Wednesday, October 31, 2012

Saturday, October 27, 2012

Random musings: do bridges matter?

If you spend enough time reading old archives of the framebuilder's email list (from back in the dark days of usenet) or any of the current or defunct framebuilding forums on the web, the topic of chainstay bridges (and to a lesser extent, seatstay bridges) comes up repeatedly. There's quite a bit of debate on the topic of whether or not the bridges are necessary; and what effect they have (usually with regard to lateral stiffness).

There are two camps:


-The butter-side-up folks say the bridges are mandatory, and that frames without them will be noticeably less stiff as well as more fragile.

-The butter-side-downers argue that bridges are a historical artifact. They were first used, the argument goes, to mount kickstands and fenders and simply became de rigeur on all frames; the vestigial tails of the bike world (unless you want to mount a kickstand or a fender, of course). They often go on to claim that if anything, the bridge serves as a stress riser and makes the assembly *weaker*.

If you're really bored, you can google it up and read on and on.

Of course, like most internet arguments, the question never really got resolved. I generally don't use chainstay bridges unless specifically asked, so I guess if anything I'm the "it doesn't matter" camp, but I'm hardly a serious partisan when it comes to bridges, so when I recently realized that a natural experiment had occurred, I was pretty pleased.

The root cause of this was my own laziness - I recently built a super-fun cargo bike and was, as usual, too impatient to really *finish* the frame before riding it. I left a lot of things unfinished but notably for the last several weeks I was riding the bike around (with some pretty big loads, too) with *no chainstay or seatstay bridges*. The bike rode, well, fine. It's long and gangly and doesn't get around tight corners well, but when mashing the pedals to haul dogfood up the hill to our house, I didn't notice any untoward flex.

Fast forward to Wednesday, when I installed a HUGE (2" wide 1/8" thick plate!) chainstay bridge and a seatstay bridge as well so that I could park the bike and not get my butt all wet (both good things). At the time I wasn't really thinking about their potential effect on the riding characteristics of the bike - I just wanted to be able to park it. So theoretically, I was pretty unbiased or at least had minimal expectations going in.

Did I notice a great improvement in lateral flex? A now rock-solid ride? In a word, no. In fact, the effect (if any) was so far below the threshold of detection that until I started thinking about the issue this evening I did not even realize that I'd just done what might be (short of some kind of true double blind with hundreds of different riders) the perfect experiment. Consider:

-The bike weighs 60 pounds and often has me (150#) and a decent load (80-100#) onboard. There's a LOT of force trying to make every part of it flex under those loads.
-Other than the bridges (and fender/kickstand) there was no change in ANY other aspect of the bike's construction or geometry. Just one variable changed.
-While I'd never claim to be unbiased, I wasn't doing this intending it to be an experiment and didn't really have any conscious expectations going in.

Bottom line: at least in this case, bridges don't matter much. That's not to say they never matter, or that it's somehow wrong to want them on your frame. But next time you get into beef with someone online about the subject, send 'em here.

Friday, October 26, 2012

Pictures and words from Mark


Man, the Shenandoah 100 sounds hard. And it looks hard too.

Before/after pix courtesy of Mark, who writes:

A quick note on my bike. 

Wonderful. 


Marvelous. 

A pleasure to ride. 

As you can see in the pics, we went to Shenandoah back in September. It was wet. It was muddy. And the bike kept me going, no mechanicals and a front end with steering that was easy to handle all throughout my 10:29 finish. Climbing was great, even on the Death Climb and other various and sundry rises. Carving the single track was sublime, nothing unexpected but rather nice and predictable. 
Kudos and huzzah, thanks for a great frame!


Tuesday, October 23, 2012

Sick day #5 - Cargo Bike!


Yes, I still have the flu, so I'm getting my MTBR/blogger overdose for the year. Some of y'all will find this interesting (I've also posted it on the Cargo Bikes board), some not so much. Huge shout out to Eddie who basically walked me through all of the difficult parts and saved me from some (thought not all by any means) of my inevitable screwups.

Just thought I'd share this since it's (almost) done now. I recently moved my shop to SLC and needed a "break in the tools again" project to do that would allow me to make sure everything was set up and working right. Since I make it a point not to drive my car unless I absolutely have to (it's a 2002 with 50k miles on it, so I've done ok, I guess) I figured a long john would be a fun thing to have (in Boulder, I just used our Chariot and/or a backpack to haul stuff around) so I built one.

