How To Properly Set Up A Cantilever Brake

Today I am going to share my best method for setting up a cantilever brake.  I do not believe in ‘toeing’ the brake pads (except maybe on a painted rim), which greatly reduces the effective power and gives the brake lever a really mushy feel.  With a few small tricks, your cantilever brakes will feel solid and powerful (as they are meant to be) and won’t squeal either.  Let’s begin.

Here is an example of a fairly standard TRP cantilever brake.

It actuates from the top by the brake cable, which is attached to a straddle wire reaching down to each brake arm.  When the brake lever is pulled, both sides move inward and apply pressure to the braking surface on the rim.  As you can see on this model, the left side has a convenient barrel adjuster built in at the top of the arm.  A barrel adjuster somewhere in the line is essential to this setup (which you will understand further down).  If your cantilever brake doesn’t have one of these, I suggest installing an inline barrel adjuster somewhere in the cable housing routing.  An inline barrel adjuster example is below as well as a cantilever brake hanger, which is mounted between two of the headset spacers at the end of the cable housing route.

Either of these three barrel adjuster options will work great, but I don’t suggest having more than one (redundant). The first step in this process is giving the straddle wire the correct angle in reference to the brake arm, shown below.  A 90 degree angle is the most optimal for this style of brake.  However, there are wide position cantilever brakes that do not follow this rule precisely.

A narrower angle or wider angle will degrade the performance of the brake.  I have seen some cantilever brake hangers that mount at the bridge of the fork that aids in reducing the shuddering experienced in the front brake, but most designs give ample room for the 90 degree angle.  Once this part has been set up correctly, take a look at whatever style barrel adjuster you have and unthread it about 2/3 of its total capacity, shown below.

The last third of the barrel adjuster should still be threaded in.  As you unthread the adjuster, notice how the brake will begin to tighten and close.  By extending the barrel, you can provide adequate clearance for the brake pads and this will be the key in setting up the pads properly.  With the barrel adjuster extended 2/3, loosen either the 4mm or 5mm anchor nut for the brake pad.  Some cantilever brakes use a 10mm hex nut to hold a post style brake pad. The arrows point to each mount style.  The 10mm hex nut in the second image is on the back side of the brake arm.  Both examples shown below.

 

Once loosened, the post style brake pad can be moved inward or outward and at about any angle.  In the 4mm (or 5mm) style, make sure that you have extended the barrel adjuster so the brake pad touches the rim, since it cannot move inward or outward (only angled up or down).  Using one hand, press the brake pad against the rim flush and parallel.  It should look like the brake lever was pulled when the brake pad hits the rim.  This sets up the proper contact of the brake pad to the rim.  Some style of brake pads have an angled back edge to aid in reducing noise (a second reason why toeing is not really necessary).  Example below.

With your one hand holding the pad against the rim, tighten either the 4mm (or 5mm) nut or the 10mm hex nut (post style) and keep an eye that the pad does not move.  Sometimes, an improper setup in the past can create an indent in the spacers and that will make the pad ten to want to go back to its skewed position.  If this happens, use greater force to hold the pad and try again until it is parallel with the rim.  Now, above I mentioned that the barrel adjuster (extended two-thirds) was the key to all of this.  Well, this is it.  Thread the barrel adjuster back in and watch as the clearance between the brake pad and rim expands.  This gives you the preferred modulation and spacing of the pad in reference to the rim.  Some people prefer a really tight pull of the brake lever and can thread the adjuster back in only partially.  Some people like a little more modulation and thread the adjuster back in all the way.  You should have several mm of spacing between the brake pad and the rim so that, if your wheel is out of true after riding for some time, the rim will not hit the brake pad.  Experiment with how much to thread the barrel adjuster back in until the brake lever actuation is to your liking.

Lastly, it is good to apply a bit of triflow to the spring and pivot point on the brake arm so that actuation is smooth.  It is a bit of preventative maintenance that will keep your brakes working great throughout the season.  As your brake pads wear down, you can extend the barrel adjuster (unthread) to regain the correct clearance as the initial setup.  Lubrication points shown in the example below.

