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Mid-'40s René Herse tandem

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Mid-'40s René Herse tandem

Old 09-30-20, 05:41 PM
  #151  
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Also did some work on chainrings!

I used Sprocketeer to do an ANSI 41 tooth profile. This is a perfect match for bicycle chain roller, as confirmed by several websites, in spite of the information on the Sprocketeer website itself. I had these waterjet cut from 0.160 aluminum plate, the closest match for 4mm plate I can get here in the USA.

I thinned the teeth down on the lathe, and cut the tops off the teeth. The teeth are 2mm wide. A 6-speed chain will roll on and off of them by gravity, so I think this is acceptable! Phew.

I beveled each with a file.

Then I hand-filed the mounting ears for a perfect fit on the cranks, which are not perfect by any stretch.


It seems a lot of hand-matching with files was done at the Herse shop. I am finding original things that look "off" in one way or another all the time. I do my best to reproduce with fidelity, but they're real artisanally-made bikes. No two will be alike. These cranks are not quite a 70mm bolt circle. Maybe 70.5? 71? I doubt the bolts are even in a circle, if we want to split hairs.
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Old 09-30-20, 08:15 PM
  #152  
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Originally Posted by scarlson
Also did some work on chainrings!

I used Sprocketeer to do an ANSI 41 tooth profile. This is a perfect match for bicycle chain roller, as confirmed by several websites, in spite of the information on the Sprocketeer website itself. I had these waterjet cut from 0.160 aluminum plate, the closest match for 4mm plate I can get here in the USA.

I thinned the teeth down on the lathe, and cut the tops off the teeth. The teeth are 2mm wide. A 6-speed chain will roll on and off of them by gravity, so I think this is acceptable! Phew.

I beveled each with a file.

Then I hand-filed the mounting ears for a perfect fit on the cranks, which are not perfect by any stretch.


It seems a lot of hand-matching with files was done at the Herse shop. I am finding original things that look "off" in one way or another all the time. I do my best to reproduce with fidelity, but they're real artisanally-made bikes. No two will be alike. These cranks are not quite a 70mm bolt circle. Maybe 70.5? 71? I doubt the bolts are even in a circle, if we want to split hairs.
Oof! Rene Hubris, indeed!
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Old 09-30-20, 09:52 PM
  #153  
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Originally Posted by gugie
Oof! Rene Hubris, indeed!
I calls 'em like I sees 'em. That's how I got this here nickname.

That stem I just did was roughed and finished mostly with bandsaw and files. The mill was really only for boring, counterboring, slitting, and slotting. Manual work is a good way to really get a feel for the object. The next one I make will be CAD and CNC, which is why I'm doubling down on tolerances and dimensions now. The way I made this drawing, I can change the length with a few keystrokes and output a new file. Hopefully it works and I don't break something! Maybe I make five and not even worry about brazing.


I know René Herse didn't have CAD nor CNC, so I cut him some slack I suppose. I mean, the way some of this stuff is made, it's like there was only one working caliper in the entire shop!!
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Old 09-30-20, 11:00 PM
  #154  
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Originally Posted by scarlson
I doubt the bolts are even in a circle, if we want to split hairs.
Unless they are in a perfectly straight line 3 points will always define a circle!

But I'm pretty sure you mean the 3 holes are not equidistant from each other.

I love those "home made" chain rings, its great to see you making progress on this restoration again!
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Old 10-01-20, 02:07 AM
  #155  
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Huge props for Mr. scarlson

This is fantastic and fascinating at the same time.

Simply amazing and so glad you are sharing all the details with us.

CNC/CAD one minute, seat of the pants, spitballin hand file the next.

No amount of brain cells or elbow grease spared what so ever.
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Old 10-01-20, 04:39 AM
  #156  
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Great to see that you are back in the machine shop and doing some great work! Chapeau!!
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Old 10-01-20, 04:44 AM
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Originally Posted by Treasure Cycles
I also kept away from this forum and didn’t realized (to my pleasant surprise) that it had picked up Again and with some wonderful Posts by not only you but also “timdaw”. It’s great to see friends share all the knowledge we possess without needlessly holding “secrets” back. Speaking of which; I didn’t quite catch the original thought about the need for “Nivex rear derailleur”, but in the spirit of sharing (and feeling part of the brotherhood of vintage quality French bicycle restoration), I’d like to volunteer any and every piece of information I hold and let you know that I currently own a Nivex rear derailleur that still hasn’t been installed onto my Alex Singer tandem, and would be willing to not only take measurements but more than that lend it out to you, my already good friend “Scarlson” so that you (Having the proper engineering skills can take your own measurements In order to share it with others that may want it in order to produce aluminum replicas of the same. I know I would personally love to own one of those! Also, I have a real need for a replica of a stoker stem such as the one our friend posted on here from his Rene Herse tandem in order to replace the smaller, less comfortable Phillipe stem currently on my tandem IF anyone gets to duplicate this.
That's great, but isn't the tandem version different to the bike version? I don't know if it is, but it is with other makes such as Cyclo, which had a scaled up version for tandems.
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Old 10-01-20, 05:13 AM
  #158  
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By way of contrast, here is a picture of the two main types of Herse stem. On the left is the early version, on a 1946 machine, and on the right the 'modernised' version by Jean Desbois c.1980. They are quite different, but both are beautiful. I just wished that Desbois had continued using the beautiful chamfer-headed screws, rather than allen bolts. The early version had the visible expander bolt head, which was replaced a little later by the concealed expander beneath the name cap, and the stem also has an integral brake cable 'bridge'....see second photo of 1953 machine.



