, semi-metallic pads, and steel-braided brake lines.

Rear: Stock MC, disc, pads, and lines. Relocated actuator pivot point and offset link.

Nerb 1 ABS shutoff switch mod.

I'm done!

 

Great to hear! Thanks  for the MC suggestion. I was looking long for a 11mm MC with brake sensor. I ordered the same
Can you tell me moreabout "Relocated actuator pivot point and offset link." It sounds interesting! 

[BADDANDY]

I welded a tab to the brake lever (red), drilled a new hole (green), and bent up a new link (yellow).

 

 

Edited April 10, 2023 by BADDANDY