On Friday, September 21, 2018 at 12:45:50 PM UTC-7, Joerg wrote:
A friend has a vintage Peugeot PX-10, once upon a time nicely upgraded
with Phil Woods axles and BB. He is heavily into MTB, home-made electric
bikes and stuff and I have a hard time convincing him to fix up his road
bike. IOW, the bike doesn't need much other than new shifter handles, a
new freewheel and new tires. However, he doesn't want to put a lot of
effort and money into that.

The corn cob freewheels don't work in our hilly area for us, ahem, older
guys. What is the largest cog size a PX-10 can take without installing a
new derailer?

My old Shimano 600 was said to max out at 28T but I got it to easily
shift up to 32T by moving the wheel slightly forward in the dropout
slots. AFAIK that isn't possible on a PX-10 because it has short slots.

--
Regards, Joerg

http://www.analogconsultants.com/

Dude, its Phil Wood hubs and not Phil Woods "axles." Phil would be spinning in his grave.

The short answer is that the bike probably has a Simplex Prestige or LJ derailleur that will handle a 28t cog and maybe larger. You will have trouble finding a 5sp freewheel with a larger-than-28 cog. Its more common for 6sp to get into the 30t range.

Having been through this exercise with a PX10, a few points: (1) the derailleur hanger is French threaded and will not accept a modern derailleur. The hanger will have to be tapped to 10mm and filed for a b-adjuster, (2) it has 120mm spacing, and the stays will have to be spread to accommodate a modern 130mm hub if your pal wants to join the modern era. That is no big deal for a competent shop. I did that at home, but I also have dropout alignment tools. (3) Your pal is hosed when it comes to headsets unless he can find NOS French. Viola! https://www.amazon.com/Velo-Orange-T.../dp/B004JKGW9U He's also stuck with a 22.0mm OD stem, unless he can find NOS or wants to sand a new stem to 22.0mm. Don't ream the steerer. None of the bearings are standard size and neither is the DT if he wants to change his FD. The seatpost is probably 26.4 or some other odd size. If its the old Simplex seatpost, it also weighs about six pounds. The French went out of their way to make their bikes incompatible with the rest of the world..

If I had an old PX10, I'd sell it to a collector and get a modern bike. Skip all the hassles.


-- Jay Beattie.