Chumba Racing VF2 / Lefty Build part 3

Today I am feeling a little like Dr. Frankenstein. The doctor, mind you, not his creation.

Bwaahhh hahhh haah ha...Its aLIVE!!!!

Well, sort of. I did install the lefty onto the frame using the adapter. Still a ways to go.

This is a closer look. You can see the upper crown of this Lefty is offset upwards. This is an option Cannondale only started to offer last year. The traditional layout is for the upper crown to look pretty much like the lower crown. The new upper crown option will allow the Lefty to fit many more frames than before. The limitation of the fork is that the head tube plus headset height must fit between the fixed spacing between the crowns.

I created this exploded view to show how it all goes together. In this case I had split the race (make a cut across it) to make assembly possible. It is hard to explain, but if the race has a bigger diameter than the adapter sleeves it must be split. Most races are either small enough or split anyway. But the Chris King race is an example of a race that is both too large and solid so I needed to modify it. It does not affect the performance of the headset.

Chumba Racing VF2 / Lefty Build part 2

The most important piece of the project arrived today, the Chumba Racing VF2 frame, a tapestry of hyroformed aluminum alloy and carbon fiber. (most images clickable).

Ooh, the anticipation has reached its crescendo.

And there it is at last. Like any new project of mine I need to analyze it to death. Which looks to be a lot of fun in this case, this frame has a lot going on. But first things first. I have to weigh it. Not because it is the most important thing, but because I need to do that before I put a single component on the frame. And the frame, fully dressed with quick release, derailleur hanger, shock and all hardware, size medium is 6.1 lbs. A full pound lighter than my Chumba XCL decked out the same way. I am very pleased with that number. In spite of all the marketing claims out there it is hard to find a full suspension frame below 6 pounds, and it usually takes some compromises in stiffness to do it. Only riding will tell for sure, but this frame does feature a lot of Chumba's stiffness tricks.

I love frames that are made with attention to detail. The VF2 does not disappoint.

Lots of frames feature asymmetric chainstays nowadays. The VF2 bottom bracket shell and head tube arrive faced, which is a nice touch. The VF2 uses Chumba's signature wide mounted pivot at the bottom bracket shell. Excellent machining and weld quality are evident throughout.

Chumba pulled out all the stops when it came time to hydroform the top tube and down tube. Their complexity cannot be captured in 2D all that well. The downtube is an amazing design. Many downtubes ovalize to match the bottom bracket shell. This one takes it a step farther: its cross section changes to allow the greatest possible contact between the downtube and the shell. The bottom transitions to a large, wide flat shape on the bottom, allowing a firm embrace on the drivetrain.

Chumba Racing VF2 / Lefty Build part 1

Today I begin the project of building my next mountain bike. It is going to be a Chumba VF2 with a Cannondale Lefty fork and a lot of new components from various manufacturers. I am going to go pretty deep with the build, I have found there is usually a lot of interest in this kind of thing.

Oddly, the starting place for my build is the front hub. The hub is made by this great little company called Project 321. They also made a Lefty fork adapter, a Lefty truing adapter and a Lefty hub cap, which we also carry. But this new hub is my favorite piece so far, at least without riding it. Weight, without hub cap and bolt: 115g. Those caps are 11g.

It has a lot of great attention to detail and is worth a close look. Lefy forks use hubs specific to the fork. They are not QR, 20mm or anything like that. The hub axle is integral to the fork leg, and the hub does a light press fit onto the axle. The result is super low flex, in spite of appearances. I feel the Lefty has less flex than any QR fork. It is in a league with 20mm thru axles. The hub a real gem. I hate to mention Chris King at all, but they are the standard here in my opinion. And this hub being made in the USA with this kind of craftsmanship begs the comparison.

What is interesting here is the way the seal is done with an extra snap ring for a better seal. Lefty hubs all seem to wrestle with the issue of getting a little better seal and this is the best approach I have seen.

Cannondale makes a Lefty hub, but so does Mavic, Crank Brothers, Shimano and others. This is how Mavic, Cannondale and some of the others add an extra seal to the Lefty hub. It is a hard plastic cover. They are known to create drag and not seal all that well.