As always, I welcome any other tips you may have from your own setups and hope that my experience will help save time and frustration.  I have seen plenty of cantilever setups and this method seems to work the best to get the most out of your brakes. Even an inexpensive $20 basic Shimano or Tektro Oryx cantilever brake can feel exceptional when properly set up.  Thanks for reading!

• SNC

 

 

First Thoughts and Review of the Specialized Turbo Levo Ebike

Hello everyone!  I have some exciting information and photos to share with you on the new Specialized Turbo Levo mountain bike.  One of our guys got to fly out to Moab this past weekend for some press release testing and rides and gave me the low down on many of the specs and what to expect from this new kind of bike. 

First off, the Levo gets much of the DNA that exists in the Specialized Stumpjumper.  The bottom bracket is a bit higher though as well as shorter crank arms and chainstays to avoid striking rocks.  It has the shortest chainstays in its class.  It comes stock as a 6fattie wheel setup and can also be converted to a 29er.  The 29er, however, only gains a slight 6 watt gain over the 6fattie.  My thoughts would be that the bike will be most stable with the larger tire.  It also has a low center of gravity to help keep it stable. The rear shock has been specifically tuned to for the additional weight of the bike.

The Levo comes in three configurations.  The SWORKS weighs in at 42lbs and will cost about $10,000, the Expert level weighs in at 44lbs and will cost about $6-7,000, and the Comp level weighs in at 47lbs and costs about $3,500.  The SWORKS and Expert level Levos are equipped with a 504 Wh battery and the Comp comes with a 400 Wh battery.  Both are Lithium ion batteries that use the same cells that exist in the Tesla.  A Tesla has 8000 cells, where a Levo has 40 cells and the Turbo S has 60.  So, that’s a pleasant feature because cheaper cells usually do not react well from vibration (much less from jumps and drops).  The battery weighs 9lbs.

The motor is integrated into the bottom of the downtube and has a 250 watt nominal power with a peak of 530 watts and a torque of 90Nm.  It is definitely the smoothest on the market and extremely quiet with a Gates belt drive.  In order for the motor to engage and apply power, torque must be sensed on the pedals and the rear wheel must have rotation.  The power meter to sense the torque in hidden inside behind the rear rotor.  This is great because if there is no movement, but you are pressing on the pedals, the bike won’t engage and lurch forward.  it will only apply the power once you are moving and pedaling.  This makes a lot of sense because you don’t really need the motor part when going down hill for the most part.

Both the motor and the battery are Bluetooth and ANT+ compliant, which removes the need for an LCD screen.  Diagnosis, battery level, and other features of the state of the bike are communicated to either your phone (via the Mission Control app) or through the Garmin Edge 1000 or 520.  The harness for the battery is magnetic and (once the bike is off) can be easily removed and charged on or off the bike.  The motor is also removable and can be diagnosed through the app.

As far as the ride quality, it is top-notch.  A 3-5 hour ride is easily feasible for a single charge, which is mostly due to the mid motor setup versus the hub motor.  The field test rides done in Moab were almost 50 miles together with about 5,000 feet of climbing.  The turbo mode is almost too much power and can cause skidding, but is fantastic to be able to ride to the trails and back.  Most of the effective riding was best done at the Eco mode with a little Trail (more robust) mode here and there.

Climbing is exceptionally great (it was able to clear two foot ledges with ease uphill).  The bike audibly tells you to change gears if the motor is working too hard.  A higher pitched whine from the motor occurs if you are in too low of a gear and a deeper low rumble if you are in too high of a gear.  Like most full-suspension mountain bikes, it is best to be seated while climbing .  Because of the extra power, 3 mile ascents are much easier to handle without issue than with a standard mountain bike.  For descending, it handles great and the extra weight keeps you close to the ground.

So, additionally, Specialized has gotten together with Strava to create a new ebike category on segments, which will have their own KOMs and leaderboards compared to regular mountain bikes.  In summary, I think this is going to be an awesome bike to let people have a great mountain bike ride even if they are not exceptionally experienced.  It is spec’d really well and I have followed social media of people testing them in Europe for a while, so I would expect that most of the bugs have already been worked out.  More to come when we get one in the shop to build.  I’ll post a good article of the build and closeups of all of the features it has to offer.

