Winfried

Hello,

For easy week-end getaways by train, I'd like to buy a bike with 26" wheels with a frame that can be easily taken apart (I'll also need a rear-rack and mudguards that can be easily removed, but that's for another thread). I tried a foldable bike with 20" wheels, and frankly, I was already sore the second day :-/

I did some research: Considering the prices for regular bikes, I was wondering if it'd be more interesting to get those and ask someone to cut the frame and add an S&S ("S and S Coupling a.k.a. Bicycle Torque Coupling (BTC)"):

www.sandsmachine.com

If you have good experience with that kind of thing, what do you think? If that doesn't sound like a good idea, I guess I'll take a deeper look at collapsible bikes (is this the right expression?) from Montague, Dahon, etc.

Thank you.

unterhausen

S&S are a great idea. Next time I go to France, it will be with a S&S coupled bike. The only problem with S&S is that reassembling takes a little more time that might be desired. I don't know anyone in Europe that installs them, and it is a bit expensive. People report that a good folder like the Bike Friday is a good substitute though. I know someone that rode Paris-Brest-Paris on a Bike Friday. Ride report here

MassiveD

Folding bikes... Collapsible is more of a spontaneous folder.


If I was running 20 inch, I would assume I was getting some benefit in efficiency from the smaller wheels, and I would spend some of that moving up the scale on either tire size or some sort of suspension effect to counter the wheels.

S&S is a good product, though there are other methods of achieving the same thing that are more frame buildy, VS the CNC approach taken by S&S. Rene Herse was a well respected french maker and had demountable bikes, as did others in France. Not sure who offers what, at what price currently.

https://www.43bikes.com/herse-demountable.html

https://www.cycles-alex-singer.fr/cat...o-camping.html

Yates and Bob Jackson in the UK make excellent bikes and handle S&S jobs.

fietsbob

A Bike Friday travel Bike uses very strong 20" wheels , and was designed to knock down
intentionally, to go in a Suitcase .. Oodles of them are ridden around the world..

SandS lists builders they sell the connectors to, see where one is nearby.

unterhausen

I'm not sure their list is up to date, but it can be found at this link
You might want to email them since there are no builders in France. They are pretty good about answering emails. I'm sure Singer could do it if they felt like it.

You could also check with Rando Cycles. I saw some of their bikes at PBP, they looked good.

busdriver1959

I haven't tried a coupler bike but I can recommend the Bike Friday. It is built to fit the same as your full sized bike and if you ever fly with it, the airlines won't charge their bike charge since it is just another suitcase to them. It rides about 1 or 2 MPH slower than a full size bike at the same effort level. Not sure why, maybe more rolling resistance on small diameter wheels. I've got a few thousand miles on mine and have handed it over to baggage handlers many times with no damage.

JGaerlan

s&s is a good coupler but there are other diy solutions. back in the late 80's, somebody was even selling stainless pipe couplings which mimicked the s&s. Check the Ritchey breakaway frame where the downtube inserts into a male tube at the bottom bracket and the toptube is coupled to the seattube via seatpost.



The 20" wheel will make packing easier but not everybody likes the look.
I personally ride a 20" homebuilt frame where the rear triangle rotates towards the front triangle.
if you're building it, you can do what tickles your fancy

MassiveD

I checked in the Breeze system a while back and it sounded cost effective, and maybe there aren't the sales restrictions.

JG, that is a great looking bike, do you have detail Photos? Love to see more.

Scooper

Bill Holland showed an Exogrid break-apart frame at NAHBS in Sacramento this year that was sweet.

unterhausen

That's the Ritchey scheme if not Ritchey parts. Is the wiring for Di2? I was thinking about doing something similar for lighting on my S&S bike

Scooper

I believe so. Scroll to the bottom of THIS PAGE on the Holland website.

MassiveD

The Ritchey system costs 75 dollars for the one year license, and 75 dollars per kit. Plus you need an extra clamp for the time you are building.

MassiveD

Rob English has an interesting system in which the CSs are attached to clamps that fit over the sides of the BB shell. And the stays at the top attach to the cluster area with bolts, Bike Friday style. No licenses, or other BS, though the frame does not break in the middle and that could cause problems for packing.

Winfried

Thanks everyone for the infos.

rodar y rodar

JG, do you plan on marketing those, or were your old Gotravels the end of the line as far as "for sale" Gaerlan Bikes?

Scooper

JGaerlan's frame reminds me of the early Montague BiFrame MTB folders with 26" wheels. These frames have two concentric seat tubes, one for the front triangle and the other for the rear triangle, and folds around the seat tube. A latching mechanism keeps the front and rear in alignment for riding.

