Tuesday, 1 April 2014

Levers Part 4 - Pedals

I got the levers back from SSM this week, actually I got them back the same day as I took them in. I like SSM, they look after the little guys. Now that they have been normalised it means I can file the welds by hand, there are no longer any hard spots or residual stresses from welding or work hardening from bending and rolling. When you buy chromoly it comes in a normalised condition, I'm trying to get back to that condition. Time will tell if I have been successful I guess.


A trial fit.

This week I'm going to make the pedals

There's not much to them really, I mean not much material, there's heaps of work to be done.

The first job is to make the boss that sits on the ends of the levers. 
I made this slightly tapered to be a nice fit. It's double ended since I'm going 
to make both pedals as one assembly to start with.

The body of the pedals will be made from an old 1" seat post, I need to bore a hole for the boss to locate through,
 this seemed the easiest way to do it. Locate at centre height...

...then just drill and bore through until at size.

Next make a little jig to hold the strengthening gussets at the correct location. 

The gussets are both made from the same plate. Have I ever mentioned that I enjoy filing?

This slips over the boss and holds everything square when clamped up. 
My son asked why I was making Cybermen

Next ask Pete to Kung Fu them up for me. Don't look at the arc. You did didn't you?

Then give the welds a little tickle with a mini carbide burr in my Dremel. 
Have I ever mentioned how much I like my Dremel?

Then saw the assembly in half.

The central part of the boss is not required...

...so it gets removed.

Then decide which is the right and left pedal, they are not symmetrical in two planes you see. There is the obvious bias to the width of the pedal and also the pedals are slightly tilted forwards.
The pedals are fixed to the levers and cannot rotate, this means that as the levers follow their arcs, the pedals change their orientation to the feet. This forward tilt is to compensate a little for this otherwise at the bottom of the stroke, the little tab to prevent your foot going into the spokes is at the wrong angle to be useful. The width of the pedals is much narrower than would be considered normal today, these pedals are only 3.5" wide. People were generally smaller back in the day and certainly had smaller feet, the style of shoe worn was also narrower as an attempt to make the feet appear smaller. Look at contemporary illustrations of Victorians and the feet are always drawn as tiny as possible, funny eh?

The distance between the pedals is also worthy of a mention. In relatively recent years, the term 'Q factor' was invented to describe the width between the outer faces of cranks on a bicycle. A low Q factor was deemed desirable and triple cranks with a wide Q were disparagingly called 'birthing cranks'. The inventors of this modern term may or may not have known that the Victorians already had a word to describe this dimension. They called the distance between the centres of the pedals the 'tread' of a bicycle and again a narrow tread was deemed desirable. Manufacturers used to boast about how low the tread was on their machines. The figures are widely quoted in the reviews and catalogues of the day. A tread of 12.5" was considered very narrow for a penny farthing. The Singer 'Xtraordinary was published at 10", and a conventional facile was also 10". The tread on the geared facile is very, low at 8.25" and Ellis & Co. certainly advertised the fact. This is mostly because it has a small wheel and simple trig. means that a smaller wheel with the same angle spokes will have a shorter axle. But also because the pedals are biased towards the outside, 2" versus 1.5" and the measurement is rather mischievously made from the centre of the lever not the actual centre of the pedal. Slightly misleading advertising is not a modern phenomenon.

Slightly forward biased pedals.

Next make the little end caps...

...and silver solder them on.

Next week I'll glue the all lever parts together.

In other news, I'm afraid there is none, I've been working too hard for any other stuff to have happened. An hour before work in the workshop and then several hours after work trying to get this bike finished. I'm hoping that next week will be a little more relaxed.

Carry on.


  1. Replies
    1. Hi Andrew,

      Yep, Only the white one belongs to Pete. Look closely, that is definitely not an Anglia engine...