Thursday, September 27, 2012

Tension...

Cables stretch, housings compress, and in today's era of modern bikes, exact cable tension to both brake and shifting performance are crucial to having a perfectly tuned bicycle.  Mountain bikes have built-in adjusters on shifters and mechanical brake levers.  It used to be there was some redundancy.  The rear derailleur had an adjuster at both the shift lever and the derailleur.  Then a few years ago, the adjuster at the derailleur disappeared and it was only found on the lever, presenting a challenge when trying to combine mountain and road components.

It used to be all road bikes had an adjuster at the down tube shift boss or threaded stop (or head tube depending on brand's locations).  Then external cable stops disappeared as carbon fashion dictated that all cables should be hidden internally.  This left road bikes without a convenient, frame mounted, method to tension shift cables.  It also left front derailleur adjustments to chance.  While it was possible to dial in cable tension via anchoring the front derailleur cable with the lower limit screw turned in a bit and then backing out the limit once the cable was attached, thereby tensioning the cable enough for the front indexing to work properly, it was a bit of a trial-and-error method.  Much easier to adjust Campy front shifting than it was Shimano or SRAM.  It was much easier to dial in front shifting if there was an in-line adjuster.

For older Shimano shifters, one of the Ritchey designed, now a Jagwire product, Rocket STI adjusters worked great for both front and rear shifting.  The adjuster fit into the lever body's cable stop and allowed easy mid-ride adjustments.  The only problem was that during constant shifting, rattling, turning...the adjuster could thread itself in just enough over a period of time that shifting performance could suffer.  Easy enough to keep in check by making small adjustments when shifting was felt to falter.  

Then Shimano followed suit with Campy and SRAM and ran their housings under the bar tape.  Plan B.  Mid-cable housing adjusters.  These handy things have been around since the early days of mountain bikes when riders chose to run drop bars on their bikes and lost the brake lever's barrel adjuster.  At first, these in-line adjusters came from the motorcycle side and required special ferrules that perfectly fit the oversized ends.  Eventually, in-line adjusters became available from Jagwire that fit with standard bicycle ferrules. 

I like to put together bikes that incorporate road and mountain components.  Sometimes you want the low gears that mountain bikes have, but you want the comfortable, multi-position bars from road bikes.  In cases like these and if the frame has no threaded cable stops, there isn't any way to properly tune index shifting or take out cable stretch on the brakes.  However, if you have a Black Mountain Cycles frame, I got you covered.  And depending on the part, I have ways to add in an adjuster through the use of a certain part or an in-line adjuster.  This is the stuff that's fun to figure out how to make adjustments not only possible, but easy.  Here's some ways to ensure you can tension your cables.

3-Speed Cross
Here is a Tektro CR710 canti brake that has a threaded adjuster built into the straddle cable.

3-Speed Cross
This is the Jagwire Rocket II adjuster fit into a Sturmey-Archer 3-speed shifter.  This adjuster also fits into older Shimano STI shifters with exposed cables.

BB7 Adjuster
The Avid BB7 brake caliper doesn't have a built in adjuster.  I used a Dia-Compe threaded adjuster for this application.  The cable tension keeps it in place and this is really only for micro adjustments.

 IMG_0001
These are two in-line adjusters that came from the motorcycle side.  These actually require oversized ferrules (or oversized housing) to be 100% proper with the smaller 5mm housing. 

IMG_0002
This custom in-line adjuster is made by Charlie Cunningham to work with standard 5mm housing.

IMG_0004
The Paul Mini-Moto has a built-in adjuster at the top of the lead pipe.  Very nice detail.

IMG_0010
On my cross frames, I incorporated an adjuster behind the seat tube for front derailleur cable adjustments.

IMG_0009
When I use a Shimano road shifter (bar-con or STI) with a Shimano Shadow type rear derailleur, I use one of the Jagwire Rocket II adjusters fit into the cable stop on the derailleur. 

(What's playing:  KWMR Coast Highway Blues)

Monday, September 24, 2012

What's playing...

Almost since day one, actually, since this post, I have ended each post with "what's playing."  I have music on pretty much all day so I end blog posts with the song that is playing as I finish writing a post.  I guess readers like this parts because on one post a while back, I plumb forgot to let folks know what was playing and I heard about it via a comment or an e-mail.  I think the comment was something like "yeah, but what was playing?"  I read that and couldn't figure out what he was talking about until something went "click" and I realized readers actually like seeing what's playing as much as what's in the stand.  

