mostaza

Well that was an unmitigated disaster!

A beautiful, quiet lockdown morning in Manchester, so I thought I'd try taking it out for a gentle ride to see how it felt.

Within the first few seconds the chain was slipping.
This was under any moderate forced - seated or stood up.
Slipping about one link at a time.
Couldn't tell if it was the sprocket or chainring.

Here are the drivetrain shots as requested...

https://drive.google.com/file/d/1PHw...w?usp=drivesdk

https://drive.google.com/file/d/1PP_...w?usp=drivesdk

I've pushed the tensioner to it's forward limit in the second shot (obviously can't do that for the other direction, but it travels about half as much as the forward direction).

So issues now are:
1. Noisy
2. Chain repeatedly slipping a link under medium force


------------- EDIT -----------
What are thoughts on shortening the chain and adapting the tensioner to push up?

tFUnK

This is exactly what I was about to suggest, but I wanted to confirm your setup first. Can your tensioner be run in push up mode?

mostaza

Would you expect the chain to be slipping in its current setup?
46T front and 20T rear. Chainline good and tensioner as shown.

I'd say around at least ¼ of the sprocket teeth are engaging - so around 5/6/7.
I've seen plenty of conversions with much smaller chainring/sprocket combos - admittedly most without a tensioner.

Litespud

Although I'm trying to picture how your current setup would allow the chain to slip like you're describing, I might be inclined to get more chain wrap around the sprocket - most S/S and derailleur setups wrap the chain at least half way around the sprocket. Can you reconfigure the tensioner to push up a shorter chain, which would give you significantly more chain wrap?

tFUnK

I agree with litespud. You want more engagement between the chain and the chainring and cassette and you can achieve that by using the tensioner in push up mode. Back in the day I had skipping problems on a ss conversion with similar setup as yours, but I was using takeoff rings and cogs that weren't ss specific.

Miele Man

Can you not forgo the use of the chain tensioner?

Cheers

Unca_Sam

He could, if he has a magic ratio drivetrain. That's a vertical dropout.

Miele Man

That's where a half-link comes in handy.

Cheers

mostaza

​​​I've come to the same conclusion.
I measured without the tensioner and would definitely need a half link.
Will try it in its current format for a while, then look at getting rid of the tensioner.