And it basically does just what I wanted it to, plus I learned a lot building it. If anyone is curious I'm happy to post some specs on tubing and geometry and such, just ask.

Having ridden a bunch of different cargo/utility bikes, I can happily say that this is by far my favorite configuration. Heavy loads are much, much easier to deal with than rear-loading setups because they're carried so low, which is important for me since I'm usually doing stuff like getting ~80# argon tanks from the welding supply or making runs to Costco for dog food or whatever. The bike is super stable with a load, handles nicely at both low and high speeds, and also gets lots of attention from other cyclists and motorists, which is always fun.

That said, there's a bunch I'd do differently if I built another one, and I'm sure as I spend more time running errands I'll find shortcomings that need to be addressed.

Stuff I really like:

-The bike can pretty easily (note the HUGE stack of spacers) be set up for anyone from about 5'2" to 6'4" or so by moving the seat and swapping stems/raising or lowering the bars. This is a feature that my friend Eddie designed into his long johns which I blatantly copied. Standover is about 27", and it could easily be lower, but both my wife and I have very long legs (36 and 34" inseams) so it seemed pointless to make things more compact in this case.

-I can carry really heavy and/or bulky loads pretty easily. I've put lots of attachment points on the platform for tiedowns or bungees and the anti-skid diamond tread material works really well to keep things from sliding around.

-The ride is surprisingly comfortable with a 20" front wheel, simply because the bike is so long that the keel can flex a little bit and smooth things out. I've been running pretty high (50-60 psi) pressure and thick thornproof tubes and have been quite comfortable even on rough pavement.

-Everyone who sees it loves it. Kid trailers and even big dummies are pretty common in SLC but I'm not sure anyone else in town has a long John, so I get to spend a lot of time talking to people about it. This may end up being less fun after a few months, we'll see. I think the bike will be a good rolling advertisement, which is nice.

Now, the bad:

-I suck at woodworking and don't really anticipate putting my son on the bike for at least a few years (he rides in the chariot right now) so I made this a dedicated *cargo* bike. You could probably build a seat/box like a CETMA and bolt it on, but this one is not very modular. In other words, if you want to haul your kids or drunk friends home from the bar, this isn't the best configuration and it would be somewhat hard to change that. Maybe I'll do something a little different for #2.

-The push rod that steers the front wheel is a bit ugly, because I put the bend too far back and didn't make it tight enough. I'll probably do another push rod at some point but it's hardly visible under the cargo platform and works fine, so maybe I'll just resolve to do better next time.

-Next time I will put a coupler in the middle of the keel so I can break the bike down to store or move it. It takes up a TON of space and is very heavy and awkward (probably ~45 pounds) to hang up in the garage, though it can be done. Luckily I think I have a good spot to park it on our front porch. If/when we move next, I'll have to make some hard decisions about what to do with it, as it's going to be quite hard to transport.

-My last-second decision to decrease the offset on the fork means that there's very little room at the front for a fender between the tire and downtube/keel. Gotta do better with that next time (a little slacker on the HTA and a little more fork offset). Thanks to the fact that I've bolted a big plastic box to the front of the cargo platform, I basically have a fender anyway, but soaking the box every time I'm riding in the wet isn't ideal (I don't think the contents will have a problem, though).

In any case, long story short I really like this bike. It is going to save me from a lot of driving and hauling heavy loads on it is a breeze. Plus it's just fun to ride around with 80 pounds of dog food and impress/horrify all the people at Costco.

So if you're considering a long john, I say go for it. I really think it's a lot more practical/fun than the alternatives if you're looking to deal with heavy loads on a regular basis. For those who just want to transport kids, maybe not as ideal (though once I get my act together to do another one with a box and seat, who knows).

Oh, random notes:
-Bridges for the fender and kickstand aren't on yet. I should have time to do those this week. I have a cheapo roll-back kickstand coming that may or may not suck.
-The cable routing for the front brake (which is IMO mandatory to have for what I am doing) was not finalized yet when I took this photo. If you look closely you can see a bunch of electrical tape and zipties. Very professional!
-I'm going to have her powdercoated this week, I think. A nice sky blue.
-Box is just a random one I had sitting around. It's bolted onto the platform with 3 M5 bolts (there are tons of water bottle bosses all over the place on the platform).


