Folding Bikes - Downtube folding bike

ooops, the link is www.cruzbike.com. I have corrected it in the original post.

Here's a picture from their website:
http://i39.photobucket.com/albums/e157/sesamecrunch/SofriderStudio300.gif
And here's a mock-up:
http://i39.photobucket.com/albums/e157/sesamecrunch/foldingbent.jpg

Hi there, I need to find some replacement parts to fix my Downtube suspension fork. All the travel in the fork has gone so I've no bounce to the ounce!

The bike shop said that they were familiar with the zoom brand but couldn't source parts from them as zoom only deal with manufacturers and not repair shops. does anyone have any info that can help me?

Searching through this excellent forum and google I can see that its possible to source various forks and parts in the US but I can't find much useful info for UK owners.

Does anyone know of a fork, suspension or not, that I can use as a replacement for the zoom, sourced in the UK? preferably with V brake mounts and similar geometry (tall order?)

Does anyone have any info as to how I can replace springs/elastimers/various bits in the zoom fork in the UK?

Hope someone can help - if only i lived in America i'd be laughing!

Barney

I'm not sure about the UK, but the suspension fork can be had on http://www.nycbikes.com/catalog.php?item_type=Forks&item_cat=WAREHOUSE For 9 dollars american. I'm sure they'd be willing to ship it over to the UK, it'll probably cost more for shipping than the suspension fork itself, but still, it'd be brand new.

ooops, the link is www.cruzbike.com. I have corrected it in the original post.

And here's a mock-up:
http://i39.photobucket.com/albums/e157/sesamecrunch/foldingbent.jpg

WHOA! That looks do-able. When I first read your post I couldn't picture it, but that helped a lot. Cruzbikes are pretty cool, the only negative I've heard is the adjustment to peddling as you turn...

Keep us posted!

Dan

I will keep you posted. I haven't fully decided yet whether it's the folding bike or the mountain bike that gets converted. Each has its own benefits. I should do both....

For a Cruzbike mod, that seat looks way too close to the hinge: might impede x-seam adjustment. Also, for the front wheel drive, won't you have to widen the forks? That Dahon-looking bike in the photo would not be a good candidate for such a mod, esp. if it comes with the narrow Dahon forks. It also looks like the hinge on the handlebar post would prevent a secure mount for the Cruzbike stays. Nice idea though.

Well I said I’d post a pic and give a quick report when I was able to take the bike out for a shakedown run. First, the bike came out of the box without a flaw. A few adjustments and it was ready to go. I was impressed with the handling and the ride-ability – definitely a nice bike for the price. I’m planning on swapping out the seat. Is there any real weight savings by removing the rack and kickstand – they appear to be light – but looks can be deceiving…

Dan

http://home.comcast.net/~dbhmgb/DT1.JPG

Default seat is very heavy. Rack is fairly light.

For a Cruzbike mod, that seat looks way too close to the hinge: might impede x-seam adjustment. Also, for the front wheel drive, won't you have to widen the forks? That Dahon-looking bike in the photo would not be a good candidate for such a mod, esp. if it comes with the narrow Dahon forks. It also looks like the hinge on the handlebar post would prevent a secure mount for the Cruzbike stays. Nice idea though.
Responses to your observations:
- First, this was just a rendering done by the designer of Cruzbike, not a "real" plan
- I would move the seat forward a bit as you say,
- I would be converting a DT IX Front Suspension, not a Dahon
- The Cruzbike kit comes with a bracket that attaches to the front forks which would widen it to 130mm,
- I don't quite know how the handlebar hinge would work yet. Have to see the kit in person.

I still don't know which bike I want to convert, but it's been fun thinking about the possibilities.

Spambait, do you have a Cruzbike or done a conversion?

Why do these Downtubes have adjustable stems?? Fore-aft adjustment is very small unless the stem is drastically set to 90* almost. Height is taken care of by the telescoping post, so it seems redundant...

Spambait, do you have a Cruzbike or done a conversion?
No I haven't done one.

