Kuromori

That's an excellent reference picture. I knew it wasn't quite flat on the bottom, which is why I said it tends to follow, but it was always hard to see how much since most pictures are at an angle. It's very elegant and subtle. I'm not exactly sure how RH did the quill stems, but Reynolds (as in Reynolds 531) had some two-part aluminum quill stems where the extension was bolted down onto to a keyed and tapered shaft. I might have a PDF with a diagram somewhere.

rhm

Good luck with that!

I used to make my dynamo wiring much too complicated, buck puck, switch, etc. What I found was that when it's all together and it should work, and it doesn't, it's really hard to diagnose the problem. Every soldered connection was a potential cause of failure, and there's no way to test each one without ripping it apart and starting over. I now make my dynamo light systems absolutely as simple as possible, the absolute bare minimum of connections. Bridge rectifier? Phooey.

​​​

scarlson 

Yeah I know, it often frustrates me too. I've had my share of problems. The method I have found to work, I like to call "awake brain surgery" after the type of surgery where they'll work on a patient's brain under local anesthetic only, and the patient will be constantly asked a series of test questions to assess brain function in real time. Applied to lighting, it's basically "keep spinning the wheel and testing things while you wire it up". At least you can tell if you've just made a short.

But this will be my first foray into Buck converters and is a long way off. I just think it would be really nice for camping, not to have to worry so much about conserving battery. I'm pretty confident that the heart of the $175 "The Plug" is just a $5 Buck converter, or even simpler, a 5-cent LM7805 voltage regulator.

rhm

Well, check this out:

https://rover.ebay.com/rover/0/0/0?m...2F132535159690

For a little under $24 you get
1. a 12 v side wall dynamo, which you can discard.
2. hardware to hold that dynamo to your bike. This may be useful somehow, I dunno. If in doubt, throw it out.
3. A cell phone holder. I would discard this.
4. Hardware to hold that cell phone holder to your handlebar. Eh, discard that too.
5. A little black box converts variable AC current to standard 5.2 USB DC, with a normal (not mini) USB plug Very useful!
6. A wire that connects that box to a dynamo. Also useful.

I use that #5 and #6 thing to keep my GPS charged, or my cell phone. I don't know if the electronics is as advanced as that in a plug or a sinewave, but the price is pretty good.

santa fe 2926 

thought this might be enjoyed
Timken 1111

L134 

is this something you’ve used with a dynamo hub and it works?

rhm

Yes, I have. But I'll qualify that:

I've bought a few of these. The first one worked great but I busted it by jamming the USB plug in backwards in the dark. The second one usually worked but sometimes didn't. That may have been my fault. I switched in a third one and have had no trouble. On long brevets I can keep my GPS charged indefinitely, or my phone, but keeping both charged is difficult. And I don't use it at night if I can avoid it; it seriously weakens the headlight.

I think this is as good as the Dahon Joule unit that costs three times as much. I have one of those. I have no experience with the Sinewave version or other relatively expensive ones. They should be much better, and maybe they are. Well, here's a cheap alternative.

scarlson 

This is some good real-world data!

I was thinking I could probably assess the efficiency of these devices by running a few different ones on a hub held at a given rpm in a machine spindle, and looking at the 5VDC output with an oscilloscope. If they have a Buck converter circuit, unless equipped with very good filtering, they should have some telltale wavy output from the chopper circuit, changing with load. The simpler and less-efficient resistive voltage regulators wouldn't have this, but might let more of the AC spikes from the dynamo through.

scarlson 

I would like to see that!!

Kuromori

Looks like I managed to download the relevant document from VCC before the paywall went up, although I'm missing a few. I've put the relevant page up on my Reynolds page ( https://kuromori.home.blog/reynolds-531/#alloy ). I'm not sure if they key was cast or forged into the extension, but I can only imagine that if milling a stem from billet it would be easier to broach a keyway. The diagram shows a stem for a clip type headset so there's no expander at the bottom. I don't know if the cone provides any internal support, but I suspect it just allows the stem to use a smaller and shorter bolt for attaching the head to the shaft. I believe expander head would have a larger hole for a larger full length bolt and would be slotted and internally tapered at the end of the shaft for the expander. The leaflet was dated to 1946, but I have next to nothing from Reynolds in the 30s when RH was first starting out. I don't know how proprietary this design was to Reynolds either, but many of the other girder type stems were made in one piece or brazed steel. These components seem more or less contemporary to RH, RH would have had access to Reynolds products, the limited sizes would be a strong motivator for RH to machine his own extensions, and a keen observer would note that the shaft on RH quill stem either tapers or necks down as it enters the extension.