Will I offer Long Johns for sale? As of now, the answer is a qualified "no". I need more experience with this (and time on the bike) to see what I need to change. As of now, I don't consider it a professional product and and as such I won't sell them. If, however, you live in SLC and would like to borrow the bike and give me feedback, then serve as a guinea pig for #2, I might consider it. If you're not local, no way, at least for the time being. Cost would be somewhere around $2500 for a complete bike similar to what is shown here (but obviously powdercoated and with fenders and such).

Monday, October 22, 2012

Random announcements: forks

I am way too sick to do useful work in the shop today (and managed to be bedridden through the entire nice Indian-summer fall weekend that we just had, darnit) so I'm updating some random pages on the website.

News! Some changes to custom forks:
-I'm now offering a 1.5 steerer (note that this is NOT a tapered steerer - it is 1.5 all the way up) for an extra $75.
-For those interested in running a rigid fork on their frame designed for a tapered steerer, I recommend a King adapter baseplate ($20). I'm happy to install one on your fork before it ships, and you'll be able to swap back and fork with zero hassle.
-Road forks (with segmented/tig welded crowns) are now available.
-24mm axle (Maverick hub) option is now available for an extra $75. 
-Pricing has not changed ($300 without a frame or $250 with) for the base model custom fork.

Apropos of nothing, here's a picture Matt sent me of his bike in the Laguna mtns. 


Sunday, October 21, 2012

Weekend.... RECIPE?!?!

Yes, it's back. The dreaded (by those of you who like to read about bikes) weekend recipe. It's been too long!

As an aside, I had no idea, prior to this weekend, how much having a sick family makes it impossible to get any work done. Wow. Whole new ballgame when there is a kid involved.

Anyway.

Waltworks Quinoa Pie!

-Cook up a cup (uncooked) of quinoa. While you're waiting for it to cook....
-Peel and cube up a small (or half of a medium) butternut squash. Put the cubes in a tupperware full of H2O and nuke in the microwave for 15 minutes.
-Chop up a bunch of fresh sage (20-ish leaves), a small onion, and 5 cloves of garlic in some olive oil. Saute them until the onion is nice and transparent.
-Grease up a 10" pie pan.
-Mix everything up and add a couple of eggs to hold it together, plus some black pepper and salt if you want. Oh, and a cup of finely grated Romano cheese.
 -Dump it in the pan and bake for 20 minutes at 450F.

Super, super good. Seriously.

Friday, October 19, 2012

Family sick day

Sarah, the Bean, and I are all a little under the weather today, so I won't be getting any work done probably. Just FYI.

More pictures of Chris' bike tomorrow and some geometry geekery.


Thursday, October 18, 2012

Chris

Some in-progress pictures while I wait for the temps outside to climb out of the 30s (wow, I'm really not ready mentally for winter!)

Geometry data to follow at some point, for now, just a few photos.


Subtle seat tube curve - just enough for tire clearance. Note the insert for 27.2 post that will be welded in. You've gotta use an oversized seat tube if you want to curve things (or else accept that your post won't go in very far) so this is typically the way I go for curved setups. The seat tube is a nice 1/7/1 Supertherm from True Temper.


Front end almost ready to tack up.


Weight loss surgery for sliders - that's way more tab than I need to TIG 'em, saves 40 grams or something and makes my right arm huge from the hacksaw work...cutting stainless is a pain! Note that the inserts are all gunky and semi-burned looking because they're the ones I use to hold everything together while mitering/joining the stays. So they've been though a lot over the years. Chris will get shiny new ones to actually build up the frame and ride on.

Media coverage?

For 36er tires? Really? Now everyone will think I'm an even bigger weirdo than I actually am...

Yep, amazingly Bikerumor published a little blurb about the tire. Neat! Of course, I think they'll basically publish anything.

Monday, October 15, 2012

36er tires - Order now

Tires are in stock and shipping within 1-2 business days of your order!

PLEASE NOTE that the production tires came in heavier than our preproduction samples. Approximate average weight is 1625g.

-Cost is $125 per tire.

