Any question answered...

I think it would be funny and/or interesting to ride around on a retro MTB with a very cheap eBay tri-spoke

Search for 559 trispokes instead :) There are a lot of Spin trispokes out there in 26"/559, probably more than there are 650C/571 clincher ones since racing on clinchers didn't come into fashion until 650C went out of fashion for normal sized people.

Yeah, but they have to be cheap; those are probably triple what I've spent on the rest of the bike! There's a lot of 650c tri-spokes around from youth bikes or track bikes that had a smaller front wheel and stuff, so I'm just wondering in case I spot a bargain in future.

Edit: In terms of the price it looks like some of the 650c tri-spokes sold for under £100 which I'd maybe consider paying. Also I'm not tied to tri-spokes; a disk wheel would be even funnier considering what a piece of shit the bike is. And there's those absurd 5-spoke magnesium wheel-shaped-objects out there too.

Shimano FH-M756 Hubs - do these work with 10 speed cassettes? I was convinced they were compatible but just noticed the tech doc says 8/9 speed.

Do I need a FH-M756a instead?

10 fits on 8/9.

Ironically, this requiem only a engineer could write is largely based around the hook from Ecclesiastes 1:9.

Thanks, no rush.
I've been pondering this for months.

based around the hook from Ecclesiastes 1:9

#rep

Tenn hi viz velcro overshoes are no more. I should have bulk buyed at £9 or whatever they were. Any other cheap hi viz overshoes around, velcro only, no zip?

#req

Chain tensioner + fixie + skid = broken chain tensioner?

Not necessarily, depends on what kind of chain tensioner. Definitely a terrible idea, skids or not, but destruction is not a certainty.

What are my options if my chain tension is shocking and I don't have enough lateral movement in the dropouts to remove a link? Change to a smaller chainring?

Change to a smaller chainring?

Or a bigger one. The magic gear chart is here

I'm on 50/18 with a 26" x 1 1/2" tyre so about 70 gear inches with 18 skid patches. 52 is only 9 skid patches, 48 is only 3. So I'd have to go up to 53 or down to 46, neither of which is very appealing. 52 might be alright I suppose. Or find a 51 or 49.

Edit: don't know my chainstay length - I'll have to measure it later - but with 1% chain stretch it was fine with one less link. The new chain ballsed it up

Another edit: a 53 gives 73.5 gear inches which I guess I could manage. And a ridiculous 36 skid patches. I'll check chainstay length later and get either a 52 or 53.

with 1% chain stretch it was fine with one less link. The new chain ballsed it up

49/18 should work in that case

chain stretch

Thought you'd say something. You've changed man.

Looks like 49t 3/32" chainrings are £30 which is more than I paid for the back wheel... I can get a 52 or 53 down the road for <£5. So I'll see if I can get one of those to fit first.

Thought you'd say something

My work here is done; if other people comment, I don't have to.

I can get a 52 or 53

52/19 would work, 52/18 is going to be too slack.

I also ideally don't want to buy a new sprocket. And if I do have to, I'd much rather buy a 16t or 20t as those are cheaper (it's a 6-bolt sprocket that fits on a disk-hub; there seems to be only Hope and "Gusset" whoever they are that make them. The Gusset ones are a lot cheaper but only in even numbers).

According to your calculator above if 50/18 fits with 1% stretch then my chainstays are 41.7 cm plus or minus n chain links. Which means that 53/18 is pretty bang on at 41.66 cm or so. I'm assuming that everything is modular so that if my chainstays are 1 inch longer and I have two extra links the results are the same? This is not technically accurate because the chain isn't going perfectly horizontal, it's at an angle.

Re. chain stretch; what's the proper term? It's not 1% chain wear because really the chain is 100% worn. "A 1% increase in chain length due to wear" is a bit wordy

it's a 6-bolt sprocket that fits on a disk-hub; there seems to be only Hope and "Gusset" whoever they are that make them

Velosolo make 6-bolt sprockets, lovely ones at that. Phil Wood does too, but I get the impression that you won't like the idea of $75 sprockets :)

Velosolo do them as well. I think I have an 18t that I dug out of the garage for someone else, if you’re interested? (They wanted a 16)

53/18 is pretty bang on

It's also a big increase in gear ratio. It's your funeral, but I wouldn't be going over 70" on a beater.

They do look nice but the Gusset ones are half the price. Like I said, the back wheel on this bike was only £26 and consequently spending £19.50 on a sprocket seems rather senseless.

@c00ps I'm already on an 18t but thanks for the offer!

the Gusset ones are half the price

And a quarter of the quality :)