SRAM eTap Actual Weights

About a week ago, we finally got all of our SRAM eTap groupsets in the shop.  We got six full groups out of the first batch of twelve to hit the US.  They come with the wireless components (derailleurs and shifters), a Quarq power meter crank, and SRAM Red brakes, cassette, and chain.  Out of the groupsets, two were TT eTap groups, which have the wireless ‘blips’ that actuate the derailleur like the paddle on the shifter.  I will be posting a good installation article that goes more in depth than the initial article I wrote on eTap.  In the mean time, I thought it would be cool to have some photos of the components and their actual weight.  Pretty light stuff and I really think it will be a popular option.

SRAM eTap Rear Derailleur

Interchangeable battery for SRAM eTap

Interchangeable battery for SRAM eTap

SRAM eTap Front Derailleur

Left SRAM eTap Shifter

Both SRAM eTap Shifters

265 grams (Shifters), 160 grams (Front Derailleur), 238 grams (Rear Derailleur) = 663 grams.

So, after seeing the weights, I obviously wanted to see what the comparison was with Shimano Dura-Ace Di2 9070.  Here it is

230 grams (Shifters), 107 grams (Front Derailleur), 214 grams (Rear Derailleur), 50 grams (Battery) = 601 grams.  I am pretty sure that while the wires do weigh something, it’s not hardly enough to make it heavier than the eTap (maybe if you use 1000mm wires for all of the bike, haha).  So, while eTap is slightly heavier, it is not by much.  If you look at cassette, brakes, and cranksets (not a Quarq), chain, and bottom bracket, it is still lighter than Dura-Ace by almost a hundred grams.  This savings is almost entirely in the crank and cassette weights.  Anyways, hope this shed s a bit more light on the newest groupset.  I am also anxiously awaiting more photo leaks of the new Dura-Ace 9100, which looks to be wired, but will have an A Junction that can be updated and adjusted wirelessly.  That is a way more efficient way of easily checking firmware and diagnosing issues.

 

 

SRAM eTap – It’s etapular!

Hello everyone!  I was able to cover and help with our first SRAM eTap build in the shop for our SRAM rep and I will tell you it is a force to be reckoned with.  They have really thought out the design completely and it works very well.  Plus, having only the brake cables running from the bars to the frame is looking so clean and fresh.  Swappable identical batteries are a big plus if you run out of juice (approximate life is 1000km or so).

The build itself is ridiculously easy and the Parlee frameset was made for eTap (no frame fittings except the rear brake).  With only an internal brake cable to route, it saves a lot of time.  Pop on the front and rear derailleurs.  Pop on the shifters. Sync up the system in about a minute or less and you have a working electronic drivetrain.  Pretty awesome.  In addition, it is great to see a derailleur off the bike on the counter fifteen feet away and actuate it while a customer is checking out.  They’ll think it’s possessed!

Here are some photos of the build (what little there is) and then a couple videos of the derailleurs in action.  To shift the bike the left paddle controls shifting the rear to a higher gear and the right paddle controls shifting to a lower gear in the rear.  Pressing both paddles shifts the front up or down depending if you are on the large chainring or small.  Charging the bike takes only about 40 minutes.

Actually, the videos are more interesting than the photos.  Here they are, photos below that.

 

The above three videos are of the derailleurs actuating wirelessly from the the shifters.  Pretty awesome and syncs easily.  Press the small button on the rear derailleur to start sync.  The LED below the button will start flashing.  Proceed to press the same button on the front derailleur and it will also flash.  Last, sync each shifter by pressing the same little black button on the inside of the shifter paddle.

 

SRAM eTap rear derailleur without battery

SRAM eTap rear derailleur with battery placeholder

Front view of the SRAM eTap rear derailleur.  Note the little black button sticking out right at the bottom for syncing the components.

SRAM eTap front derailleur with battery placeholder

Limit adjustment screws on the front derailleur

Rear view of the SRAM eTap front derailleur

SRAM eTap front derailleurs use a support wedge to stiffen the actuation of the component. Contrasted to Shimano’s support screw in design, but both are easy to install with a set screw anchoring the wedge based on the angle of the cage.