It's mentioned in the Herse book that the stems were made by hand. The holes for the slot were done on a drill press and then four hours of filing later, the stem was complete!! I'm not so sure though - How was the ridge around the handlebar exits made? I think you should have been authentic and carved it by hand...........only joking!!

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Old 10-01-20, 08:00 AM
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Originally Posted by jackbombay
Unless they are in a perfectly straight line 3 points will always define a circle!

But I'm pretty sure you mean the 3 holes are not equidistant from each other.
Ha! What do you know, hubris goeth before the fall. Of course you're right. Equidistant from the bottom bracket axle and each other is what I had in mind!!
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Old 10-01-20, 08:07 AM
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Originally Posted by timdaw
By way of contrast, here is a picture of the two main types of Herse stem. On the left is the early version, on a 1946 machine, and on the right the 'modernised' version by Jean Desbois c.1980. They are quite different, but both are beautiful. I just wished that Desbois had continued using the beautiful chamfer-headed screws, rather than allen bolts.
Yeah, I wonder if he couldn't have turned the allen bolts down on a taper like the bottle and rack bolts you see on 1980s Nishikis, to achieve the look of the chamfer-head screws along with the versatility of the allen heads! Of course then he'd have needed to rechrome them and everything, assuming they are steel.

It's mentioned in the Herse book that the stems were made by hand. The holes for the slot were done on a drill press and then four hours of filing later, the stem was complete!! I'm not so sure though - How was the ridge around the handlebar exits made? I think you should have been authentic and carved it by hand...........only joking!!
I have an answer all the same. I'm pretty sure the ridge was done on a lathe. I see tool marks consistent with lathe work next to the ridge on mine. They must have had a shaft in the lathe spindle, and clamped the stem to it, and then turned a very slight taper. Hence the stem gets very slightly narrower as you approach that ridge.

Originally Posted by timdaw
That's great, but isn't the tandem version different to the bike version? I don't know if it is, but it is with other makes such as Cyclo, which had a scaled up version for tandems.
What was scaled-up on the "tandem" Le Cyclo, exactly? My two examples of Le Cyclo derailleurs are both from tandems, but to my eye they look the same as all other Le Cyclo derailleurs I've seen. On my Taylor I have the rare five-speed, and on the Herse, two tension springs were used in parallel to help deal with the long chain, but the arm and pulley look pretty similar to everything out there.
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Old 10-01-20, 09:15 AM
  #161  
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Wow. I would love to learn metal machining.

I could not connect to Sprocketeer, as I could not get a secure connection, as reported by four browsers I tried.
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Old 10-01-20, 09:57 AM
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Originally Posted by scarlson: I'm pretty sure the ridge was done on a lathe. I see tool marks consistent with lathe work next to the ridge on mine. They must have had a shaft in the lathe spindle, and clamped the stem to it, and then turned a very slight taper. Hence the stem gets very slightly narrower as you approach that ridge.[/QUOTE
I agree, I can see exactly what you mean, that would make sense.

What was scaled-up on the "tandem" Le Cyclo, exactly? My two examples of Le Cyclo derailleurs are both from tandems, but to my eye they look the same as all other Le Cyclo derailleurs I've seen. On my Taylor I have the rare five-speed, and on the Herse, two tension springs were used in parallel to help deal with the long chain, but the arm and pulley look pretty similar to everything out there.
Here is what made me think that:
On the left is a Cyclo from a pre-war Barra tandem. On the right is the standard Cyclo from post war. You can see that the left one is generally of beefier construction, and the rod along which the sprocket assembly slides is of larger diameter. The adjusting screw is correspondingly larger too.



