I have heard of tubes for 1.5"-1.75" and 1.75"-2.25". Are there tubes for 1.35"-1.75"?

I sent them an e-mail asking what the range is for the tube. No answer yet.

-G

The tubes at cambriabike will fit 1.5" width tires.

Note that Nashbar has Vittoria 20" x1 1/8- 1 1/4 tubes on sale ...

http://www.nashbar.com/profile.cfm?c...cat%3A%20Tubes

-G

@kb5ql:

Important question: What is the wall thickness of the Dahon seatpost that you were using with the frame that broke?

Well my Swift is essentially complete (for now). here is what it looks like currently:

http://i160.photobucket.com/albums/t...wift_sm001.jpg

Still to do: Anodize steering riser tube and seat post adapter.

Specs and a web page to follow. It weighs in at 9.0kg.

http://i160.photobucket.com/albums/t...wift_sm012.jpg

Nice achievement. If you remove the bar ends you get an even lighter bicycle.

Here are my Swift specs:

Frame: latest Xootr aluminium with thicker tubing
Gears: 9 speed
Weight: 9.0 kg
Gearing: 32" to 99"
Brakes: Avid SD 7
Brake levers: Avid FR5
Derailleur: Shimano Deore XT
Shifter: Shimano Deore XT
Cassette: Shimano Deore XT 11-34T
Cranks: Shimano Ultegra octalink
Bottom Bracket: Shimano Ultegra octalink
Chainring: Vuelta 58T, 130BCD
Chain: KMC 10X SL
Pedals: Crank Brothers Eggbeaters SL
Cable Outers: generic
Cable Inners: generic stainless
Hub Front: American Classic 58 micro 16 spoke, radially laced
Hub Rear: American Classic 205 road 28 spoke, 2x and radially laced
Spokes: SAPIM Race single butted 15g stainless & brass nipples
Rims: Velocity Aeroheat
Tyres: Primo Comet Kevlar 1.5"
Skewers: bolt-on
Tubes: Schwalbe presta
Steering riser: Custom 28.6mm 6061 T6 aluminium
Steering clamp: Salsa 28.6mm Liplock
Seatpost: Ritchey Pro aluminium 31.6x400mm plus custom adapter to 34.0mm
Head Set: Ritchey Logic 1 1/8" threaded
Stem: Ritchey Pro 100mm 6deg
Grips: Ritchey WCS foam
Handlebar: Titec XC Enduro flatbar
Barends: SMICA micro bars
Saddle: Tioga Spyder

Very impressive specs!

How do you like your Tioga Spyder?

I am considering using my Brompton as my main commuter/century ride, and I am looking for ways to make it not only slightly lighter, but pretty much for efficient. I am considering carbon crankset, bigger chainring (I agree with you, single front chainring may give enough gear range for now) and maybe carbon seatube. Now my saddle may be a good place to start since I always neglect to upgrade it. I am not a big fan of Brooks Saddle but the Selle Anatomica looked like something I may consider:

http://www.selleanatomica.com/images/Black%20A.jpg

A lot of people like it, but we have to agree your Tioga Spyder has a way more...futuristic looking.

:)

14R

Nice job Jur.
How does it ride?

Edd

Gearing ramblings:

The 32-99" gear range, while fine for touring, is proving (against my expectation) to be a bit on the small side for fast road rides. I am a spinner when on long fast road rides, and want the low end for spinning the uphills while seated. (When standing on the uphills, I shift up 2-3 gears and can go for long without sitting down.)

However, for going fast downhill, I like to pedal a bit slower and here I am spinning out when reaching +70km/h. So maybe, after things settle in, I can come to a final conclusion about needing taller gears for the high end, or perhaps ditching the low end ones and going to a bigger ring. I'll be riding a 200km audax event this weekend. In hindsight, I should have gotten the 60T Vuelta ring.

But going to a bigger ring presents it own problems: The chain is on the short side due to the derailer hitting the frame when going to the 11T cog. I think this gets worse as the chain gets shorter.