I looked into it a couple years ago, but didn't have the kind of bike they wanted you to use (i.e. a mountain bike with a sloping top tube). I see they're selling kits with their own bikes now, but like you, I think modding my own would be more fun.

Recumbent kits for Bromptons and Birdys have been designed and sold in the past, but they were short lived.

Default seat is very heavy. Rack is fairly light.

Thanks. Yeah, that seat is a boat anchor!

Hi,
Well, as someone else pointed out you can get replacements really cheap. But if you want to fix yours, here's what I did. I took it apart, removed the old grease, and re-greased it. The old grease had turned into a consistency like putty, which was preventing the fork from acting like a fork. Initially I had though I needed a spring replacement, but that turns out not to be the case. Once I filled it with new grease and put it back together, it was working almost like new again. I think I posted a description of how to take it apart in another message.

Morgan

Hi,
Well, as someone else pointed out you can get replacements really cheap. But if you want to fix yours, here's what I did. I took it apart, removed the old grease, and re-greased it. The old grease had turned into a consistency like putty, which was preventing the fork from acting like a fork. Initially I had though I needed a spring replacement, but that turns out not to be the case. Once I filled it with new grease and put it back together, it was working almost like new again. I think I posted a description of how to take it apart in another message.

Morgan

thanks mcgurme

i've never done any kind of work on a bike at all - do you think a beginner could do a job like this? i found your post and i know i need a long allen key, grease - patience? any thing else?

thanks mcgurme

i've never done any kind of work on a bike at all - do you think a beginner could do a job like this? i found your post and i know i need a long allen key, grease - patience? any thing else?

I'd love to know as much as possible about this job also. After reading your previous post, I have been meaning to do this as a preventive measure.

I finally finished the upgrades to my Downtube VIII Folding Bicycle

This is my second folding bike. The first was a Batavus Bat-a-fold with a square steel seatpost, built up with a Shimano 3-speed when I was working in a bike shop while goin to college in the 70s. This bike was damaged by the airlines (they dropped it and bent the front chainring). The gearing was limited and since I have way too many other bikes I haven't replaced it until now.

I bought a Downtube VIII with the 8-speed Sturmey-Archer hub in November 2006.

I plan on using the folding option in three ways:
1) I leave the bike in the back of my car so I can get exercise at lunchtime when I want

2) I want a bike for road trips which can safely be locked up inside the car without taking up too much room and having the option for riding on dirt trails as well as pavement.

3) I want a bike I can pack into a airline legal suitcase (Samsonite Oyster) for trips.


Modifications
I replaced crankset and bottom bracket with a used Shimano 105 39/53 tooth. The gear ratios with the stock chainring are too high. THe 39 tooth front ring makes for a much more useful bike.

I filed down teeth on 53 tooth chainring to make it into a chainguard. This chainring was used and I would never use the 53 tooth option on this bike. More useful to have it as a chainguard.

Replaced folding alloy pedals with Shimano SPD pedals. I prefer SPD pedals and cleats and the non-folding pedal is not an issue.

I like the little bar-ends and the stock bars, but replaced the stem with a longer one to get a better reach. That takes weight off the rear wheel and puts it onto the front wheel. I have the seatpost up about as far as it can go and that moves my rear-end close to being over the center of the rear wheel, which makes the bike climb poorly. The longer stem gives me a bike position similar to my other bikes and improved handling.

Replaced chain with SRAM chain and masterlink. Having a masterlink makes chain removal for suitcase packing easy.

Replaced brakes and brake levers with Avids. Nothing really wrong with the brakes that come on the bike, but I prefer the smaller Avid levers and the Avid brakes have more adjustment options.

Replaced stock saddle with WTB saddle. I prefer the smaller saddle and really like WTBs.

Removed rear fender after suitcase packing test. I plan on putting on a small coroplast plate under the rack to act like a fender. One less thing to worry about when packing the bike.

Added a Topeak pump, Planet Bike Aero wireless bike computer, new grips after the originals ripped, and added a bell I had lying around. Added a small seatpack for tools and misc stuff.

