EBC GPFAX

SteveA · May 27, 2018

storm42 said:
Do single discs cause that much of an imbalance that it becomes a problem?

Absolutely no.....assuming your fork bushes are in good condition.

SteveA · May 27, 2018

But I should probably also say....if I changed from HH pads and had been happy with them, but tried something else as a possible improvement, and then found it didn't suit me!

Well I would just refit the HH!

storm42 · May 27, 2018

Fast Eddie said:
I wasn’t at Donington but will be at the Mallory Festival and hopefully Beezumph.

I’m doing a track day at Cadwell the Thursday before Beezumph then going directly to Anglesey (well at least that’s the plan).

The Cadwell track day is run by the Morini club and they had spaces last I checked.

How do you know the Mallory Festival is full? Attendance has been low these past years, I’d be surprised if they’re booked up.

I have done the Morini track day a couple of times and I think I am free that weekend so I will have a look at doing that.

I live in the Sheffield area if you would like a stop over on the way to Anglesey.

When I looked at doing the Festival, I thought it said the entries closed in April.

Fast Eddie · May 27, 2018

It would be great to see you at Cadwell if you can make it (Thursday 11th July).

It would be worth ringing the VMCC, if there are spaces I’m sure they’d be willing to take your money, dealing or no deadline !

Thanks for the offer of digs, I think I’m sorted though.

storm42 · May 27, 2018

o0norton0o said:
I have a modified brake system on my commando too. I got rid of the leaky lockheed 5/8" diameter master cylinder. I bought a master cylinder from Don Pender (madass is his name here) which doesn't leak, has a 13mm diameter (I think) and has a perch shape which enables you to mount the stock lucas switch cluster. It was a welcome change in both better brake lever feel and power, with no more leaking of brake fluid, which over the years had ruined numerous paint jobs on my fuel tank.

I also modified my bike to accept cast wheels and a 1" diameter larger yamaha disc. I still use the stock lockheed caliper mounted on an offset bracket to give clearance for the larger disc. It all works way better than the stock commando parts I had previously. I can brake powerfully with 2 fingers on the lever and the sensitivity is very good. I got lucky in some respects because I didn't design the system specifications. I threw it together from what was available and it happened to work well.

Don's master cylinder came with a braided steel fluid line too. It was a bargin and an improvement. I know Don makes an entire kit which include a lightened rotor and high tech caliper along with the master that I bought.

*** The reason we grind the pads for a certain race car was because that "Class" of cars didn't allow a proportioning valve to be used, so grinding the pad was a legal way to bias the brake force amongst the 4 wheels. It worked, but it was a pain in the ass. The car we ran in the next class up had a proportioning valve because it was legal in that class.

You should find out if it's legal to run a single disc in your class, that sounds like the best option because of the lightening effect of losing a disc and caliper on one side. Then experimenting with different pads may help you dial in your braking preference. A lot has been said on the site here for resizing the master cylinder to improve braking. After switching to Don's master, I also would suggest either sleeving down the lockheed master (which there is a kit available) or switching to a different master altogether.

Regardless of what choices you make, you can always experiment with grinding the pads you have to adjust your braking feel at a last resort, only potentially ruining a pair of brake pads if it doesn't have a positive effect...

Post some pictures. I'd love to see your race bike.

Ha, these pads are over $100 for 4, much cheaper to try different ones me thinks.

It is leal to run 1 disc as I am only doing track days at the minute.

I have just took some pics and when i find out how to post them !!!!

SteveA · May 27, 2018

Grinding away brake pads is something I would only ever try on a rear brake!

Because I don't use it except in emergencies!

The mere mention of proportioning valves sounds like part of a Honda nightmare solution to a problem that never existed in the first place!

I have used a proportioning valve (simple pressure reduction valve), but only when we could not use the preferred solution of a dual master cylinder, adjustable bias bar linked pedal box on a rally car, to play with the balance between front and rear braking to allow deliberate overbraking on the rear to turn the car on loose surfaces! But is a long time since I regularly practiced my Scandinavian Flick!

Fullauto · May 27, 2018

I run a Production racer front end with a Lansdowne conversion, 11.5 inch floating disc with the AP caliper with, as far as I know, standard pads. I have one of the 13mm bore standard master cylinders from AN. For the road, this is a really good setup, with good, progressive feel and very powerful stopping. Very linear delivery. If you want more, squeeze harder! But, this is a road bike. Going to a single disce would remove a lot of weight.

storm42 · May 28, 2018

Here you go oOnortonOo, Pics.

The offending items.

storm42 · May 28, 2018

Rear tires aren't going to last long.

storm42 · May 28, 2018

I have a small LiPo battery so I need to keep an eye on it.

My paddock scoot dwarfs it.

storm42 · May 28, 2018

SteveA said:
I am racing a Rickman with a single Lockheed caliper on a 11 inch cast disc and GPFAX pads......they replaced Ferodo race pads and were a noticeable improvement. There is some more noticeable disc wear, but not horrendous.

I have a 14mm master cylinder (early '70s Honda CB500 copy) and think 13mm would be an improvement. I don't think I would try 11mm, maybe 12 as a minimum. Though 14mm and the single disc works for me, I would note I have momentarily locked the front due to a minor lack of feel on deep standing water at the end of a straight. I have outbraked bikes fitted with more disc and less weight! (I am 100kg plus riding gear).

