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-   -   New Dahons for Asian Market? (http://www.bikeforums.net/folding-bikes/718836-new-dahons-asian-market.html)

JosephLMonti 03-09-11 08:01 PM

New Dahons for Asian Market?
 
http://www.zzfish.cn/redirect.php?ti...&goto=lastpost

Dynocoaster 03-09-11 08:03 PM

Cool, I like the Cheetah and Arc.

seawater 03-11-11 05:08 AM

Disappointed the Curl is not feature in the models.

chagzuki 03-11-11 06:12 AM

Blimey, new folds! Hmmm. . . unusual.

Azreal911 03-11-11 08:08 AM

very new folds indeed, at least they are experimenting with it which is good! I really like the curve looking ones with and extra top tube which would probably make it feel even more rigid. Not sure if we'll ever see these new designs anytime soon unfortunately.

tcs 03-11-11 08:57 AM

A lot of evolutionary stuff from Dahon, including some striking hydro-formed frame members, but the Jifo 16 looks revolutionary. The bi-fold frame appears to make a very small package when collapsed. It appears that because of the linkage, the rear hinge will be driven by the latched front hinge, speeding folding time. The lower section of the seat post is also linked and seems to deploy/retract automatically, simultaneously creating a support foot for the folded machine. Nice touches: the plug-in behind the saddle for the demountable pedal; the cables routed internal to the frame (I see there are provisions for a gear cable as well on this single speed model).

I'd like to see the folded dimensions and a video of the fold on this one.

Quote:

Disappointed the Curl is not feature in the models.
Yeah, I hear you, but what if this Jifo is less expensive and less complicated, but folds as small or smaller?

Probably more on these next week @ the Taipei Cycle Show.

Dynocoaster 03-11-11 09:31 AM

The Jifo has a 5 second fold according to a couple of articles I read.

vmaniqui 03-11-11 11:19 AM

i wonder why asian market only...

brakemeister 03-11-11 11:20 AM

and where did u guys see that bike first ?
hint....
http://www.thorusa.com/eurobike/eurobike.htm
its green

hehe that page takes a little while to dl but the pics make it worth while
-----------------------------------------------------

Now about that 5 sec fold..... I kind of getting to the point where I start to hate the Marketing BS .... Its fast ... but it takes more than 5 secunds to close my fly .... or blow my nose.... cmon .... its fast ...

thor...

Dynocoaster 03-11-11 11:23 AM

When will you get the Jifo 16?

brakemeister 03-11-11 12:48 PM

absoluetly no idea .. maybe in 2012
maybe I say ...

thor

feijai 03-11-11 01:15 PM

Riddle me this. Why does Dahon put a rake on a 16" front wheel? This must be the most squirrely bike in the world. They did this on every 16"-er on that site.

http://www.zzfish.cn/attachaents/mon...RRLB5ThGeE.jpg

brakemeister 03-11-11 02:15 PM

its friday and my brain is mush... but the more rake the more solid ride... no rake= squirrely

jur 03-11-11 03:54 PM

Quote:

Originally Posted by vmaniqui (Post 12345912)
i wonder why asian market only...

In the western world folders are such a tiny niche market that it does not make economic sense to put up a whole raft of new bikes up against existing inventory. Just take the Mezzo sellout in Canada and the Birdy fold-up in the US. And here in Australia Greenspeed have given Brompton the flick, as I found out just yesterday from Greenspeed.

feijai 03-11-11 06:37 PM

Quote:

Originally Posted by brakemeister (Post 12346730)
its friday and my brain is mush... but the more rake the more solid ride... no rake= squirrely

Brain is mush indeed! :-) You have it the wong way around.

More rake decreases trail by moving the axle forward with respect to the line of the steering angle. As a result, with MORE rake the ride is LESS stable, MORE squirrely.

Rake is sometimes justified because of a notional suspension effect, but in such a short and stiff fork that effect is probably close to zero.

ratdog 03-11-11 06:59 PM

Quote:

Originally Posted by feijai (Post 12348031)
Brain is mush indeed! :-) You have it the wong way around.

More rake decreases trail by moving the axle forward with respect to the line of the steering angle. As a result, with MORE rake the ride is LESS stable, MORE squirrely.

Rake is sometimes justified because of a notional suspension effect, but in such a short and stiff fork that effect is probably close to zero.


I don't get it, I always thought it was the way Thor said it was otherwise why do Touring bikes have more rake than track bikes and road bikes?

BruceMetras 03-11-11 07:56 PM

Quote:

Originally Posted by ratdog (Post 12348110)
I don't get it, I always thought it was the way Thor said it was otherwise why do Touring bikes have more rake than track bikes and road bikes?