Wedge screw anchor threads.

Top view of the SRAM eTap support wedge.

Most of the brains for the system are housed in the rear derailleur.

I hope you’ve gotten a good first insight into the new SRAM eTap system.  More will follow as we work with it more and any hacks will of course be shared.  Thanks for reading and checking out the videos and photos!

 

Installing and Troubleshooting the Turbo S Wiring Harness

It’s been a little time since I had a good update of info and experience with working on the Specialized Turbo S (in this case, the first gen version) and have had notable experiences that deserve to be logged and written about.  So, here goes.

In my last post, I was working with a Turbo S that had error code LEDs for the 1st, third, and fourth on the battery and would subsequently turn off after about five seconds of turning it on.  I have been working constantly with Specialized on this one and the valuable experience I have gained will be explained below.  In the end of my discussions with the Turbo experts at Specialized, it was determined that the wiring harness was malfunctioning and needed to be replaced.  It was estimated at about a two hour job, uninterrupted and I think that accurately reflects the time it takes for someone familiar with the Turbo.  Below, I will run through the process and how to do it with advice on what to avoid doing or what helps the install go more smoothly.  As of now, this is the first coverage I can find anywhere on the Internet on how to do this, so I hope the documentation is thorough and helpful.

After swapping several of the components with new ones from a known working 2013 Turbo S, I encountered the same errors on a consistent basis (even with two other batteries).  When the wiring harness came last week, I was psyched and ready to dive in.  I took photos of the whole process so you can visually compare when working on this project yourself.

The first part of the project involves removing the old wiring harness first.  This is literally every wire that runs from the handlebar connectors (the brake motor disengage, the mode selector, and the control interface) to the back of the bike.  First, remove the small 2.5mm hex bolts that attach the frame stops/guides for the wires on both side of the frame where the downtube meets the headtube.

Once this is done (by the way, put these tiny screws in a magnetic parts bowl, because you WILL LOSE THEM OTHERWISE), remove the anchor bolt on the non-drive side of the bike (which holds the main part of the wire harness in place).  It is a 6mm bolt that uses blue loctite.  In addition, this is a great time to replace the rear derailleur cable as the housing where it fits into the rear derailleur housing stop usually is bent and stretched.  Clip the housing on each end clean.  Any exposed housing casing will cause friction in the cable and affect shifting.  In the fourth photo, you will see a tiny 2mm screw right in front of the wire harness in the battery compartment.  You MUST remove this screw (which holds the brake housing securely under the downtube).  More photos below and then the next step.

When doing this project, I suggest removal of the crank.  While the bottom bracket isn’t necessary to remove, uninstalling the crank is a good idea so you have better angles of working with the bottom bracket access point on the frame.  It’ll make your life a whole lot easier.  I also discovered that you only need to loosen the two hex bolts (5mm) inside the bottom bracket access point in order to successfully route the harness.  Each individual wire (3 of them, black, red, and orange) is easiest to pass through the routing individually.  When pulling the wiring harness center out of the frame, it’s a good idea to take a nice flat tip screwdriver and carefully pry the rubber casing on the harness wires going down the battery compartment before pulling out the main unit.  The connection plug to the front wiring (7th and 8th photos) must be routed through the frame.  Allow some slack ont he wire from the frame stop and push the frame stop perpendicular to it’s mounting position through to the inside of the frame and then the wire connector itself.

Take a good look at the above photos and then I will explain them.  At this point the bulk of the wiring harness from the front of the bike should be ready to remove.  Now, we take a look at the progression of the wires through the bottom bracket and out to the hub motor and the rear taillight.  The rear wires are encased in  “Chinese finger trap” style mesh once they exit the frame to the hub motor.  As you compress its length, it widens and allows removal.  The new harness came with heat shrink tubing to cover the connections and the mesh harness is used again to protect the wires running into the frame.  The fittings for the red, black, and orange wires are compression fittings into the plastic plug that connect to the motor.  It takes a significant amount of pulling force to remove these, but they do so without much of a problem.  The key is installing the new connectors back into the plug, which  I will cover shortly.  The next few step include literally pulling on the old wires to get them to exit under the pressure plate (the motor and communication wires) and the seatpost light wires (through the seatpost and then through the seat tube).  By the way, I think one of the hardest part of the install is the installation of the seatpost light.  However, that is a sweet feature of the bike and requires considerable attention.  i show a decent way to do it, though I think there might be an even better way.  Here is the next series of photos.