However, when I checked the Cyclo derailleur (5 Speed) on my 40's Herse tandem, I found that it is, as you say, the same as the standard bicycle one in all respects. Again you are right that the spring is doubled up to provide tension for the 'long chain' arrangement.
So, maybe there was a Tandem specific Cyclo pre-war but not post war? I'm not expert enough to know that but maybe someone else can confirm? Clearly we need a Cyclo catalogue of the period....anybody?
Cheers, Tim
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Old 10-01-20, 11:57 AM
  #163  
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Originally Posted by noglider
Wow. I would love to learn metal machining.
You can get a free download of Fusion 360, the CAD software I use, from Autodesk. I don't think you even need a .edu account. Then buy yourself a small desktop CNC router for a few hundred dollars, and you'll be in business! Those can do aluminum and other soft metals. The reason I didn't go that route is because they mostly can't fit a 48t chainring.
As for machining manually, when/if covid is over, there is probably a 'maker space' with mills and lathes you could get a membership to. I was given a 40-hour training course to learn the basics in order to make some things for my lab, but most of the specialty stuff is self-taught via Youtube videos. Youtuber 'Abom79' is a lathe virtuoso, and 'This Old Tony' and 'Clickspring' are also good.
Or, one day I will have my own shop and I can invite you over.

I could not connect to Sprocketeer, as I could not get a secure connection, as reported by four browsers I tried.
Huh, yeah, my link doesn't work, but when I go through my browser history it does - and it's the same exact address! It does say "not secure" for some reason. I'm really not sure what's going on. Maybe try to go through a search engine? Or click through from the home page itself, idleamusements.com ?
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Old 10-01-20, 12:09 PM
  #164  
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@scarlson for about a year I had a job in the Engineering school at Columbia University. The makerspace was down the hall from my office, and the chief said I could use it any time for free. Like a fool, I never got around to it, though I did visit from time to time. Maybe I'll find a way. I want to teach middle school or high school when I grow up, and this would be a great thing to teach, if the schools can find a way to bring shop class back.

I'll look into the tips you gave. Thanks. I've done some "machining" with files and my bench vise. Nothing amazing, but somehow I've amazed my friends.
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Old 10-01-20, 11:41 PM
  #165  
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Getting closer!!
I slitted the steerer tube clamp, opened the slot in the middle of the stem to within 0.1" of the bar clamp, and fabricated and installed the cable housing stop. It is a press-fit 7mm rod. I press-fit it and then bored with a tiny end mill and drilled the tiny hole for the front brake cable. Also drilled and tapped the hole for the bell.



And I did a test-fit. It fits well!



I'm done with major machining steps on this, and ready to give it a nice finish-filing and polish!

The weird bolts I used do not have slots yet. They are just hex head bolts I turned into Herse-shaped heads on the lathe. They're stainless, so not true to original. I may find a better solution (ideally pre-slotted steel screws) that I can send to be chromed along with the rest of the hardware.
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Old 10-02-20, 12:56 AM
  #166  
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Originally Posted by scarlson
I calls 'em like I sees 'em. That's how I got this here nickname.

That stem I just did was roughed and finished mostly with bandsaw and files. The mill was really only for boring, counterboring, slitting, and slotting. Manual work is a good way to really get a feel for the object. The next one I make will be CAD and CNC, which is why I'm doubling down on tolerances and dimensions now. The way I made this drawing, I can change the length with a few keystrokes and output a new file. Hopefully it works and I don't break something! Maybe I make five and not even worry about brazing.


I know René Herse didn't have CAD nor CNC, so I cut him some slack I suppose. I mean, the way some of this stuff is made, it's like there was only one working caliper in the entire shop!!
calipers? Think dividers.
good work!
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Old 10-02-20, 11:33 AM
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Thinking ahead, while I had the fork in hand, I measured the carbon brush socket in the steerer. The carbon brush was missing, but luckily the spring and insulator are still there. The inner diameter of the insulator measures 5mm. I'm going to buy some 5mm pure graphite rod from Ebay (I guess used as old-school carbon arc lamp or really old-school carbon arc welding electrode) and give it a try. There's continuity in the original wires through the frame and insulation from it, so no reason to change anything!

I did look for actual motor or alternator brushes, figuring they'd be sintered with copper and possibly more durable and/or more conductive than pure graphite, but they don't come in 5mm round, and any less lathe work I have to do on this thing will be better. Anybody have any ideas, or know whether the brushes he used would have been pure carbon or something better?
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Old 10-02-20, 11:36 AM
  #168  
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Originally Posted by timdaw
On the left is a Cyclo from a pre-war Barra tandem. On the right is the standard Cyclo from post war. You can see that the left one is generally of beefier construction, and the rod along which the sprocket assembly slides is of larger diameter. The adjusting screw is correspondingly larger too.

