Excellent Information! Thanks kgibbs51.

I also commute by motorcycle (kawasaki), but I'd hardly call my travels urban.

DaFriMon:

I was looking at your measurements and also comparing them to the ones on the Dahon website, you're spot on. The interesting thing is your measurements are within the range of the way my Downtube INXS is setup right now. I probably won't be able to completely verify this until I can physically line the bikes up, but it looks like the Curve has a much roomier cockpit than the INXS (I've even extended the cockpit on my downtube with a dahon folding handlepost and 135mm stem).

One question, the stem that is inserted into the folding handlepost, what is the diameter? Are they still using a 1 inch diameter stem?

It's one inch by my own measurement with a caliper; it isn't marked. There is a groove on the front of the stem that catches two little bumps on the inside of the handlepost to help align it, and keep it from slipping too far to the side if it were loose. There could be a problem changing it for another stem if you were thinking that.

I would appreciate some point-by-point comparisons between the Dahon Curve and the Downtube Mini. It's not particularly easy to go test ride either one, so the comments of owners would be very helpful! A virtual comparison shows the following highlights:

Mini:
8-speed hub.
Real suspension

Curve:
More adjustability in handlebar height
Better tires?
Pump built into the seatpost
Fenders
Luggage rack
Magnetix system to hold the folded bike together
Kickstand

Looking at this list, it seems to me the advantages of the Mini over the Curve are few, but pretty fundamental, and anyway, it ignores the most fundamental question: how do the respective designs and quality of manufacture stack up? It sure would be nice to hear from someone qualified to comment on that.

Other than that... Both bikes have nice internally geared hubs, but the Mini's 8-speed, I imagine, not only makes the bike more versatile, but probably makes the whole bike feel a little stiffer since one would get a lot of stability from a relatively constant cadence. Is there any truth to that speculation? The Curve offers some interesting extras, but they vary in usefulness, and can (mostly) be added to the Mini if needed. I don't need the kickstand, for example, but the adjustability of the handlebar might be crucial for getting the bike to fit right. So to evaluate these, we have to know if they're really any good. Any comments on the pump, the rack, the Magnetix system? And so on.

And finally there's the frame geometry. I've posted a picture of a nominally similar bike in the thread on folding bike spec's:
http://www.bikeforums.net/showthread.php?t=287409
... and it would nice to have the corresponding dimensions on the Curve and the Mini as well...

Rudi

Rudi:

We kicked this around a bit on another thread.

http://www.bikeforums.net/showthread.php?t=284493

For me it boiled down to my just liking the Curve better like some others but here is Jim's bottom line:

Downtube Mini 8 Speed:

+Granny gear for hill climbing & more speeds
+Easier to upgrade
+Built in suspension
+Includes carry bag
+You can email the inventor (added by kgibbs51)

-Higher cost ($432 shipped)
-Possible bad parts (BBs) and/or bad lubrication
-Handlebar height not adjustable
-Tires not as nice

Dahon Curve D3 3 Speed:

+Lower cost ($360 shipped)
+Better tires
+Includes fenders and rack
+Handlebar height is adjustable
+Folds and/or stays folded better
+Mounting bracket for KlickFix bags & baskets on front
+Reflective strip around tires
+Dealer Network (added by kgibbs51)
+Magnetix system to hold the folded bike together (added by Rhm)
+Kickstand (added by Rhm)
+Tire pump (added by Rhm) (although most people ditch them for a better seat post)

-Needs odd size suspension seatpost (no suspension built in)
-Missing granny gear for hill climbing & less speeds
-More difficult to upgrade
-Carry bag not included

It is tough to decide. They are close in pros and cons.

FYI, I purchased the Birdy bag/cover for $20 from http://blackdogbicycles.com/birdyfoldingtravelbike.html
I never use a carry bag because I push the bike when I don't ride. I just needed a bag as a notional cover so the conductor doesn't throw me off the train.

Yes, I was thinking of possible options, in case I need to make it a little longer. I have some ideas, but I'll put away the dremel until I actually see how it fits. :D

BTW, I placed a backorder for the Curve SL and will give a full report when it arrives sometime in July probably (or should I say hopefully).

I ended up picking the Curve over the Mini. I do have to say that I really like the Curve. I did 10 miles on it yesterday, and it was a lot of fun. I passed most bicyclists I met. The bike is faster than I thought it would be. Although it doesn't have a true "granny" gear for hill climbing, I have been able to sit and spin up all of the hills I have encountered around here.

I can't say enough good things about the Cane Creek Thudbuster suspension seatpost. It is a remarkable invention. I would be shocked if the DT Mini's suspension was any better. Although this accessory adds quite a bit of cost compared to the purchase price of the bike.

With gearing, I am surprised at how well I can get along with only 3 gears. There really is quite a range available. That being said, I would prefer to have the Curve SL with 5 gears and a slightly wider range in gear inches. I think the DT Mini has more than enough gears for it's gear inch range.