-Shipping costs are included for residents of the lower 48 states.

-If you live outside of the continental US, please DO NOT ORDER using the buy it now button. Contact us for a shipping quote and we will send you an invoice.

-If you wish to purchase a large quantity of tires (10+) please contact us for a quote, we may be able to save you some money on shipping








Vital statistics:
Size: 36" x 2.25"
Weight: 1625g +/-40g
Tubeless Ready: Yes
Max PSI: 65
Bead: Wire
TPI: 36
Durometer: 60 Shore A

These tires are significantly lighter (you'll save more than a pound per tire) than the competition, which help you accelerate more quickly and reduces the weight of the wheel at the rim allowing for faster/longer rides with reduced effort.  They are tubeless ready and setup well allowing for lower pressure and more grip. Bicyclists have found 18-23psi to be a good range while unicyclists have gone a bit higher to 32-40psi. 

Tread pattern lies between a Kenda Nevegal and Schwalbe Racing Ralph in terms of tread depth and design, creating good grip across a wide range of terrain and conditions while maximizing speed off-road and on.  Tapered and ramped center knobs along with ramped transition knobs provide traction and control, while tie bars connecting the triangular transition knobs to side knobs help with cornering.

Friday, October 12, 2012

Speedy delivery!

 

For the record, Andrew's fork is the first item delivered to Fedex by the cargo bike.

It was a less than glorious run, since I forgot to tighten down the pinch bolts on left crank arm, and as such it fell off halfway there... but it's a start.

Monday, October 08, 2012

Humble beginnings

Sarah just found this - the first thing I ever "welded". Done with a cheapo MIG in 2002 or something, at the CU physics department shop. I gave it to Sarah as a gift the same day. She was quite impressed, as I recall...not.





Fun stuff.

Friday, October 05, 2012

A fascinating look at framebuilding - with numbers!

A fellow in the UK named Matt Wilkinson did a neat survey of US framebuilders (I was not surveyed) recently and I thought I'd post some of the more interesting bits. For those who want to read the entire 45 page thesis (? I'm actually not sure what genre of writing it is) you can read it here:

http://www.wcmt.org.uk/reports/891_1.pdf

Following are some of the more interesting survey responses, presented without comment. Maybe I'll post some reactions tomorrow. Click on the images to see them bigger/clearer/actually legible.




At the trough


                             Healthy appetite. Terrible table manners. That's the Bean...

Thursday, October 04, 2012

Damon

This was was fun and unusual, simply because it's a 650b and so I spent a lot of time double checking things (can that chainstay angle really be right?) because I build 90% 29ers, so my intuition about where things should go and how things should look isn't always right for 26 or 650b setups.


Building 29ers all the time does make building for smaller wheels seem super easy, though - I'm used to absolutely *cramming* in the tire, chainrings, chainstays, seat tube, etc to make everything work right with the big wheels. 650b almost feels like cheating - minimal manipulation necessary to get the rear end clearances needed, no worries about fitting a front derailleur and having it interfere with the tire, able to easily run any size chainring Damon wants - I've opined before that 650b is great, but man, it's also a dream come true from a builder's perspective, at least if you're used to doing 29ers!

Anyway, here's the geometry breakdown:
-71/73 angles
-For a 100mm travel (can't say what, it's officially a no-no!) suspension fork
-59cm ETT and 62.8cm front center
-30.5cm/12" BB height
-42cm (actual, 41.7 effective) chainstays
-Plenty of room for 2.3s or so
-S-bends, guides for full length housing

The intent is to make something a little shorter/snappier for his trails (he rides a 29er I built him 7 years ago, before the advent of things like direct-mount front derailleurs and long-offset forks made modern snappy 29ers possible). His body type and trails are IMO pretty much perfect for the 650bs, so I'm excited to see how he likes it.

Tuesday, October 02, 2012

SRAM XX1

...is available to me for preorder now, for November (supposedly) delivery. If you are a frame customer and you're interested in this (warning, it is not cheap) kit, please email me for details.

I am personally pretty excited about the idea of ditching the front derailleur without giving up a super wide gear range. I am not so excited about the cost, but I bet some of you early adopters out there won't blink an eye.

If you're not a frame customer, sorry, I can't help you out, please don't bother me.