Modding Road Bike Frame To Stay Current

I had an old road bike frame with the shifters mounted on the down tube. I like the frame because it was quite light for an aluminium frame, only about 1.7+ kg and the aero design. Since I prefer disc brake rather than rim brake, I decided to rework the frame so that I can use disc brake plus some changes to the cables routing and an additional water bottle on the seat tube. Here are the brief details of the work done;

Brake cable runs through inside the top tube, cable holder welded on the seat stay, mount for disc brake welded and extra water bottle cage mounting on the seat tube created. A slice of 8 mm aluminium tube welded on the seat tube, to make it thicker, before holes were drilled and tapped. Also mounting for the side stand on the chain stay removed

Old brake cable holders on top tube removed as also the mounting for shifters on the down tube. Stoppers for shifter cable housing were then welded underneath. The carbon fork bought from Ebay and cable holder fashioned from aluminium tube glued to it with resin

Here is the finished bicycle, a Gravel Bike running 700x32C tyres.

DIY Protective Jacket For Sigma 150-500mm Telezoom Lens

Simple protection against light knocks, abrasion and light rain

The soft casing of this Sigma lens is big and takes a lot of space in the bag. I need another form of protection from all those knockings and jostling that are inevitable while the lens is in the bag during handling. I need to take care of it even from scratches so I decided to make a protective jacket for the lens.

I folded a camping mat around the lens and did some markings. Then I laid it flat and drew the outline for the jacket and cut it. A piece of black cotton cloth was then glued and covered all the surface area and lastly I sewn Velcro® straps on three locations. Since there was empty space at the mount side of the jacket with the lens inside and to prevent the jacket from caving in, I cut out strips from the camping mat and made a circular filler for the space.

The finished jacket

Filler to plug in the cavity on the mount side

Filler in action

In retrospect if I were to do it again, I shall glue on one side with cloth of the same exact size and on the other side with cloth of bigger size and then just fold it over.

During one of my outings, I found another use for this jacket. Since the lens is not weatherproof, I found it quite adequate to use as a protection against the weather when it drizzle slightly.

Update 27 January 2012:

It can also be used as a backup lens hood. Tried and tested recently when I forgot to bring along the hood.

Gray-Hoverman UHF Antenna

My rented house in Kulai (now Kulaijaya), Johor, Malaysia do not have an outdoor antenna. For local tv channels reception using indoor antenna, it is good since the transmitters are on a mountain nearby. I want to receive good analog tv signals from down south Singapore as well as from Riau, Indonesia which I estimated some 80 to 100 km away.

Since the ball had started rolling in constructing antennas (previously for my wireless client and the access point), I began to search for a good high gain UHF antenna. After a while, my attention was immediately focused on a little known, at least to me, Gray-Hoverman antenna. Interesting comments and feedbacks. What made me attracted to this design was the high gain plateau that covered most of the channels I’m interested in. Without much hesitant, I began on planning although I felt that this antenna was a bit on the hard side to construct.

Gray-Hoverman Dimensions

more details here.

Having had the diagram in hand, I figured about doing it my way based on those projects done by others. Once done, I laid down the plan. The reflectors would come from aluminium tubes salvaged from scrap antennas although some were of different diameters. Frame would be constructed from domestic pvc water piping tubes, T joints and tube holders. The radiator elements would be a 6mm diameter copper tube. I then listed down what were the items needed to be bought, the amount required and the length.

In constructing the antenna, first thing I did was the frame, then the reflectors, followed by cutting and bending the radiator elements. After attaching the radiator elements in place, I placed 4 short pieces and 2 long pieces of pvc plastic wiring conduit that had the sides cut off to hold them in place.

Here’s the rest of the construction pics at certain stages.

Update 13 Jan 2011

Actually I had a different idea for attaching the reflector elements, but I don’t have with me a tube that will fit in the reflectors nicely. What I had was a tube with internal diameter bigger than the external diameter of the reflector. So I cut it and riveted the reflectors to it. Also I did cut a small V groove on the flat side of the tube holder so that the reflectors will stay fixed and not to slide out.

Update 15 August 2013

I have constructed a GH10n3 Gray Hoverman which can be viewed here.

Flattening Engine Head & Block

This is the picture of Daihatsu CB23 engine block’s head that I flattened it with 100 grit initially followed by 600 grit finish. Plate glass is used to achieve the flatness. It’s not as precision as the machine shop but then it gets the job done.