As I understand it, I think touring bikes with touring loads would have much heavier steering and require more rake (less trail) to make up for the sluggishness of steering input .. the more trail (less rake) you have, generally the more stable, as in a racing bike .. mountain bikes would have more rake (less trail) to maneuver around obstacles easier.. or so my brain has digested it in the past..

tcs 03-11-11 09:50 PM

Quote:

Originally Posted by feijai (Post 12346435)
Why does Dahon put a rake on a 16" front wheel? This must be the most squirrely bike in the world.

A) Brompton and bikefriday put offset in the forks of their 16" wheel bikes
2) The Chinese text describes the bike you pictured as 18"
iii) The handle post, hinge and focal length of the camera create something of an optical illusion as to the true head angle of the frame

jur 03-12-11 01:43 AM

What a load of bull...

Rake does indeed reduce trail. I suspect that in many cases it is simply done because "that is just the way to do it". In bikes which have lots of trail, rake will imbue stability by putting weight below the steering axis which tends to straighten it statically. Trail also straightens, dynamically.

Sixty Fiver 03-12-11 03:28 AM

Quote:

Originally Posted by feijai (Post 12346435)
Riddle me this. Why does Dahon put a rake on a 16" front wheel? This must be the most squirrely bike in the world. They did this on every 16"-er on that site.

http://www.zzfish.cn/attachaents/mon...RRLB5ThGeE.jpg

To optimize trail.

feijai 03-12-11 07:11 AM

Quote:

Originally Posted by ratdog (Post 12348110)
I don't get it, I always thought it was the way Thor said it was otherwise why do Touring bikes have more rake than track bikes and road bikes?

I believe I am describing it correctly: please correct me otherwise. Perhaps the following Wikipedia diagram can describe what my understanding is:

http://upload.wikimedia.org/wikipedi...TrailDIAG2.jpg

Trail is one measure of the degree to which the wheel acts like a caster. To be a caster, the point of intersection of the steering axis with the ground must lie ahead of the axle. The further ahead, the more the wheel resists turning. If you make the head angle steeper, or if you add rake, you decrease the trail. Lots of trail makes the bike feel stabler; but in some situations (like if there's going to be a big load on the front wheel), you don't want it resisting steering on top of the load doing so, so the trail is reduced in porteur bikes etc.

Quote:

Originally Posted by tcs (Post 12348785)
A) Brompton and bikefriday put offset in the forks of their 16" wheel bikes
2) The Chinese text describes the bike you pictured as 18"
iii) The handle post, hinge and focal length of the camera create something of an optical illusion as to the true head angle of the frame

I don't believe that's an 18" bike. Look at the size of the cassette compared to the tire. Compare to the Tikit picture below. Surely that Dahon is a 305.

The Bike Friday Tikit has only a very *very* slight degree of offset as shown below. As a Tikit owner I am at a total loss as to why they did even that: it'd be a bit stabler without the offset.

http://www.cs.gmu.edu/~sean/stuff/ti....JPG.thumb.jpg

The Brompton has a fairly significant offset, and THAT is a total mystery to me. The Brompton's trail is quite low as I understand it. Certainly it feels a lot more unstable than the Tikit.

http://foldingbikes.wikispaces.com/f...ton-L6-800.jpg

There could be something to the head angle I suppose. But it'd have to be a pretty dang steep head angle to make up for such a rake on such a small bike. I'm guessing the big rake is for some other reason: making the fold smaller or the wheelbase longer given the rider size, or something like that? These don't seem like good reasons to reduce stability tho. Because their small wheels make it difficult to establish enough trail, folding bikes in general have significant stability issues. Dahon's been (unfairly) sued over it before in fact. One would imagine making the bike stabler would be an important consideration.

brakemeister 03-12-11 11:16 AM

http://www.bicycle-touring-guide.com.../geometry1.jpg

brakemeister 03-12-11 11:20 AM

http://www.bicycle-touring-guide.com.../geometry1.jpg

F in the pic above is the rake ...
Trail would be defined by the rear wheelbase, the rake, the angle of the headtube ......

therefore if you change the angle of the headtube you could live with a straight fork with the same results as having a little rake in the fork. Straight forks are maybe more modern and some marketing folks find all kinds of resons why, the good old fashioned raked fork has its place, offering very little but noticable front shock absorbtion.

We can make it easy ...
a touring frame ...LONG is less squireeley than a TT frame SHORT ... right ?

Thor

Sixty Fiver 03-12-11 12:56 PM

People should read this... it explains things very well.

http://davesbikeblog.blogspot.com/20...le-bit-of.html

neilfein 03-12-11 01:48 PM

Quote:

Originally Posted by JosephLMonti (Post 12338216)

The first bike on that page, the yellow one, looks like a Dahon Curve had relations with a Bike Friday Tikit. Good to see they're letting their designs change over time.


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