I really enjoy the looks I get from the children that I see when I am riding. They look so surprised to see an adult riding a "child's" bike. A lot of the adults look puzzled as well. Especially when I cruise past them on their leisure rides.

I am strongly considering purchasing the Curve SL when it becomes available. I think it will be a really nice product. I don't think it's a good monetary decision. The extra $240 doesn't get you much in my opinion. However, I think it will be a great bike. Not to say that the Curve D3 is not a great bike too. Who knows, maybe I will stick with the Curve D3......

The only problem I have with my Curve D3 is that the tires are not round. Either the inner tubes are not installed correctly, or my rims are not round, or both. It is still ridable, but I would prefer to ride on round tires.

I'm willing to bet money on incorrect tyre bead seating. Have you followed my advice? It can't be the tube, BTW. But it can be the rim. Is the wheel true, ie does it spin with no side-side or up-down movement on the rim itself?

It will be helpful if you find someone who has done extended riding on both. I had ridden neither before making my purchase; it came down to this.

I wasn't looking for a bike that would be good for long, hard, road rides. I have other bikes for that. I wanted a good bike for running errands in a relatively small area, one that would be easy to bring inside. Given that, the 8 speed vs 3 speed hub wasn't that big a selling point, although it was attractive. Same for waiting for the 5 speed Curve SL.

The fixed height stem on the mini would have had to go. People have changed these out, but that's an extra expense. So would be fenders and a rack. Given that the Mini cost $50 more at the time I made the decision anyway, that made the Curve seem like more of a bargain.

I'd probably have wanted to change the tires on the Mini, too, but that isn't certain.

I had experience with Dahons, and felt I knew where I was with them. Had no experience with Downtubes. Not arguing with the many fans on this forum, it just seemed I'd be taking more of a chance.

The seatpost pump on the Curve was not a factor. I would have found a way to carry my Topeak Road-Morph pump otherwise. Since I've got it, I suppose it's a neat feature, but I've improvised a fix to keep the pump head from falling out the bottom of the seat tube while riding. See the Dahon forum for a couple of threads on this; it's a known problem. I do like having a seatpost that will take standard saddles, I put a Brooks B-67 on mine. The SL will have the SDG seatpost that only takes their single-rail saddles. Of course, this can be changed, at extra expense.

I'm quite happy with my Curve. If I'd been dead set on getting an 8 speed hub, I wouldn't have had too many worries about ordering a Mini. It would have been necessary to work out in advance what I was going to do about getting the handlebar height right for me, but I would have expected to be able to handle any other issues.

By the way, I like the kickstand. :)

From the other thread:

"Tyre wobbles are (probably) most often the result of improper bead seating. You can spot improper seating by the fact that the tyre has at one place a LACK of bulge, ie it bulges 'inwards'. If you look carefully at the sidewall at that place you will usually spot the sidewall is hidden behind the rim a bit more than in the rest of the tyre. What happens is the tyre bead is still located in the rim well and has not slipped out of the well and not nestled in the rim sidewall corner.

Not so easy to fix in my experience, but possible.

Take the tyre off and lubricate the beads with talcum powder. Lubricate the tube and rim well also. Put it back and inflate it until it has seated correctly, then deflate (if necessary) to the desired pressure."

One of the bulges was completely ridiculous. It looked like there was a distorted tennis ball inside of my tire. As though a snake had swallowed something. It bulged the tire badly. If I rode many miles that way, it would have worn out the tire in that spot quickly. I think the inner tube was bent over on itself there.

To reduce that problem, I deflated and squished that area repeatedly and then reinflated. It is better, but not gone.

The rims have no side to side wobble. There is a very slight up and down wobble, but I would consider them "true enough".

The tires have reflective stripes around them, and it is really easy to see if they are seated properly. The answer is no, they are not. However, they really aren't seated that bad.

When Thor sent me the Dahon Thudbuster seat post, he included two new inner tubes in case I blow out the ones I have. If we get a bad weather spell, I may try to take the tires off of the rims and see what is going on. I really don't like doing that job. I suppose I could pay a local bike shop to do it.

That or I could ignore the symptoms and wait for the blowout to occur. However I don't want it to happen far away from where I started my ride!

To give you an idea, the original bulge was so large in my tire, that I could not use the SKS fender without rubbing. It was a big problem. If I had a video camera, you would have been amazed at the wobble!

Now it is minor in comparison.

Yeah, I agree 100% with jur. The tire isn't seated right. Possibly the tire is defective. The tube cannot be the problem, unless (as MequonJim suggests) it's folded over on itself or, more likely, stuck under the bead of the tire somewhere; and this is especially likely if the tube is too big for the tire; but that's an installation problem, not a tube defect. Replacing the tubes no more likely to fix the problem than just reinstalling the same tubes, which is the first thing I'd try.

