I’ve been thinking about product testing these past few months as I’ve been doing a lot of work with disc brakes on road and cross bikes. The process is simple enough I suppose – come up with an idea and see how it works. The tough part relates to the time involved. In the case of disc brakes I’ve been riding them for a few months now in this snowless winter and beating the crap out of the entire system. I rode them without issue for a few months before even mentioning discs in public because I wanted to have preliminary testing done and out of the way first. But this won’t tell me how well they will last in the long term and if design changes will need to be made to make sure they are safe for a lifetime. So to that end I will be using them for the next year, give or take, before any orders I’ve taken for them come to the front of the queue. In the end they will have more than a year of hard use and abuse and tweaking before I even consider selling them to a customer.  The prototyping of the original JKS was the same way – about a year of testing and tweaking before the first customer ever threw their leg over one. The same thing with the JKS X – about a year of constant hard use and testing before a customer gets one. Being sure and getting it right takes time.

Lately I’ve read some things online about new tubes, tube shapes and fork blades being made available to builders and I wonder aloud if any of this stuff is being tested by the builder before it is offered to the pubic. I think much can be assumed by considering the design of the tubes and the material being used but only real world testing can make the builder sure everything will be OK in the long run. I’ve even heard some builders say that the tube sizes don’t matter in terms of ride quality, stiffness or strength and that the tube sizes are best chosen to match the aesthetics of modern components. I’m all about stuff looking right and agree that tube size changes the look of the bike (sometimes for the better and sometimes not IMO) but these aren’t hemlines or tie widths we are talking about – they are structures that behave a certain way based on the overall design and the materials used to realize that design and we trust our fun and our lives to these structures. Tube size and shape change the ride of a bike – period – full stop. This is not my opinion but simple structural, mechanical and mathematical fact. This can of course be a good or bad thing but one thing is for certain – changing the size/shape of the tubes will change the bike and the way it rides and lasts.

The frustrating thing about this to me is that the builders would know this if they built one and rode it. But for some reason they don’t and think that because they think the big tubes look cool with modern cranksets that that is more than enough. I couldn’t disagree more. Products should be tested first. They should be proven to be the proper stiffness for the intended rider and use, to be strong enough and tough enough (strong and tough are two very different things) and to be safe. If after all that it gives the look the builder is after then that’s gravy. The idea that this is being reversed and that bikes are being designed and built with the look being the most important thing makes me think that the person who came up with the ‘no white after Labor day’ rule should be a tube/bike designer………or maybe not.

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Karin and I are in the middle of a slight revamp and remodel of our website and I’ve been putting some thoughts into words over the past few months when the mood strikes me. One of the pieces I’ve written is about my history with product testing and how it affects my product design. I had the luxury to learn proper testing protocol while working at Serotta years ago and it’s this experience that I draw on for my current product testing. This piece will be put into the site and no doubt edited a bit before it ends up in a semi-permanent spot but I will include it here now in its first draft form to give you an idea of what I’m talking about.

One closing thought……….please do not shy away from asking the builder of the bike you will trust to be safe and ride right to tell you how the product was tested before they sold you one. Bike design is not just a matter of fashion and the builder should know more than it looks cool.

Thanks for reading. The ‘testing’ article is below.

Dave

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Testing –

I’m very proud of the design, materials and processes I use to make my bikes. These have all been developed in the light of things I learned over many years of building and testing of bicycles both on my own and when I ran the R&D/testing program at Serotta. I think it’s safe to say that Serotta has probably done more testing of their products than most any other small company – and I am proud to say I played a large role in that early testing.

After working at Serotta for a few years I transitioned into the role of custom builder and the next logical step was to build and test new products we wanted to offer for sale. This all sounded great but there was little info out there pertaining to acceptable safety standards for bikes and nothing out there that we’d ever seen pertaining to performance standards. So when it came time to build and test prototypes of new stuff we started with a blank slate.

One of the first products we wanted to test was a new carbon fork Serotta called the ‘F1′. It was one of the first carbon forks designed not to just be lighter but to perform better in turns and braking and of course in terms of safety. I was enlisted to help finish the fork’s design when the engineer in charge of R&D left the company before completion of the project. I worked with the composites house to help design and finish the mold used to produce it as well as test the safety, durability and performance of the fork.

