Brakes
Earlier in the year whilst watching the 750MC Roadgoing Bike-Engined Car racing at Snetterton I got talking to a nice chap by the name of Martin Bell, who runs the Kit Car Workshop. Some time after whilst Martin picked up a set of alloys with slicks on from me he showed me a set of prototype brakes he was developing specifically for bike-engined cars in conjunction with Hi-spec Motorsport. Martin kept me informed as the brakes took shape during about a 3 month development and test period and in the end, after hearing nothing but great news about their performance and weight I ordered a set, which were the first production set to be delivered.
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The calipers are a standard alloy 4-pot, which are then radially mounted onto a billet alloy machined mounting bracket which is specific to the upright and disk size. In my case the Striker uses an Escort mkII based upright and I opted for the 278mm x 9mm solid grooved disks fitted to machined billet alloy bells. This is the largest size that still remarkably fits inside a 13" rim. Other smaller disk options are available including using the standard 248mm Escort mkII disk, but skimmed down to a more appropriate thickness and weight for a bike-engined car. This is a very cost-effective solution being around the same price as a pair of Bremsport/Westfield4-pot calipers alone. Various sizes of vented disk are also available for heavier cars than mine!
The most amazing thing about these brakes is how light they are. The calipers are 825g each and 1.3Kg including pads, mounting brackets and fixings. The 278mm disks are 2.65Kg each, which is over 1Kg lighter than the original 248mm disk or about the same weight as a skimmed 248mm disk, but being much larger diameter offer much improved braking torque and feel. The complete setup weighs 7.9Kg, which is less than half the unsprung mass of the standard cast iron Ford M16 setup. The quality is also exceptional. The attention to detail in machining out unwanted material from the calipers and brackets, the quality of the finish and also important, but often overlooked, how easy they were to fit. I have heard many examples of brake kits needing fettling (usually with an angle grinder) to fit, but not with these. The brackets were machined to fit exactly to the upright and everything else went together very easily indeed:
Pre-Assembly
First of all it is a good idea to do a trial fitment just nipping up the bolts (just use two on the disks for now) in order to determine two things:
1) Whether a shim washer is required between the bracket and upright and
2) Which way round to mount the disk to the bell
In both cases you are trying to get the disk centred within the caliper. In my case it was necessary to use a pair of thin washers between bracket and upright on one side to get the caliper dead-centre.
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With the exception of disk to bell, everything only goes together one way so it's all very straightforward.
Disks
Once you have worked out which side of the disk is bolted to the bell and which way round you want the grooves on the disk pointing you can bolt the disk to the bell. All the fixings are supplied, including stiff nuts. For an extra security measure I also applied some Loctite Threadlocker 242 to the nuts and torqued them up to 11Nm.
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Hubs
With the disks assembled you can bolt them back to the hubs. I have Fisher Sportcars Escort mkII pattern alloy hubs and I torqued the disk to hub bolts up to 50lbft with spring washers and threadlocker for good measure.
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The complete hub/disk assembly can then go back onto the stub axles. The hub nuts need to be tightened to 27lbft whilst spinning the hub anticlockwise to seat the taper bearings and then backed off by 45 degrees to provide the correct clearance. I did originally back the hub nuts off by 90 degrees which I understand is what is recommended in the Escort Haynes manual, but this was too loose and the wheels were noticeably rocking on the bearings - you could hear them knocking if you jumped up and down on the front of the car. On my car 45 degrees is just right - the hubs still spin freely but are not loose. You may need to do this a bit empirically yourselves to get the right feel. Put the castlellated sleeve back on the nut and put a split pin through to hold it all in place.
Fettling
Due to production tolerances two cars are never alike. This is why the brackets are supplied with shims. In my case it was also necessary for me to file a tiny bit off the corner of the upper ears on one upright and the lower ear on the other side to clear the disk bolts.
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Calipers
Bolt the bracket back onto the upright with shim washers between as necessary. Torque up the bolts to 110Nm. I also used a dab of 242 threadlocker. Bolt the caliper to the bracket. Torque up to 77Nm with another dab of threadlocker.
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Pads
The pads simply slip into the calipers and are secured by the pins, which in turn are secured by R-clips.
I chose Greenstuff pads because of their high friction rating with acceptable temperature range for road use. Part number is DP2197/2 from a Lotus Elise / Nissan Skyline. These were also supplied by KCW.
In my case it was necessary to file a tiny bit off the outside of the outer brake pad where it was just touching the inside of the wheel rim. I suspect that having the grooves in the disks sweeping outwards is pushing the pad out to rest on the retaining pins and that if the grooves were sweeping inwards (as recommended) this would not happen.
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Hoses and Bleeding
I also purchased a pair of stainless Goodridge brake hoses from KCW with a banjo connector on the caliper end to keep things neat, which is another advantage of these calipers is that they use metric fittings rather merkin fittings that need adapters. The system was filled with DOT5.1 fluid and well and truly bled.
At last brakes, I can go for a proper drive now :-)