Added reflective tape to frame, stem, and cranks, and front and rear LED lights for night riding. The rear light is attached to the rear rack, replacing the reflector which came with the bike. The rack protects the light when the bike is folded.

The bike can easily be rolled around while folded which is a plus. I use Velcro One-wrap straps to hold the front fork to the rear rack when folded and to keep the handlebars with the bike when folded. When rolling the bike I leave the seat extended and use it as a handle. The bike balances nicely when being rolled.

I am very impressed with how nice the bike rides. Stock tires are OK and work well on pavement and dirt/gravel paths. The suspension fork smooths out the ride. Ride quality is good, and the bike handles well at speed. I am still having some minor issues with adjusting the hub, but like the range of gears. If you use a folding bike as a folding bike it will get banged around and internal-gear hubs are less prone to damage versus derailleur bikes.

http://home.wavecable.com/~spholmen/things/DT_VIII.jpg

http://home.wavecable.com/~spholmen/things/Chainguard.jpg

http://home.wavecable.com/~spholmen/things/Handlebars2.jpg

http://home.wavecable.com/~spholmen/things/ReadyToRoll2.jpg

Pine Cone:

Very well done. I really like what you did with the crankset! Clever idea. Very good choices overall. Sounds like you're going to be very happy with your setup.

I have a question about the fork and the possibilty of replacing it. Is the fork a threaded or threadless fork? Is it possible to replace the suspended fork, with an aftermarket non suspended version? If so who makes it, and how would it be done?

DT has a version with a rigid fork.

I know, but I was looking at the IH version or the FS version. I emailed Yan directly about this before, and he advised against changing the fork to a rigid one, but I still want to know if its possible. And if it is, what route to take to do so.

I know, but I was looking at the IH version or the FS version. I emailed Yan directly about this before, and he advised against changing the fork to a rigid one, but I still want to know if its possible. And if it is, what route to take to do so.

I was wondering the same thing. I would like to get the internal hub, but would try to shed as much weight as possible if I went that route, and the fork might be a part of that (anyone know how much difference it makes?) Wonder why Yan advises against it-did he say?

John

PS - my first post BTW-I am shopping for my first folder, and am down to Xootr Swift (need to save more $) vs. Downtube (can affordit now)

-John

I was wondering the same thing. I would like to get the internal hub, but would try to shed as much weight as possible if I went that route, and the fork might be a part of that (anyone know how much difference it makes?) Wonder why Yan advises against it-did he say?

John

PS - my first post BTW-I am shopping for my first folder, and am down to Xootr Swift (need to save more $) vs. Downtube (can affordit now)

-John

I think I was was slightly misquoted.

I mentioned that the VIIIH's geometry was set up for a suspension fork. I never tested it with a rigid fork and will not have time to test it for a long time. Hence I discouraged the idea.

Thanks,
Yan

Kinda similar situation for me. I really really want a swift, but the value of the DT makes it almost worth it to try and make it equivelant to the swift. So that's why I'm trying to explore the options of the DT.

**edit**
Looks like Yan answered the question about the fork. I couldn't find the original email I got from him.
As for why Yan suggested against changing the fork, I believe he said it would alter the geometry of the bike.

I have swapped forks between the Front Suspension model and the Non-Suspension model. I, too, was trying to make the Front Suspension model lighter for the "sporty" riding that I was using the bike for. The NS fork is about 1/4 inch taller, although i don't know about angles & such, but both rode fine. I've ridden them in the swapped mode for a while and am going to put things back as they were.

If you want to buy aftermarket forks for 20" wheels, you can try here:
http://www.gaerlan.com/bikeparts/frame/forks/fork.html


I was wondering the same thing. I would like to get the internal hub, but would try to shed as much weight as possible if I went that route, and the fork might be a part of that (anyone know how much difference it makes?)
-John
I haven't weighed the two, but it feels like a couple of pounds difference between the suspended fork and non-suspended fork. In other words, pretty significant in the context of bike weights. Also, the first thing one would do is to swap out the sprung seat, which has got to be around 2 lbs by itself.