What I needed to do was design a test rig that would put the fork through its paces in a safe, controllable and repeatable manner. This meant taking it out and riding into curbs until it broke was off the menu (thank goodness) so I constructed a testing table to do the dirty work. The test table held the fork by the steerer and pushed back and up on the front hub with a pneumatic cylinder with preset and adjustable load. This allowed me to test three things – the deflection when subjected a given load (stiffness), the ultimate strength of the fork (by turning up the load until the fork failed) and the fatigue resistance of the fork (testing at a low load but with a very high number of reps until failure). All good things of course but without some numbers to compare things to the results would mean little. So we set benchmarks by testing forks that had been shown to have low failure rates out in the real world. I tested Serotta’s traditional steel fork as well as carbon forks from most every major manufacturer on the planet. We learned a lot by doing this and it set a consistent and high standard for Serotta’s new F1 fork.

The F1 did pretty well right out of the box in its first iteration. We tweaked the design and it got better and better and got to the point where it was stronger and tougher than even the best steel forks. One of the things we ended up changing was the adhesive used to bond the fork tips into the blades. I’d wondered how hot it got in a trunk of a car and after placing a thermometer in a black car trunk and seeing how hot it got (up to 150°!) I developed the ‘black car trunk test’. I worried that the temperature would get so high that the adhesive would breakdown so I made an oven type device that was placed over the test table so that I could run the fork test at 150° F. Sure enough the adhesive softened and we saw failures where the fork tips were bonded into the blades. A change of adhesive kept those riders who left their bike in the trunk of their car all day so they could ride right after work safe. It was a very good lesson learned. In the end we tested and broke over 160 F1 prototypes before a single one was sent out the door and the real world failure rate was extremely low. Even after the fork was introduced I would pull one out of the bin every few weeks and put it in the test rig and run it until it failed just so we could be sure that something didn’t slip or change over time that would affect the end results.

There is of course more than one type of testing that is important and while safety is paramount it’s a moot point if the fork doesn’t perform as it should. Being a racer and having ridden more different bikes than I could count gave me a good basis to compare different versions of the F1 to one another and to other forks on the market. So I rode all different versions of that fork – some were wonderful and others not so much. We tweaked and fine tuned and I’m proud to say came up with one of the best riding and handling forks of its day and I’d even put it up against the forks of today.

In time the testing program greatly expanded from forks to frames, framesets and stems. I made a modular testing system so I could do all of it on the same test plate. I ran tests similar to what was done with the forks – we bought all kinds of frames (different brands, models and materials) and broke them. After they failed they were cut up, measured and analyzed. I cataloged the results and then set about making sure Serotta’s products surpassed the level of its competitors. This was not all that hard frankly once the standards were set and you could watch the frame fail in front of your eyes on the table. Make the tube butts a bit shorter or longer, change the shape of a lug, braze or weld it differently…all these little things changed how the bikes lasted in the fatigue tests and in time we were able to set a new standard of strength, toughness, durability and safety. The simple changes we made to improve the product would never have been made had we not done the testing that had shown the weak links – it’s hard to improve things unless you know the areas that could use improvement.

The other aspect of testing was performance testing. There are no hard and fast numbers when it comes to performance testing – no clear pass/fail in most cases. My job was to come up with new designs and take them out and ride them to see how they felt to me and then tweak them and reevaluate. It seems like a never-ending cycle but in time certain things became clearer and the focus narrowed. Some things were very straight forward – like – does the Ti road bike ride better with or without a chainstay bridge? It would save the company real time and money if the bike worked as well or better without that little piece of tube welded in between the chainstays so it was worth testing. Build the bike without the bridge and ride it for a few days and then tear it down, weld in the bridge, build it back up again and ride the same roads and hills I did a few days prior. It was much better with the bridge. Other things were less clear. Steering geometry was one of the less clear things and frankly there is a lot of personal taste and preference here. With something like the chainstay bridge it was obvious and I doubt you could find anyone who’d prefer it without the bridge but determining what head angle, fork rake and trail we wanted to use was less black and white. In the end it was decided to make bikes that pleased us first and foremost and then let the chips fall where they may.

