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-   -   Long-term report on Dahon Curve D3 and Speed D7 (http://www.bikeforums.net/folding-bikes/640430-long-term-report-dahon-curve-d3-speed-d7.html)

JeremyZ 04-27-10 12:07 PM

Long-term report on Dahon Curve D3 and Speed D7
 
A couple years ago, we bought my wife and I a couple of folders.

I wanted internal hub gears, (thought they'd be a lot less trouble with alignment and cleaner) and liked the idea of the 16" wheels, so I opted for the Curve D3.

Kate wanted something comfortable and didn't care what kind of gears it had. I didn't think the single speed would cut it with our local hills, so I got her a Speed D7.

I wish I had also gotten a D7. The D3 doesn't have a granny gear, so climbing hills is tough. Standing up and pumping results in the handlebar twisting in its stalk. Not dangerously, but annoying. A low gear is really necessary for a folder for this reason. I like the idea of the puncture-resistant Schwalbe Big Apple tires, but either because they're fatter or because they're smaller diameter, it is more effort to ride this bike than the D7. Also, the folded size between the 20" D7 and the 16" D3 is negligible. Lastly, the D7 was about $100 less.

The D3 has needed shifter adjustment a couple times. This morning, it wouldn't stay in 1st gear; kept trying to jump to 2nd.

The D3's wheels are not quite even. They're a little thicker at the seam, so that when I brake, it is not smooth at all. The seam has torn a bit of rubber off the pads, so now the screech as I'm coming to a stop.

The D7 has cheaper tires. (Kenda) We haven't gotten punctures on either, but the D3 has a lot more miles on it than the D7.

What would make it better is slightly lower gearing all-around; smaller front sprocket would do it. That, or a 2-speed coaster brake shifter, like some Schwinn bikes had in the 70s. That would eliminate the cables going to the rear of the bike and make the whole thing more trouble-free. The first gear would be very low, the 2nd gear would be low/medium. With these small wheels, going fast is not a good idea.

The stock seat sucks, and although they really tried with the grips, they are not comfortable. They would be better if they were just plain round ones, without anything sticking into my palms.

I have had more seat time in my D3 than her D7, but the D7 is a nicer ride.

Overall, I give the D3 a 6/10. Build quality should be better for the price. (referring mostly to the non-uniform wheels) I looked into sending the wheels back, but they wanted the whole bike shipped back, on my dime.

I give the Speed D7 a 8/10. Smoother ride, more stable, faster, less expensive, more gear options, and the fold is only a tiny bit bigger than that of the D3.

snafu21 04-27-10 12:30 PM

Thanks for that. A Speed D7 was my first folder and I agree with you on everything. I missed it so much after I sold it, I recently bought its alloy brother, the Vitesse D7. They are great all-rounders. I haven't ridden a Curve.

Dahon rims of a couple of years (2006-2007 bikes) ago seemed to go through a lumpy stage. My 2007 D7 front rim nibbled lumps in brake pads, the rear was ok. The current ones (2009-2010) seem fine.

I didn't like the Big Apples either. Comfort - yes, slow and heavy (er) - yes. Schwalbe Marathons on the current scoot.

The stock Dahon Kendas I always liked. Kenda have improved a lot in the last few years, the MTB boys tell me.

Geekybiker 04-27-10 12:37 PM

After several months with my speed d7, I know I wish I had a IGH. The chain jumps off just often enough to be annoying. Last thing I want on the way to work is chain grease all over my hands.

ShinyBiker 04-27-10 12:43 PM

Thanks.

On the Curve, did you think about doing a front chainring swap for a smaller one? Perhaps the rear cog as well. That could give you a good granny gear.

snafu21 04-27-10 01:02 PM

Geekybiker - The 2010 bikes have a plastic doo-dad at the base of the seat tube where a front mech would be, to keep the chain coming off the inside of the chainwheel. My chain came off once, (only - so far) on the outside of the chain-ring after a wayward stationary gear-change - where an IGH would help. There's an interesting note elsewhere on the forums about chain-drop (on any bike) also being caused by a sticky freewheel. Maybe a ferret around the rear hub and R/D might shed light on this insouciant irritation.

feijai 04-27-10 01:03 PM

Quote:

I didn't like the Big Apples either. Comfort - yes, slow and heavy (er) - yes. Schwalbe Marathons on the current scoot.
On the 16"/305: I guess I'd go with the Primo Comets at 1.5 (not the 1.35 versions). Though I wonder how the Maxxis Hookworm rolls.

On the 20"/406: I strongly suggest you try the Greenspeed Socrcher TR (kevlar). Though that huge Comet in 2.1 is interesting.

Geekybiker 04-27-10 01:11 PM

Quote:

Originally Posted by snafu21 (Post 10731438)
Geekybiker - The 2010 bikes have a plastic doo-dad at the base of the seat tube where a front mech would be, to keep the chain coming off the inside of the chainwheel. My chain came off once, (only - so far) on the outside of the chain-ring after a wayward stationary gear-change - where an IGH would help. There's an interesting note elsewhere on the forums about chain-drop (on any bike) also being caused by a sticky freewheel. Maybe a ferret around the rear hub and R/D might shed light on this insouciant irritation.

