50.4 Chainring Modification
#1
Junior Member
Thread Starter
50.4 Chainring Modification
I have access to a machine shop at work and the machinist is often happy to take on side projects when things get slow.
Here are a few pictures of a tool holder he made in order to remove the worn out teeth from an old 50.4 Stronglight Chainring. I’ve yet to use the part but thought this may be of interest to some.
Here are a few pictures of a tool holder he made in order to remove the worn out teeth from an old 50.4 Stronglight Chainring. I’ve yet to use the part but thought this may be of interest to some.
Likes For Nwvlvtnr:
#2
www.theheadbadge.com
Join Date: Sep 2005
Location: Southern Florida
Posts: 28,514
Bikes: https://www.theheadbadge.com
Mentioned: 124 Post(s)
Tagged: 0 Thread(s)
Quoted: 2422 Post(s)
Liked 4,396 Times
in
2,093 Posts
Likes For cudak888:
#3
Shifting is fun!
Join Date: Aug 2009
Location: South Holland, NL
Posts: 11,007
Bikes: Yes, please.
Mentioned: 280 Post(s)
Tagged: 0 Thread(s)
Quoted: 2198 Post(s)
Liked 4,611 Times
in
1,765 Posts
I see candles and witches in its future.
#4
Freewheel Medic
Join Date: Oct 2005
Location: An Island on the Coast of GA!
Posts: 12,886
Bikes: Snazzy* Schwinns, Classy Cannondales & a Super Pro Aero Lotus (* Ed.)
Mentioned: 140 Post(s)
Tagged: 0 Thread(s)
Quoted: 1453 Post(s)
Liked 2,196 Times
in
963 Posts
This could become an interesting side business re-cycling (sic) old-worn-out chainrings into guards, trivets, art, etc. Well done!
__________________
Bob
Enjoying the GA coast all year long!
Thanks for visiting my website: www.freewheelspa.com
Bob
Enjoying the GA coast all year long!
Thanks for visiting my website: www.freewheelspa.com
Likes For pastorbobnlnh:
#5
Senior Member
Join Date: Dec 2005
Posts: 17,160
Mentioned: 481 Post(s)
Tagged: 0 Thread(s)
Quoted: 3811 Post(s)
Liked 6,716 Times
in
2,613 Posts
Nice work! I’ve done that the old-fashioned way with knippers, bench grinder, and file:
Likes For nlerner:
#6
Senior Member
Join Date: Feb 2013
Location: Alta California
Posts: 14,272
Mentioned: 415 Post(s)
Tagged: 1 Thread(s)
Quoted: 3814 Post(s)
Liked 3,345 Times
in
2,182 Posts
#7
Senior Member
Join Date: Feb 2013
Location: Alta California
Posts: 14,272
Mentioned: 415 Post(s)
Tagged: 1 Thread(s)
Quoted: 3814 Post(s)
Liked 3,345 Times
in
2,182 Posts
I have access to a machine shop at work and the machinist is often happy to take on side projects when things get slow.
Here are a few pictures of a tool holder he made in order to remove the worn out teeth from an old 50.4 Stronglight Chainring. I’ve yet to use the part but thought this may be of interest to some.
Here are a few pictures of a tool holder he made in order to remove the worn out teeth from an old 50.4 Stronglight Chainring. I’ve yet to use the part but thought this may be of interest to some.
-----
you may wish to append this to the 5 vis appreciation discussion:
https://www.bikeforums.net/classic-v...on-thread.html
-----
Likes For juvela:
#8
ambulatory senior
Join Date: Dec 2016
Location: Peoria Il
Posts: 5,998
Bikes: Austro Daimler modified by Gugie! Raleigh Professional and lots of other bikes.
Mentioned: 76 Post(s)
Tagged: 0 Thread(s)
Quoted: 1955 Post(s)
Liked 3,662 Times
in
1,680 Posts
#9
blahblahblah chrome moly
Join Date: Apr 2009
Location: Seattle
Posts: 1,994
Mentioned: 92 Post(s)
Tagged: 0 Thread(s)
Quoted: 1181 Post(s)
Liked 2,576 Times
in
1,076 Posts
They say to a man with a hammer, everything looks like a nail. But I do have a lathe, and I still think sawing is a faster way to make these things.
I find it very fast to hacksaw, following the advice of Billy Ketchum who made this creation, "the world's lightest chainring":
I don't know how he ended up with an unbroken ring, maybe photoshop? I end up with a "closed C" because the circle is broken where the hacksaw first enters. But after that, the sawing goes amazingly fast, with pauses now and then to reposition the ring in the vise (about 5 times). I suppose it might be harder and slower for someone with less experience hacksawing (I have tons) or without a good bench vise (I have several. Ain't I special...)