The same thing was done with tube diameters, wall thicknesses, and shapes. We tried different brands and alloys and custom mixes of tubes and I got to do a good bit of the testing. I loved this part of the job. It meant going home with different bikes made in my size and riding them hard to see how they felt. At first it was hard to tell the difference in certain things but in time one develops a feel that they can trust. In a way I think it might be like wine tasting. With time and attention one really starts to recognize and appreciate the differences.

I learned much during that intense time.  I didn’t realize then that I was doing work that wasn’t being done at other small companies – in fact I figured they all did this – but I was wrong. Very few did anything more than build something and ride it around for a bit before selling it to the public………and some didn’t even do that – they would just build it and sell it and the first time they were ridden was by paying customers. The wonderful thing it did for me was to teach me how to design both frames and frame components, and build in a way I would never have done without going through this long process. It also let me ride many bikes in many different configurations and it was through this process that I was able to develop a feel for how small changes can make profound differences in the end product. I was fortunate to be given a big task, have it well funded and then let loose to get the job done and learn as much as I could. It was a lot of fun and the knowledge and experience I gained at that time helps shape the bikes I build today.

I’m bringing 3 bikes to this years NAHBS and here are a few shots of the 3rd. This one is a JKS X with the optional Terraplane stays. It’s a dedicated Di2 frameset with fully internal wiring and under the c-stay battery mount for quick and easy battery removal/recharge.

The frame is of course built up with Shimano Dura Ace Di2 and it has a Deda bar/stem, Fizik saddle and carbon post (currently one of three 30.6 mm Fizik posts on the planet) and Lightweight brand wheels. This bike, like the Red Bike, is on loan from it’s owner for use in the show and I very much look forward to getting it to its new home directly after the show. It’s about time this bike gets ridden hard.

Please stop by my booth, #413, if you attend the show and take a good look at this and the other bikes. I’m afraid my photography skills fall behind my framebuilding and JB’s paint skills so the bikes always look better in person than they do in photos…………..and I think they ride better than they look……which to me is by far the most important thing.

Thanks again for looking – see you soon I hope.

Dave

The good folks over at Bike Rumor have been doing a series of interviews with different builders headed to NAHBS and my number came up today. Check it out here -

Bike Rumor – Kirk Frameworks

While there take a look around and check out the rest of their stuff and the other builder interviews. A good way to spend some ‘work time’ not working. I won’t tell your boss……….

Dave

I’ll be putting the bikes into the crate and sending it off to Sacramento tomorrow and thought it’s about time I post a few photos of them. I know some other builders like to give a tease and not show the bikes before the show and I understand the motivation………..on the other hand I doubt your seeing them here will stop you from walking into my booth to see them in the flesh so it seems more than worth the risk. Couple that with the fact that even though the show will see about 7000 folks walk through the gate to see the bikes and that leaves more than a few billion who won’t be there but do have internet access so these photos are for them.

You’ve seen the raw fillet bike already so it’s time to check out the Red Bike. It’s a JK Special Classic all built up with Campagnolo Super Record, 3T bars/stem, Fizik saddle and post and Fulcrum wheels. It has a one off paint job by Mr. Bell and it a custom mixed red just for this bike. The frame is of course made-to-measure for the customer (as they all are) and features Llewellyn lugs, Reynolds tubes (953 main tubes and Kirk by Reynolds stays), Kirk Triple F dropouts and my special hand fabricated hollow side-tack seat stay caps.

I look forward to showing off the bike in person in the booth (number 413 by the way) and then to sending it off to it’s new home once it gets home.

Thanks again for looking,

Dave

Prep for NAHBS is winding up and the new bikes will be going into the crate and off to the west coast early this coming week………..and I have the new wheels made just for this bike by the good folks at ENVE. These will be really fun to flog through the mud and NOT grind away the sidewalls every time I need to slow down.

I have the new bikes back from paint and all built up and I’ll post some photos of them soon.

Snowboarding tomorrow!

Dave

Have I mentioned that it’s NAHBS show season? Something tells me I may have brought it up. Well this time of year is largely consumed by getting ready for NAHBS – making reservations, arranging shipping, putting bikes together, checking out the booth…..etc. More than enough to do.

