I b̶r̶o̶k̶e̶ fixed the Peugeot.

[BDC]

Well, the derailleur anyways.

Sad pic:

I didn’t see the memo about not undoing the spring tensioner 2977 and now it’s done-for.
I tried to adjust it and rounded the end so it no longer engages the flat sides of the lug 2978. It just spins around. Nil tension.

The spring was broken too – which also explains why it was slipping gears so badly.

I can find a new spring on ebay, but the other parts are not to be found – and they are ‘factory set’ anyway, so time for plan B.

I bought this direct mount Sunrace unit which has very similar dimensions to the Simplex, and I’m going to tap a 10mm thread into the existing hole in the frame – it’s a 8.9mm opening so should work for M10 OK. And there is already a notch to adjust hanger angle against. It will fit the style of the bike pretty well too.

I also bought a new chain because I shortened the existing one, to try and get more tension, before I knew about the broken spring.

The other issue is that the axle is slightly bent – so the freewheel oscillates slightly. That might have been the original cause of bad shifting.

The problem here is it’s 126mm axle (an old standard) and I can't find one that length anywhere. I can find used 126mm complete hubs – but I could just be buying the same bent issue.

So I have ordered a new 135mm QR axle and plan to cut it to length. Any tips there?

Or in the overall process?
What about pointers determining correct chain length?

TIA.

 

[rickpaulos]

Wobbling freewheels was pretty common even with straight axles. Mostly due to the freewheel threads on aluminum hubs not being cut exactly in line with the center line of the hub. Or in the case of cheap steel hubs that were 3 (or more) parts pressed together, not being pressed square. Usually not an issue. It's easy enough to see if the axle is bent, just turn it in the hub. Worn bearing cones can cause the axle to turn oddly but that's a different motion from a bent axle. Any attempt to straighten a bent hollow axle will just speed up the breakage. Put the cones on the axle before you hack saw it shorter, then back the cones off to smooth off the cut threads.

The derailleur was made by Simplex. Mostly famous for their plastic derailleurs in the 1970s bike boom. Simplex made many models, many were very nice looking. As bad as those plastic derailleurs were, the metal springs would break before the plastic and they broke a lot. Those cheap springs weren't chrome plated. Chrome plating can certainly weaken the metal. I wonder if the plastic Simplex spring would fit in this model. The spring end tabs point the same direction. Now days, plastic is very common for cheap derailleurs from Shimano and Sram and they fail quite often.

When you tap the hanger, do that from the back side. Worst case, you bugger the hanger completely: cut it off to match the left side and use a claw mounted derailleur or go for a single speed/fixie conversion.

Chain length. Long enough to shift into the big-ring-big-cog combo with a link or two to spare. Too short is a quick way to destroy the new derailleur if you try to shift in to the big-big combo. Most derailleurs have an adjuster screw that presses on the hanger to rotate the derailleur backwards to take up any loose chain in the small-ring-small-cog combo.

 

[BDC]

Cheers - It's the same size freewheel as the original - 28T. (From memory - but I did check at the time.)
Coincidentally I did have a larger one and didn't use it.

The failure is due to operator error.

Thanks for the help - will do. .

 

[rickpaulos]

A description from disraeli gears for this model:

There’s something about French touring derailleurs after about 1960. Just one look at this Simplex SX610 GT is enough to make me feel utterly exhausted and dispirited. I can almost hear the chain hysterically clattering on the inaccurately cut teeth of the wide ratio Maillard freewheel as the SX610 GT pathetically attempts to find bottom gear. I can almost see the bemused expression on the face of the owner of a Peugeot tandem as I attempt to invent a reason why a seemingly rational company like Peugeot had chosen to fit his relatively demanding machine with a poorly constructed derailleur with a plastic inner parallelogram plate.

The basic idea for the Simplex SX610 GT was unoriginal but acceptable - Simplex thought they would just copy a mid range Shimano touring derailleur. The execution was terrible - it weighed a ton (tonne?), it looked dreadful, the springs lasted about 23 milliseconds, it had Simplex’s tedious hanger bolt system and it simply never quite worked right.

It’s enough to make you down a bottle of Absinthe in a single gulp and run off to join the Foreign Legion.

 

[BDC]

Absinthe makes your f@rts go 'Honda'.

 

[MattiThundrrr]

Absinthe makes your f@rts go 'Honda'.

Classic

 

[Captain Awesome]

You had me at Absinthe

 

[BDC]

In the absence of absinthe ... it's a really good result. The bike has never shifted better.
Tres reliable now.

I haven't addressed the axle issue - I suspect RickP is correct - its the thread on the hub - but next time I pull it down for a service I'll investigate further. The part hasn't arrived yet anyhoo.

I did get some new stickers of ebay though:

Trial, meet error:

Cheers.