Hi I’ve just purchased the mariner not collected it yet but I’m looking on the website where I bought it the picture shows it has a Dahon rear mech but on the spec list it states it has the shimano Altus rear mech this may sound picky but this could be a deal breaker if it comes with the Dahon branded mech has anyone any idea why on some bikes it comes with shimano and on others Dahon thanks Pete

I wouldn’t worry much about the brand of the derailleur, both the Dahon and the Altus derailleurs are perfectly adequate, unless you are someone who comes from a background of motorcycle riding, and shift your bicycle as often as you shift on a motorcycle. If you ride a lot of bikes, and use the gearing all the time, you would notice the difference in shifting performance between different levels of components, and likely choose a bike with higher-end components, or swap them onto your existing bike (drivetrain upgrades are not hard to do).

Meh. Because of COVID the cycle manufacturing supply chain (well, every industry's supply chain, really) has been pretty messed up.

Dahon EU shows and spec's the Dahon derailleur. Dahon UK shows the Dahon derailleur but I can't find that it ever gives a particular specification. Halfords shows the Shimano...and some other detail component differences. Halford's is most likely picturing last year's model.


https://eu.dahon.com/new-york-times-...tops-the-list/

https://www.bicycling.com/bikes-gear...xFTdNXMZawe5P8

I shift my bikes a lot more than I used to shift motorcycles. Human legs, even strong ones, are really low torque engines.

My 12-year old Dahon has a SRAM derailleur. I shift it constantly and it still works perfectly. I can't say anything about the Dahon derailleurs, but the OP can swap it out later if he doesn't like it. It's not like decent derailleurs are all that expensive.

Pete, is the bike going to be used on a boat? I kept mine on a boat for some years but I found it too bulky (even on a 54' sailboat) -- the Jetstream has 20" wheels and doesn't fold all that well. I'm in the market for a Brompton to keep on the boat.

My Moulton came originally with a 1x8 driveline, which I converted to a 2x8, and then recently upgraded it to a 2x11. I added more gears as I began planning tours to more mountainous places. But even the cheap Alivio derailleur which originally came on the bike managed to get through more than a decade of regular use without any issues.

That sounds right.

Moultons are lovely bikes. My Jetstream is kind of Moulton inspired -- small wheels and full suspension. It works great.

I've been riding bicycles for nearly 60 years and have used a great variety of derailleurs. Although I keep my bikes for a long time I don't recall ever having problems with any derailleurs other than needing to lube and adjust them on occasion. I bend them from time to time (especially when I kept the folding bike on the boat) but I've always been able to bend them back and get them working well again.

That being said, I like hub gears and am in the market for an electric cargo bike (I have been carless since 2014) with hub gears and belt drive.

At an industry trade show back in 2002 Dahon showed this prototype:



The front suspension is patterned after the Alex Moulton AM series; the rear suspension is patterned after the Moulton Bridgestone.

Apparently, the distributors and dealers were not excited and the bike never saw production. A few years later Dahon came out with the Gotham City and then the Jetstream which more closely resemble mountain bikes.

I don't know the Gotham City. The Jetstream is possibly kind of usable as a MTB, but I think the use profile is pretty close that of Moultons.

The frame and suspension concepts are different, of course, but function pretty much the same, other than the fold.

I did that with my P8, Gravel convert with 2x9 Sora... it was fun to take with the kids.

This is my most recent photo, though I have upgraded the wheels and seat post since it was taken. Its not foldable, but then I only have to fold my bikes when I travel. I found a custom Ostrich carry bag which contains the various parts very compactly, and makes it easy to put on a train or airplane.

Beautiful bike!

The brand of derailleur matters less, than the *style*. Older Dahon 20" folders used a "compact" derailleur that mounts forward of the rear axle. It does not shift well, at least with cheaper cassettes without true hyperglide ramps on the largest cog (original Dahon), and shifting is reversed in direction and spring force ("Rapid Rise"). Those older bikes had no conventional rear derailleur hanger, however I have replaced with a conventional derailleur with a "claw mount" that goes under the axle nut. Newer 20" Dahons have a proper mount and use a conventional derailleur mounted just behind the rear axle; That's the one you want. Either brand should work well, and is easily replaced for about $15 new part, if not.

You can put a conventional derailleur hanger can be installed on the 'rapid rise' equipped bikes.
I did

Very interested in details; Older Dahon Speeds (mine) had a mount for compact/rapid-rise but no conventional mount (which is why I had to use a claw-mount derailleur), later steel frames had mounts for both (with integral conventional mount if a steel frame), then later still steel frames were only conventional mount. The aluminum frames (Mariner, et al) were only different in that they had a compact mount, then went to a separate conventional hanger (steel) that fit under the nut/quick-release plus a bolt and could be replaced if damaged, I don't *think* they ever used an integral conventional aluminum mount; That last style separate hanger, fit into a recess on aluminum frames; I don't know if you can just slap it on the outside of a steel frame. I think steel frames did not use a separate hanger, as that recess would have thinned the dropout too much, but I could be wrong about that. I looked for a hanger like that, hard to find, and they were more expensive than the whole derailleur with the claw mount. Which, though dirt cheap at $13 at the time I think, has worked amazingly well.

Mine had both.
It had a placeholder piece that was the upper part of a derailleur that could be removed.
It could be replaced by a #27 hangar.

https://cimg8.ibsrv.net/gimg/bikefor...f1e3c8ba2f.jpg

Thanks for the pic. Yep, that would be nice for two reasons (versus a universal claw mount derailleur): 1) Derailleur is not hanging free when wheel is off (claw mount came with screw and nut but does not line up to anything on the Dahon frame, it's designed to fit the end of a long horizontal-slotted dropout), and 2) Could mount any derailleur; Fortunately the claw-mount Shimano Tourney TX has worked amazingly well, despite its low price.