Change of freewheel and shifting became (nearly) impossible

Hi all,

I recently got around with building the rear wheel of my Peugeot (boy, was it more difficult than the front!) and I decided to go for a modern 5-speed freewheel.
Beside the questionable look (the cogs are obviously made of metal - cheap looking - but the body is some composite material suspiciously looking like plastic), shifting gears has become nearly impossible. Going from 3rd to 2nd, which incidentally is one of the two most common shifts I use, is so hard to nail that I am now convinced is not just the matter of getting used to the new spacing, there is something wrong.
Actually, the spacing should be the same. I didn't bother measuring it, but it should be the canonical 5.5mm.
Is it possible the old-style chain doesn't agree with the new cogs? It's not particularly worn out, but it looks a fair bit thicker than a modern chain (again, not yet measured, but will do), which would explain why anything but the most perfect alignment makes it rattle.
I could easily swap the chain for a new one, but I wouldn't want to find myself in the same situation, with nothing solved. Because at the moment I'm still in time to swap the new freewheel for my ol' reliable. Which I would have done already if I had the remover tool...
What do you suggest?
Thanks

Re:

How "old" is the old freewheel and chain? If its old enough then it's possible that the might cause issues with shifting.
Regardless, using an old/worn chain on a new freewheel can often cause problems as the old chain and freewheel will have worn to each other, so the old chain may not work nicely with the new freewheel.
Is the dishing of the new built wheel correct?

Got a pic of the bits you're talking about?

Re:

It's very likely they are still the stock parts, dated 1985, but they don't have much wear on them.

At the moment I only have this picture.

Re:

first, back in '85, a 5 speed block was probably just a 5 speed block with no emphasis on any particular spacing, as STI hadn't been invented (or if it had, it was just shimano, the rest of the industry hadn't adopted it)

Second, the chain does make a difference. I recently put a new chain on my pubber, which is indexed 5 speed 5.5mm. The chain was a 3/32 cheapo Chinese, which ran ok once engaged, but gear changes and indexing was impossible. Put on the standard sram/sachs 5-8 speed chain and all works well.

You have said that chain looks too thick, as Pigman said, put on a normal 7/8/9 speed chain and it should shift much better.

https://www.ebay.co.uk/itm/KMC-Z51-6-7- ... 1343640318

For a penny less than 7 quid you can't go too far wrong lol

Re:

I bought a chain. I'll fit it tomorrow and see if it makes a difference

It didn't.
As expected, replacing the chain had no effect.

Have you had a good look at whats happening when you shift with the bike in the stand? It sounds like the rear mech is not happy. These old Sachs Huret are not the best especially if not set up right.

But less of the arms folded defeatist attitude there, there's lots of help available the cassette and chain are designed for each other whereas the mech isn't quite but they can be made to work

*have you checked the chain is going around the jockey wheels correctly and not fouling anything or caught on the cage anywhere? This is common fault when putting a chain back on.

How well does everything move without the wheel in?

Does freewheel move freely in the frame? Make sure it doesn't foul the rear stays when in the frame.

Re:

Thanks for the suggestions.

What does "foul the rear strays" mean?


The mech is as happy as ever. It was shifting fine with the old freewheel. With the old chains the problem was that unless the derailleur was perfectly aligned, the chain was getting caught by the upper cog (obliviously this does't happen when I shift into the lowest speed) but not quite enough to make it shift.
I think it happens because the new freewheel has the fancy profile in the cogs, instead of the simple, smooth profile of the old Maillard freewheel. I understand this profile is supposed to help shifting, but maybe it's not compatible with old chains.

Anyway, with the new chain this happens less, but it's still not happy. I noticed on my way to work that one of the links is stiff. I didn't notice yesterday because, I wasn't really expecting for a stiff link in a new chain :facepalm:
This was causing the chain to skip a tooth in the jockey wheels.
I will try to fix it once I'm back home. Hopefully it should be enough to wiggle the two links free with pliers. Maybe some drops of oil will help too.

Once that is fixed I will test again for the issue I was having before. It seems a bit better, but I refrained from shifting this morning, so I can't say for sure.