The next part is great.  This is where the skill comes into play.  Before the installation of the new wiring harness, I suggest using an air compressor with a ‘crack pipe’ disc adaptor to clean out the frame of the dust from usage and age.  My buddy, Curtis, photobombed the second photo pretty well and helps me keep focus during these diagnoses.  To loosen the battery pressure plate mounts so you can route the wires, use a long L-hex 5mm to turn them counterclockwise until you can move the plate from the battery compartment with your hand a decent amount.  Note that the frame routing for the rear chainstay motor wires is quite small.  I suggest you route each under the pressure plate and the chainstay separately.   Route each under the pressure plate and then each through the chainstay (check the last photo above for the entrance point).  The wires are pretty stiff and pass through the frame relatively well.  Once you see each (with a nice flashlight), use a pokey tool to route them out of the chainstay. At this point, slide the mesh protector onto the wires and the shrink wrap from the earlier photos.  This will make your life easier in the next few steps. Apply a tiny tiny tiny amount of  dielectric grease to the brass collars of each wire before pushing into the original plastic plug.  This will help seat each wire in the plug a little easier.  It is tough to push them through.  Use a small blunt pokey tool to push from the rear of the plug.  I did it successfully on the second attempt.   Then I I hit the shrink wrap material with a lighter and tightened to the connector and wires.

 

Once this is done, it’s a matter of connecting everything.  To route the seatpost light wire, I ran a brake wire cable through the tubes and out the seapost drilled hole, taping the connectors in a row to minimize diameter of the hole it had to exit through.

Once I had done this, I realized the new harness use d a male and female connector for the rear taillight. Well, I rewired the old connector so it fit, and it worked flawlessly. 🙂

Here is the last of the install photos.

I also realized that the control unit docking station wire was malfunctioning, so I replaced that as well from a known working Turbo S in the shop.  Other than a small few inconsistencies in startup, the firmware was updated successfully as well as the battery communication issue software.  I am still waiting to hear back on the error reports from Specialized.  Bike performs successfully 90% of the time, but a final confirmation from them is necessary.  Thanks for tuning in.  More to come.  I am compiling a great Campagnolo EPS diagnosis article that should be up in the next few days.

 

SNC, David Polk

Further Troubleshooting the Turbo S & Other Fun Things

Well, I had two choices when I got home from the shop.  The first was to update my recently built cyclocross bike with some newly acquired 10 speed 105 and Ultegra (along with two nice red Specialized rib cages).  The second was two write a new article on first thoughts with the newest edition of the Turbo, which has split into several more models and options and really continues to develop the lower price point and affordability.  So, thus, I am writing the article (mainly because I don’t really care about 9 versus 10 speeds for a few more days of riding around in dirt and gravel.  Pretty sure it is working quite well).  In addition, I have come across some good troubleshooting problems and solutions (particularly the first gen Turbo S from 2013-14).  In fact, the solution for the issues in diagnosis are still in the process of being resolved.  However, due to some great communication with the lead Turbo experts over at Specialized, we have a solid direction toward fixing the issue and this will really mark the first time since they’ve arrived on the market that one can assess the long term durability and dependability.  I will go ahead and say that I certainly think it is worth it and, if you ride regularly (or wish to) year round, it’s a far better bargain (particularly in the DC metropolitan area) that sitting in traffic all the time with a car.  Let’s dig in!

