On 2018-09-22 13:42, jbeattie wrote:
On Saturday, September 22, 2018 at 11:40:39 AM UTC-7, Joerg wrote:
On 2018-09-21 23:57, Sir Ridesalot wrote:
On Friday, September 21, 2018 at 5:34:11 PM UTC-4, Joerg wrote:
Snipped
He is a machinist and tool & die maker by trade, has a fully
equipped garage with lathe, mill and so on. He is building
stuff for his various vehicles all the time and made a couple
of parts for my MTB so I could build a sturdy rack.

120mm is a pain though, 10mm is a lot of widening. Looks like
this one can be shortened by grinding off the outer cog:

https://www.ebay.com/itm/Shimano-TZ3...4/322007138705




Snipped

Is he going to grind down the body too?

He should read Sheldon Brown:
https://www.sheldonbrown.com/speeds.html and
https://www.sheldonbrown.com/freewheels.html

"The freewheel threading on these older hubs is generally
interchangeable except for some very old French units. If you go
from a 5-speed freewheel to a 6- or 7-speed freewheel, you will
usually need to add some spacers to the right end of the axle
between the cone and the locknut. Once you have done this, you'll
also need to re-dish the wheel to bring the rim back to the
centerline. You may need to re-space the frame if you have added
spacers to the axle. See my Frame Spacing Article for details on
this."


Right. I also had to re-dish my rear wheel after UG freehubs were
no longer available. It wasn't fun but I got it all done in under
an hour including replacing the freehub.


"How Many Speeds?


Doesn't matter. Actually, the less speeds the better.

Really? Wasn't the complaint that he needed more gears to get up and
down the monster hills?


No, just a much larger cog than is on the corn cob right now. We all
become older and often due to a slowing metabolism also heavier. This
nonsensical 9-10-11-12 speed craze is unnecessary. Same with me, I
always shift across 2-3 gears, or 5-8 on the MTB, in one swoop. However,
I do need that 32T in back which I could do without when I was 25.


The olde tymie wide step 5sp freewheels weren't much fun with the big
jumps.


I loved those! Except, of course, that these were prone to axle breaks
which I had a lot.

My old MTB has 7-speed, the new one has a 10-speed cassette. I did not
perceive any advantage whatsoever. It's just that when I bought it they
were all 10-speed and I wish they weren't because then the chain would
still be a sturdier wide one.


... but it's a better arrangement than the current corn-cob. Also
check his crank. Some of the PX10s were spec'd with weird chainring
sizes with big small rings. I think mine had a 45t inner or something
like that.


My road bike has 42T and the smallest available for that set was 39T. So
some day I might throw a 40T in back as the largest cog but that would
also required a longer cage derailer.


... Again, he could make some good money selling the bike in
the collector's market and then go out and buy a nice gravel bike
with lots of gears, lighter and stiffer where it matters with even
more tire clearance for the gnarly gravel riding that you have to do
in the wilds of Cameron Park. There are some really good deals out
there on aluminum frame gravel bikes with hydraulic discs. I think
updating a mid-fi French bike is a waste of money. If he can get by
with throwing on a freewheel, then I would stop there -- otherwise,
go shopping.


That's also what I'd do. Especially since he is a mountain biker by
heart so doesn't want to spend much time fixing a road bike.

As for gravel bikes, most of our trails are really not suited for that.
Lots of loose rocks and stuff, it won't be fun and likely break the new
bike. Even if the gravel bike survives it could result in serious back
pain for older riders:

https://www.youtube.com/watch?v=l5cjAW_nrl4

--
Regards, Joerg

http://www.analogconsultants.com/