I've seen two replicas that believe RH quill stems were made in another way. One uses a partial taper, then is threaded to made with the same thread as the top cap. The issue with this design is that early RH quill stems don't have the threaded top cap. The bolt head is simply exposed like the Reynolds stem. The other is just an interference fit, but I don't see a good reason to neck down the shaft for this purpose, and on real examples, the taper appears to extend into the extension and has a good fit, indicating that the bore in the head has a good fit to the shaft. Given that the bottom of the heads is not perpendicular to the shaft, this would tend to indicate a hole with a matching taper/neck. At the very least, it seems likely that the shaft doesn't neck down then enter a straight untapered hole and have a plain interference fit.

DMNHCAGrandPrix

Chris Bishop made a Herse style stem for a Brett Horton custom bike that was exhibited at NAHBS in 2011.

Here's a good photo collection of the laborious milling and filing process:

https://www.flickr.com/photos/bishop...th/5447914251/

ThermionicScott 

That stem is too cool. I like how he routed around the cable stop instead of pressing in an aluminum rod at the end.

repechage

I think the one process change I could see that might be useful was the slotting of the quill expansion slot might be done after it was pressed into the "girder"
A few key images are missing, that and the thread that the stem cap fitted into. Hey, I know, secrets....

scarlson 

Thank you for that, it will help me a bit in my process. Much respect to those who continue to manually machine all this stuff. I am so lucky to have access to the CNC mill at work. The photo captions are very informative. He says the quill is stainless steel and is just press fit in there, with knurling and bonded with some Loctite product. Interesting and definitely an easy way forward without precision machining of tapers and keyways. Get a little chatter on the taper with a reamer, or mess up with a boring bar on the compound and you're toast, the thing will never fit right.

Ugh, secrets are the worst, but this guy seems pretty above-board, which is refreshing! It's not like he's going to lose business by showing how the sausage is made!! Easy to do that thread on the lathe with a four-jaw independent chuck especially since concentricity isn't the biggest deal considering it's just a cap. Or get lucky and have the correct die on-hand. 3/4 x 24 maybe? M18 x 1.0? I'd definitely slot the quill beforehand, probably holding it in a 5C collet block. Probably with a hacksaw, honestly. I hate running slitting saws and I know that makes me a bad machinist.

TenGrainBread 

I am tooling up to make heat-treated stainless stems. It presents an interesting problem for slotting because no hacksaw blade will cut the precipitation-hardened tubing (KVA MS3). I also hate using slitting saws on the mill. I bought an Evolution TCT chopsaw for the job. They offer carbide-tipped blades for stainless, as well as blades for aluminum and mild steel. It's noisy but works quite well for slitting. Much faster than the mill.

Treasure Cycles

Recently came across this amazing post and wanted to first of all thank Mr. S.Carlson for sharing his wonderful Rene Herse tandem and tutorial with us. Wanted to let you know that I came very, very close to purchasing this same bike from the seller back in France earlier the same day he sold it to you. We even got to negotiate both pricing as well as shipping, only for my wife to raise hell and shout the “divorce” word back at me! I regretfully had to write back to the seller and kindly retract myself from the buy, later that same day (and after she calmed down a bit) telling her that I would live to regret pulling back from the purchase and that I would never, ever let her forget that SHE was the culprit of me passing on this once-in-a-lifetime treasure. Last night while surfing the web, I found this post and read it in its entirety. Incredible job you seem to be doing. I’d say much, much better than I could ever hope to accomplish. For this reason, you have brought some sort of “closure” to my bitterness. I am so very glad this bike ended in the hands of someone such as yourself with enough knowledge, skill and adoration of this timepiece. Please don’t stop with the project, and whenever possible, please include more pictures of the project and how it’s coming along. I have become your #1 fan and admirer! So happy for you, and proud that you were able to “pull the trigger” and purchase this amazing piece when others such as myself could simply not do so.

timdaw

Hello. I'm interested to know how this project is progressing? I'm a recent member of this forum, and found this thread most interesting. I have a very similar Herse tandem which was in a comparable state to this one. My one was probably made around 1941/2 and then, like this one, it went back to Herse for some modifications. It then got a new frame number of 109. Luckily, apart from the surface rust, it cleaned up quite nicely, and the all important chain rings were fine. I use it regularly with my wife as stoker, and we love it. There is a post on my blog about the bike if you search 'vintage bicycle blog Herse tandem' (as a new member apparently I can't post my URL)
Some of this forum contributors have been saying nice things about my blog, including in this thread....thank you! There are a number more Herse, Singer and other French constructuers on there.
I realise that I didn't post pictures of the finished machine, so I will rectify this in the next few days.
By the way, the last info from Mr.Carlson was that he was going to machine a Herse stoker stem. My tandem has a steel stoker stem, brazed to the seat pin. It has one of Herse's special alloy bolts which suggest it's original.
Also, because I think new chrome on pitted metal is a crime, I painted the racks black and it works well, I think.
I'll notify when I post detailed pictures of my tandem on the blog.