One thing I needed to do was to modify my ‘booth in a box’ that I used for the first time last year. It seems that the powers that be at the show changed the rules concerning how one can use the spot they paid for at the show. I buy a 10′ x 10′ spot (the smallest) and my display was designed to pretty much fill it. When I built the booth there were no rules about how one could use their space and after a few years of having my booth neighbors set up something tall and wide, blocking the view of my booth from the isle, I decided I needed to provide my own backdrop so the backside of my neighbors booth wasn’t what was being looked at from my space. So that’s what I did and last year I ended up being ‘that guy’ who blocked out the next guys booth. Bummer.

The new rules for the most part prevent this from happening and I feel are a good thing. The only bummer was being informed of the new rules about a month before I needed to load the booth in a box onto a truck. I think there will be many who have not seen or been told about the new rules and this can only cause friction. All the above meant that I needed to redesign my display so it could be set into the space, meet the new rules and not bum out my booth neighbor and friend Nick Crumpton. I think it came out OK and I was happy to be able to salvage all the time and money I put into the booth a year ago. Done and done.

I should have the two painted framesets back from JB tomorrow and will hang the parts on them as soon as they arrive. They they go into the box and onto the truck. That will feel really good.

And then I can take a day off! I’m excited for that.

Here are a few shots of the booth taken in very tight quarters in my basement. It has on the the show bikes in it (raw fillets with new Enve disc wheels) and other bikes that were hanging on hooks down there.

I hope you all can come by the show. It’s worth the trip.

Dave

On the heels of yesterday’s disc brakes for road comes today’s disc brakes for cross. If ever there was a screaming need for discs it’s on a cross bike. I promise that today’s entry will have many fewer words and lots more photos.

This is my 3rd and final show bike for NAHBS and it’s my personal cross bike for the 2012 race season. It’s made with a mix of OS and XL tubes and all the main tubes are Reynolds 853 Pro. They are all filleted to my special Kirk by Reynolds chain and Terraplane seat stays. It will be shown as is, in the raw and ready for paint, and as soon as I get it back from the show it will go off to JB so he can work his magic.

I’m excited by the wheels I have coming for this bike – Enve carbon with DT hubs, 6 bolt disc mounts and 135 rear spacing. Should be tough and light and kick butt on the rough stuff and in the mud – especially without having rubber blocks grinding the sidewalls of the rims away during muddy events.

I’ll shut up now and let you look at the photos – 201 words today – not bad!

Dave

It has been the longest fall I’ve ever experienced with very little snow here in the valley and warmish temperatures. This has really not done the skiing any favors but it’s been great winter riding weather and perfect for product testing. This soft and friendly weather has allowed me to move ahead on the testing of disc brakes on my road bike that I hadn’t planned on doing until spring.

So – I took the plunge and had the good guys at Joe Young Wheels build me up a set of wheels using DT rims and DT 6 bolt hubs – the rear being spaced at 135 mm. I then got to work and made some custom disc brake tabs to work with my frame and fork design. The designing of the tabs was the time consuming part as there are many considerations in getting it right – they need to be stiff enough both laterally and rotationally, they need to be light, they need to distribute the braking load well and they need to be attractive. After cutting them from steel plate I dove in and ruined an otherwise perfect paint job (sorry Joe Bell) and fillet brazed them in place. I didn’t bother doing any finish work or polishing as I just wanted to see how the set up worked and thought I may just end up removing them anyway.

Now I can hear the mix or reactions out there right now and imagine they range from “very cool!” to “no one needs disc brakes on a road bike!” and for what it’s worth I was thinking both of these things myself at first. Disc brakes have been around in the larger world for a very long time. They were first made popular by Dunlap on the Jaguar C Type of 1953 after having been proven on aircraft. Discs have been in common use on mountain bikes for a solid 15 years now and the bugs have been worked out of the system. So when the UCI approved discs for use on cross bikes recently I could very easily see a further cross over to road bikes.