Compare this with my Chris King headset, which will also find a home on my project. Sorry I don't have a hub laying around to compare with, it may be different. But King headsets feature this extra metal snapring around the whole bearing seal. It is an elegant way improve the seal without extra flanges, o-rings or plastic strips. And Project321 chose to go this route on their Lefty hub. So far, so good. I am waiting on much of the build, including the rest of the parts needed for the wheelbuild. I hope to start that next week.

Electric Century: 100 miles in a day on an electric bike

Since putting together my Electric Kona Ute I have been toying with the idea of a reaaally big one day ride. 100 miles, or a century ride as roadies call it. The idea is simple. You just need enough batteries. You could load a trailer with batteries on any eBike and go. You could recharge during the ride and carry less batteries, but there are only so many hours in a day.

Why? Well, yes because it is there. But more than that, I get lots of people interested in eBikes, but their objection is that the range of the bike is just too short. This is a common objection people have to electric cars and motorcycles, too. And recharge times take too long, too. So I decided the best way to deal with those objections would be to just go and and do a big ride and see what it takes.

I started by doing the math. I had almost enough battery capacity at my disposal. I figure I need a little more than 50Ah of 36V packs. If I kept a pace of about 15mph and added some pedal power it should be no problem. BUT 15mph is boring. And I wanted to include some hills in my loop, and there would be headwinds. So I brought chargers. There are 4 separate packs, which means 4 chargers and lots of charging ability. If I used 4 chargers at 4A each, I could pump 16Ah back into the packs in a 1 hour lunch stop that I would take anyway. That would increase my range and speed options a lot.

Click on images to see the full res versions in our gallery. I planned the route as a combination of well known scenic routes with places to recharge along the route. This is the route, extracted from my Garmin GPS and displayed on Google earth.

I use my Cycle Analyst and Garmin GPS to keep an eye on things as I ride (no bike computer set up on the Cycle Analyst yet). By the time I get to Cooks, this is the situation:

I am using my Ah faster than I wanted to, but there is nearly 1500 feet of climbing to get from my house to Cooks. Since I will eventually descent that same 1500 feet to get back home, I figure I am ok. Plus, Cooks is very cool and has given me permission to recharge there.


Here the bike is sucking down all the amps I can feed it. A full charge of all the packs costs less than a buck. I don't get to keep my creation out front with all the other cool bikes at Cooks. It needs powahhh. And it is very tipsey with all these packs so I prefer that it be out of the way. Besides that, it is not a Harley. Well, ok, its not even a motorcycle.

So I let it charge and have a look around Cooks. First, let have some breakfast. Good news for Cooks fans who happen to be geeks: they have free Wifi now. You don't even have to mess with a password or logging in. In other geek news, I discovered the Skyfire browser for my Windows phone. It is faster than IE or Opera mobile, it lets me browse sites as a real browser, not WAP, and it supports Active X pages perfectly so far. Even IE does not do that, ironically. And the food was pretty good too. The outdoor setting is very nice.
You never know what you will encounter at Cooks. Unless you read their schedule they post on their website, I guess. There were lots of booths being set up from bike clubs and charities, the lot was full early and the weather was perfect.

I make it through Santiago Canyon and stop for a rest at the plaza at Jamboree Road. I don't recharge the bike here, but I get myself a little energy.

I managed to avoid the glare in most instrument pics, but not this one. Still you can see my progress. Another 500 feet of climbing. The Garmin measures cumulative climbing, not net. So if you go up and down a 100 foot hill 10 times,it will show 1000ft of climbing.

The next leg of the trip was down Jamboree, then east on Portola a short distance to pick up the bike trail that continues south all the way across the Back Bay.

Did I mention is was great weather for a ride?

From the Back Bay it is a short, beautiful trip over PCH to Balboa Island. I took the ferry across the harbor to reach the peninsula...and because I love taking the ferry. The big party barge passed in front of us, but I can't really say the got in our way. No one was in any kind of hurry.

The Balboa Fun Zone was living up to its name. There was a lot of activity, including happy kids, even in November.

