New Bike: Front Frame and on the road

 

Source material: 28mm steerer fork for top of front frame, stripped down bike frame with only bottom bracket and down tube. I stripped down 3 frames before I was happy with the down tube diameter. 

 

Hi

For a while I have been working on a new leaning trike, and I'm proud to say that is is on the road and going well. I still have some painting and finishing off to do and want to make a new design of tailbox for it. This post shows making the front frame of the bike, I already had a spare seat / tailbox which I am using temporarily. A comical "guy / bikeart piece" emerged halfway through the build process: this was completely by accident but having made one, I can make more now!

It's basically the same as the leaning trike I completed in this post and have been riding this year. However I've changed the front frame configuration, eliminating 2 joins in the "downtube" section and making a small, unobtrusive support frame. This small frame can be easily swapped out if I decide to use another fork. I have also eliminated a join in the steerer section of the front frame.

There was a small amount of drama getting the bike on the road. It was finished except for control cables when I received a Friday night dinner invitation. I got back home about 10, worked on the bike in the lounge room till 11, fitting the V-brakes and derailleur cable. The first trial of the bike was the next morning heading off to Wecycle. It all worked fine with only a few allen key tightenings required. I want to paint it red and yesterday bought some red 3d printer filament to make matching 3d printed parts.

Obtaining a length from the old bike for transfer to the new. This shows one of the joins which was eliminated.

Tubemitre plot used to hacksaw ....

the fishmouth join in the front frame steerer section.

Steel bar used as a brazing jig to ensure bottom bracket is parallel

Comparing old and new.

Larger part of the front frame. Another piece was brazed to the top later.

Housing for small frame on fork made from a bikes stand plate

The plate attached

Trike setup before the small front frame was made

Trialling a "small frame" configuration.

Small frame was set up on the trike before brazing: the whole front part of the trike was a jig

And this guy....

emerged from the

... manufacturing process!

Finished small frame, gear and brake cables in place.

After 1st ride at Wecycle

Later in the day - nothing special here, it looks just like my other trike and most of my friends at the shed are used to my trikes.

Small front frame on the front part of the trike and just before brazing

Some towing

 

Hi

The bike shed I volunteer at was due to have a cleanup and I managed to get in early with an improvement to one corner of the room. There is a corner where the brake and gear cables are kept, and often stuff would just be chucked up on top of the boxes and it would be a real mess. I'd been working on furniture at home and had some spare timber so I knocked together a cabinet for the shed. To bring it to the shed I dug out and repaired (fixed flat tyre and made new hitch) the bike trailer I have. This got me reacquainted with the trailer - eventually I will put a better hitch on the load carrying version of my new bike.   

The load carrying itself went well but I celebrated too early! At the intersection near the shed I undid my helmet strap where the shed key was secured, and was then mystified when I got to the shed that I didn't have the key. A bit of a think, a backtrack and a wander into the middle of the intersection / bike path at the right cycle of the lights and (whew!) I had the key again. The keyring was a  bit crushed  but the key was ok (also whew).

Anyway, I got the cabinet fitted ok, and the next weekend (actual cleanup day) I removed all the crap hanging from the windows. So the after picture is even more improved.

Regards Steve Nurse 

The cabinet

Before

After

 

New Bike: The Rear Frame

Measuring up the frame - this is getting the size for the front part.

Marking the frame centreline for drilling the headtube holes

Cutting the front part square

 

Drilling the head tube bearing holes

And filing them.......

 

and done - well one side at least.

Rounding the front part of the frame. I did it manually for the most part but used an angle grinder at the end.

3D printed frame separators and M8 Tee Nuts

Transferring positions from the back part of the frame to the front for drilling small holes.

The cool tool! The front bolt keeping the frames together is a low-profile M8 allen bolt because clothing gets caught in it if it is a higher bolt. I put the tool to undo it into the other bolt which is underneath the bike.

Rear bottom bracket assenbly consists of YST bottom bracket, 2 custom castings, 2 spacer bars and 2 spacer bar retaining studs.

 

Ta Da.....

The.......

Finished Frame

 As mentioned in my last post, I have been building a bike for a few days now. I'm trying to document it in some detail but I do have bits and pieces of old bike around which lets me skip forward a few steps. For this 2-part rear frame, I had most of the back part built and only needed to saw an end off, drill a few small holes and fit parts. But I made the front part from scratch, and this involved marking positions for, hole sawing and filing holes for the head tube bearings.

This work was fun and not too hard, about 10 hours work in getting this made. 

Update July 26

Over the last few days I have worked on attaching the back wheels to the rear frame as well as making the front frame. Here is the process of adapting shafts and making spacers for the rear wheels. The wheels were too narrow for the shaft, and simply shortening the shaft is no good as that would make the outer bearing sit on a recessed bit of of the shaft. Who designed the shaft? What were they thinking? (Oh that's right its me!) Anyway, I made appropriate spacers with a pipe cutter, marked up the shafts for shortening, shortened the shafts on a lathe, retapped the shaft thread, and finally fitted it all up. Pretty good now! Wheels are from MR Recumbent trikes and an 89mm aluminium square taper unicycle crank set is from the Australian branch of Unicycle.com

 

Marking the shaft protrusion before trimming shaft to length

Spacer cutting. This leaves a big burr on the inside - I filed it quite roughly to get the right inside diameter to suit the shaft.