Has anyone ridden the IXNS or VIIIH in light-to-moderate wet weather - do the fenders work well or do you need a mudflap attached on back? Is a chainguard (chainguide?) needed to protect from greasy water flying on your pants?

One of my the few shortcomings of the Downtubes is the fenders. They are great value for the money you pay, but if you plan on riding them in variable weather, one of the first upgrades you should get are a pair of Freddy Fenders. They're fairly easy to install yourself, although I don't know if all the newer DT models have attachment points for them. These fenders make a big difference in reducing splash-up, are reasonably priced, and look a lot better than a recycled home-brew solution.

I'm riding a 2005 DTVIII, front-suspension.

I love my Freddy Fenders. I had to use zip ties instead of bolts on the front one to keep the fender stays on. Couldn't get nuts on the bolts with the front suspension, not enough room.

Anyway, definitely love them. People may also want to get Lizard Skinz neoprene covers for the suspension fork if they have one, it's a 9 dollar fork sure you could get another any time, but why go through the hassle. B/c the suspension fork is cheap, any gook that gets inside will fairly quickly jam the suspension up. I also have the lizard skinz for my rear derailleur.

I love my Freddy Fenders. I had to use zip ties instead of bolts on the front one to keep the fender stays on. Couldn't get nuts on the bolts with the front suspension, not enough room.

Anyway, definitely love them. People may also want to get Lizard Skinz neoprene covers for the suspension fork if they have one, it's a 9 dollar fork sure you could get another any time, but why go through the hassle. B/c the suspension fork is cheap, any gook that gets inside will fairly quickly jam the suspension up. I also have the lizard skinz for my rear derailleur.

BigMac:
Regarding the front fork you provided a link for last time - The website indicated a 1" steerer tube. Isn't our bike 1 1/8"? Do you know for sure?

Hi everyone-

I have been reading through the bikeforums and checking out different foldable bikes. I'm really interested in the Downtube 2007 IX (front suspension bike ) Folding Bicycle 9 speed (http://www.downtube.com/Downtube_2007_IX_front_suspension_Bike_2006_IX.html) ($299) and the Downtube 2007 VIIIH ( front suspension Sturmey Archer hub) Bike Folding Bicycle (http://www.downtube.com/Downtube_2007_VIIIH_front_suspension_internal_hub_Bike_VIIIH.html) ($399).

I will mostly be using my bicycle to commute and take recreational city rides, but will occasionally want to take a weekend camping tour and possibly a 2wk-1month tour sometime in the next couple years. Do you all think that these models can endure a long distance tour? If so, which model would be better for this?

I think I'd prefer the one with the internal hub for maintence reasons, but am unsure, if it would be able to handle some of the larger climbs on a tour through say, the mountains in New Mexico, without having to take it to a bike shop to have the gears modified. This concern comes from the large number of people who have written about needing to lower the gears.

Also, this might be a silly questions, but can these models be taken on an occasional beginner / intermediate mountain bike trail without causing trouble?

Any guidance / advice is greatly appreciated.

Thanks,
eli

Good question Sesame, I have no clue.

Eli, if you do not live where there is adverse weather, the rear derailleur should be fine and gives you that extra gear range. But if you're not going to be going off roads or paved/crushed stone paths, you may want a non-sus so you can load it up with more gear for touring.

I will mostly be using my bicycle to commute and take recreational city rides, but will occasionally want to take a weekend camping tour and possibly a 2wk-1month tour sometime in the next couple years. Do you all think that these models can endure a long distance tour? If so, which model would be better for this?

I think I'd prefer the one with the internal hub for maintence reasons, but am unsure, if it would be able to handle some of the larger climbs on a tour through say, the mountains in New Mexico, without having to take it to a bike shop to have the gears modified. This concern comes from the large number of people who have written about needing to lower the gears.


The gear range you need to tour will end up being a personal thing. If you own, or have a friend with, a bike that has very low gears, load it up and find a nice steep hill to climb. See how low you need the gears to be to climb the hill comfortably. Convert that low gear to gear inches using the wheel diameter of the bike you used for the test. Your target bike should have a gear (as measured in gear inches) that is that low if you plan to tour on it.

