I've got a Peugeot UO8 and I'd like to switch out the cottered crankarms for something else. I've read the (thankfully extensive) threads having to do with just this and what I've gathered is that my easiest potential solution is to keep my BB cups and replace the old spindle with a series 5 spindle so I can get a different crankset.

Does anyone have a suggestion for where to get a 5 spindle? Harris Cyclery is out of them for the time being and I'm checking around other places to see if I can find anything. I've looked at loosescrews.com, biketoolsetc.com, and peter white cycles and either haven't found them or don't know quite enough to know what I'm looking at. Of course, I'd be looking for a crankset to fit w/ the 5 spindle as well.

I do know the sugino cups that would fit the French shell (which Harris does have) would facilitate a 3 spindle, which would be great but I think if I can find a 5 spindle it'll be cheaper. Obviously if I'm wrong, let me know the course you'd suggest. Thanks all.

Yellow Jersey used to carry them. I bought a couple a year or so ago from them. Might have one laying around some where.

I checked and didn't see anything, but I'll email them just in case. Thanks a lot.

The "5" spindle option definitely works - I did this with a UO-8 last year, with great success. As stated though, they are hard to find. I'm lucky in that I work in a community bike shop that recycles old bikes and parts, so "5" spindles turn up a little more regularly.
However, if my memory serves me correctly, I seem to recall doing this at an earlier stage with another UO-8, but used a "3" spindle - this was a single speed conversion though, so that may not work if you are simply trying to change the crankset for a lighter alloy double. I can't check what "3" spindle it was, because I no longer have the bike.
I've actually just ordered some French Sugino cups off of eBay for a PX-10 that I am rebuilding. The price with postage to Canada was $24.95, and if you are in the States, probably even less. Granted, a PX-10 is worth more to me (and most others) than a UO-8, hence I can justify spending the extra dollars, and the Sugino cups provide a lot more options in terms of spindle selection. Even if you managed to find a "5" spindle, there is the issue of getting one the right length to suit your needs.

"The "5" spindle option definitely works - I did this with a UO-8 last year, with great success. As stated though, they are hard to find.
However, if my memory serves me correctly I seem to recall doing this at an earlier stage with another UO-8, but used a "3" spindle - this was a single speed conversion though..."

Actually, I have the UO8 down to single speed--52/16. If there's some way of using a 3 spindle w/out getting new cups, I'd be into it. To remain practical, however, I'll check for french cups online--I looked on ebay and didn't see anything available, but I know that changes. $25 or cheaper doesn't sound too bad.

In the meantime, I'll keep looking for the 5. When you used a 5 spindle on your UO8, what length worked for you? I'm not sure what factors go into figuring out length--crankset and chainline?. I think I read something about around 115mm?

Thanks a lot!

To be honest, I can't remember what length spindle I used. I don't have either of these bikes anymore, so I can't check for you. Getting the spindle and crank to fit is the biggest pain with a UO-8 S.S. conversion, so my advice is to just experiment with some different spindles (if you have some old ones spare) and see how you go. I have flipped spindles around in the past to reduce the chainline when needed - spindles are rarely symmetrical - it just means that the left side will stick out a little bit more than usual. You can always just put the fixed cup side in (with the grease and balls of course) and loosely push the drive side crank on to get a rough idea.
As for the French Sugino cups on eBay, here they are:
https://search.ebay.com/search/search...ino&category0=

The old Series 5 spindles are usually asymmetric. I think I put a 119 or a 120 on my UO8, but I used the end on the drive side that gave the best chainline. Chainline is not all that critical on these old bikes with friction shifters so long as the derailleur has enough range.

True enough for derailleur gearing, yes. But Jagee is making his into a single speed, so chainline is a little bit more important...