First, I had a new customer stop through recently with an amazing modification of a 2015 Turbo S that made my eyes pop thinking about future possibilities with ebikes.  Her name was Marissa Muller and her website is http://www.marrissamuller.com.  Her Turbo had not only a aero wind shield, but could run indefinitely with the solar panel she attached to her Burley bike trailer.  Unbelievable!  Using extension wires with Rosenberger connection plugs (the same kind on the Turbo), she outfitted it so the Turbo could keep charging at a rate slightly more than the rate of battery discharge from riding it.  Essentially, it charged faster than you could deplete it!  Carrying an extra battery (which apparently wasn’t needed), this woman rode cross-country on an ebike pretty much without ever plugging it in.  Think if the frame was covered in super efficient solar panels.  Never charge the bike.  Use the free energy of the sun.  It’s both a noble concept and challenge to make it happen.  Unfortunately, adding this technology directly into the bike now would make the price skyrocket to a likely 15k or more.  So, rigs like these now are proven for the meantime and is a great way to tour the country without fear of running out of battery power.  Here are some photos of the setup!

She was super nice and had a great knowledge base to understand how the setup worked.  With extension Rosenberger connectors, she was able to route a cable from the solar panel to a the front of the Turbo into the charging port.  It was by far the best mods I have seen yet on an ebike.

Concerning the troubleshooting, I had a customer come in from visiting other shops with unsuccessful results in need of service with his Turbo S (first gen).  When the battery was started up, it’s on-board diagnostic LEDs showed errors for the motor, light, and remote.  The battery would finish the diagnostic and then immediately shut down.  This is a first for me.  After speaking with some of the experts at Specialized on this case, they suggested I take a look at all of the connections to make sure they were tight and not discolored.  Apparently, while a rare case, some of the Rosenberger connections would have one of the two pins discolored dark, which would mean it somehow went bad.  This was not the case as you can see in the photos.

   

I even removed the central core of the wiring harness at the top of the downtube to check for bad connections and/or frayed wires.  As you can see, there were none that stood out as bad.  I triple checked the regular connections of wires at the front of the bike (where the motor disengage connects to the remote and mode wires, and then into the bike).  The connection for the light was not quite tight and when tightened, it responded well by turning on correctly, though it still read as a fault in the system.

After inspecting everything and also trying to remove and reinstall the battery several times (and unplugging the motor connection near the non-drive side rear dropout and cleaning it with electronic component cleaner), I am of the assumption at this point (along with the guys at Specialized) that the wire harness may indeed be worn out.  In an effort to fully check this before replacing, I will be performing a diagnostic of the ebike with the newest edition of the software.  Once this has been confirmed, I will update the article accordingly and link this one to the other articles I have on the Turbo.  It is reasonable that the wire harness is worn out for a three year old bike, but maybe not since this one was purchased only about a year ago.  Either way, it seems to be solvable issue.  If the wire harness does need replacement, this is an extensive installation that will require quite a bit of time.  I plan to record this process with my GoPro and will post it here with the conclusion of the article.

On a side note, the battery error report showed some irregular data as well as the absence of data regarding some controls of the motor and battery cells.  For instance, there is a field of data readings that mention a note every time a permanent failure occurs and this data was completely gone from the report.  Anyways, once the issue is resolved, the Turbo should be back up and running.  I also used a different battery from a brand new Turbo with the same exact error LEDs, so this is also why I believe the issue is not the battery itself, but the communication between it and the other components.

 

Congratulations to Peter Sagan today on winning the UCI World Road Championship.  It was such an epic win and was smartly finished by attacking on the cobblestones.  It was the type of race where perseverance and smart racing skills took the field.  Let’s look forward to some special edition painted Specialized bike for him winning.  Thanks for tuning in!

 

• SNC

The New Specialized Venge Vias

Hey everyone!  We’ve just got the one of the first Specialized Venge Vias bikes in the shop.  More photos of the completed bike to come later today!  It definitely looks sleek with the aero brakes and curvy handlebar.  The 64SLX Rapide wheels seem really light and also quite aero.  I’ll try to have a few photos of actual weights for the wheels and the complete bike with Shimano Dura-Ace Di2 11 speed.  While the brakes look tucked into the frame, they seem easy to work on and I noticed all the little bits in the packaging made sense with flexible brake noodles leading to the brakes and the wires and junction tucked away nicely in the stem and under the bottom bracket.  One thing I really liked the concept of was the control unit and charging port located under the bottom bracket shell in a nice protective case (Junction A).  This means Junction B is placed up at the stem (hidden away), which is reverse of how you would normally install them.  More to follow!!!

