Bevel rear brake

griff851

So having mounted my U beaut Brembo rear floating caliper that snapped off its opposing arm after 40 years, I had to modify it and remount the arm on the caliper. If you ever see a pic of the first TT2, they either snapped one or decided it was stupid.
Because it’s got a centre stand. The frame rod is stood off to clear the springs with a machined chunk of Grade 5 Ti. With 7075 control arm. So with nothing much better to do (bullshit) I whipped up caliper to control rod link and pin. 4140 machined and hardened. Link tempered to 550° and bolt to 270° as seen by the cool colour!
Just did the numbers. Bolt yield at 1550-1580 MPa, ultimate tensile strength somewhere 2000 MPa. Link bracket yield about 1000 MPa, ultimate tensile 1230MPa. A grade 12.9 bolt is yield 1100 ultimate 1200 Mpa. The hard core guys soak in liquid nitrogen for 24 hrs before plating. Sick bastards!

So basically I have totally over engineered the things probably considering the bracket and caliper cast Aluminium tensile strength somewhere between 200-400 MPa (massively actually) 😁 I reckon if I was doing 400 kmph, on the Dinosaur, and I hit a flat out stray Hyabusa coming the other way on the salt flats, the bits would still survive. You just never know when these thing happen, best be prepared! 😁

In the next day or so they’ll get a nickel plating then a bake for 24hrs at 250° to piss the hydrogen off.

Made new correct size axle sliders for chrome moly swing arm out of 6061 anodised, and a Grade 5Ti adjuster stud as well. LB 8009 is the go too anti seize for Ti according to Boeing just by the by.

Way too much fun in the shed!

Mr.R

I didn't bother to fit a full floating rear caliper, I just think that it's not actually needed.
Rather I mounted a Mag' alloy AP Lockheed "Brembo P8" copy to a Mag' mounting plate that matches my small early 900/750SS and Roundcase SS lightened disc.
This set up works perfectly and weighs less than a fully floating set up.
As I very rarely use the rear brake I've never been troubled by rear wheel hop.

Steve R

griff851

The original fit back in 84 was more about cosmic intervention than anything else. I was at the shop on a Friday night and a box of spares the boys ordered turned up. Our Italian mates must have been doing a clean up as they used workshop manuals as packing, and threw in a few odd bits as well. The calliper holder was one of them. The boys having no use for it gave it to me along with a couple of manuals. So I fitted it.
I must admit it only came in handy a couple of times.

I use to ride from Brisbane to Melbourne and back a couple of times a year to see my mum. It's a 1800km trip each way and took 2 days with an overnight in Dubbo. A lot of the time is feet on rear pegs and head on tank bag and try and sit on 140-160kmph. Use to cost about $70 in fuel and accommodation and $360 in speeding fines each leg. 😁
I had a few holy shit moments over the years and having a controlable greasy rear end saved my arse from certain doom trying to steer a decelerating 200kg 'I beam to avoid wayward trucks, cars and livestock. So I'm a fan, but agree they are not for everyone. Look god damn cool but! 😁

RWG

I just love this forum

griff851

Nickel plated. Job done.

griff851

Fail. I knew I had to bake post plating to remove hydrogen. Didn't realise needs to be with in 4 hours of plating. Oh well remove and repeat.

griff851

Well, that was entertaining. Nickel stripping using electrolysis, is a dangerous game. A lot of rate changes due to geometry and field strength, and perhaps a slightly too heavy handed approach. Its gone from a machined piece to a casting. 😁 the threads escaped relatively unscathed, but not completely. Big darn it there. Slightly more running clearance, still very serviceable. Loctited anyway.

The colour in the nickel comes from nickel rust. Low amps per inch causes the formation of nickel oxide. Tarnish. So I've been using it after laying down an initial clean coat.
Matched with NCR/Brembo gold, I'm calling the effect Italian Steampunk. 😁

The bolt head had to be reduced to increase the don't scrape the disc margin. Had to use a ceramic tip I use on sprockets. So hardening and tempering seemed to go as planned. Let out a little yey griffy there.