De-Linked Front Brakes Check

[texasmoto]

I'm de-linking the brakes on an 850t3 restoration and wanted to run by my plan for the front brakes:

The front has dual disc Brembo F09 calipers. I'm planning on routing each caliper to the valve housing using a two-hole banjo bolt. Of course, the other end of the housing routes to a Wilwood master cylinder.

This seems pretty straightforward, but just wanted to double check since I've never done anything 'custom' with brakes before.

[guzzisteve]

That  sounds like one way, the other is to use a T on the fork lower triple. This lets you run 1 hose 1/2 way.. Both work.

[Perazzimx14]

You may also have to look at getting a smaller mastercylinder fo rth efront brakes since you are reducing th esystem by 33%??

On my 850 the OEM mastercylinder was oversized from the factory (for 3 discs if memory serves) and the brakes felt wooden. Installed a 10.9mm (again going from memory this was back in 2016-ish) Mastercylinder and the brakes feel and pull was greatly improved.

As is were you can run individual lines to each caliper double stacking them at the mastercylinder. Or as an alternate you can run one to the fender add a splitter and individual short lines to each caliper or you can entend one brake line to one of the calipers then extend anotehr hose from that caliper up over th efender and down to the other caliper.

[Dukedesmo]

I used a Brembo RCS15 for my LM2 delinked front brakes, works perfectly.


As for the lines, I went with a dual banjo at the master cylinder and 2 separate, braided hoses to the calipers as, IMHO that's the best/easiest setup as it avoids complicated 'T' connectors or a loop over the front wheel. 

[blackcat]

I went with the dual banjo fittings at the smaller master cylinder on my CX with a longer threaded pressure switch at the end of the fittings.  Never got a round to changing the rear master cylinder but I only use it for slow parking lot type stopping but I kept the splitter valve.

[John Croucher]

You may also have to look at getting a smaller mastercylinder fo rth efront brakes since you are reducing th esystem by 33%??

On my 850 the OEM mastercylinder was oversized from the factory (for 3 discs if memory serves) and the brakes felt wooden. Installed a 10.9mm (again going from memory this was back in 2016-ish) Mastercylinder and the brakes feel and pull was greatly improved.

As is were you can run individual lines to each caliper double stacking them at the mastercylinder. Or as an alternate you can run one to the fender add a splitter and individual short lines to each caliper or you can entend one brake line to one of the calipers then extend anotehr hose from that caliper up over th efender and down to the other caliper.

I used option 3, bottom image.  Run one hose to right caliper with a curved banjo, long two hole banjo bolt.

Ran second line over fender with a 90 degree banjo on each end.

Buy banjo bolts first, install, then measure hose lengths.

Vintage Bake .com has a good chart for calculating m.c. piston size.

Too small and the brakes will be soft, too big and they will be hard, but no stoppower.

[wirespokes]

The F09s are bigger than the stock calipers, so you might need a larger front master. I like the feel using the stock master for both front calipers - F08s.

As for brake lines, I like the stock setup with flex lines only where they're needed and kept as short as possible.

[texasmoto]

I used a Brembo RCS15 for my LM2 delinked front brakes, works perfectly.


As for the lines, I went with a dual banjo at the master cylinder and 2 separate, braided hoses to the calipers as, IMHO that's the best/easiest setup as it avoids complicated 'T' connectors or a loop over the front wheel. 

Would simplify if I could but the Wilwood master cylinder doesn't have electrical connections. I have to keep the junctions for the rear brake light switch. I would like to be able to drive on the road lol

[texasmoto]

I used option 3, bottom image.  Run one hose to right caliper with a curved banjo, long two hole banjo bolt.

Ran second line over fender with a 90 degree banjo on each end.

Buy banjo bolts first, install, then measure hose lengths.

Vintage Bake .com has a good chart for calculating m.c. piston size.

Too small and the brakes will be soft, too big and they will be hard, but no stoppower.

That is a very helpful resource, thank you.

I bought a 5/8 Wilwood master cylinder, but with the 2 48mm F09s calipers (2 pistons) I'd have had a ratio of 18:1, which can result in a lockup. If I go smaller to 14mm, I'd get a 23:1 ratio.