I passed by the second recharge station, which is in a park on the peninsula, figuring I would use it when I doubled back and came this way again. There was a big pet fair going on and the police department had a booth. There was a police motorcycle parked next to where I wanted to charge. I am still cautious when riding the electric bike. Not all law enforcement officials are aware that electric bikes are legal. And I was pretty sure recharging from an outlet in a public park was OK. But I did not want to have to discuss the whole thing with a cop if I could avoid it.

I hoped things would clear out by the time I passed back there again. I followed the coast to Huntington Beach, where I turned around. The weather was in the upper 60s. Between that and the time of the year, the beaches were almost completely empty. That used to really amaze me when I first moved to California, but I am used to it now.

So I turned around and headed back to Balboa to my recharging station. The pet fair was still going but at least the police motorcycle was gone. The Gazebo was being used for presentations and a sound board was plugged into one of the outlets. That left 3 more outlets for me and I had a power strip. But I was afraid of throwing a circuit breaker. I settled on plugging in the two of the 4 chargers. The sound system did not crash. That was nice. I retrieved some Mexican food from Great Mex - a place frequented by the locals - and joined the fair and ate while the bike charged again. Sorry, no pics of the food this time.

Then I added up the time it would take to finish and realized I would be riding in the dark. I departed and quickly made my way back to San Clemente. I had equipped my lights before I left for just this possibility. I was coming up short on miles as I approached the turn off of coast highway that would take me home, so I rode back and forth on coast highway until I knew I would hit 100 miles as I got home.

Commited to a night ride at this point, I stopped in the flagging light to assess my situation and get in a couple more pics. I figure I have plenty of Ah left. So I don't attempt to conserve any for the final miles. I finish well after dark with my trusty Light and Motion Stella 200 blasting a cone of 200 well focused lumens in front of me. That and the nice evening temps actually make the night ride portion fun, short though it was.

I finally arrive home.

Some final stats.

So my estimates were close. It took a little over 50Ah and I used a little over 18 Wh/m. And the 4000ft of cumulative climbing was more than I figured on. It required some capacity as well. I estimate I had 10AH left or so by the time was done.

I may go for it again after the Ute gets a series of changes, like frame mounted batteries and some other small stuff taken care of.

Kona Ute Electric Conversion

I have wanted to make a longbike for a while. As a dealer for Kona parts, I can get a Ute, so I decided to go for it.

The Ute is a long wheelbase cargo bike. For 2010 it comes with front and rear disc brakes. It comes as a 700c bike, but my only motor sitting around was a 26" model. I am working on lacing up a 700c motor but I don't have the right size spokes yet. So I quickly assembled it with what I had available. Fill size images can be seen in the Photo Gallery Here.

It is a work in progress, but it is rideable. It has a BMC 600W Speed (V2S) rear motor, standard 30A BMC controller and a random assortment of 36V battery packs. Even at 36V it is good for around 25mph. I have some 48V Li Ion packs on the way, I will claim one for myself, I expect a top speed of over 30mph with them.

The great thing is that there is room for a whole family grocery trip back there, even with the batteries. And there is no need to figure out a rack mount. With this capacity, all day riding and touring should be possible. I am thinking about a west coast tour ride at some point.

On its maiden voyage I just threw the battery packs in loose. I plan to try other battery mounting options as time goes on. It rode pretty well with a 26" wheel in back and a 700c in front. The big 2.35" Big Apple made the 26" close to a 700c in size. It is nice to know that monster tires do fit. And with discs front and rear you could put 26" tires/wheels on it if you wanted to.

For a later ride I did a grocery trip and came back with 4 12-packs of soda, a gallon of milk, enough groceries to fill all the bags on the bike, and I had my batteries in the bags. That was probably over 100lbs of stuff. The bike handled the load. Really heavy loads just sitting in the bags can sway a bit, which makes the whole thing wag a bit in the back. As long as I rode and pedaled smoothly everything was OK. But if I wiggled around on the bike or shook the bars while riding (remember, I was doing a test), the back end magnified it. If I had the kind of load that I could lash to the top of the deck or secure on the sides on the Ute that amount of weight would be fine.

