Moved rear brake master cylinder to handlebar

[Ricknc]

One of the things that attracted me to the DCT is the possibility of moving the foot brake to the handlebar. I have size 13 feet and in my touring boots the foot brake ergonomics don’t work well for me. I also have some circulatory issues with my feet that includes bouts of numbness in the toes.
I researched here a month or so ago and contacted a forum member who had converted his. Using his advice coupled with my substantial experience with automotive hydraulics. I put together my plan.

The primary consideration was that any mods I made had to 100% undoable. If and when I ever sell the bike it will have to leave with the OEM system and wiring intact.

Most brake master conversions I have seen involved piggy backing the handlebar master cylinder to the reservoir of the foot master cylinder. The forum member who advised me plumbed to the ABS modulator with his version. I went a different way and plumbed the handle bar master cylinder to the junction of the foot brake hose and the hardline to the ABS modulator. The advantage of this was not having to remove the frunk to access the ABS modulator. I just had to remove the right side panel. Because of the location of the brake hose to Hardline junction I had to make a wrench to hook around a side panel mounting tab to hold the new hose fitting while tightening.

I used a Honda fsc600 scooter rear master (43510-msf-305). I had intended to order a new one but they have been on back order for the past 6 weeks. I found a $30 used one on Ebay that I rebuilt.The SS braided 3mm hydraulic hose and AN fittings came from Pegasus Racing.

The 5th photo shows routing of the rear brake line. It follows the parking brake cable past the swing arm pivot and then looping back to meet the hard line. ( marked with red dashes) Instead of tapping into the brake light wiring of the front master cylinder I ran wiring back to the original plug(SC-1103) for the foot brake. (Marked with yellow dashes). Brake hose and wiring is covered with 1/4” wire wrap to prevent abrasion.

I bought a handlebar bridge/brace (22mm )through Amazon to use as a mount for the parking brake

I have about 150 miles on the bike now and it is working well for me. Much easier to modulate the rear brake. The effort is not as high as I expected, though it takes a powerful squeeze to set off the ABS.

*January 2023 update; For those in Europe and elsewhere the NC750 Integra scooter is sold, the Integra rear master cylinder is a perfect match functionally and cosmetically for this mod. Honda part # 43510MGSD71 lever assembly # 53180-MJL-D71

 

[670cc]

Excellent work.

With your experience, maybe you can answer this question. If Honda put the rear master cylinder on the left handlebar instead of at the right foot peg, could they not easily also put a swing out clip on the rear brake hand lever pivot, to also use the main rear brake caliper as the parking brake? This could eliminate the whole secondary mechanical parking brake caliper, the cable, and the lever.

Honda does this on the Ruckus scooter. I just flip a little lever and it holds the rear brake lever engaged. No need for a separate parking brake. However, the Ruckus has a mechanical drum brake. I don’t know if there are potential problems that could develop from keeping a hydraulically actuated brake engaged long term.

 

[Ricknc]

Excellent work.

With your experience, maybe you can answer this question. If Honda put the rear master cylinder on the left handlebar instead of at the right foot peg, could they not easily also put a swing out clip on the rear brake hand lever pivot, to also use the main rear brake caliper as the parking brake? This could eliminate the whole secondary mechanical parking brake caliper, the cable, and the lever.

Honda does this on the Ruckus scooter. I just flip a little lever and it holds the rear brake lever engaged. No need for a separate parking brake. However, the Ruckus has a mechanical drum brake. I don’t know if there are potential problems that could develop from keeping a hydraulically actuated brake engaged long term.

They could, What Honda came up with seems unnecessary for the size bike the 700/750 is. Something like the Ruckus lever would be far less complicated and save a few pounds of weight.
When I was researching I saw a scooter where the parking brake cable was pulled by putting the side stand down. I thought that was ingeniously simple. I seriously considered doing that and if I ever reach the point of not caring about resale I might do that.

 

[lootzyan]

.... I don’t know if there are potential problems that could develop from keeping a hydraulically actuated brake engaged long term.

I think, for heavier scooters, Honda designers didn't want to have brake system pressurized for extended period of time, to avoid potential leaks. Brake fluid is quite corrosive.
I understand what they did with Ruckus scooter. My SH150i has similar design for parking brake.

 

[TheIronWarrior]

Honda does this on the Ruckus scooter. I just flip a little lever and it holds the rear brake lever engaged. No need for a separate parking brake. However, the Ruckus has a mechanical drum brake. I don’t know if there are potential problems that could develop from keeping a hydraulically actuated brake engaged long term.

In most cases, the "parking brake" on small airplanes just locks the hydraulic brake on. It is generally accepted this is mostly used to hold the brakes on while you go through the run-up checks and not for actual parking. When parked, most airplanes have the hydraulic brakes released and the wheels chocked, with windy days or long-term parking involving tie-downs.
There are a few reasons for this. As mentioned above, possible leaks would cause a huge mess, as well as release the brakes. This is only a secondary concern, as braking systems ideally don't leak.
The main concern is that of temperature changes affecting the applied pressure. If the ambient temperature rose, you could end up applying too much pressure and causing some problems, but the bigger issue is if things cool off, especially if you just used the brakes and things were hot. Everything expands when hot and contracts when cool. It is likely that on a cool day, everything would contract after parking (rotors, pads, fluid in the lines) and there wouldn't be enough pressure between the pads and rotors to keep the wheels from turning. Locked hydraulic brakes just don't have the same reliability/consistency as cable operated parking brakes (or other methods of securing the vehicle).

