Dahon Jetstream P8 as my new commuter
 

After quite a lot of looking around and considering various options, I chose to get hold of a Jetstream P8 from Holland bike shop.

I have an older Speed P8 as a spare and commute on a similarly aged, second hand, Helios P8. The Helios has been pretty good, but is showing some signs of age and I decided it may be a good time to upgrade to something newer and decommission (pass on) the old bike before anything needs replacing.

The bike is intended mainly for my shortish cycle only commute. A small folding bike was desired, though a compact fold not essential. Nor was performance and/or gear range. So, lots of potential contenders really, including the fairly obvious Bromptons, Birdys, Terns, and a few Dahon models.

The 20" Terns are, unsurprisingly, similar to the Dahons I own. A couple of models offered by Evans Cycles fit the bill pretty well. However, a suspension option and possibility of switching to disc brakes gave the Jetstream some extra appeal. Other options seemed to mean a move away from a pair of bikes with similar(ish) parts.

Based somewhat on what was available where and at what price, I went for the bronze, v-brake equipped Jetstream P8 (photos of the bike as it was supplied).

http://bikeforums.net/attachment.php...hmentid=364877http://bikeforums.net/attachment.php...hmentid=364878

The model comes with the Kore seatpost (slightly shorter than the more regular 580mm) and a fairly sporty saddle to match. I planned to replace/switch seatposts, and get hold of a post pump (not essential, but should hopefully lessen the trouble of punctures fixed away from home).

V-brakes mean that the front forks and front hub are the more typical Dahon 74mm. The frame does have disc tabs on the rear triangle as well as v-brake bosses. The rear hub is 130mm, drop-outs seemed to measure about 132mm (Speed and Helios both measure 130mm).

The cranks are FSA Tempo, with a 53T chainring.
Derailleur is an SRAM X-7, which fits on a standard derailleur hanger.
The rear cassette is a Shimano HG41
Rear shock is a Suntour EPICON, 150mm eye to eye. Front suspension forks are Dahon/German A elastomer (not adjustable). No lockout front or rear.

The rims are quite nice looking WTB double wall rims, 15mm inner width (marked 15C).
28 spokes at the back, radial on the non-drive side. 20 spokes on the front.

Tyres are Schwalbe Marathon Supreme, but of the wired variety rather than the lighter folding type (I suspect this may also be the case with the Tern bikes, which seemed equipped with supremes).

The bike came with mudguards. The carrier that can be used on 20" Dahon and Tern link bikes can't be directly fitted to the jetstream.

Pedals are wellglo alloy pedals, but, I had switched over to MKS promenades on the old bike, so the MKS pedals did move across.

The handlebars were 580mm, noticeably wider than the 540mm on my other bikes. I chose to get hold of some cheap low rise bars to cut down to 540mm, I would have cut them down a wee bit more, for filtering in traffic, but there isn't spare length after grips, twist shifter and brake levers.

The non-adjustable handlebar post gives a slightly lower position than I had been using, but short legs do mean that the position is pretty comfortable for me.

I had a go at weighing the bike. It seemed to be pretty much 13kg.
Noticeably heavier than my other bikes, even though they both have rear carriers. Even heavier now with the switch to the postpump (718g) and less sporty saddle.

I haven't ridden the bike far yet, so can't report much. Suspension is definitely a relief when it comes to bumps and holes in the road surface.

Beautiful bike, congrats on you purchase.

Great bike. Congrats and enjoy!

Om,
Yan

I am sure you wont regret going to full suspension, British roads are not getting any smoother. Have fun riding the bike.

One of the best. Not really a commuter, but a comfortable ride. Enjoy the off road sections if you find any shortcuts!
Devises more recognition.

If you want it to be quicker consider a spare set of wheels with a close cluster block and kojack tyres. Then fit some fat knobbies for off road and you have virtually two bikes. I have done this when I lived in a terrace house and could not store two bikes.
Also can use a fast seat post and a comfortable seat/suspension to this concept.