However, when I checked the Cyclo derailleur (5 Speed) on my 40's Herse tandem, I found that it is, as you say, the same as the standard bicycle one in all respects. Again you are right that the spring is doubled up to provide tension for the 'long chain' arrangement.
So, maybe there was a Tandem specific Cyclo pre-war but not post war? I'm not expert enough to know that but maybe someone else can confirm? Clearly we need a Cyclo catalogue of the period....anybody?
Cheers, Tim
Whoa, that's really interesting! I found one on Ebay with the larger dimensions, and it is indeed sold as a "tandem" model. And likely pre-war. I'm now tempted to buy it as a curiosity item. Such bad habits!
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Old 10-02-20, 01:35 PM
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Originally Posted by repechage
calipers? Think dividers.
good work!
True enough, I used my calipers as dividers a lot doing this stem. The measurements match up equally often to inches, metric, or nothing-in-particular!

It will be comparatively easy to CNC mill these in various lengths, or maybe waterjet, so that's what I'll be looking to do next, provided there is not another lockdown. If there's a lockdown, I'll braze a stoker stem like timdaw, and maybe see about a cheap desktop CNC router. It is theoretically possible to do them all with a drill press and some files after the basic shape is roughed-out, but it is quite tedious.
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Old 10-03-20, 11:55 AM
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Originally Posted by scarlson
True enough, I used my calipers as dividers a lot doing this stem. The measurements match up equally often to inches, metric, or nothing-in-particular!

It will be comparatively easy to CNC mill these in various lengths, or maybe waterjet, so that's what I'll be looking to do next, provided there is not another lockdown. If there's a lockdown, I'll braze a stoker stem like timdaw, and maybe see about a cheap desktop CNC router. It is theoretically possible to do them all with a drill press and some files after the basic shape is roughed-out, but it is quite tedious.
the center slot is a big swallow on a CNC router... I guess a bunch of passes.
the underside of the stem at the headset I find interesting, old memories of Rene Herse stems, I thought they were straight across at the nut, or at least counterbored to fully mate with the headset lock nut.
Way Way back on my first club ride in 1972, a club member had a RH, what an attractive bike! Really looked intensely at the details, including the stem. I had a "pedestrian" by comparison Bertin C-37.
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Old 10-03-20, 12:17 PM
  #171  
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Originally Posted by noglider
@scarlson. . .

I'll look into the tips you gave. Thanks. I've done some "machining" with files and my bench vise. Nothing amazing, but somehow I've amazed my friends.
...and thus was born the Industrial Revolution..

Like you i’m fascinated by this restoration.
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Old 10-04-20, 08:33 PM
  #172  
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Excellent work SCarlson,
I have prewar French Cyclo mechs in 2 speed and 3 speed for 1/8 chain. I assume they were available in 4 speed for 3/32 chain. Not sure if there were 5 speed prewar mechs. I suspect there was. All English Cyclo mechs were like the prewar French mechs. These were available in 3 and 4 speed for 1/8 chain. Those 4 speed 1/8 mechs could be converted to 5 speed 3/32 if the “jockey” sprocket is machined. Could be useful for those that want to try 5 or 6 speed compact free wheels on prewar French tandems.

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Old 10-05-20, 09:53 AM
  #173  
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Originally Posted by scarlson
Also did some work on chainrings!

I used Sprocketeer to do an ANSI 41 tooth profile. This is a perfect match for bicycle chain roller, as confirmed by several websites, in spite of the information on the Sprocketeer website itself. I had these waterjet cut from 0.160 aluminum plate, the closest match for 4mm plate I can get here in the USA.
That's awesome. I've been meaning to do something like that but as a 50.4mm BCD version of this classic Gazelle sprocket. I'm not the greatest at CAD but I have played around a bit with Google Sketchup in the past so this is a welcome basis.

And it turns out there are some good manuals available for Sprocketeer!

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Old 10-05-20, 12:14 PM
  #174  
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Wow, that is so impressive. Machining is just such a fascinating thing. Looking forward to seeing this all together and finished. I think you could give This Old Tony a run for his money if you were to start your own youtube channel. How's your snarky humor?
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Old 10-06-20, 12:02 PM
  #175  
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Originally Posted by repechage
the center slot is a big swallow on a CNC router... I guess a bunch of passes.
the underside of the stem at the headset I find interesting, old memories of Rene Herse stems, I thought they were straight across at the nut, or at least counterbored to fully mate with the headset lock nut.
Way Way back on my first club ride in 1972, a club member had a RH, what an attractive bike! Really looked intensely at the details, including the stem. I had a "pedestrian" by comparison Bertin C-37.
It's possible that the early stems are different from the later ones. My original stem has only the very slightest angle where it meets the headset top nut, and there is no counterbore to speak of. This was discussed in an earlier post in this thread, where you can see a photo I took of it with a straightedge alongside. I tried to recreate that as best I could on the reproduction!
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