Since the last time I did one, I've purchased a bandsaw*, which should make this job very much faster and easier, even faster than setting it up in the lathe. Yes the lathe leaves a precision-machined surface, but this application doesn't require precision. After cleaning up the saw marks on the belt sander, I'm left with a nice-looking part. If I wanted it even nicer, I have a scotchbrite wheel on a bench grinder, and a cloth buffing wheel if you need it even shinier than that. No one without a dial test indicator would be able to tell that it's less precise than the lathe-turned version.
*the bandsaw I got is a small portable one, often called a portaband (though that's a brand name, like kleenex or xerox, and I didn't get that brand). Meant to be hand-held, but then I got an aftermarket table that turns it into a stationary vertical bandsaw, perfect for making bashguards. But the table detaches (with an actual bike quick-release!) to let you use it in hand-held mode.
These portaband tables, purchased or DIY, are a game changer and a must-have for the tinkerer. Hot tip: also get a foot switch to turn the bandsaw on, so both hands are free to manipulate the part. Also good for safety, since if anything goes wrong it's very quick to turn off, just lift your foot. I use this bandsaw all the time now, it's like "where have you been all my life!!" I hardly ever hacksaw anything anymore. In the thread about cutting handlebars for bar-end shifters, somebody mentioned doing it with a pipe-cutter and I'm like "Fine, if you live long enough!". Bike handlebars would be literally about 5 seconds on my bandsaw — 2 sec. per cut, with 1 sec. to flip the bar over. Another 5 sec to clean up the saw marks on the belt sander, if you care, but those saw marks don't matter with barcons.
Mark B
I find it very fast to hacksaw, following the advice of Billy Ketchum who made this creation, "the world's lightest chainring":
I don't know how he ended up with an unbroken ring, maybe photoshop? I end up with a "closed C" because the circle is broken where the hacksaw first enters. But after that, the sawing goes amazingly fast, with pauses now and then to reposition the ring in the vise (about 5 times). I suppose it might be harder and slower for someone with less experience hacksawing (I have tons) or without a good bench vise (I have several. Ain't I special...)
Since the last time I did one, I've purchased a bandsaw*, which should make this job very much faster and easier, even faster than setting it up in the lathe. Yes the lathe leaves a precision-machined surface, but this application doesn't require precision. After cleaning up the saw marks on the belt sander, I'm left with a nice-looking part. If I wanted it even nicer, I have a scotchbrite wheel on a bench grinder, and a cloth buffing wheel if you need it even shinier than that. No one without a dial test indicator would be able to tell that it's less precise than the lathe-turned version.
*the bandsaw I got is a small portable one, often called a portaband (though that's a brand name, like kleenex or xerox, and I didn't get that brand). Meant to be hand-held, but then I got an aftermarket table that turns it into a stationary vertical bandsaw, perfect for making bashguards. But the table detaches (with an actual bike quick-release!) to let you use it in hand-held mode.
These portaband tables, purchased or DIY, are a game changer and a must-have for the tinkerer. Hot tip: also get a foot switch to turn the bandsaw on, so both hands are free to manipulate the part. Also good for safety, since if anything goes wrong it's very quick to turn off, just lift your foot. I use this bandsaw all the time now, it's like "where have you been all my life!!" I hardly ever hacksaw anything anymore. In the thread about cutting handlebars for bar-end shifters, somebody mentioned doing it with a pipe-cutter and I'm like "Fine, if you live long enough!". Bike handlebars would be literally about 5 seconds on my bandsaw — 2 sec. per cut, with 1 sec. to flip the bar over. Another 5 sec to clean up the saw marks on the belt sander, if you care, but those saw marks don't matter with barcons.
Mark B
Likes For bulgie:
#10
www.theheadbadge.com
Join Date: Sep 2005
Location: Southern Florida
Posts: 28,514
Bikes: https://www.theheadbadge.com
Mentioned: 124 Post(s)
Tagged: 0 Thread(s)
Quoted: 2422 Post(s)
Liked 4,396 Times
in
2,093 Posts
Likes For cudak888:
#11
Bike Butcher of Portland
Join Date: Jul 2014
Location: Portland, OR
Posts: 11,639
Bikes: It's complicated.
Mentioned: 1299 Post(s)
Tagged: 0 Thread(s)
Quoted: 4682 Post(s)
Liked 5,803 Times
in
2,286 Posts
Likes For gugie:
#12
Senior Member
Join Date: Aug 2010
Location: south kansas america
Posts: 1,910
Bikes: too many
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 411 Post(s)
Liked 234 Times
in
140 Posts
I've been contemplating taking an tired outer chainring from a Viscount Aerospace (the iconic "circle cutout" design) and remachining it down from a 52 tooth to... well, I don't know. I'm not sure how far I could take it down, and leave enough matl. for the new teeth pattern. Sadly, I don't have a machine shop as handy to access for such things.