1998 VFR 800 - Brake Delink Project - Front & Rear Master Cylinders (Step 4)

I have a bit more prep work before I start putting components back on the bike. I purchased both a front and rear master cylinder from a CBR600 F4. The front uses a 5/8" piston and the rear uses a 14mm piston (can not figure out why companies are still interchanging English and SI units). I selected the 5/8" from a CBR600 F4 front master for two reasons. First, it matches the existing VFR brake and clutch lever assemblies, so it will look stock on the bike. Second, the 5/8" size will provide a brake feel that is within the range of the stock VFR and the VTR. Some quick math told me that the caliper piston area of the 954 calipers is 6041mm^2 and the area of the CBR600 F4 master cylinder is 199 mm^2. That yields a caliper / master cylinder ratio of about 30. A stock VTR has a ratio of about 33. The VFR stock ratio is about 26. So I am right in between.

For the rear, I performed a similar analysis and selected the 14mm from the CBR600 F4 also. The ratio of the VFR caliper (with the three pistons connected together) to the CBR600 F4 master is about 9. The stock VTR has a ratio of about 7. The stock VFR ratio is about 9.5. So again, I am in the ball park.

The front master required no modifications (sweet). The rear master required that I trim the connecting shaft that connects to the brake pedal. I just trimmed an amount to make it the same dimension as the stock VFR rear master. See the pictures below.

That is all the writing for this morning. Next steps will be to swap in the VTR forks after I replace the springs with some new Racetech 95kg springs that the nice UPS man brought to me last night.

 

Hi Mike - I've been searching hi and lo for part 5 [and part 6 if it exists] of your brake delink project. Do parts 5 & 6 exist? If so, can you point me toward them?

Thanks

 

Sorry for the tease..I don't think I posted anymore follow up pics or comments. I will look to see if I have any additional pictures. Truth be told, once you have removed the existing system, prepared the front and rear calipers, obtained the correct front master and obtained and modified the rear master, the rest is just putting things back together.

I did get creative with the rear brake hose routing through the swing arm.

I will look for pics on my computer and post as a Part 5 and final.

By the way, I love riding the bike with de-linked brakes...

Mike

 

No worries Mike - no need to resurrect your project, though I would dig on seeing photos of your through-the-swingarm brake hose routing.

I read all four parts of your project carefully, and was looking for part 5 to answer the two questions I couldn't find the answer to:

[1] Were you able to use the stock gen 5 axle, axle spacers, and wheel on the VTR forks with no modification?

[2] Which fender and/or adapter brackets did you use?

Thanks

Lance

 

Photos and a small explanation regarding are always a welcome sight, ya never know who's doing what here. I'm about to do this very thing, only item left is figuring out how I want the brake lines to work out , that and the bridge on the rear caliper

 

Calipers are cheap: Drill it. You do need to split the caliper and remove the pistons, but rebuild kits are available. Pop a stainless M10 x 1.25 hex pipe plug into the extra port. So much nicer than faffing about with external manifolds or hideous u-turn brake lines.

Btw, the 6th gen rear caliper has slightly different pistons than the 5th gen. My calculations suggested that Mike's calculations are correct, and that the 6th gen rear caliper is a better match for the 14mm rear master, so I bought some (and the ABS version is nice and gold).

Ciao,

 

Good to know as a fact, as I was pondering that idea too. In that just maybe I'll hunt down a 6th gen rear Caliber and work it over. I'm a believer in keeping the look and action as simple as possible. In that regard what "Y" if you did , use on the front? I'm preferring one line leaving the MC then splitting it off at the lower triple.

 

RVFR - looking forward to seeing your project come into being. You've been doing good research and asking good questions.

Good call on the rear caliper treatment JZH - drilling is so tidy. Thanks for mentioning the slight but advantageous difference between the gen 5 and gen 6 rear caliper ratios. Is the gen 6 better with 14mm rear m/c because the caliper has larger or smaller pistons? I ask because I'd like to understand if the power of the 14mm m/c is optimized when paired with slightly larger caliper pistons or with slightly smaller caliper pistons.

Do gen 6 rear calipers bolt onto gen 5 caliper brackets? Or is some adaptation required?