Gear inches (like gain ratios and gear development) is a way of describing the gearing on a bicycle that is invariant to the wheel diameter. For an explanation see: http://www.sheldonbrown.com/gloss_g.html#gearinch

Speedo

Good question Sesame, I have no clue.

Eli, if you do not live where there is adverse weather, the rear derailleur should be fine and gives you that extra gear range. But if you're not going to be going off roads or paved/crushed stone paths, you may want a non-sus so you can load it up with more gear for touring.

The steerer is 1 1/8"

Thanks,
Yan

Hi everyone-

I have been reading through the bikeforums and checking out different foldable bikes. I'm really interested in the Downtube 2007 IX (front suspension bike ) Folding Bicycle 9 speed (http://www.downtube.com/Downtube_2007_IX_front_suspension_Bike_2006_IX.html) ($299) and the Downtube 2007 VIIIH ( front suspension Sturmey Archer hub) Bike Folding Bicycle (http://www.downtube.com/Downtube_2007_VIIIH_front_suspension_internal_hub_Bike_VIIIH.html) ($399).

I will mostly be using my bicycle to commute and take recreational city rides, but will occasionally want to take a weekend camping tour and possibly a 2wk-1month tour sometime in the next couple years. Do you all think that these models can endure a long distance tour? If so, which model would be better for this?

I think I'd prefer the one with the internal hub for maintence reasons, but am unsure, if it would be able to handle some of the larger climbs on a tour through say, the mountains in New Mexico, without having to take it to a bike shop to have the gears modified. This concern comes from the large number of people who have written about needing to lower the gears.

Also, this might be a silly questions, but can these models be taken on an occasional beginner / intermediate mountain bike trail without causing trouble?

Any guidance / advice is greatly appreciated.

Thanks,
eli

Eli:

Both are very good bikes and great value. If you were only doing commute and recreational rides, I would have recommended the VIIIH in a heartbeat. The range and convenience of the internal hub is very appealing to me. Changing the gearing on the VIIIH to suit your riding needs is a very simple matter and, in my opinion, should not be a factor in the purchase decision.

However, I would be reticent about taking the VIIIH on a long distance tour (depending on where you're going). Parts and service may be more difficult to find for the hub. There are many people who tour with Downtubes, they're described in some threads on this forum, so you should be confident of that. (There are some upgrades and maintenance items I would do before touring, however.) But, it sounds like that trip is only a possibility. If so, I would get the VIIIH and ride the heck out of it.

As for riding on easy trails, just put on some knobby tires and you're good to go. I think both those bikes come with a sprung saddle plus the front suspension - you can ride in dirt paths with no problems.

Good luck with your choice.

The steerer is 1 1/8"

Thanks,
Yan
Thanks for clarifying, Yan.

Eli_D, check out the gearing here: http://www.sheldonbrown.com/gears/. The cranks as so, so, and I'm not sure how you would change the front chainring, but you can probably find one that will fit your needs.

Make sure to true the wheels and check for spoke tension before a tour.

Also, think about your size needs. The Mini and the NS are the smallest, I believe.

Dahon NS weights.


All in all, I am grateful I bought the Downtube over the Dahon I think it is a great bike! Even though we always complain about this and that, I hope Yan knows how much we like his bikes. I too would like to give him my list of things I’d like to see.

That list would up the price enough that the Downtube would loose its great place in the market. So I am glad changes to the Downtube are done slowly and that Yan listens to his customers but at the same time recognizes that trying to grow to fast would destroy the company we all want to see succeed. Looking forward to seeing what changes occur in 2007 ½ (March?) and possibly my second Downtube.

I decided I’d like to slim down my 2006 ½ NS 9 speed Downtube and bought a scale to check out some weights, while this list is not a complete list. (I don’t have a desire, at the moment, for a complete disassembly.) So take it for what it is worth.

I also made an incomplete list of bolts sizes I will post if anyone is interested in using TI and Aluminum to lighten up things.