Does it have a "Handbuilt in the EU" decal like snafu21's Vitesse D7? I understand the big boss @ Maxcom (Dahon's manufacturing partner in Bulgaria) rides a Jetstream.

Yep. A nice little sticker on the back of the seat tube.

I've made a few trips to work and back now, not a lot of miles so still early impressions. It's more or less as expected, and as it felt the first time I took it out. Not surprising since it does feel pretty much the same as my other two Dahons.

I have the rear suspension fairly hard, currently the case at around 60psi (though I am not at all light weight). There's no obvious feeling of movement from the rear. The front it much more noticeable, and can bob a little bit if I lean forward. Overall, definitely softer over bumps. The somewhat wider tyres, at about 75-80psi, may also have an effect.

I'm not so sure the bike could be considered a mountain bike, but does seems quite suitable for paths and pretty rough ground. I reckon the suspension is pretty good for the combination of small wheels and London streets.

I know the bike is heavier than my others, and it feels quite obvious when it's lifted about, but probably not noticeable on the road (only a few percent difference in total weight). It does feel a little slower, I'd have to guess the heavier and larger diameter (maybe 3%) tyres making me feel like it's harder work. Really hard to say.

Since SRAM cassettes were cheap from CRC, I picked one up with some spares and swapped to the same 11-28 that I was using with the old bike. My commute is nearly flat, and the 28 hardly gets used. The 14 and 12 teeth 6th and 7th do get used quite a bit (my "go" gears for zipping along the flat, though I'd guess at fairly moderate cadence).

Must try some longer trips at some point soon. Maybe a post with further impressions when I've been using the bike for a bit.

Always found the Jetstream an interesting model but that isn't an original Dahon design but a rebranded Fuji-ta Hanma model or at least that is where the frame comes from. I wonder if Dahon has exclusive rights to sell it outside China or some other arrangement. Fuji-ta is the manufacturer of many oem frames for both Dahon and Tern in the past as well as a huge range of other western brands and I don't think anyone can deny the fuji-ta connection on this one it's such a specific frame design with unique geometry and features. It's in fuji-ta's portfolio of folding bike frame designs. Under fuji-ta's own brand you get disc brakes and they smooth the welds on the frame and other minor variations but the frame is identical. Also it looks nothing like a typical Dahon designed bike to be honest.

HANMA8 - Tianjin Fuji-ta Bicycle Co.,Ltd.

I probably should have come back earlier to post the intended update after riding a bit. I think I've covered more than 3k miles on the Jetstream, including an 80 mile ride the summer after it's purchase, quite a few visits to London's Richmond Park, and, last year, a few evening loops (35-45 miles).

Since we have a question about the suspension, and weight, I'll start with that.

I cycle more now, and on hills or accelerating I do notice the difference between lighter and heavier road bikes, but, in general, I don't find modest weight differences to be much of an issue. However, I hardly ever carry the folded Jetstream.

As I suspected, the suspension isn't really required for commuting. I do think it nice to have and, given that I don't mind the extra weight, it is probably worth the weight.

If I were to choose another folding bike I'd be torn between a, probably higher end, bike with suspension, or a simpler/cleaner bike. I guess that wider tyres can be used be used to soften a ride, but these would add weight, and I've been pretty happy with 406x35-40 at, say, 70-80 PSI.

Commuting, I did notice that the rims wore down pretty quickly. So, I'd look for disk brakes now.

The main clamp needs to be fairly tight. I added some insulating tape on the inside surfaces of the clamp to prevent some of the creaking that tends to arise.

Position wise, since I'm not very tall, the bars are perhaps a couple of centimetres above the saddle. I'd now be happier with slightly lower bars, so, though the Jetstream doesn't have the extending handlebar post, I guess that many taller riders will be happy with the bar height. My position on the Jetstream is fairly upright compared to the slightly lower, and further forward, bars on the road bike on which I commute these days. For brisker riding, and particularly for climbing, the Jetstream feels like much harder work.