 

[auldain]

They could, What Honda came up with seems unnecessary for the size bike the 700/750 is. Something like the Ruckus lever would be far less complicated and save a few pounds of weight.
When I was researching I saw a scooter where the parking brake cable was pulled by putting the side stand down. I thought that was ingeniously simple. I seriously considered doing that and if I ever reach the point of not caring about resale I might do that.

Can you give more details if possible about the scooter with the link to the parking brake.

 

[the Ferret]

Nicely done. Wish I had those kind of skills

 

[Ricknc]

Can you give more details if possible about the scooter with the link to the parking brake.

 

[Ricknc]

2 month, ~3000 mile follow up. I had the opportunity to ride quite a bit this past 2 months in a variety of situations and conditions. The rear brake pedal to handlebar mount has worked flawlessly. Part of that is I also ride bicycles so I am accustomed to handle brakes. The only ergonomic adaptation has been to coordinate using my thumb for operating the down shifter and the turn signals while rear braking with my fingers . It took me a few rides to get that right.

 

[670cc]

2 month, ~3000 mile follow up. I had the opportunity to ride quite a bit this past 2 months in a variety of situations and conditions. The rear brake pedal to handlebar mount has worked flawlessly. Part of that is I also ride bicycles so I am accustomed to handle brakes. The only ergonomic adaptation has been to coordinate using my thumb for operating the down shifter and the turn signals while rear braking with my fingers . It took me a few rides to get that right.

That’s good news. Thanks for the follow up post.

I have Honda scooters, and both brakes are on the handlebars. As I’m also a bicycle rider, I reversed the front and rear brake positions on the bicycles to match the format of the scooters, with the front brake operated using the right hand. It was a little more work to reverse the brakes on a bicycle with hydraulic disk brakes, but the hassle was worth the effort.

 

[auldain]

One of the things that attracted me to the DCT is the possibility of moving the foot brake to the handlebar. I have size 13 feet and in my touring boots the foot brake ergonomics don’t work well for me. I also have some circulatory issues with my feet that includes bouts of numbness in the toes.
I researched here a month or so ago and contacted a forum member who had converted his. Using his advice coupled with my substantial experience with automotive hydraulics. I put together my plan.

The primary consideration was that any mods I made had to 100% undoable. If and when I ever sell the bike it will have to leave with the OEM system and wiring intact.

Most brake master conversions I have seen involved piggy backing the handlebar master cylinder to the reservoir of the foot master cylinder. The forum member who advised me plumbed to the ABS modulator with his version. I went a different way and plumbed the handle bar master cylinder to the junction of the foot brake hose and the hardline to the ABS modulator. The advantage of this was not having to remove the frunk to access the ABS modulator. I just had to remove the right side panel. Because of the location of the brake hose to Hardline junction I had to make a wrench to hook around a side panel mounting tab to hold the new hose fitting while tightening.

I used a Honda fsc600 scooter rear master (43510-msf-305). I had intended to order a new one but they have been on back order for the past 6 weeks. I found a $30 used one on Ebay that I rebuilt.The SS braided 3mm hydraulic hose and AN fittings came from Pegasus Racing.

The 5th photo shows routing of the rear brake line. It follows the parking brake cable past the swing arm pivot and then looping back to meet the hard line. ( marked with red dashes) Instead of tapping into the brake light wiring of the front master cylinder I ran wiring back to the original plug(SC-1103) for the foot brake. (Marked with yellow dashes). Brake hose and wiring is covered with 1/4” wire wrap to prevent abrasion.

I bought a handlebar bridge/brace (22mm )through Amazon to use as a mount for the parking brake

I have about 150 miles on the bike now and it is working well for me. Much easier to modulate the rear brake. The effort is not as high as I expected, though it takes a powerful squeeze to set off the ABS.

*January 2023 update; For those in Europe and elsewhere the NC750 Integra scooter is sold, the Integra rear master cylinder is a perfect match functionally and cosmetically for this mod. Honda part # 43510MGSD71 lever assembly # 53180-MJL-D71

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Can I ask what was the length of the hose needed to go from the lever to the Hardline junction. Also what was the size and style of the union needed at the Hardline junction. Regarding the wiring, I like your use of the existing plug from the footbrake master cylinder rather than splice into the front brake wiring. Can I ask is the plug SC-1103 you quote a Honda part and dies that simply fit into the original plug that fitted onto the four brake master cylinder. Does this set up make the original pressure switch in the foot brake master cylinder redundant? Your help will be much appreciated.

 

[auldain]

2 month, ~3000 mile follow up. I had the opportunity to ride quite a bit this past 2 months in a variety of situations and conditions. The rear brake pedal to handlebar mount has worked flawlessly. Part of that is I also ride bicycles so I am accustomed to handle brakes. The only ergonomic adaptation has been to coordinate using my thumb for operating the down shifter and the turn signals while rear braking with my fingers . It took me a few rides to get that right.

More queries. Can I asked what connections you used to connect your custom hose to the ABS fixed line. I’ve attached a photo of the OME flexi hose to hard line “block.” The flexi hose connection block is shown as all one piece as part of the flexi hose, so I’m not clear how you connected the custom hose to thd fixed line.