Peddles Alloy Folding 268g each (536g pair)
Back fender W hardware 88G (W/O hardware 59g)
Bell 19g
Chain Ring W Plastic Guard 305g (232 W/O guard)
Seat Post Clamp 33g
Seat post collar 15g
Kick Stand W/hardware 281g
Stem Adjustable 243g
Rack and reflector W/o HW 630g
Bar Ends (Pair) 107g
Velo Comfort Seat 735g
Seat Post 425g (20g) seat post bolt
Threadless like post section 122g (With Star-nut)
Top Cap 10g
Top Cap bolt 8g
Crank bolt 14g (each)
Grips 8g each side
Brake Lever “APSE” 106g and 109g
Skewers “Quando” 117g (Front 56g Rear 62g)
Frame bolt “M6 x10mm” 5g (x2)


Another comment.
I think the bell is awesome, much better than the one I had.
I don’t know why there were so many complaints about the bag? I like the bag ,particularly that it came free with the bike, nice touch!

What are the 8-gear-inches as installed on Downtube's internally-geared model ? Thanks.

ggia-

someone else will need to confirm this, but I'm pretty sure that the gears are as follows (i don't know if it's possible to convert ratio to inches?):

Gear Ratio

• Overall Range - 305%
• Gear 1 - 1.00 (Direct Drive)
• Gear 2 - 1.28 (+28%)
• Gear 3 - 1.45 (+45%)
• Gear 4 - 1.64 (+64%)
• Gear 5 - 1.86 (+86%)
• Gear 6 - 2.10 (+110%)
• Gear 7 - 2.38 (+138%)
• Gear 8 - 3.05 (+205%)

(taken from the Sturmey Archer xrf8 site at http://www.sturmey-archer.com/hubs_8spd_XRF8.php)

(maybe check the tech manual too: http://www.sturmey-archer.com/pdfs/XRF8.pdf) (http://www.sturmey-archer.com/pdfs/XRF8.pdf)

Baldone:

Thanks for sharing this information!!!! If you get more, please share also! I am particularly interested in how much the fork weighs. Judging by some previous posts, I think some others would be interested also.

It's good to get facts on our bikes once in a while.

Hi everyone,

Don't have a downtube yet, but I'm pretty sure I'll be getting one sometime this year.

Thanks for all the info (wow, rather extensive)!

Anyone know how much the wheels weigh on the 2007.5? (no cassette, no tires)

Baldone:

Thanks for sharing this information!!!! If you get more, please share also! I am particularly interested in how much the fork weighs. Judging by some previous posts, I think some others would be interested also.

It's good to get facts on our bikes once in a while.

Welcome.

The NS 9 has a threaded headset.

I believe, I do not have the correct wrenches to retighten the headset one I loosen it. I know very little about threaded headsets. I can't remove the fork without removing the headset.

I will check my Zinn bike book and see if I can do it with regular wrenches.

A complete threadless design would be nice in this application as it is more simple and of lighter weight. I don't know what it would do to costs.

Yan do you have any plans to go threadless on the forks/headset of any of the downtubes?

I can get the wheel weights on the 2006.5 (2007) model if I get some time this weekend. I'll also do the tires, cassette, chain, and while I am at it, the tubes also.

I posted this in its own thread but just wanted to let everybody here know: Mauna Kea did a sweet mod with a thud buster where he hacked the original seatpost and combined it with a thudbuster to make a telescoping post that would give the taller riders the ability to achieve more of a road bike riding geometry. Well, that was when the Downtube seatpost was 31.4mm. Now it's the fairly standard 27.2, which is good because you can get the Thudbuster XL which is 450mm. But, it still wasn't enough height for me at 6' for a road geometry. Well, the "butt buddy" from http://www.sidetrak.com adds another 3 inches or so in height to any seatpost. It's a bonus that it's also a suspension saddle accessory. Now, on my bike, that means I've got double seat suspension. But, for all you Downtuber's looking for that extra little bit of height, this device (despite the name) is fantastic.

