Improving the brakes


#21

Ah, right
Thanks for that.
That’s good to know.
I thought the early Cb1 had the 41mm, before the 1300 got the 43mm.
Then again, relying on non-technical sources for this kind of information had its risks :slight_smile:

So will an early CBR set up slot into the VF yokes? As in, wheel, etc?


#22

Forks are the same length and diameter everything else is bolt on


#23

Right, so.
That’s the best plan.
Off to T’Interwebs!


#24

Here is my brake setup on my 1983 CB1100F special, I have 1992 VFR 750 forks with Honda Firestorm Sliders and 4 piston calipers in VF1000 Yokes, with a VF1000F front wheel with 296mm discs, awesome brakesIMG_3119


#25

Very interesting.
The combination of 4 pots and the larger diameter disks looks good for braking effort.


#26

Well, the Goldfren brake pads arrived today!
They look very nice.
Very nice and wrong!

I’ve no idea what they are for, but they are incorrect.

Arse feckery!

Bloody Germanians and their giving the impression of ruthless efficiency. :wink:


#27

Can you post some pics of them?


#28

It looks like I may have been somewhat hasty. The back plate design just look different, butt he measurements look correct, compared to the Brembos that are in it.

That said, I’ve just discovered that there are now Brembo carbon Ceramics available for the VF range, so there’s another option if the Goldfrens turn out to be chocolate.


#29

UPDATE:
Got a chance yesterday to get stuck in and I stripped both callipers for a good clean and grease.

They were both more or less spotless, which is encouraging.

Seals and dust seals were perfect. The pistons are stainless, butt here was some encrusted crud on the exposed ends. Some wire wool got them acceptable.

I reassembled and then put in the new pads and put ti all back together with some brand new fluid.

Bleeding took a while, even having used a vacuum pump to actually fill the lines and callipers.

I’m still not entirely happy with lever feel, as there seems to be more travel than previously to sustained pressure.

An hour’s shake down today to bed them in however, has proved most disappointing.
While initial bite is mildly better, there is still little progressive build up of stopping power.

I did another bleed after returning, and lever feel is a but better, but even then, not as good as before.

Overall, it was about €80 including new fluid and pads and all for fuck all benefit as yet.

I has a sad :frowning:


#30

Just tie the brake lever tightly back against the handlebar overnight, that normally improves things by compressing the fluid it helps remove any air trapped


#31

Did that, thanks. Not really improved things.


#32

Further update:
After a long spin the other day, I left it overnight and then bled both sides again.
That at least got the lever feel back to where it was before.

I took it out for an hour again today on country roads and gave it a spirited ride.

The best I can say is that the Goldfren pads are no worse than the Brembo HH ones.

Their initial bite is a little better, but it takes hard and sustained three finger squeeze to get anywhere near what I would term confident stopping power.

It answers the question of whether there is something fundamentally wrong though. It would just seem that it is about as good as I am going to get from the current set up — which I find entirely inadequate.

I intend to have this as my daily driver until at least the end of 2019, so at this stage, I may look at other options, like a radial master cylinder, as a new front end to accommodate VTR callipers is beyond the budget for now.


#33

Just completed plumbing the front brakes up on my project bike,I have fitted this with radial master cylinders for brakes and clutch.
I am also using Firestorm fork lowers,brakes and a vfr750 wheel and discs.
As an interim measure I could recommend trying a radial master cylinder.
It will vastly improve your present set up and will also work with any upgrades you do
Regards Bif


#34

What radial MC did you go for?


#35

PNG
Didn’t want to go stupid money so gave these a try.
Be careful tho the port thread is 10x1mm not standard Honda 1.25 pitch


#36

Many times when bleeding the front brakes can be very difficult to get all the Air out, A method I have been using for a few years to fill and bleed the system easily and effectivley is to use an oil can filled with brake fluid and fill the system through the bleed nipples on the calipers, this method works well as you are forcing the air up through the system, i start with the system empty, then i loosen one bleed nipple and pump fluid up until it reaches the master cylinder, i then tighten the nipple and switch to the other caliper and repeat, then fill the master cylinder and blled normally, i can normally bleed the front brake sucsssfully in 15 miniutes and if it does fell slighty spongy I just tie the lever back against the handle bar for a few hoursjpg~original


#37

After long experience with fairly shit Tokico calipers on a line of Kawasakis, I invested in a Mityvac vacuum pump.

However, I still find the way to go is the vacuum pump to fill the system, and then the old fashioned bleed to finish it off.

But this is not my problem now. Even with very firm level feel, the braking force is just not there. It still feels like the force at the lever takes a long time to turn into actual retardation. Hence the search for a sharper MC to drive more pressure.

With the standard 5/8" (15.875mm) MC I reckon I could go to 14mm for some benefit?

What would that translate to in a radial MC? Most of the one’s I’ve found seem very short stroke (18mm) compared to the standard 41.6mm.


#38

Update:
Decided on an experiment.

Bought a radial matter cylinder on Aliexpress. It’s a 17mm one. As the existing one is 5/8" or 15.875 mm, so the radial effect combined with the larger fluid displacement should add up to better braking. Not planning on having it as a long term solution, but it was so cheap, if it proves the concept, I’ll invest in something better quality.

I know a smaller bore size is what gives you more pressure, but having read all the gubbins about how the radial MCs work, it seems the mechanical advantage of the lever action more than overcomes the slightly smaller piston.

We’ll see.


#39

the Chinese MC has arrived and I have to say it looks spot on.

It is easily as well made as an OEM Brembo I have seen on Triumph SteamTriple, thought obviously I can’t yet comment on seal quality.

Did a quick test and my pattern mirrors even fit the remote reservoir mount - score!

It also has a bleed nipple, which should make that final bleed a easier.

@bif you had mentioned that the port thread is 10x1 as opposed to 10x1.25. Does that mean I need a new banjo bolt to fit? And what are you doing for a brake light switch?

Will fit over the weekend and report in full.


#40

The master I used has a switch fitted but was also supplied with a switch integrated into a banjo as an alternative.
Worth checking the banjo thread I had to buy a 10x1 single banjo