dahoneezz

dahoneezz

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tomtomtom123

The Launch D8 hinge is interesting. I wonder, when it's locked into place, the left hinge pin is then taking much less loading than the other hinge types?
I assume the left pin needs extra tolerance so allow the 2 frame halves to slide up and down. I wonder if this extra play has any effect on stability or if the lock-jaw is enough by itself to provide clamping and rigidity.
Also, when the frame is folded, would the left pin slide around?

Visc Evo price is too high compared to Visc D18. It's just swapping out the cassette, derailleur, and shifter with 10 speed which don't cost much more than 9 speed.

What's the reasoning behind the Holize design? I guess the higher seat clamp allows for a larger triangle and stability, but the seat post would need to be longer to be able to touch the ground when the frame is folded. The fold size would be taller too.

dahoneezz

I have no idea with regard to the Holize. I think its called the Horize (for Horizontal?). Its not a new design, so perhaps they updated the paint scheme. I also see two bikes (K3 and D8) with the Deltec cable thingy. Maybe they realize that mid hinge fold is not a good idea after all and you need to put the cable band aid in case hinge breaks.

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tomtomtom123

Oh I didn't notice the cable on the launch d8. I wonder how easy it is to get the right tension. Just a little slack and it no longer supports. Although the the lever pushes up the front half of the frame which would add a little bit of tension. To tight and it won't fold.

tomtomtom123

The dahon press release says the brake and shift cables are running inside of the deltec cable (or perhaps that is possible to do so)

dahoneezz

tomtomtom123

Oh, after looking closer at the images, the brake/derailleur cables are not running inside the deltec, it's just along side with the twisty coil wrapper thing that they usually put around the cables in front. So it's easy to remove the brake/derailleur housing, just unwrap the coil wrapper.

fietsbob

Buy them all and submit them to a lab doing destructive testing.

that is how you gather meaningful data.

rather than opinions which are free..

tomtomtom123

I did a google search and this image came up of the lockjaw hinge. Only thing that worries me is that there isn't really a safety in case the latch pops open. Everything is held together by the black thing under the lever. If it breaks off, the jaw will immediately spring open. I would feel better if in combination there was a second latch on the right side, maybe like a simple safety catch.
I also wonder what happens if the teeth closer to the right side gets worn down, then the teeth closer to the hinge would be a tighter fit while the right side would be loose. And I wonder how well it would close if some sand got in between.

dahoneezz

rhenning

Are you sure there is not a safety latch that mounts on the bike not the hinge? All my Dahons have such a safety devices on them and they are mounted on the bike not the hinge. Roger

tomtomtom123

The Launch D8 looks like it has a safety clip to keep the lever from opening, but what I meant about a safety system is something on the right side to prevent the hinge from folding in case the jaws are pushed apart and no longer in contact. The 2 halves are sprung, so if the black thing that the lever presses against breaks, the spring will push the 2 halves apart and will risk folding itself.

A safety clip could also help hold the 2 halves together when unfolding, so that the jaws are aligned and would help make closing the lever easier to do. A simple plunger could work. Also reversing the effect of the spring so that the 2 halves are constantly pressed together instead of being pushed apart.

The other 2 main types of dahon hinges, the V-clamp, and Visegrip are pressed directly against the frame, maybe with a small bushing to reduce friction and wear. If the bushing breaks on these, I assume the hinge would become loose but not open up.

Well, anyway, I think a horizontal hinge is more stable and safer than a vertical hinge, something like the Dahon Qix. It's just that the Qix dimensions is a bit short, and the handlepost folds to the right in between the 2 halves, so you can't fit long or L-grips on the handlebars.

rhenning

These are pictures of the type of safety devices on 2 of my Dahons. I use them but find them really not needed as the latches over center so tight when they close that they are hard to open when you want them to open. Roger

tomtomtom123

I wonder how this BMW folding bike frame handles. It double folds under. The headset doesn't look like standard Dahon type though. Also doesn't appear to have rear rack braze ons.
https://www.shopbmwusa.com/PRODUCT/6...W-FOLDING-BIKE
https://shop.bmw.de/bmw-de-responsiv...bike./2447964/

tomtomtom123

I also saw this on bikefolded's youtube video of a Lekuma Fly, but the Lekuma website has no information about it. Looks like an e-bike with the battery in the center tube. Double under fold. Possibly 16 or 18" wheels. I don't see any rear rack braze-ons though and I wonder about fenders. I would be interested in a non electric version. Video starts at 2:44

fietsbob

Older butt welded Brompton , used a forged, hinge plate, brazing a skilled job..

now the hinges are cast, but the tubes go inside bored out , a lug essentially

they can be done in a more efficient procedure, faster.. , repeatedly, the same..



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