What advantages does a disc brake have over a traditional rim brake and what are the disadvantages? I’ll jump right to the disadvantages -

* disc brakes add weight – how much depends on what type of brakes you are replacing. The disc caliper is a bit heavier than most rim brake calipers and there is a disc rotor for the caliper to grab that you otherwise don’t need. It’s not a lot of weight but there is some.

* disc brakes require ‘bedding in’ – when you first set up a disc brake in the work stand they seem to work well and then take it out for a test ride and to be frank they dont’ work very well…….at least at first. Disc brakes require heat to bed the pads to the rotors and until this occurs the braking power is just not there. It takes just a little bit to bed them in and I did it on my bike by going down a hill near my house dragging the brakes until they got really hot. Once this happens the braking is sublime.

* disc brakes require different skills to set up – when you think about it a rim brake is really a big disc brake with the rim doubling as the braking rotor. A disc brake works the same way but the braking force is applied to a small rotor bolted to the hub – you squeeze the lever and the disc pads clamp the rotor and the bike stops. The real difference in setting the two type of brakes up boils down to how one sets up the disc caliper on the frame/fork. This technique will be specific to the brand of brake used but with the Avid BB-7′s I’m using right now it could literally not be easier. You leave the two main caliper bolts a bit loose, squeeze the brake lever to align the caliper to the rotor and tighten the bolts and you are now 95% of the way there. All that’s left is to spin the two dials to set the pads the right distance from the rotor and you are done. I see this as less of a disadvantage and more of something new to learn. Once you learn it I think it’s as easy and quick as dealing with a rim brake.

Advantages -

* disc brakes are safer on long fast descents – The issue with rim brakes with long downhills is that they heat up the rim and this in turn heats up the air in the tire and increases the air pressure. Not a big deal on regular hills but a very big deal when riding in the high mountains. This increased air pressure can lead to the tire blowing off the rim or in the case of carbon rims can cause the rim to fail. This is rare frankly but it does happen. You can also have your rim glue holding on your tubular tires soften allowing the tire to roll off. We saw this a number of years ago in the Tour when Beloki hit a patch of goo on the road on a fast downhill that had lots of braking. His bike slid in the warm tar and when it hit the grippy stuff his tire rolled off and it effectively ended his career. Again – this is very rare but it’s something that those of us that ride in the mountains now have to keep in mind and manage.

* disc brakes work in all weather conditions – the issue with rims brakes in the wet is well known. The problem is that the braking surface is right down next to the wet road constantly being doused with water. Add road grit and oils and the braking can be downright bad. Discs on the other hand are up and out of the road slime and since they get hot almost instantly they burn the water off the rotor within a single rotation of the wheel and you get the same braking you get in the dry. Think of how well your car brakes work in the rain. Hit the pedal and stop. Bike discs are the same way, even in the wet.

* disc brakes don’t wear out your expensive rims – normal rim brakes grab the rims with pads and grind what ever dirt and grit on them into the rims. This in time wears the brake track of the rims and can actually wear the rims out. This doesn’t happen often with aluminum rims but it’s all too common on carbon rims.

* disc brakes don’t care what size tire you run or if you want to use fenders – A rim brake has packaging issue around the tire. You can only run a tire so large under a short reach caliper brake and fenders can be difficult to fit unless the bike is designed for a long reach brake. A disc brake doesn’t care what size tire you use. If the tire fits in the frame/fork it will work. You also have the added benefit that you don’t need to quick release the brake to remove the wheel – just undo the skewer and the wheel drops out.

* disc brakes don’t care if your wheel is true – with a rim brake a broken spoke can be a minor pain or make for a long walk as the rim won’t spin between the pads. With a disc brake the wheel will turn as long at it clears the frame.

* disc rims can be lighter – this is an as yet unrealized advantage. Rims designed and made without the need to have brake tracks will end up being lighter. The rim brake type rim needs to have a flat surface for the pads, needs to be able to deal with the compressive force the brakes apply to them and needs to act as a heat sink. A rim designed to just hold the tire will be lighter and the word on the street is that we will see rims weights drop soon for disc wheels.