What was in the stand yesterday (and today)?

So I had a rather interesting limited edition bike come through the shop for an appointment for general servicing and, as some projects occasionally do, it had a complication that was a good call for photos and explanation of a component that shifts the bike through an internally geared hub developed by SRAM around 2006 called an iMotion 9 hub.  It has nine gears or varied range and changes the gearing with moving the chain.  A wire cable runs from the inside of the hub to a long barrel adjuster and then up the frame of the bike to the shifter. The bike is a limited run of commuter style Cannondale hybrids with a Headshock lefty fork and no non-drive side chain or seat stays, hydraulic quad piston brakes, slick commuter style tires, and a fully enclosed chain.  Take a look:

The client mentioned shifting issues, which usually happens with most bikes as the cables stretch.  Tighten them up to the correct tension and the cable pulls the gears in the hub into an easier or harder gear each time you twist the shifter (smoothly and quietly).  I initially installed a new cable and with a bit of a learning curve and several adjustments of cable length (pretty specific without using up one of the two available barrel adjusters)(I would also mention maybe trying an additional one as an inline adjust about a foot from the shifter).  I went to test it outside (where it was much nicer) and after sever shifts I noticed the cable went slack so I felt the shifter and could feel a bit of play in the cable and stopped the bike.  Once back in the stand, I noticed something I had not previously seen due to it’s hidden position behind the chainguard housing.  A crack in the entry point of the cable into the hub had separated about half of it’s cylindrical length (about 7mm).

(This is inconveniently located in my photo underneath the greased up axle bolt.  I will take a photo of the fixed piece or possibly the still broken piece if I can’t repair it today.)

This part is made of plastic and, after a bit of research, I realized that apparently none of these parts are sold separately, even in the normal version of this hub.  This is when a little fabrication and small detail work will hopefully save the day.

I took apart the wheel and have opened the hub to examine any other issues and make fixing the piece much easier.  A little epoxy was applied to both pieces after greasing the cable running through (proprietary piece of cable that can’t be removed) so I can reinforce it with a collar of sorts today.  Here are a few photos of the hub being taken apart.  The spring in the third photo will likely be a challenge to get back into the shell, but can be done with a bit of concentration and effort (and persistence). The first photo shows the plastic threaded piece coming out from the circular housing.  The spring keeps enough tension on it in the photo to join the broken piece with the rest of the body, but moves significantly under load.

I will take a few more photos today and update the situation in tomorrow’s article.  It’s supposed to hit the upper 80’s around DC today.  Make some time and go for a ride!  I will certainly be taking thorough test rides after tuneups today.  Follow @pixalias on Twitter for updated photos and good tech that rolls through the shop!

2015 Turbo and Turbo X Preview / First Thoughts

The 2015 Turbos have arrived! I was psyched on Friday to see the truck roll up with four brand new Turbos and 1 new Turbo X (with a  suspension fork and knobbier tires).  We had been expecting them and I started the builds right away.  I documented the process of unpacking and setting up the bike and the pros and cons of that and exploration of the features as a quick first look.  I am sure we will be seeing them find homes shortly and will continually add summary progress in a troubleshooting article that will build with time.

They were the middle range motor/battery option which seemed to top out at around 21 mph with moderate effort.  Both models feature some great new tech options and builds upon prior years’ success.  They substituted their own branded stem on both models this year instead of the Crank Brothers model from prior years.  The key and battery lock look like a different make and the disc brakes are Formula C1 models.  Much of the rest of the bike is the same.  The Turbo X front light mounts on the handlebar, which I prefer over the Turbo mount at the crown of the fork.  The Rock Shox Paragon 50mm (regular QR) air fork with remote cable lockout is a nice touch on the Turbo X. It is also spec’d with Trigger tires, which I believe might be better suited to substitute Electrak tires.  The first nine photos are of the Turbo X and the rest are of the Turbo and its accessories.  The LCD controller looks the same and mounts in conjunction with the shifter and brake lever.

What I didn’t know about electric bikes

After a lot of research this weekend, I learned quite a bit more about electric bikes and how they work.  I particularly concentrated on how the motor in the rear hub operates and how it can provide power without any moving parts.  My first goal from this point will be to open the hub shell of an Ultra Motor brand hub motor in the rear wheel of a Stromer.  I’ll detail all of it in a well-covered post.

