Originally Posted by
energyandair
How much shorter and why is this a problem?
The wheelbase influences riding stability.
Here are the geometry details of the Dahon:
Dahon main tube length: 58cm
effective top tube: 63cm (horizontal distance of steering axle to seat post at seat high)
wheelbase: 103cm (Birdy has 99cm, as far as I know)
seatpost to handlebar distance: 63,5cm
My MTB (XL frame, 53cm) for comparison: 60cm, 62cm, 107cm, 74cm
You are a tall guy and an agressive rider. I'm guessing that you were riding a Birdy with the 10 deg "comfort" stem. The Birdy comes with a variety of stems to suit different sizes and styles of rider. The 25 deg "sport" stem puts the handlebars more than 3" further forward and would be a much better fit for you.
yes, good point. I was wondering about the cramped saddle-to-bar-distance. Might have been a different impression on a "sport" variant. Can you provide the geometry to compare to the Dahon above?
A related point is that the suspension is quick and easy tp configure. The front comes with a medium/soft elastomer but a hard one is available. The rear comes with a medium elastomer that can be changed to soft, hard or extra hard.
I think the Birdy I rode has the "soft" elastomers. I probably would need the "hard" ones at my weight.
If you want speed and agility in city traffic, you want narrower tires not wider. Maraton Racers are a lot better than the OEM tires that came with my Birdy Red. Kojaks are a lot better again.
I agree that Racers and Kojaks are very good tires. But for the city a wider tire is preferable. We have a lot cobblestone here in Berlin, tram rails within the street, etc. I did several test. And surprisingly the Big Apples where considerably faster than Racers and even more compared to Stelvios. Unfortunately the Kojak is not available in 20"x2.0". With suspension you can go for slightly narrower tires, though.
My fixed length sport stem seems solid to me, more so than the Dahon's I tried.
yes, the fixed length sport stem should be more solid.
Same is true for the stem variants on the Dahon.
There are 5 types of stems:
a) telescoping (standard)
b) fixed length inside fold (Mu Uno)
c) fixed length outside fold with VRO stem (Mu SL, Sport, EX)
d) short fixed length outside fold (Jetstream P8)
e) short fixed length outside fold with VRO stem (Jetstream XP)
Most solid is e) as it is clampless and shorter. The a) flexes more and needs to be set to min extension and tightened carefully, then it is ok.
Dahon did a change in 2005 to their handlepost hinges. Older models' hinges are quite fragile. Then in 2008 they changed the hinges to an outside V-clamp technique, again giving some improvements in stability.
The >2005 Dahon hinges are very well engineered, have a closer look on them. BTW, they usually do not require any maintenance or re-ajustment.
I think many Birdy owners only know the cheap standard Dahon bikes.
But in comparison to a Birdy one would need to look at the premium Dahons, a Jetstream XP, for example (similar price as a Birdy light).
I was prepared to pay for what I felt was a better design with superior comfort and proven longevity
The Dahons have lifelong warranty on the frame. Their main hinge is a design compromise (also providing a lot of benefits), but much more robust than you might think.
The Birdy fold is not that intuitive and there is a definite learning curve. Once learned, it is quite fast, is quite a bit more compact than any single fold arrangemets I have seen (eg the Dahon's I looked at)
Yes, my Dahon Mu Sport is 79x66x28 cm folded so slightly bigger than the Birdy (76x58x28cm). But not by much. Also suitcase fold (wheels out) is as compact, and both bikes fit into a airline legal Samsonite Oyster.
I wanted a single bike for: riding around town, longer trips in comfort, commuting, fast riding, pootling, fitting in a standard suitcase for air travel, fitting two bikes with luggage quickly into the trunk of an average car and good enough at all of these things that I wouldn't spend my time wishing I was on something else. The Birdy was the only bike that I could find that met all of these criteria.
I have the same goals.
My Mu Sport does the job. But I have had a Mu SL before (got stolen, unfortunately) and this was even better.