Here are some details of the build such as it is.

I installed a nice wide mountain bike riser bar. This eliminates the upright riding position of the stock bars and is a personal preference. I am a regular cyclist (no electric assist) too, and the single sided clipless pedals seen in the crank pic below go along with that. I don't even notice the long back end of the Ute when riding, BTW. Another note is on the light. I runs on its own stock battery for now. DC-DC converter power is on the list of things to do. Any good eBike can be an endless source of projects if you want it to be.

The Ute comes with a 26-36-bash guard crank. I installed a road triple crank. But then the chain interfered with the stock kickstand, so I installed an Esge model where both legs fold up on one side of the bike. With the 11t small cog in back I have a big enough gear to allow me to add pedal power at all speeds.

The controller held in place with my version of bailing wire and duct tape: zip ties and inner tubes. It will get a better installation in time. I will do the same with the batteries, too. The BMC controller is nice, I will stick with it for now. Maybe in the future I will swap in an Infineon. But I like the 36/48V jumper on the BMC controller, and its sustained 25A output is plenty for me. Even at 36V it can handle the big hills where I live.

The bike comes with a very nice drivetrain for the price. But, as usual, Shimano trigger shifters will interfere with twist throttles. The solution is Sram thumb/thumb style trigger shifters. If an 8 speed cassette fits back there, I will install Sram Attack models. It will require extra long shifter cables, which I have at the ready.

I will post an update after making some changes to the bike.

Interbike 2009 Focus on Electric Bikes

This year I decided to focus a bit on the Electric Bikes at Interbike. There are brands that sell only electric bikes exclusively as well as electric bikes being introduced by makers of regular bikes. How popular and viable will this form of transportation be in the US? Who will sell and support them? There are many questions surrounding ebikes, as they are called, but I figured it time to have a close look at some of the products out there.

This model is a folding electric bike from Kilowatt Bikes, who brought their "A" game to the show. The battery is in the frame. I think there is a lot of interesting possible uses for folding lightweight eBikes. They can be carried along with other kinds of transportation like in the trunk of a car, in an RV, on a boat, in a train, etc. They can fill a gap in areas with limited mass transit, like in our home in Southern California. You could park a long way from a destination where parking is difficult, possibly getting free parking, then ride the rest of the way on the ebike.

Kilowatt makes this daring carbon fiber electric bike, including a carbon fork with a front mounted hub motor. I say daring because I am willing to bet most consumers don't realize carbon can be used to make a super strong frame. This would be a no-no with any off the shelf carbon frame/fork. "Beefy carbon fiber" is not a phrase you usually hear, but that is what this bike is. And in case you couldn't tell from the picture, that is a bamboo top tube. Very earth friendly.

I have seen a lot of A2B on the road and they are expanding their line this year. In addition to the bikes they are known for, they are introducing some 26" wheeled versions. Here you also see some accessories.

By making some simple changes to their existing bike they were able to make this electric scooter - almost anyway. You dont have a complete flat deck to put your feet on like a scooter, but it is close. If you don't pedal anway you can loose all the weight and complexity of the pedal drivetrain.

My favorite electric bike at the show was the Kona "Electric Ute". The bike is not released yet. The name alone practically wins it for me. The "Ute" (as in short for Utility like Sport Utility Vehicle) has been in Kona's line for a few years. It is almost like they named it in anticipation of a future electric version. The extra long cargo format of the bike and big bags make its purpose clear: carrying all the stuff you need to get your errands, commuting, etc. done. The small thumbnails below are clickable for higher res images.

The bike has no throttle, it is pedal assist style. This little handlebar mounted unit controls it and displays more than just the time when it is working.

The internal cable routing is a nice touch. Just be careful to attach a snake and leave it in the frame when removing cables for maintenance.

Bionx is a perennial favorite in the eBike world, it was great to see them at the show.

Madsen does not make an electric bike, but their cargo bikes are innovative and would make a nice electric bike platform. It is not like I spoke with them and got some inside info, I just saw them, liked them and took some pics. The tub option on the back is huge. The possibilities are endless.