After retapping the shaft is done

Turning down the shaft length

Done!

and done, the turned down shaft matches the bearing face

Assembly with YST bottom bracket, unicycle cranks, frame and bottom bracket holder.

Full assembly, for more details see here .

 

Contraptions: Introduction to a new bike.

 

Crocodile / Bicyclette from the Wieber Bijker book "Of Bicycles, Bakelites and Bulbs"

 

Rover Cycle from Bijker

 

 

"You be the contraption,

And I'll be no-one, 

I think I owe one

Too-oo-oo-oo You-ou-ou-ou"

With apologies to Kasey Chambers (Misquoted from "The Captain")

 

I think that everything that ever been made starts off as a contraption. Even the bicycle which we hardly glance at today was once a contraption. By bicycle we usually mean the rear wheel drive safety bicycle, and one of the first of these was the Bicyclette or Crocodile from 1879. The bike had all sorts of hangovers from its penny farthing predecessors. It also had remote steering which seems completely unnecessary. But I am talking with hindsight here. The inventors of the day hadn't quite worked it out but they were getting there, and within five years the Rover safety had been made, Dunlop's pneumatic tyres were in widespread use and the bike as we know it today was born. 

Branestawm illustration by George Adamson: "Penny in the slot poetry"

Branestawm by W. Heath Robinson

Branestawm by W. Heath Robinson

Branestawm by W. Heath Robinson

Branestawm by W. Heath Robinson

We actually don't see many contraptions today but I was bought up on them through Norman Hunter's Professor Branestawm books illustrated buy W Heath Robinson and others. There is my name scrawled by a young me inside a Professor Branestawm book from 1964! 

3 views of a moving bottom bracket tilting trike by Myshkin

Some of my bikes have been contraptions and I'm proud to own that, but eventually if something is to work properly it has to end up a bit more refined than a contraption. One of the latest and greatest contraptions I've seen is by Myshkin whose tilting trike is shown in a video here . The main criteria for this trike seem to be that it is rideable, that it is small enough to get out of an upper story flat and that it is fun to build, which seems to me to be justification enough to make anything. 

Some modern things are contraptions when they shouldn't be!  An example is electricity bills. Different companies can supply my house with electricity, and they charge different amounts. When my solar panels generate electricity they pay me different amounts. It's confusing and contraptiony which I don't like.

Getting back to bikes, I would like to show a few examples of modern contraptions. Yes, I'm calling them out!

 

The laden bicycle: traditional load carrying on bikes is an aerodynamic nightmare. Yes, you can carry stuff, but it almost always sticks out in the wind. Bikepacking was a reaction to this. 

   

 The rear wheel drive recumbent bike:  Not all of these bikes are the same, but I have recently been fixing and tuning an Optima Stinger to give away as an OzHPV prize. There's a lot of complexity there. The chain needs to be lengthened or shortened depending on the rider height, the chain is long and tries to twist the frame whenever power is applied, the chain is managed by 2 pulleys and 2 tubes which sap energy, the back wheel and chain are likely to get mud from the front wheel and most load carrying will not be aerodynamic. You can't just run and jump on it, the steering gets in the way. Phew! 

 

 

Now on to my own leaning trikes. This one isn't all that contraptiony although some will never get over the 2 back wheels! Due to the fixed bottom bracket design, it's impossible to steer hard and pedal at the same time and it has outrageous tiller steer. Its quite big with the front wheel waaaaaaay out the front. But the load carrying is good, the tailbox doesn't get in the way of the back wheel, it is aerodynamic and carries a decent amount of luggage. The front wheel drive means seat adjustment is independent of chain length, there's hardly any chain management, and the chain is up the front and high, away from muck. You can run and jump on it which is great, and it has 2 YST bottom brackets which are the same, and 2 V- brakes which are the same, which keeps things simple.

 

 

It's only in the last six months that I've refined and got riding on my own design moving bottom bracket bike. Up to now front wheel drive bikes have been fixed bottom bracket but I spent a year or two with the Cruzbike Quest as my favorite bike, however the steering caused me shoulder pain. I'm enjoying my new bike a lot and don't want to change it much, however I have two different styles of tail box. One (corflute and plywood) is light and aerodynamic for touring, training and racing, and one is heavier for load carrying. 

To swap tail box styles I currently have to swap tail boxes which takes a bit of time. So I'm building a new bike so that I can put the fast tail box on it, and keep the older bike for load carrying. The new moving bottom bracket bikes could be called a bit more contraptiony than the old fixed bottom bracket style. But I don't care that much. The new bikes are much more fun and involving to ride and also shorter by about 30 centimeters. 

They have 2 types of bottom brackets and two types of brakes. The brakes make construction a bit more fiddly as there are two systems (V- and disk) to deal with. It has been great to start afresh on a new bike of this type months and several hundred kilometres after building the first one. It's possible to see details that can be made less complex and therefore lighter and simpler and it is great putting those details in to the new build. In my next post I will report about building the new bike with some photos. A new, more aerodynamic tailbox is planned but I'll leave details of that for another post. 

 

Regards Steve Nurse