Its not dropping on the front, but on the rear. Mostly the derailer overshifting past 7th. I've adjusted the stop screws several times and still it keeps happening. I can only assume that a IGH with a perfectly straight chainline will be unlikely to ever jump the chain rings front or rear. My D7 has the chain guard you are talking about on the front. (Its a 2008 I think)

My ideal transmission would be a IGH with belt drive.

Foldable Two 04-27-10 03:08 PM

Our original folders were 2005 Boardwalk D7's. They were very good bikes. The problem ended up being having enough gears, especially low ones required to ride back home from Downtown Vancouver, WA or get up onto several of Portland's tall bridges during the annual Providence Bridge Pedal.

When we got our 27-speed Bike Fridays (Dual Drive) the wife ordered me to sell the D7's. Last year, when we needed a second of folders, she was wondering why we ever sold them!

Have to say though, the BF Pocket 8's are more solid than the D7's, and feel just like our custom Fridays. The D7 wasn't really tall enough for a 6'3 person like myself, either. With the Large frame Pocket 8, adjusting it to my arm and leg length is no problem.

I looked at changing the gearing on the D7's, but it was not easy due to the proprietary parts. We have never had chain jumping problems on the folders that 'adjusting' couldn't cure. We have Kenda 1.75" tires on the Pocket 8's, and they are very nice tires.

Lou

Abneycat 04-27-10 07:23 PM

Quote:

Originally Posted by Geekybiker (Post 10731486)
Its not dropping on the front, but on the rear. Mostly the derailer overshifting past 7th. I've adjusted the stop screws several times and still it keeps happening. I can only assume that a IGH with a perfectly straight chainline will be unlikely to ever jump the chain rings front or rear. My D7 has the chain guard you are talking about on the front. (Its a 2008 I think)

My ideal transmission would be a IGH with belt drive.

No properly adjusted derailer system should be constantly dropping the chain or moving farther than its stop screws will let it. There is most likely another issue with your drive train being overlooked.

I have owned 2 Dahon Speed D7's now, neither of which had any recurring gearing problems, nor did those of anyone else I personally knew. The Neos is not particularly impressive, but it is fairly reliable.

Kenda's build quality on their tires doesn't compete with some higher end brands like Schwalbe or Continental, but its quite acceptable. That's the feel I had from the Speed D7 as a whole, doesn't compete with other bikes component wise, but overall it offers a good value for its price point. Good enough that I owned and enjoyed one for quite a while.

JeremyZ 04-27-10 09:32 PM

Well, the gear jumping might be caused by the constant moving of cables that folders experience.

I had to adjust my D3 this morning, because it couldn't decide if it wanted to be in 1st or 2nd gear. Of course it will never jump off the sprockets though.

Dahon.Steve 04-28-10 09:32 PM

The Sturmey Archer 3 speed was really ment for city riding. Dahon actually geared their 16' inch folders correctly with second gear around 52' inches. However, 1st gear would only drop to 38' inches (I think) which would be too high for hills. Lowering the gear range would make 2nd gear too low dropping it below 52 is just useless.

snafu21 04-29-10 02:29 AM

It's funny how perceptions change. Back in the 60's when I got my first bike, the 3 speed Sturmey Archer IGH was seen (in England) as a device for the granny bikes that mums took shopping. More often than not they weren't working, stuck forlornly in one gear, the index chain hanging out of the end, and with a broken trigger or twist-grip shift. They had thus a reputation for unreliability way beyond the actualiti�. Had they been maintained, they would probably have not died.

As a consequence, even twist-grip shifters were tarred with the non-sporting unreliable 'shopping' image of Sturmey-Archer, but I prefer twisters for fast shifts on rear mechs - especially on folders where they don't interfere with the fold.

I understand the convenience of IGH bikes, and the desire for a lack of deraill�ur adjustment, but not the problem of replacing an IGH should it die, the extra weight (which probably isn't much) nor the extra cost. Belt drive is still a dream for most of us.

Of course, I'm a dinosaur now by any standards, but I can't let go of the erronous 'shopping bike' image of anything with an IGH, cmpared to the 'Tour de France' Image of a snappy deraill�ur shift. I've never had an issue with a dangling cog-swapper, Dahon or otherwise, probably why I prefer them, but plenty of people have. If they break, they can be replaced or upgraded very cheaply, and they can usually be adjusted in a minute or two. Unless they are bent or corroded.

Of course, now we can choose either on our folders, (also once considered 'granny bikes') and the recent developments in gizmos like the Alfine, and electronic shifting (Shimano Di2) make all of this irrelevant, other than the cost.

The other work of Satan in the 60's was the hub mounted or rim mounted dynamo. More weight, more drag, more hassle.

Now, all of these things are seen as upmarket accesories.


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