Over the years I have heard a lot of tricks, often involving lubricants such as talcum powder or soapy water, to get tires to seat properly; I have never had any luck with any of them. Some tires seat more easily than others; sometimes the combination of a certain rim and a certain tire give you a reliable seat, sometimes it does not, which can be incredibly frustrating. I suggest you take the tire and tube off the rim and put them back on, and practice seating the tire. Try all the tricks, see if you can get one of them to work for you. If you cannot get a tire to seat properly, consider replacing it. Riding on a defective tire is just a bad idea.

Here is a picture of my Curve D3 with the Dahon Thudbuster seatpost. Both the seatpost and the handlebars are at maximum recommended levels. I posted some measurements to the thread discussing that stuff.

http://img511.imageshack.us/img511/1382/curved3ge4.jpg

That's a sharp looking bike dude. Ripped the fenders off I see. I left mine on because I'm wearing business casual to work and if it rains, well I don't want to risk it.

Sure looks better without them though.

Anyone else noticing some scratching on the rear frame from the handlebar extension/tension lever? Its a shame they didn't put another rubber sticker on the frame at this point or made the tension lever offset or swivel-able an inch to the left or right.

Great picture and great information, MequonJim. Thanks!

Yeah, I have those, and I agree it would have been a good place for the clear rubber circle. I think I scratched over there when I did the fold incorrectly. I have to fold it differently with the Dahon Thudbuster seatpost.

I agree that it looks better without the fenders. If it is any consolation to you, they are extremely lightweight, so you aren't carrying around any extra weight by having them.

Ya I noticed that when the handlebar flip lever's black retaining band is not swiveled to the side enough the clasp prevents the handlebars from folding down 100%. This in turn causes that handlebar extension/tension lever to hit the rear of the frame.

I just spend an extra 1/2 second to turn that black band to the side enough to fold the handlebar down so it won't rub. Too bad it took me 2 weeks to figure out what I was doing wrong. No biggie.

Just for the record,

I am extremely happy with my Curve. Due to my academic situation (trying to bring closure to my Masters degree in Human Anatomy) I am not riding as often as I want, but the Curve is one of the most reliable folders that I ever had: Perfect brakes, perfect shifting, no chain problems, no folding issues. If I win the lottery tonight I will give her an XTR upgrade and paint it Stealth Metalic Black, and send pictures to this forum from all over the planet...


UPDATE: I did not win the lottery, so my Curve will not get the XTR upgrade. Yet.

Last weekend I finished an 8 mile tour of Chicago from the loop to Chinatown, down to Comisky Park, over to Bronzeville/IIT, and back up to the loop near McCormick Place. I easily kept up with the full sized bikes and there was even a hill climb (pedestrian overpass over Lake Shore Drive) where I beat the other 7 riders without much effort.

Before we started on the tour the guide at the rental shop said to me "you are going to use that bike?" I told him unless we were going to Madison, WI that's what I was riding.

It was such a nice weekend when I got back home (just folded it up and took the L) the wife and I cancelled our movie plans and went for a 10 mile ride. For a second I thought I might want to take my full size mountain bike but instead I unscrewed the water bottle holder from it and bolted it on the Curve and took that.

At this pace I might think about selling my mountain bike.

Great report. You are still riding the bike with the stock components, correct?

Its 100% stock. I took the rack and stand off though. No need for $100+ seats. I'll save the money and use my legs as shocks.

So to conclude, that was an 18 mile outting last weekend separated by maybe 3 hours of down time. I held my own against 21 speed full size treks. This is 8 miles of technical urban riding (potholes, pedestrian overpass ramps, in and out of stores/public transit, etc) and then 10 miles of paved trail riding with some small unimproved crushed stone sections.

Sorry only about 500 feet of mountain biking through grassy prairie to get to the trail. That's one thing a folder isn't going to do for me.

I agree. However, if we end up getting used to the small (VERY SMALL, let's rephrase) wheelbase or our Curves and avoid importing our previous experience with real off road bikes, there is room for improvement. Once in Orlando I asked the guy that used to be the biker for the La Nouba show (Cirque du Soleil) and he said with proper training you can look like you have some kind of gift doing anything...anything.

Right, you've seen those guys offroading with unicycles right? They have a pretty short wheelbase. :D

Every time I ride my Curve D3, I am amazed at how well it performs. It is hard to believe how much you can do with 3 gears.

Many people that see me on it look surprised at what they are witnessing. It is odd that this little bike can do as much as it does.

I'm totally newbie in bikes and I'm planning to order Dahon Curve.

TheFitnessStore.com offers a professional assembly + Double Boxed Shipping option at $19.95.
I'm just wondering whether this so called professinal assembly is necessary for a newbie like me.

I think that it is necessary for the warranty.