TenGrainBread 

Tim - you're the proprietor of vintagebicycle.wordpress? Lovely blog, one of my favorites. Your "preservation, not restoration" approach is spot on and I have gotten quite a few good tips from your blog. In fact am going to start on preservation of an old lowish-end Routens, with derailleurs 4 speed Cyclo rear and Routens front. It came with the original curved stay Routens front rack (solid rod, not tube) that is painted black and has a support broken at the joint, which I will re-braze and touch up. Will be using some of your paint preservation tips on this one.

timdaw

The original Herse stems are all alloy. The quill is a tight fit into the block part, and it's smaller diameter than the rest of the stem, so there is a shoulder beneath the top part. An alloy slug is then dropped into the tube and pressed into the narrower part, to expand the quill and lock the stem together. I don't like the idea of a simple press fit and loctite for a stem....particularly on a tandem!!

scarlson 

Right now I am locked out of the university where I work, which is where the machine shop is. Recently received word that during the "ramp-up" I am not allowed back in the machine shop until further notice, so the project is indefinitely on hold at this point except some minor stuff. I've removed some of the gobs of awful blue touch-up paint someone put on this frame at some point in the past. And I've just been exhausted, in spite of not doing much. I should be productive but it seems I am always caught under a mound of housework and endless zoom meetings talking about nothing in particular of substance. Some people seem to thrive on the red tape, but not me. I'll get it done in due time, but everything is much harder now, so maybe years now, not months like my Taylor.

What makes you think mine went back for modifications? I think I came to the conclusion that it didn't, based on Jan Heine's post regarding the date of manufacture, and if it had, it might have received a 5-speed derailleur or at least a new serial.

I'll be one more person saying nice things about your blog. I saw it years ago, and it's provided a lot of good information over the years. Looking forward to seeing those photos of the finished tandem! Here's the blog URL for those who could not find it.

Yeah, I'll machine one in due time. I am a proficient manual machinist, but the future is all CNC, so I was thinking of setting up a home "CNC router" to do aluminum so I could do the chainrings, maybe a stem, and learn some gcode debugging in the process, but this would likely irritate my downstairs neighbors, who hate me already. These things are LOUD. And a decent setup would likely cost me a thousand dollars, to build or to buy, and at that point why not just get a clapped-out Bridgeport mill? To do that, I really need a house, but people in my generation can't afford such things. I have a lot of money saved for a down payment, but it's not enough for even a run down foreclosure in this area. Phew.

I would like to see your brazed steel stoker stem, not because I'd go this route, but just to see more variety.

Thank you for the explanation of the Herse quill stem construction. It solves a mystery for me and some machinists I talk with. It really makes sense to do it that way. Simplifies machining, and we know he liked to rivet and press things together so it's consistent.

I ride a Vitus 979 on "go-fast" day rides, so I'm inclined to trust glue. I would use Araldite 2011 as in the Vitus patent. The glued-together stems mentioned earlier are threaded together as well, so I don't think there is much to worry about there. Bet you'd hear it creaking before it let go. In any case, the front stem on this bike is a clamp-on style, directly clamping to the steerer, so I don't have to do any of this. But if I end up with fully debugged toolpaths for CNC machining a stoker stem, I may as well do another, with different length and different sized holes, for extra bling on my Ron Cooper or Trek. The major cost is in getting kinks worked out. After that, it's just mass production.

scarlson 

Hey, thanks for the heartfelt post! I appreciate hearing from you. You're now the second person who has approached me saying they tried to buy this tandem, so it's interesting to hear your experience. The other person was Chris Gonzalez, who I met at the last French Fender Day.

The seller was kind of a jerk to me, actually, and now I see that he could probably afford to be a jerk with so much interest. I finally put my money where my mouth was, partially because I was sick of the seller's nattering on and stalling for time! My buddy who picked the bike up in France described the seller as a classic flipper. Said he saw a pinball machine being sold at the same time, along with other bikes and all manner of "antiques" cluttering up a large shed. Good way to make tax-free money in France, I guess. He had lightly abused the bike in an attempt to make it photogenic, still unforgivable but luckily nothing I couldn't undo, just bent the seat clamps and bolts to fit some wrong-sized seatposts.

