Sunday, April 28, 2013

Short update

This weekend I finished some minor things on my bike. I spot welded the front fork and did some other preparational things.
A general view on progress:


I found my old and weathered Brooks sadle back in a box of old bike parts. This sadle will look great on the bike!


Thursday, April 25, 2013

Front forks - part one

Ok, time to have a go at the front forks.
I had a design in mind with standard square tubes. Square tubes are more easy to handle and don't roll of the table ;-)
I first started out with cutting the 4 fork leg tubes equally to the correct length.
Next I paired the leg tubes two by two and clamped them together as a pair:


Check out the left end of the tubes in the picture above: I filed them round so they will accept the bearing housing later on. Also in this picture is the steering assembly which will go on top of the forks (just above to the right) and the axle with the bearings and bearing houses installed (in the middle of the picture).

Next, I needed to cut and file the contours of the steering assembly in the leg tubes:


To keep the tubes together, I already welded them them at the bottom (on the inside of the fork legs).


Needless to say I repeated this for the other pair of tubes.

Back when I made the steering part, I made sure I had a hole in the bottom of it through the center of the steering axle. This hole was tapped with M6 thread. I now used this hole as a reference to the center of the steering axle. As you can see in the picture below, I screwed in a threaded bar and used it to hold the fork legs equally spaced from the center. I also made sure there was no 'wobble' in the fork: both ends of the fork assembly must be flat on the table to make sure the big wheel will run perfectly in the center of the bike.


I haven't done the final part yet: spot weld everything together. I just want to run some checks tomorrow: I have to make sure the axle will run parallel with the steering part.

Anyway, the fork assembly will look pretty square after I weld it together. Everything will have to be ground and filed round and smooth. But let's just take one step at a time... cleaning and finishing up the whole bike is still a couple of months from now...


Wednesday, April 24, 2013

Rear fork - part 2

So with a little thinking I came up with a 'jig' to hold the fork legs in position.
This picture shows the jig mounted on the fork before cutting:


Basically, it is a bar of M10 thread passing through the center of the fork with a piece of square tube for the axle. When torquing down the nuts, everything is fixed in place.
The white tape you see on the fork legs is to mark where I have to cut off the legs to shorten them.

Next step was the cutting:


And finally, bringing the fork legs to the new position by adjusting the nuts:


Sunday, April 21, 2013

Rear fork - part 1

I haven't mentioned this yet, but I was able to salvage a fork from a vintage bike I had lying around. It was beyond repair - at least for me - so I decided to recycle the front fork, to serve as rear fork for my ordinary bicycle.


I was thinking how to adapt the fork for my needs: since the rear wheel of my ordinary bicycle is considerable smaller, the fork legs need to be adjusted:


The solution I see the most is to simply cut off the fork legs and re-attach the flanges that hold the axle for the rear wheel. Since I like the curve in the rear fork, I would like to see that on my bicycle, so I will try to figure out another way of doing this...

Rear wheel

The rear wheel hub was picked up on Friday and drilled when I got home.
I had some trouble with the spokes on Saturday morning, but in the end, everything turned out ok. Only a few more spoke nipples to be done. The bearings and rear axle fit well...


Friday, April 12, 2013

Rear hub - part 1

Just finished the hub for the rear wheel! I spot welded the parts together and will take it out next week for a proper weld. After that, the holes for the spokes will be drilled.


As you can see, I fitted one of the bearings for testing purposes.

Saturday, April 6, 2013

Front wheel assembly - bis

Ok, I don't want to show off... but I'm so proud the big wheel is getting there (only a few nipples left to mount, but the tap broke again).
So here's another picture of the wheel with me behind it to put things into perspective. It's huge. I hope my legs will reach the pedals!


This is a close-up of the hub:


Front wheel assembly

I picked up the front wheel hub at the welder. He did a nice Tig welding for better strength and I started with  mounting the spokes right away. It went better than expected!
I could tighten everything down and this is how the wheel looks like after 1/3 from the spokes is mounted:


Seeing the wheel getting finished spoke by spoke is very satisfying! After finishing the big wheel, I expect the rest to be fairly straight forward... (fingers crossed).

Next will be the making of the axle and necessary parts to hold the hub. Otherwise I won't be able to true the wheel with enough precision.

Thursday, April 4, 2013

Spokes - part 5

Another cutter broke during the weekend. Very annoying and given the cost for a cutter, pushing the price for a spoke up with about 0.5 euro (as long as I don't break any more from now on!!!).
I spend the first hour in the workshop with making a new tool. As you might remember, I clamped the cutter in the chuck of the lathe and feeding the spoke manually. I found a way to turn this around for a much more stable way of cutting the spokes:


The thread is coming out cut perfectly symmetrical. So the stress on the cutter must be much more divided between cutting lips. I hope I will be able to cut the rest of the spokes for the small wheel without further problems...