Edd: It is an excellent ride. For one thing, it is the lightest bike I have owned so far, with by far the lightest wheelset, and it accelerates like a bullet. I guess I am used to my Raleigh Twenty's heavy weight with heavy back wheel, which accelerates sluggishly. The Swift responds like it's not there. It is also much more responsive than my previous lightest bike, a Giant CRX2, which I had modded to just over 10kg. Partly wheelset, I guess.

The great thing is, it not only is faster and more responsive than my Giant, it also rides much softer. It feels like it has a small degree of suspension when going over bumps slowly. I am unsure where this comes from - I have the tyres at 100psi. But despite that, it is not noodly at all - on the contrary, when I stand up and hammer, it feels very stiff and shoots off. I am of the opinion that this softness comes from the seat tube bending, since there is no main triangle.

I am happy with my seatpost adapter design - effectively it is the original seat post with the top cut off and hollowed out to accept the Ritchey seat post. The section at the seat tube separation is original thickness, and in fact it goes into the bottom section further than the original seatpost, so is stronger.

14R: The Spyder saddle is surpisingly comfy - it is quite flexy and conforms a bit while allowing the sit bones to do their job. It is a fair bit narrower than even my Brooks B17 Narrow, but even so it is not an ass hatchet. But is is no Brooks either - I am unsure if I will be taking it on my 200km brevet this weekend. It was fine on two 5h rides last weekend, but I was feeling a bit tender at the end. This was not due to the web but the shape.

It is less stable riding no-hands than my Twenty - less trail. The Twenty feels like it's on rails, very stable, while the Swift will veer over the road a bit.

The very low aero handlebars setting was a gamble - with surprising results. I thought It would result in stiff neck and numb hands. Well my neck was a bit stiff, but this was clearly due to me not being used to such a low position yet. My hands were not numb at all, whereas on the Twenty I get numb from time to time. Can't explain that yet, except perhaps that the Twenty's Brooks B17 makes me slide forwards a bit. In fact when I got back on the Twenty for the commute to work, it felt very high and I flipped its stem.

I won't be commuting on the Swift except for training rides, commuting is such heavy duty use and I don't want to wear the drivetrain out that quickly.

Here is the web page photo album of my Swift:

http://tinyurl.com/23mxcb

I just measured this. Looks like no thicker than 2mm. Hope that helps.

Sorry, I don't have calipers so I had to eyeball it. Most likely it's in the 1.75mm range.

The original Swift seatpost wall thickness is 3.2mm. That means the moment of inertia for the two cases differs by 30%, I take that to mean the Dahon post would bend 30% more than the Swift for the same applied stress. I think perhaps this was the reason for your frame's failure, rather than the tube diameter. I think it highly unlikely that a seatpost that is marked as 34.0mm would be slightly less, especially in seat posts where this is a critically controlled quantity.

I have ditched my earlier shim design in favour of a heavier, stronger design. The first shim was simply a section of 34mm tube hollowed out to a wall thickness of 1.2mm, to shim up the 31.6mm seatpost to 34.0mm. The (mental) problem I had with this design, after satisfying myself it would never shear off, was one of elastic bending. The manual that came with my frame says that the seat post is an integral part of the strength of the frame, so I thought the thin-walled shim would be unable to provide the required bending moment at the junction of seat tubes.

I therefore made a new adapter, not a shim this time. Starting with the same tube material, I hollowed out just enough to allow the Ritchey seat tube to tightly slide in up to its minimum insertion mark. The rest of the tube is the original 3.2mm wall thickness. The wall thickness at the seat tubes junction is 3.2mm since the Ritchey post is too short to reach this point. The section extending into the bottom section seat tube is longer than the original post, so I have even more strength further down than with the original Swift post.

I told them to get me the longest post. No worries now. :D Your explanation makes perfect sense, however I had hoped to banish the frame destruction due to my incompetence from my mind. Thanks for bringing it back up...

