Turpakäräjät @ Ullan Pakari - 8th of September 2021 - Riihimäki, Finland

Time to check out photos from week 36 😎

'73 Suzuki GT250 - Part 17 - Front brake system

To finish the front brake system I had to find a master cylinder and a caliper for it. Flat brake disc design doesn't allow much space near the wheel spokes so multi piston calipers with pistons on both sides were out of the question. I ended up going with front brake parts from a 1991 Kawasaki KX80. Master cylinder has 11 mm bore and brake caliper 30 mm bore.

Both front master cylinder and brake caliper required refurbishing. After disassembling both of them I stripped black paint out of master cylinder with paint stripper and soda blasted both of them. Aluminum pieces got a quick polish. I bought a new lever made by Motion Pro (#14-9318) and a rebuild kit made by ProX (#37.910001) for the master cylinder. I replaced old fasteners with DIN 912 hexagon socket head cap screws where I could. For the brake caliper I bought standard brake pads made by EBC Brakes (#SFA083) and sealing kit made by TourmaX (#ACK-451). Assembly vaseline delivered with the sealing kit turned out handy when putting both assemblies together and avoiding scratching new seals. 

Polished front master cylinder parts

Parts of master cylinder rebuild kit

Details

Parts of master cylinder rebuild kit

Piston and new spring and seals

Piston assembled

Washer, stopper and cover seal for piston

Front brake lever

Black oxide fasteners replaced with zinc plated

Fasteners and return spring for front brake lever

Holder and fasteners M6x20 DIN 912

Diaphragm, cap and fasteners

Front brake caliper polished

Brake caliper sealing kit and pads

Piston, breather, spring and parts
from brake caliper sealing kit

New parts installed to front brake caliper

To get KX80 brake caliper to work with the brake disc I made for GT550 front fork and wheel I had to design a new bracket for it. I used the OEM KX80 front caliper bracket and CAD models which I created earlier for brake disc, front suspension and wheel as reference to get the geometry right for the new bracket. Once I was happy with the design I cut and machined parts for it which were then welded together. Before painting the bracket with primer and matte black I chamfered screw holes and tapped them for M10x1,5 thread. 

I turned separate spacers (10x20x4) for the bracket out of aluminum. I wasn't 100 % sure how far bracket has to be from the brake disc so additional spacers give me some room to work with if I need change the distance.

Welding assembly of
front brake caliper bracket

Dimensions for plate

Dimensions for pins

Dimensions for spacers

Parts of front brake caliper bracket

Welding instructions

Welds of spacers

Welds of pins

Front brake caliper bracket
painted with primer and matte black

Guide on one side

Bracket and pads installed to front brake caliper

Other side

Hexagon socket head cap screws
M10x45 DIN 912

Dimensions for spacers

Spacers, 10x22x4

I ordered a custom stainless braided brake hose from HEL Performance. I carefully measured length for it after installing both brake master cylinder and brake caliper on the bike. I decided to go with straight fitting on the master cylinder side and with 20 degree angle fitting on the brake caliper side which made brake hose to run in a better angle in my opinion. I fixed the brake hose with M10x1,25 banjo bolts and put aluminum washers on both sides of the fittings. To keep brake hose from moving around I made a custom clamp out of stainless steel sheet. I added piece of heat shrink tubing to the round section of it to avoid chafing.

Specifications of custom brake hose

Stainless steel braided brake hose

Close up of the straight fitting

M10x1,25 banjo bolts and washers for brake hose

Master cylinder

Clamp for fixing brake hose to the bottom yoke

Brake caliper

'01 Honda CBR600F4i PC35 - Part 1 - Introduction

Few months ago I was looking to buy a new project bike. There was one enduro bike for sale nearby which peaked my interest and price seemed reasonable. I contacted the seller but the deal fell apart and he decided not to sell it for some reason. I weighed my options I decided to try to sell my '91 Honda CBR600F PC25. On a whim I made an add for my PC25 and on the next day it was already sold. 

Now that I got more room available in the garage I started to look for a newer Honda CBR600F4i. PC35 seemed like a good option since I had purchased some parts earlier (more about those later) which would be easier to fit to PC35 than PC25. After browsing market places for available PC35s I ended up buying this one a week later. 

It had 50 058 km on the trip meter when I bought it so it was time to get it serviced. I took it to a local maintenance shop. Main thing was to check clearances of inlet and exhaust valves. Engine oil, oil filter, air filter, spark plugs and coolant were changed and charging, battery, fuel injection, suspension, control system, brakes, lights, tire pressures etc. were checked at the same time.

Overall this bike is in good condition and rides nicely. I haven't got to ride it too much yet but first impressions are good. It feels more nimble and responsive than my previous PC25 and has better ergonomics. There are small things I want to fix along the way such as rust on the silencer, scratches on the right side fairing and crack on the windshield but are not urgent at the moment. 

Turpakäräjät @ Ullan Pakari - 9th of June 2021 - Riihimäki, Finland

 Let's continue with photos from last Wednesday 😎 Take a look!

Chrysler 300

Turpakäräjät @ Ullan Pakari - 2nd of June 2021 - Riihimäki, Finland

Check photos from this week's meet 😎

Turpakäräjät @ Ullan Pakari - 12th of May 2021 - Riihimäki, Finland

Couple photos from week 19 😎 Take a look!

Oldsmobile 88

1st of May Cruise 2021 @ Riihimäki, Finland - Part I

 Here are rest of my May Day Cruise photos. Take a look 😎

Buick Century

1st of May Cruise 2021 @ Riihimäki, Finland - Part II

 Here's first part of photos from last weekend's May Day cruise 😎 Next part covers Yankee cars.

Austin 1300GT

'73 Suzuki GT250 - Part 16 - Stainless steel front brake disc

I had an opportunity to cut a front brake disc for my GT250 out of 5 mm thick stainless steel sheet using abrasive water jet cutting. After googling and looking at different front brake disc designs I decided go with similar style used in aftermarket Triumph Speed Twin front brake discs. Once I was happy with the 3D-model I exported it to a DXF file which was used to program routing for the cutting machine. 

After cutting I machined grooves around each bolt hole used to fix the brake disc to the front wheel hub with 14 mm square mill in a vertical milling machine. Once that was done I sand blasted the disc to get a good surface for paint. 

This time I decided to use simple spray paint. Before painting I masked outer edges of the disc and cleaned all the surfaces I wanted to paint with acetone. I applied a thin coat first which supposed to help the next heavier coats to stick better. Instructions in the can said to use primer when necessary so I opted to leave it out. I'm curious too see how it works without primer. If it doesn't I will prep it and paint it again. Once paint had cured I installed the disc with a 12 mm spacer I also got cut with abrasive water jet cutter and rolled the bike outside to snap few pictures of it 😊

Design for front brake disc

Dimensions

Blank

Grooves for socket cap screws machined with square end mill
in a vertical milling machine

Sand blasting before...

...masking and coat of matte black spray paint

Dimensions for spacer

I painted the outer surface also with matte black