* disc brakes have the best modulation – this is the BIG one IMO and more than enough reason on its own to consider discs. Most types of brakes, rim or disc, will provide enough power to lock the wheel when dry but a disc brake will provide much better modulation. This may not seem to be a big deal until you try it for yourself. With a rim set up you can have a hard time feeling what the tire’s contact patch is don’t on the ground and how close it is to locking up. With a disc you get much better feedback and consistent braking power and this allows you to carry more speed  deeper into a corner and then brake later and harder. This means you’ve got a longer distance at a higher speed and in the end you will get to the bottom of the hill sooner than you would have with rim brakes. Cars and motorcycles have been working on brakes for a very long time in order to carry more speed deeper into a turn but it’s rarely talked about on a bicycle. I think we will see that change as road discs become more common. One thing I can’t over-stress here is just how much fun it is to do this – barrel into a corner and then drop anchor to get to your corner speed instead of feathering your rim brakes to keep speed in check all of the time. There are very few things that can actually make you faster on downhills and discs are one of them.

According to my word counter I’ve put down 1539 words so far and that seems like enough but I have a few things to add. I don’t think you are going to die in a great flaming crash using rims brakes the next time you go down a hill and I don’t think discs are for everyone. If you live in a place without steep long hills and you only ride in the dry then I doubt you would see much advantage to having discs. I spoke to a friend the other day who said he only needs enough brake to not his his garage door when he gets home from a ride and I understand that. But if you ride in the wet and/or in the mountains I think you would enjoy the advantage disc brakes give. I’ve been riding mine for a few months now and abusing them big time and I’m very pleased and can’t picture going back to rim brakes on either my road or cross bike. One thing I feel confident in saying is that Pro Tour guys will all be riding discs in the next few years. The advantages will so outweigh the downsides for them that it will be a done deal and we will see safer descending in the hight mountains of the grand tours. The strong rumors have it that both Shimano and Sram will be offering a high end disc set up that will be lighter and more simple this next model year. We should also see a move toward hydraulic actuation soon from both these guys and the already great modulation will only get better without cable stretch.

I will be offering disc brakes builds on road and cross bikes as soon as I can. It will no doubt be a few months down the road at least but I will offer them as an option as soon as I can. At this point I don’t know how it will affect the pricing but I expect it will be a slight upcharge. As soon as I know more I’ll pass it on.

1994 words – wow, that might be a record. Thanks for sticking with me.

Dave

I live in the suburbs. Not in the middle of nowhere but just a few miles from the center of the city of Bozeman. Now Bozeman isn’t a big city but it’s a city nonetheless and yet the wildlife in and around town is something I never get used to – and something I didn’t see growing up in rural Central New York state.

One of the common animals here is the Mule Deer. We have a lot of them in our area and driving after dark is sketchy and one is best off going slow and watching very carefully. There is a road very close to our home that has a large open field next to it and unfortunately there are often dead mule deer in the field as a result of getting hit by a car. Mule deer are big heavy animals. So with this fresh meat out there for the taking we sometimes see scavengers show up for a big meal. The other day I knew I’d be driving by so I brought the camera and sure enough there were a few bald eagles hanging around trying to get a meal while being bothered by the magpies and crows. I snapped a few shots and went on my way. On the way home we went past the same spot and saw a rare sight – a coyote right out in the open. We hear them all the time on summer nights but it’s very rare to see them. This guy apparently thought it was worth the risk to be out in the open of this huge field to get the goods. It’s interesting to note that while coyotes aren’t all that big they aren’t like lap dogs either. If you compare the size of the coyote to the rib cage of the deer and then compare the eagle to the same you’ll see just how HUGE those eagles are. They are about the size of a fence post while standing and have a wingspan of about 6-7 feet. They are awesome to behold.

So – a little glimpse into life outside of a small Montana town. It never gets old for me.

Dave

It’s once again that time of year when most of my waking hours are in some way occupied by getting ready for the annual NAHBS event at the end of February. To that end I finished up one of the 3 bikes I’ll be bringing to the show and it’s about to head off to JB’s so he can do his thing.

This is a JKS Classic with side tack seat stays. it will be assembled with Campy Super Record and 3T components and is a traditional road race bike in the finest European tradition.

Here are a few in progress shots along with some of it all done and ready for paint. I’m excited to get this painted and to hang the kit on it. be sure to stop by my booth and take a look at it in person.

Thanks for looking.

Dave