Saturday, 12 October 2013

All good things come to an end

Bad news.

Structural failure of my folding bike.
the bottom bracket has broken away from
the U-tube frame
My little Cinzia folding bike, that I have owned for about 20 years, suffered a serious structural failure on the evening of the 8th October 2013.

As I was just starting to cycle to work, there was a sort of grinding crunch sound, and the bottom bracket pulled away from the main U-frame.
Picure says it all.
My Cinzia suffered a major structural failure
Close up of the bottom bracket area,
showing how it has broken away from the frame
It isn't just a failed weld, as the bottom bracket took a section of the metal from the bottom of the frame with it.
The hole in the frame, left by the bottom bracket when it broke off.
You can see the dynamo wiring and rear brake cable
running through the frame very nicely in this pic, though :-)
Is it repairable?

Well, in theory, because the frame is reasonably thick steel (none of your light weight aluminium alloys or high-strength thin wall Reynolds 531 (or similar) tubing on my little bike!), a patch could be welded on, and then the bottom bracket could have the piece of frame stuck to it ground off, and be reshaped to fit the patch on the frame, and with lots of VERY careful alignment, I could all be made to work again.

BUT, attention would also be have to be paid to the top of the rear triangle, which has twisted as the bottom bracket dropped, so the welds between the rear triangle and the top of the seat tube have also taken a beating (actually more of a "twisting").

Because the bottom bracket broke away from the frame, and dropped,
part of the force was transferred to the welds between the seatpost
and the rear triangle, Part of the weld broke, and part of the tube of the
rear triangle deformed.
Is it an economic repair?

Unless one already has welding equipment and a bit of experience with it (I do not!), then paying someone to do the work would far exceed the value of the bike.

The bike has a certain sentimental attraction for me - it is the only bike I have ever bought for myself, and I have had it nearly 20 years, during which time I have moved house twice, had three more cars (automobiles), changed jobs twice, met, then married my lovely wife, etc. etc.

But I bought it as a modestly-priced bike that would fit in the new "city" car (automobile) I (then) had recently bought, replacing my estate car (combi / station wagon) that would take a regular bike without disassembly if the rear seats were folded. I insisted on a three-speed hub gear and a compact size. I didn't buy my Cinzia because it was Italian or "classic" or anything like that, so despite the emotional rift, it seems silly to spend a lot of money repairing an odd little bike.

If it was a Puch Picnic, for example, I might repair it (the Puch Picnic was, I believe, the archetype on which  all U-frame bikes, such as my Cinzia, were based). But it's not.

A cheap little folder, of similar specification to mine (although it might have a "normal" bottom bracket rather than the "Italian" one I have) would cost no more than, say, 25 pounds (40 dollars, 30 euros) if purchased from eBay or suchlike. Even if that bike was a bit tatty, a bike could be made on the "mix and match" basis, combining the frame from the other bike with the best parts from mine.

However ...

In our collection of bikes, we have a "spare" bike already.
It was Anna's first bike in England, and she used it for shopping a lot.

It is just a cheap generic Far-Eastern made bike. After a few years, the rear wheel bearings wore out, causing excessive "slop" in the rear wheel - not a bit, a lot!
I did the temporary repair of regreasing the bearings and tightening it up a bit tighter than before, but sensing that was likely to be the first of several problems, I got Anna a new bike (that she still rides).

Anna's old bike became the "spare".

Then we cleared out the garage, and the "spare" has lived under a tarpaulin  between our two sheds (shades of Arthur "Two-Sheds" Jackson, except we really do have two sheds. I guess that makes us middle-class-aspirational, or something!) perhaps for the last year or so.

The "spare" bike

I got the "spare" bike out yesterday, and checked it over.
Judging by the seat height, I rode it last!
My workspace, with a canopy formed by the garage door
and the rear door of our car (automobile).
The "spare" bike is the pink and white one at the back

Anna says it was when I broke the chain on my Cinzia, and I wanted to cycle in to the local bike shop to get another. That's got to be a couple of years ago.
Anyway, apart from rather soft tyres (I think I pumped them up hard - for storage) last year, when the bike went out of the garage), it all seems rather fine and dandy. Chain isn't rusty, and no odd mechanical creaking sounds.

The bike is a "Universal Mermaid", a women's model "hybrid" bike, in a fetching sort of pink/lilac colour, with badly applied stickers :-)
Just a mass-manufactured bike thrown together with very low cost parts.

With the seat moved right up, it is a reasonable fit for me.
Not so easy on my knees as the Cinzia was, due to the bottom bracket being about an inch (25mm) higher from the ground.


Sorting out and transferring parts

So now I am going to spend a few days sorting out the "spare" bike.

I have to put the rear luggage carrier from the Cinzia on it (I "borrowed" it from the Mermaid in the first place, after I broke a weld on the original Cinzia carrier), and I need to sort out lights and suchlike - I have a compact LED battery-powered rear-light gaffer-taped to that carrier as a "back-up, so that will do for now.

The cheap little supermarket-bought front will be moved from my Cinzia to the Mermaid as well.

I would like to move the Steco front carrier to the Mermaid as well, and a quick check with a ruler looks like it might just fit, but there will not be much clearance between the top of the front mudguard and the front carrier.

The fancy front hub dynamo I have on my Cinzia will be more of a problem - I am thinking about taking the spokes out of the wheel, and relacing the hub to a 622 rim (also known as 700c, as on the Mermaid). I have a spare 622 rim already, so it is just a case of getting the right length spokes and doing the work. The Shimano dynamo hub has 36 holes and so does the rim :-)

I like three-speed hubs, BUT ...

I would like to change the cheapy Shimano SIS gears for a nice three-speed hub, which for me is the epitome of function for the type of cycling I do - VERY low maintenance, with enough gears, but not too many.

BUT the hub on my Cinzia is a 28-spoke hub, and I only have 36 hole rims in 622 size
I have only two rims in a twenty-eight spoke fitting, and they are both from the Cinzia, and are 406 size (also known as 20 inch).

So the choices are:

  1. Lace the 28-hole 3-speed hub into a 36-hole rim - kind of possible, but asking for trouble!
  2. Get a 28-hole rim in a 622 size - but 28 spokes are not as strong as 36, and I'm a heavy rider!
  3. Get a 36-hole 3-speed hub - the best "engineering" answer, but also the most expensive
So that will have to wait for a while.

Christmas is coming, and the metaphorical goose needs fattening up.

Like I said, fixing the Cinzia just isn't economic.
If I want a similar bike again, I really ought to get another one from eBay (after Christmas, when prices are lower).
On the other hand, the Cinzia has a plain steel frame - no fancy thin wall, high-strength alloys here!
And an arc welder isn't as expensive as it used to be ...

Where there is steel, there is hope ...
to be continued (hopefully!)

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