When you say you 'bought some" gen 6 rear calipers, what projects are you pointing them toward?

Cheers.

 

RVFR - have you read Mello Dude's brake delink/fork thread?

http://vfrworld.com/forums/showthre...ga-and-the-Interceptor-SS?highlight=f4i+forks

He used a brake line manifold from an FZ1 to split a single brake hose from master cylinder into two lines to front calipers. Very tidy.

 

I have the 14mm rear master from a CBR250RR, and it fits without much modification, but with the stock 5th gen caliper (internaly drilled) I find it too weak.
I'm thinking it would be better with a 1/2", as it will give it a bit more power.
I will hunt for one, or the later 6th gen gold caliper as it would suit the front much better.

 

When I did my delink and VTR fork install, the CBR600F4 parts that I bought came with braided lines that joined through a double banjo bolt at the master. There are enough hose clamps in the linked system to find suitable bits to secure the hoses behind the fork leg and to the front of the lower triple clamp.

For the rear, I re-used the stock hoses and joined them at the CBR600F4 master, using a double banjo bolt from the linked system (IIRC, from the PCV fitting under the seat). The second rear hose that joins the caliper to the linked system is a good fit when re-used in this way, and I did not touch the caliper at all.

 

I have read Mellos take on this, very well documented too. I saw what he used, so I've kept my eye out for one. Also thought about making one too or? I had one for the 73 Kawasaki 903 back in the day when I did the dual disc up grade, so have an idea what is needed, just figure with all the time now that bikes have had dual discs there would be a drop and play version readily available. Nothing like re-purposing.

 

I'm using different forks on both of my 5th gens, so never had to give much thought to the front 3-pot calipers and SMC. There are no elegant ways of de-linking the front brakes, IMHO (apart from doing a fork swap!)




Ciao,

 

Lance - I purchased a set of front fender brackets from someone on this forum - Mello Dude, I recall around $70, fit was perfect.

Also, I recall using the front axle and spacer set up from the VFR. You can verify by taking a measurement of the space between the axle mounts of the VFR forks when after you remove the wheel, then take a measurement of the same space once you install the VTR forks. I have some install notes in a folder somewhere. Will look to see if I kept these measurements.

 

Mello Dude is the man!

 

I can confirm that the 5G wheel, axle, spacer and discs fit perfectly in VTR forks with no mods. The fork legs need a little filing to clear CBR600 etc calipers to stop the lower mount hitting the top of the caliber. 5 minutes per leg with a hand file. I left the outer face of the mount untouched and filed a step to clear the calliper which looks untouched when mounted.


Sent from my iPhone using Tapatalk

 

Hey that's great news about the stock gen 5 axle and spacers. Thanks Mike and Terry!

I was bummed that Mello Dude had stopped producing his sweet fender brackets, but OZ is sharing his methodology for hand fabricating brackets and that will help me get it done.

 

RVFR: What is the distance between the two mounting bolts on the lower triple for the horn bracket? Perhaps the "splitter" from a VF500/700/1000 might bolt right up?

 

Here are the drawings for my guard brackets.
I used 20mm x 3mm flat aluminium bar from local hardwear store.
This is for the brackets on the front brake lever side.
You will have to keep the bends really tight, specially for the top brackets.
You will also have to make the clutch lever side bottom bracket mirror image from this.
Best to get 6mm allen bolts to attach to forks to keep the head as close as possible to the top bracket bend.
If you are out by a mm or so, you can use washers to pack them out from the forks.
Also keep the area where the guard attaches fairly small as it will push on guard if too big.
The best part about using aluminium, is that you can bash it a bit or use pliers to fine tune once attached to fork to sit it tight on the guard.
They are also in metric (mm), as we don't speak neanderthal here :smile-new:.

 

Picture of finished product.
And if you use CBR954 calipers like I did, you will have to pack them out by 3mm to center them on the disk.
I used 2 x washers per bolt to do this.
I got a lot of help and info from Terry Smith, thanks again mate, who like me, doesn't seem to be happy with anything standard.
I didn't bother with hose splitters, keep it simple, you will only need 2 hoses made as opposed to three.