I have updated the Swift to include some shinier, lighter parts:

Shimano 105 10 Spd Rear Derailleur (Short Cage)
Alex Rims 451 R390
Capreo Hub and cogset (9-speed 9t-26t)
Shimano 105 Front Hub
Tektro R556 Extra-Extra Long Reach Road Brakes
Schwalbe Stelvios

http://www.zaftig.net/gallery2/g2dat...7_21_48_50.JPG

http://www.zaftig.net/gallery2/g2dat...7_21_49_12.JPG

http://www.zaftig.net/gallery2/g2dat...7_21_49_28.JPG

http://www.zaftig.net/gallery2/g2dat...7_21_49_44.JPG

I can now officially ditch the road bike... once I figure out a solution with the front derailleur. I came very close w/ a hose clamp solution, however the seat tube is so big that the front derailleur cage starts somewhere between the big and small chainrings. I need to figure out a mounting system that attaches the clamp + derailleur somewhere just behind the seat tube similar to a bike friday mount.

Looks great!

Re the big seat tube, I have read on Sheldon's site that MTB chainlines are a bit wider than roadies' due to the thicker seat tubes, requiring the derailer to sit further out. Sounds like that is the problem here too...?

I'm also still on the derailer problem, if I get a solution I'll let you know.

I rode a 150km brevet this Saturday, and kept up with the fastest riders with looks of surprise on some faces. One guy inquired, did I have a motor on that thing? Most people look down on small-wheeled bikes as being toys. My best friend said so outright. Now I will have to get fitter to drop him and show it is not a toy. :D

Did you ever look in Japan for 40 mm derailer clamps?

2 Problems:

1. You're not using drops
2. It's not carbon monocoque

:D

That's in the original Swift thread, right? The link led to some strange anglo-unfriendly page... I'll see if I can track it down again. I was hoping to fabricate one myself that approximated it since I'm still not sure how the cable routing will work.

edit: a-ha. I see you were the instigator. I think you want me to be the guinea-pig on this... ;)

http://www.bikeforums.net/showpost.p...&postcount=509

Found this via Google. Is this the right size?

kb5ql,

I am also trying to 'pimp my ride' and like you have chosen to go with 451 wheels (R390s). However I am unable to source the R556 brakes in the UK and can't find any other brake calipers with the same reach. The The R556 caliper's reach is specified at 55-73mm. I can find plenty of 'long-reach' calipers with a 57mm maximum reach (such as R536 or its predecessor 521AG).

Please can you tell me how much into the R556's reach you actually need for using with R390 451 rims and if you think a 57mm reach caliper would do the job. From the photo it looks like your brake pads are set at the low end of the reach adjustment. If yours were only 2mm into the adjustment then a 57mm-reach caliper would

Or does anyone else out there know any other brake calipers that definately work with the swift with 451 rims?

This is probably a late response, but your Swift looks wicked scary fast! :)

Interestingly, I am using the extra long reach brakes at the most retracted position I believe. (~55-57 mm). I don't have a ruler on me right now, but a 57mm long reach set just might work w/ 451 rims. I got the long reach brakes to be safe, but you're right, you probably need just a standard set of "long-reach" brakes.

Sorry, I did not see this e-mail.

We all anxiously await the first person to put a front derailer on a Swift and talk about it ... :D

I do not recall the precise details, but I thought that the seat post tube on a Brompton is not the same diameter as the tube on a Swift (aluminum), Birdy or Dahon which are 40mm.

-G

I asked Peter Reich what the issues were with fitting 451 rims and he thought that the R556 brakes were the only ones that would fit. He also said the the bike was originally designed for both 406 and 451 brakes and at the time there was only one brake that was long enough reach: Dia Compe 'big dog'. When Dia Compe stopped making these brakes this effectively left removed the option of selling the Swift as 451-compatible. That is until the R556 brakes came out.