A complete threadless design would be nice in this application as it is more simple and of lighter weight. I don't know what it would do to costs. Yan do you have plans to go completely threadless on the stems of the downtubes?


Thanks for publishing the weights. I am certain many readers will find it very useful. Our bikes are very functional with racks, kickstands, saddles, etc that a rider can easily remove to lighten up the bike.

We would love to go with a threadless setup....I would also like to use ISIS cranks, and air/oil fork. However each of these changes has a high cost (unfortunaely we are a small company). We will make big upgrades in 2008 ( the spec's are almost final ). We may get some cool more pricey upgrades in 2009 (such as threadless stem) if sales are good in 2007, and 2008.

Thanks,
Yan

Threaded forks aren't too bad to deal with. While it is optimal to have a set of headset wrenches to work with them, you can certainly loosen/tighten them with any wrench that you can get to fit. The main problem is that the nuts are narrow, and most standard wrenches are too wide. (if you manage to get a pipe wrench to fit, prepare to have your nuts scuffed up - this can be reduced by covering the nuts and wrench with masking tape first).

Caveat: I write the following without my DT bike in front of me, and only from general experience, so there could be minor variations in the DT setup from what I'm describing here.

The two nuts work the same way as the nut/cone combo in your hubs. The idea is that the bottom nut (actually, integrated w/bearing cup) sets the amount of pressure on the bearings. The top nut simply "locks" the bottom nut in place, by friction between the two, with a washer in-between.

To remove, you simply loosen the lock nut (top) one first, then the second one (bearing cup) should be removable quite easily (usually by hand). At this point the fork can be taken out, just watch out for the bearings falling out of the bottom cup as you pull the fork out.

To install, it goes in the reverse - bearing cup nut first, then lock nut second (oh yeah, and there's usually one or more spacer/washers in-between these two nuts). The re-tightening is only slightly more tricky than removal. You basically want to get the top bearing cup tight enough so that there is no side-to-side (or fore-aft) play in the fork assembly, while still providing smooth rotation. My DT headset came from the factory overtightened, and I could tell because upon turning the handlebars, it felt like there were subtle detentes, i.e. lack of smoothness. The way I usually adjust the tightness is to a) first, slightly overtighten the bearing cup, so that steering is no longer smooth, b) put washers and lock nut on, hand tightening lock nut, c) use wrench to reverse the bearing cup nut back off, which has the dual effect of loosening the steering back to normal, while locking the cup in place against the lock nut. It may take a few tries to get the tightness right the first time, but with a little practice, it's not hard at all.

So, if you get a chance to do this and measure the weights, that would be awesome. I think a lot of the weight of the bikes is coming from the wheels. This is not a complaint - lightweight weels cost a lot of $$ so I wouldn't expect super light wheels on an inexpensive bike. But someday, when I finish other bike projects, that will be my next upgrade.

More weights
Downtube NS 9speed 2006 1/2

Rear Cassette 9sp 344g
Tire Kenda Kwest 1.5 480g
Front Wheel 24 spoke quando hub alloy v rims w/o reflector 685g
Rear Wheel 28 spoke quando hub alloy v rims w/o reflector 919g
Wheel reflector 17g
Tube Kenda 118g

Brake arms (pair) w/o bolts 168g-170g

Front fender 128g (with steel wire) w/o bolts that go in fork.
Front fender/reflector bolt 55mm M6? 14g (w/washers and nut)
Front relector and plastic assembly 29g

Threadless bolt M8 103mm long 38g (looks as this cannot be shortened)
Quill 46g
Folding section of stem, complete assembly 905g (With both quick release levers, quill, and associated hardware)(Does not include upper threadless assembly)


Note:
Spoke protector was similar to black electrical tape, but better, good light weight low-cost option and is included in the weight of the wheels. In fact, I was prepared to remove standard protector and replace it with black electrical tape. As the spokes are recest in the rim this should be fine for high pressure applications.

The tires were VERY difficult for me to remove I would doubt anyone would have safety issues with the tire coming off while riding. I broke a tire lever :eek: I guess I shouldn't have been using my multitool. Yet, perhaps that is more a reflection on me and my folding kevlar-beaded tire ways.