Most of the information I found was on just a couple websites which I somehow had not come across yet. Electric Bike is definitely well organized and provided the most information about a variety of hub motors and their corresponding controllers and diagnostic procedures.  Ypedal has an amazing and vast knowledge of the systems and has created tons of custom setups as well as details repair on several Youtube videos that is a complete procedure and well explained.

Most of the motors have a similar layout:  An outer shell to protect and encase the motor, then a ring of magnets that are positioned between the shell and coils of copper wire.  Other than a couple sensors and wires that exit through the center of the wheel near the axle, that’s about it.  Very simple and once familiar with the parts, moderately easy to work on.  I chose to first learn about the motor because it seems like this is the only component that I haven’t been able to service other than to simply install a replacement wheel.  To have the ability to fix the motors once the manufacturer’s warranty expires will be essential — especially as the number of electric bikes is increasing and they are becoming more common.

Back to the sensors and wires in the motor.  Usually there are three small square shaped sensors that are positioned between two of the outer magnets in line with each other.  These are called Hall sensors and they measure the electrical current coming out of the motor as the wheel spins.  A tapered side of the sensor body is always positioned outward and usually is set with a tiny amount of JB Weld or epoxy. Out of the top of each sensor are three uncovered wire leads that are soldered to colored wires carefully running to the center of the hub and exit from the wheel to the controller and potentially a torque sensor.  A torque sensor is generally on higher end electric bikes while cheaper versions simply use a cadence magnet to calculate the input of added power.  The torque sensor is nicer because it adds power based on a direct measurement of the deflection of the wheel backward against the rear dropout when you put pressure on the chain and pedals.  Most are robust and work accurately, giving the rider a better feel of added power when accelerating.

In some situations, I read that one or more of the Hall sensors can go bad and with the right tools, it is a small project for an afternoon that will avoid a replacement ($500-750) or service elsewhere ($100/hr).  Even if you aren’t up to doing the task yourself, you will be better able to diagnose and familiarize issues that occur.  For the avid mechanic, it is possible to upgrade your hub motor for minimal cost.  Larger wires (if they can fit through the frame and center of the wheel) will boost available power and a better controller or throttle can more accurately distribute the power.  Unless you have an extreme desire to mod your electric bike, the magnets and copper wire are difficult and costly to replace.  Some motors are spun low with larger gauge copper wire which can provide more power, but less torque on hilly terrain while high spin copper will have better power at a high cadence and will last longer.

In order to remove the motor from its hub shell, a car bearing puller is necessary.  It is an extractor style tool with three arms that pull on the shell while a center bolt pushes the axle and opposite hub shell side.  It is helpful and recommended that you tap the shell with a mallet during this process to aid in freeing the two halves.  Otherwise, direct extraction with the bearing puller could break the hub flange and then you’ll be left with a useless motor and no shell.

Considering the Stromer that was detailed in the review and diagnosis, I believe that the torque sensor was overloaded in the frame without that necessary bolt and the motor overheated and fried one or more of the sensors.  This would explain the NO_COMM lack of communication between the LCD controller and the motor.

Missing nut and spacer on axle. note the fine shavings of aluminum.

Note the scoring around the dropout.

It makes a lot of sense once the elements are broken down like that.  I also think that one of the wires exiting the rear hub is a faulty wire with a weak spot somewhere near the center of the wheel.  The torque sensor itself seems okay.  I am going to check current through each of the wires to determine the faulty one and then solder in a new one along with the replacement of the sensors.

I was very happy to find this information and come to realization that these bikes can be fixed from the ground up if necessary.  Why wait a week or weeks for new parts to install when the local hardware store and Radio Shack have all the necessary parts for a solution?  I am going to continue to do more research into the motor repairs as well as connecting different controllers to the bike for operation.  It is exciting to realize that with the right research, I can create incredibly fun bikes that are useful for both fun and transportation. Now, once I can locate a car bearing puller, I’ll open the motor and take photos of everything so you can see it.  Stay tuned!

– SNC