Originally Posted by pibach
Optimal bar position is 0-7 cm below saddle high as a general rule.
IMHO, only if the effective top tube isn't cramped. If it's cramped, then I think you really don't have much of a choice but to effect an upright position. And ahead stems are somewhat challenging on the P8 series, which folds between the wheels.
feijai, which BF do you own? A Tikit? Could you explain why you prefer it over your Helios specifically? I would be interested.
I own a modified medium tikit hyperfold. In fact, I bought it *because* of my and my friends' experiences with our various P8s. It's the reason I'm talking about both of them here.
Like cars and laptops, everyone gets ego-attached to their bikes, and I am FAR from an exception. That being said, I am one of people on the board who own multiple folding bikes and can actually compare them directly. I think puppypilgrim ought to take that into consideration. And though I clearly have a fanboy bias, I have recommended swifts, dahons, and bromptons, and montagues on this board, and I think I am pretty good at backing up my claims with numbers and admitting when I screwed up. A BF is not the choice for all tasks, but I think our Dahon folks *really* need to realize the same. [The only major folding bike I am generally derisive of is the Strida, for which I am hard pressed to think of any real niche].
Comparing a tikit to a Helios P8 (or Mu P8, or Speed P8) is a bit weird since the tikit is $1000 and the Helios, when sold, was about $500. But here goes. The tikit can be made to fit you. The Helios is one-size-fits-all, with too short of a top tube, really, for anyone over about 5'10". I have the exact sizes if you'd care to know. The Helios tends to have a LOT of clicks and squeaks, many of which are very tough to track down. The tikit is very good in this regard. The tikit's got fewer custom parts and is more readily upgraded. The whole P8 series has an unsafe telescoping stem design which suddenly pops and rotates vertically under moderate pressure, and handlebars which also pop and rotate. There really should be a safety recall on the whole stem design. The P8 series are much more cumbersome than the Tikit when folded. Bike Friday support is legendary, and Dahon's is... not (Thor excepted of course). And of course the P8 series folds slowly: for me, and for my friends, it's about 30 seconds.
But there are plenty of nice things about the Helios too. For one, it fits better in my suitcase than my Tikit does, though it takes longer to pack. It's lighter. It folds to a smaller package. It's got 20" wheels. I can fit a wider range of tires to it, including some that I really like. The Helios's stem is stiffer. The tikit also has certain potential problems: its seatmast latch is slowly wearing, its hyperfold cable was misrouted, its rear triangle attachment cup tends to wear into the frame paint. I think the Tikit's still a bit beta. And the helios (and speed P8) is at least $500 CHEAPER. One of my Helii was stolen: I was able to replace it without being hit big-time in the wallet.
Cost, I think, is the defining difference: the P8 series is a cheaper bike. I own Helii *because* of their cost: I now use them primarily to get around certain local towns in Italy, and they are perfect for that task. In contrast, I use the tikit on long rides in the US: 15 miles or (much) more. I'm thinking of doing a 300-miler on the tikit. I like my Dahons. But I've liked my tikit more.