JimBeans83

@JG - do you have more info on those mimicking couplers from the late 80s? As SS patent was 1995'ish - was there prior art that recently [to Steve's patent]?

Nice bike - remember seeing your travel bikes back before.

rodar y rodar

Bike Friday tandems and some Lightfoot Cycles options just use slip together sleeves:
https://lightfootcycles.com/products-...ustomizations/
There have also been some cool separables on VS, and a few simpler homebrews can be found on blogs here and there. For example, a nice example of a pseudo Herse coupling system:
https://www.flickr.com/photos/bensond...7601730455819/
And a not-so-pretty, but very creative demountable 20:
https://www.outsideconnection.com/gal...pv/takeapart1/

alhedges

Probably the best solution for this is to try some higher quality folders. They will be much more convenient for weekend getaways.

I've known people with S&S couplers, and they do work well. However, they aren't quick to put together or take apart; you typically have to remove the cranks, derailleurs, front brakes, fork, both tires, cables (although they make separable cables, so this isn't as bad as it sounds), etc. It takes around an hour, although you would likely get faster if you did it every week. And it's the kind of thing you would want to do in the hotel room, not at the train station. The usual use scenario seems to be someone who wants to be able to take a *particular* bike with them while traveling.

What are the rules for taking bike on trains; how small do they have to be? Also, I haven't been to France for 10 years, but I thought you could take full sized bikes on a lot of trains?

GrayJay

I like the idea of the simplicity of a sleeve but I am not terribly fond of the concept and operation of the moveable coupling sleeve at the BB on the pseudo-herse in above link. Looks a bit crude and seems like the sleeve would scratch up the DT paint when the sleeve is loosed and retracted toward the headtube. In the above bike, they left a segment of the DT unpainted to allow for sleeve movement. Looks like this excersize was a retrofit of an existing bike (see the BB/DT lug) and required the 45° miter of the DT and stub with the loose slip sleeve in order for the more fixed TT/ST joint to pull apart along direction of the horizontal TT, without any upward movement of the front section during the uncoupling. (Instead, the loose external sleeve moves up/down after the tubes are in place).

Elsewhere in this same photo set shows the TT connection;
https://www.flickr.com/photos/bensond...7601730455819/

If doing a fresh build and the top tube connection were instead executed ritchey style (with seatpost helping hold togeher the TT and the ST+SS), I dont see a reason that a fairly simple slip joint (similar to the TT connection in above picture, no loose sleeve) couldnt be used at the DT/BB. Have an extra thick and strong bilam style female "lug" extend from the BB with a split bottom and pinch-bolt clamp, male end DT slips into the lug and the entire coupling mechanism could be very discrete.

JGaerlan

I gave the frame to my brother but he is giving it back to me. Will take a pict of the couplers. THey look like pipe unions used in plumbing but are in stainless. Will post it soon.

unterhausen

there are high pressure pipe unions in stainless that probably would work. IIRC, the S&S patent hinges on the fact that their couplings will carry torque. They actually give other examples of couplers that also carry torque. Seems like that makes it obvious to a practitioner of the art, but what do I know. Ritchey's scheme doesn't carry torque, people don't seem to mind.

Winfried

I was indeed having second thoughts about having to take appart the whole bike, even if it's a couple of times.

It's complicated, and unfortunately, the "English version of our "Bike & train" pages" is 404, so you'll have to check travel forums for infos: The railroad company (SNCF) does a lot of greenwashing about being bike-friendly, but they actually offer less options than in Belgium/Holland/Germany. It really depends which train you want to take: Some (like the Thalys to... Holland) refuse full-size bikes, while some offer a few bike areas where you can hang/put a regular bike, for free or with an extra €10 reservation (but the reservation can't be made online -> go to an SNCF outlet to buy both tickets). So taking a folding or demountable 26" seems like a much more pratical solution.

I guess I'll order a folding bike instead. I did appreciate all the infos above, though :-)

Omiak

If I could afford one, I'd go with a Moulton separable frame bike.


I ride a non-folding 20" Mini Velo as my main bike right now and I actually rather like the small wheels.

Winfried

Thanks for the link. If I go for a 20", I might as well take a folding bike since a separable won't save much space.

Incidently, I went for a full day ride on Sunday with a Birdy (City) I was lent to test, and it's really neat. My back was fine but my butt hurt, so I'll have to find a more comfortable seat for long rides.

What's the Mini velo? I googled for it, but it's too generic to point to the actual product.