Due to the difficulty I had with the front wheel, I did not remove the rear tire from the wheel. I just removed everything else and subtracted the weight of the tire and tube from the front wheel to get the weight of the rear wheel.

I would love to get the fork weight but the wrenches I have are simply to wide.

Yan, here's a question:

When people first started talking about DT's on this forum, they were talked about most often as having quality comparable to Dahon, but at a noticeably lower price. I've noticed DT's undergoing a lot of different upgrades in components (which is appreciated!) but this seems to have shaved off of the price differential between the two brands. What's the plan going forward? Will there be a "value-priced" DT in order to continue selling bikes to folks for $200-$250 on ebay?

Or, if not, and the DT's start to approach Dahon in pricing, what will their emphasized selling points be? Why go on the internet to buy an untested DownTube (because they're not available in most stores) when there's probably a LBS that sells Dahons relatively close-by, and you can test-ride them first?

Yan, here's a question:

When people first started talking about DT's on this forum, they were talked about most often as having quality comparable to Dahon, but at a noticeably lower price. I've noticed DT's undergoing a lot of different upgrades in components (which is appreciated!) but this seems to have shaved off of the price differential between the two brands. What's the plan going forward? Will there be a "value-priced" DT in order to continue selling bikes to folks for $200-$250 on ebay?

Or, if not, and the DT's start to approach Dahon in pricing, what will their emphasized selling points be? Why go on the internet to buy an untested DownTube (because they're not available in most stores) when there's probably a LBS that sells Dahons relatively close-by, and you can test-ride them first?

Dahon's cheapest model in 2007 is a Speed 7 for $379. All our 20" bikes are priced between $299 and $399 and are much higher grade than the Speed 7. Our retail prices have stayed steady for over a year....I doubt we will ever approach the $600+ average selling price for a Dahon. Hence I think we are a value priced folder and sales are confirming my theory ( sales are up 300% over last year )

Later this season we will introduce lower grade 8sp models. Prices will be approximately $50 less than our current 9sp models. We will have products in the low to mid $200 price point, however they will be lower grade than our current models (closer to our 2005 models than our current 2007's)

Thanks,
Yan

More weight info - I had the chance to weigh two DT forks. The non-suspension fork on the IXNS weighs about 620grams. The Zoom suspension fork on the IX Front Suspension came in at around 1600 grams. As I had guessed, there is about two pounds difference between the two forks.

These were weighed with a kitchen scale, so no 6 digit decimal accuracy...

Hi there - i've been trying to replace my suspension fork on my 2006 downtube 9. I've come across a bit of confusing info from a folding bike shop that i took my bike to. They had a lot of forks with 1+1/8 staunchions but they said that none of them would fit the stock downtube headset. They measured the staunchion on the stock zoom fork and found it was a non standard size, so could not do the replacement. Could this be right?

Yan has posted above saying that the headsets take a 1+1/8" fork. I know alot of measurements are refering to the full suspension model and wondered if the front suspension only model might be different? If any body has ever measured the fork stanchion themselves on a downtube 9 could they post their measurement (the shop forgot their finding so i'm none the wiser).

Many thanks
Barney

Hi there - i've been trying to replace my suspension fork on my 2006 downtube 9. I've come across a bit of confusing info from a folding bike shop that i took my bike to. They had a lot of forks with 1+1/8 staunchions but they said that none of them would fit the stock downtube headset. They measured the staunchion on the stock zoom fork and found it was a non standard size, so could not do the replacement. Could this be right?

Yan has posted above saying that the headsets take a 1+1/8" fork. I know alot of measurements are refering to the full suspension model and wondered if the front suspension only model might be different? If any body has ever measured the fork stanchion themselves on a downtube 9 could they post their measurement (the shop forgot their finding so i'm none the wiser).

Many thanks
Barney

It is a 1 1/8" threaded steerer fork....the threaded steerer makes it more dificult to find replacements. Someone here swapped the threaded headset for a threadless and used a threadless fork.

Thanks,
Yan