Possible new caliper for Brian's 16" wilwood kit - NOT

[tigerdog]

Just a quick update: Porterfield immediately made good on the pads. Sent a pre-paid UPS pickup ticket via email for me to return the old ones and shipped out a set of the correct pads before the old ones even reached them.

Regarding the caliper itself - it fits! I pulled the old caliper and rotor this afternoon and discovered I, like so many others, needed to increase the chamfer on the inside of Brians hats where they meet the hub/spindle. My brother took care of that for me this evening with a grinder, while I installed a new Wifi router for his neighbor/friend ("from each according to his ability" and all that...) Came home and loosely bolted everything together. Rotor fits. Bracket fits spindle (no surprise). Bolted on the Billet Dynapro Lug Mount calipers - they fit! Took a spare wheel and placed it on the hub; no clearance issues. If anything, there's a teeny bit more room between the caliper and spokes than the photos I've seen of the old dynalites.

Tomorrow, I'll fit the new lines, torque everything down, do an initial bleed then proceed to the other side. Too bad I can't get all four wheels off the ground at once. That'd certainly make bleeding a lot easier. But I'll train my 11 year old son to work the pedal and go after it one corner at a time. If all goes well, we can put this thread to bed and move the Billet Dynapro Lug Mount caliper into the "Parts Cross Reference" section and update the wiki with the new info.

[tigerdog]

...Took a spare wheel and placed it on the hub; no clearance issues. If anything, there's a teeny bit more room between the caliper and spokes than the photos I've seen of the old dynalites...

...or maybe not. Left side was fine, spare wheel was fine. Finished up the right side, bolted on the wheel and rolled down the driveway. Clack clack... clack clack, very softly. Seems one of my wheels was cast every so slightly out of round, then machined true. No problem with normal brakes - hubcentric hole, tyre rim and lug holes are all perfectly aligned. But two of the spokes and the inner radius of the rim between are about 1-1.5mm closer to the hub than the rest of the wheel. This allowed a very small amount of contact with the caliper. Only happens with one out of the 3 wheels I've tried; I'll move the tyre to a wheel without the problem and be fine. For bedding in, I actually relieved a 1-1.5mm of material at the base of the offending spokes so the wheel would clear.

Clearance is very tight; maybe moreso than the 120-6806, maybe not, since the earlier threads mentioned very tight clearances too. I'd need to see one up close to compare. But there may well be a saving grace here. I noted the pads themselves actually ride slightly higher than the outer radius of the brake rotor. There's maybe 6mm clearance between the caliper body and rotor and 4-5mm clearance between the bottom of the caliper and the hat bolts. In short, with new brackets, the entire assembly could move in 2-3mm and solve the problem for good! There was also sufficient clearance with the pads such that the caliper could move 1mm or so inboard as well, providing even more room.

[tigerdog]

Wilwoods are installed.
Here are a few photos of the completed installation:



While most instructions suggest using thread locker on the hat bolts, I was dubious, since most thread lockers loosen with heat. Since the rotors become extremely hot, I couldn't see how a thread locker would help. Instead, I opted for good old-fashioned stainless steel safety wire. Besides, it looks really cool!

In the second photo, you can kind of make out the top of the pads is slightly proud of the edge of the rotor. New (or maybe modified) brackets will take care of that.

[theelanman]

ok doug....can I have a recap please...
I got lost somewhere in the discussion about the thickness of pad and the different caliper

I think you went for 120-9703s calipers the radial mount type....then the 7812 pad....
does this fit with the original disc diameter of the disc used in the original group buy

if I can work this one out then Im thinking just order the 6806...
cheers
Gareth

[tigerdog]

ok doug....can I have a recap please...

Recap: I purchased 120-9703 lug mount calipers for use with Brian's 16" kit. Pads are 7812-type Porterfield R4-S.
Everything bolts up perfectly. Feel is fabulous. Lots of effort but incredibly progressive; push hard enough and they'll lock. Let up so slightly and keep braking.

BUT! the calipers sit too high in relation to the rotor. The pads show about 1.5 mm of material above the edge of the rotor and clearance between caliper and wheel is really too tight for comfort. I'll either have to make new brackets or possibly fettle Brian's originals. At this point, as long as you can still buy 120-6806s, it's probably the easier solution.

[theelanman]

just a quick question then.....if youre saying the clearance is tight on the wheel.....which 16" wheel??...the s2? the fed? or both.....

cheers
G

[bobbrown]

I think the height of the caliper is the main thing that is causing the clearance issues, if the caliper was lowered the 1.7mm which is the dimension difference, and then the clearance caliper to wheel will open out.

There is a dimension difference in the two calipers Dynalite and Dynapro lug mount, the mount height 2.03” (51.6mm) and 2.1” (53.3mm) respectively, this is where I think the “about 1.5mm” is coming from.

Bob

[tigerdog]

I think the height of the caliper is the main thing that is causing the clearance issues, if the caliper was lowered the 1.7mm which is the dimension difference, and then the clearance caliper to wheel will open out.

There is a dimension difference in the two calipers Dynalite and Dynapro lug mount, the mount height 2.03” (51.6mm) and 2.1” (53.3mm) respectively, this is where I think the “about 1.5mm” is coming from.

Bob

I think Bob is spot-on. As soon as I can get access to upload a couple of photos, I can clarify.

[tigerdog]

just a quick question then.....if youre saying the clearance is tight on the wheel.....which 16" wheel??...the s2? the fed? or both.....cheers G

"read the question fully before answering" I've tested with the Fed wheel only. I don't know anyone in the area with S2 wheels or I'd be happy to test those, too.

[tigerdog]

If you have one of Brian's original kit, use the original Billet Dynalite (6806) caliper. Do not use the one I suggested here. Despite Wilwood's fudged technical info, there is a difference in height. The difference is just enough to foul the spokes on the Fed wheels and raises the pads up about 3mm too high on the rotor. I'm working with the good Mr. Brown to make a set of custom brackets but there's no reason for anyone else to duplicate my setup as long as the original 120-6806 caliper is available.