Anyway it was quite an ordeal dealing with this guy, but I'm happy to have it in spite of the slow progress I'm making now. I bet you made your wife happy not to have another bike! It looks like you keep yourself pretty busy anyhow if you're the same treasure cycles as in this link. Nice work!

timdaw

I'm sorry to hear about your difficulties, in common with many others in this crappy situation we find ourselves in. Luckily I have a garage/workshop that I can escape to, to get on with projects. The lastest is the Reyhand tandem, which is progressing well and nearing completion.
I must have mis-remembered Jan's comments about the age of your machine. Mine is from around 1941 and clearly went back to the shop, probably around the end of the War. It has the Speedy brakes, which work well. The drum brake is the same as yours and is a rarer than hen's teeth item!
I'll post photo's of the stoker stem when I am allowed to (as a newbie to this forum I have to make 10 posts first) It's actually fillet brazed to the Ideale saddle clamp. I took photo's of my Herse tandem this morning and will be making a post soon. Please do subscribe!
The front derailleur has been brutally cut off my tandem, so I could do with some dimensions/sketch of yours so that I can make an accurate copy. Then there's the problem of brazing it on without destroying much original finish. I'm thinking silver solder and using a heat sink clay material to absorb the heat.
I'm envious of your engineering skills. That's something I don't have and it's frustrating having to rely on others when it comes to machining something new. But I have become pretty proficient at preservation, or resurrection in some cases! I'm glad that some people have noticed my blog and are turning more towards preservation as against restoration.
I'm hoping that you will soon be back in the University workshop and getting this great project back on track.
Finally, I can tell you that these tandems are really wonderful to ride, and that's something to really look forward to!!

mkeller234

Oops. Realized I already commented on the Timken Bearings 😳

scarlson 

Ha, I have two of them. The first one came with my Jack Taylor tandem, curiously only spec'd with a 36 spoke rear wheel. I bought the whole Jack Taylor tandem for less than what the drum brake hub alone is worth!

Looking forward to seeing it!

Thanks for the encouraging words. If it's anything like my Jack Taylor, I will be pleased.

As far as the derailleur goes, I can give you detailed measurements in a few days.
To attach it, if I were you, I'd do one of two things:
1st option, eminently doable with minimal equipment, but riskier and a weaker joint: Use some silver-bearing tin solder (typically 6% silver and the rest tin) and killed-acid (HCl/ZnCl2) flux, and a torch. Wet rags around the area as a heat sink. Get in and get out fast. The solder will hold and you can build a fillet (I've done bottle dynamo mounts with this stuff) and is low enough temperature to require the bare minimum of heat. Of course you could also use higher silver like a 56% silver which is used for standard framebuilding, and with a hot oxy/ace torch and a quick hand, it might not even take that long to get in and out. The metal involved is quite thin indeed.
2nd option, and what I would prefer: TIG braze it. You'll need to find someone with TIG equipment and who is familiar with brazing. This process is high-temp but low-total-heat. You hit it with the arc and it's red hot in a fraction of a second. Zip the filler in and you're done before the zone around it has a chance to heat up and bake the paint. Move the wet rags in to cool things down. File down and repeat as needed. No messing around with flux. MIG brazing might also work, but I don't know enough about this technique to be able to say one way or the other.
In both cases, the strategy I would take would involve trying to dump the majority of the heat into the braze-on and then just "flicking" it over to the frame, barely enough to get it to draw the filler metal away. I learned this from welding exhaust systems, because usually the hanger bracket is thick and the pipe or muffler is thin, so you want almost all the heat to go into the hanger bracket and just barely tie into the thin metal.

A cheap welder, some filler, and a gas bottle might be $400. Then you can do SMAW and scratch-start TIG. Get your feet wet! You can't hardly get a framebuilder around here to touch a bike for that price. I would die for a garage like yours - here I have to unplug my kitchen oven in order to do arc welding at home. You can imagine why the neighbors hate me. Almost all my engineering skills are self-taught, or learned by observation. I have very little formal training. Ten years ago, I taught myself to arc weld by borrowing a welder and looking up videos on youtube. If I want to learn a process, that's often where I start. I find they have synergy: you learn one process and it helps you learn two others, like a virus they propagate and take over your brain. On the other hand, I'm nearly always dissatisfied with professionals' explanations of their work, and this alienates me especially given my lack of credentials.

HeikoS69

+1 ! The (1959) Herse Porteur is really unique!!

On topic regardings timken bearings:
Those were mentioned in Le Cycliste 03/1947, as part of a showbike tandem:
7.- Depuis longtemps, le pédalier HERSE, sur roulement Timken, a fait ses preuves.
7 - The HERSE crankset, on Timken bearings, has long proven its worth.




The following year at Poly de Chanteloup SKF bearings were "new", from Le Cycliste 06/1948
4. Nouveau pédalier ŕ roulements S.K.F. sur le tandem HERSE victorieux.
4. New crankset on S.K.F. bearings on the successful HERSE tandem.




In the 1948 catalogue, which was published 12/1947, Timken bearings are mentioned.
So regarding the bearings your tandem could have been built at least throughout 1947.