I am not really sure why you would want twin discs on your Seeley, the majority of competitive riders including Gary Thwaites on Watson's 1007, use a single disc. I planned an option of twin discs when I built the bike, but it is really unlikely I will fit a second disc. You would most likely want a bigger tyre (110/80) to cope as well, and I prefer the 90/90 for turning. If you were running a triple with twin 10" I could understand it.

I have a pair of Bendix pads in the tool box that I haven't used but I know would stop faster than the GPFAX pads because I have used them on a GSXR750SRAD...they are single finger braking from flat out, as long as they don't get wet! (Advice is if they get wet, bin them!) Upshot is I will stick with the GPFAX, I also have them on a lighter 500 single with a steel disc and a 13mm Master cylinder. I like them on that too, very much, regularly able to brake very late with that, could be the 13mm Master is better suited but I would not be allowed to use that particular one on a classic.

Just what i needed to know, the reason there are twins on it is because I have a Commando with a similar setup, of course the Commando is a lot heavier and on HH pads, every day is a school day.

I have a 110/80 on the front and because I seem to be able to use good brakes, I did set the bike up for strong brake performance, but I have gone too far.

Single disk setup is on its way. Thanks.

storm42 · May 28, 2018

SteveA said:
But I should probably also say....if I changed from HH pads and had been happy with them, but tried something else as a possible improvement, and then found it didn't suit me!

Well I would just refit the HH!

I have a similar setup with HH pads but on a Commando, I haven't tried them on the Seeley.

storm42 · May 28, 2018

Fullauto said:
I run a Production racer front end with a Lansdowne conversion, 11.5 inch floating disc with the AP caliper with, as far as I know, standard pads. I have one of the 13mm bore standard master cylinders from AN. For the road, this is a really good setup, with good, progressive feel and very powerful stopping. Very linear delivery. If you want more, squeeze harder! But, this is a road bike. Going to a single disce would remove a lot of weight.

I have Johns internals in my Commando, good aren't they!!!

storm42 · May 28, 2018

Fast Eddie said:
It would be great to see you at Cadwell if you can make it (Thursday 11th July).

It would be worth ringing the VMCC, if there are spaces I’m sure they’d be willing to take your money, dealing or no deadline !

Thanks for the offer of digs, I think I’m sorted though.

I think the 11th is a Wednesday, and unfortunately we are off to the Beezumph on Thursday so won't be able to make Cadwell. Bugger.

Just re-joined the VMCC so will give them a bell tomorrow and see if I can get an entry.

See you at the Beezumph.

Fullauto · May 28, 2018

storm42 said:
I have Johns internals in my Commando, good aren't they!!!

They certainly are! Too cheap for what they do. A bargain.

o0norton0o · May 28, 2018

Wow, nice! Now I see why you think you could go to an 11mm mastercylinder, you've got a whole lot of brakes there. It's a real beauty. It looks to me like you spared no expense putting it together.

storm42 · May 28, 2018

o0norton0o said:
Wow, nice! Now I see why you think you could go to an 11mm mastercylinder, you've got a whole lot of brakes there. It's a real beauty. It looks to me like you spared no expense putting it together.

Well, yes and no, I have just started a build thread if you want to know how it came about.

SteveA · May 29, 2018

Pretty bike. Of course as you know floating discs are not eligible for classic racing, so mine, although on an alloy carrier is fixed. You have enough braking on that to stop an overbored XR69 in full flow.

I have the same master cylinder you do. From David Silver at about £45 delivered, in both 15.8mm and 14mm, they are cheaper than a Lockheed repair kit!.

I run the 14mm but I have a 15.8mm I would have used with twin discs, but it looks pretty redundant now.

I have Heidenau tyres, 90/90 and 130/70, which are good on price and great in the wet, but am interested in the Contis as an option, they do do a 100 front.

They are a bit cheaper than Avons and quite popular across Europe and seem to be appearing more in the UK.

SteveA · May 29, 2018

Who made the frame?, it isn't Bronze welded as far as I can see so not Titchmarsh.

If like me you think the solder and black tape for wheel balancing is a bit ugly, try dynabeads!

storm42 · May 29, 2018

SteveA said:
Who made the frame?, it isn't Bronze welded as far as I can see so not Titchmarsh.

If like me you think the solder and black tape for wheel balancing is a bit ugly, try dynabeads!

I didn't know the discs aren't eligible but at the moment it is a track day bike so not a problem, I would like to get it CRMC registered as I fancy doing Chimay and Gedinne, but no rush, need to iron out the wrinkles first.

I have won an AP adjustable Master off ebay so I am going to experiment a bit. I guess that won't be eligible either

I haven't tried the Heidenau tires but I am well impressed with the Contis, having said that after I had bought them Martin at Minnovation told me they are not so good in the wet, then again, his riders are very fast. I believe the the winners of the classic endurance for the last two years have used Contis and they have a new tire now which should address the wet problems.

The frame is bronze welded but I am not sure who made it, I had Philip Colgan do some alterations to it and he did have an idea who made it but I cannot remember who, might have been Steve ???

Yes the solder is ugly but i couldn't find my wheel weights and I ran out of time. I tried Dynabeads on the turbo and had a lot of problems with them. I fitted them just before I did the legions 1000 miles in 24 hours run (had to stop for a meal as we were going to get disqualified for being under 15 hours

)

The turbo has a habit of picking its front wheel up and when it landed it would screech and spin up so fast the beads couldn't distribute properly and the wheel would be well out of balance until I slowed down enough to unstick them from where they were held by centripetal force. I had double vision for a lot of the 1000 miles, I will never use them again.

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