I love listening to music.  All kinds.  Live music is even better.  And this week in West Marin, there will be some great live music.  KWMR, the radio station where I am permitted to be live on the air 3 times per month, is in the middle of a pledge drive to raise dough.  Since the station is not a commercial station, but a community radio station, we need to ask for monetary support a couple of times per year.  The cool thing about being our own radio station is that we do not have to follow any set lists and can play whatever we want, provided the songs are "FCC clean."  But that's another story.  

To help promote this fall's pledge drive, KWMR is producing a benefit concert on Saturday September 29 at the Bolinas Community Center featuring John Doe, from X and The Knitters,  Ramblin' Jack Elliott, and Allison Harris and The Barn Owls. This is sure to be a fantastic show and anyone within range who makes it to the show will be treated to a great evening of music.  Tickets are only $30.  Ticket info is available here.   

If you are well outside the bay area, you can tune in to KWMR tonight between 6:30 - 8:30 for my friend and Bakersifield & Beyond co-host Amanda's show "Release Me" and listen to John Doe, Ramblin' Jack, and Allison Harris live in the studio.  Listening info is available on the KWMR web page.






(What's playing:  X True Love)

Wednesday, September 19, 2012

Really trick out your Avid BB7 brakes...

I'm a junkie for tech stuff.  I'm hungry to learn as much as I can about bikes and how to make them work better.  I've been getting paid to work on bikes for a quarter century and I still know I have more that I can learn.  With the internet, there is plenty of information that can be easily gleaned.  Some good, some not so good.  Part of being a good mechanic is knowing what bits sound reasonable and what is just not good information.  And a big part of being a mechanic is being open to learning new things. 

With disc brakes for road and cross on the top of a lot of news stories, I recently saw this headline "The Fall of Discs:  Trick your Avid BB7 brakes" on velonews.com and thought "great, more info to learn."  Disappointment.  The story read essentially like the manual on how to install the brakes.  No new info there to learn.  No tricks on how to get the most out of your brake.  Just the simple obvious stuff.  Not that that isn't important.  Sometimes the obvious gets overlooked and is just as important as the not-so obvious. 

I was looking for the not-so obvious and it wasn't there.  I do already have some not-so obvious tips for getting the most out of your Avid BB7 brakes when they are used with drop bar levers.  

A lot of Avid BB7 brakes are used on bikes like the Salsa Vaya and Fargo with drop bars and drop bar levers.  There is a lot that is happening underneath your bar tape that can affect the performance of your brakes.  Number one is the cable routing under the tape.  Brake levers such as the Tektro RL-520 / Cane Creek Drop V brake levers have a very poor cable exit location out of the body.  The comparable canti brake levers from Tektro/Cane Creek have a much better cable exit.  The cable exit location on the v-brake levers, however, is horrible.  

When the Tektro/Cane Creek lever is paired up with a bar such as the Salsa Woodchipper, the housing must make a fairly extreme bend up after it exits the lever body.  This puts a big kink in the housing and cable and instantly creates a lot of friction after only an inch of housing past the lever.  Luckily, the lever body is plastic and the corner that the housing must pass can be modified to give the housing a much more gentle bend, reducing cable friction inside the housing.  To achieve this, I use a couple of round files - a larger one to knock off the corner quickly, and a smaller one to finely tune the routing to make it as smooth and rounded as possible.  

Tektro Lever Mod
What the cable routing looks like with an unmodified lever.

Tektro Lever Mod
Filing the housing exit hole.

Tektro Lever Mod
Finished body with a much more gentle bend in the housing.

The other method I employ to get the most out of Avid BB7 brakes with road levers is using compression-less brake housing such as Jagwires Ripcord housing.  On bikes with drop bars and full-length housing, there is a lot of housing.  Standard brake housing compresses and over 5 or 6 feet, that all ads up to mushy feeling at the brake lever and requires the pads to be set too close to the rotor resulting in too much noise.  With compression-less housing, the pads can be set away from the rotor to minimize noise, there's a lot less mush at the lever, and the brake feel is more like any other brake.  

I don't run compression-less all the way from lever to caliper, though.  I run standard brake housing from the lever, under the bar tape to a few inches past the bar tape where I usually install in-line cable adjusters.  From the in-line adjuster, I run compression-less housing the rest of the way to the caliper.  Why do it this way?  Because the standard housing is more flexible and has less friction inside as it makes the bends under the bar tape than the compression-less housing.  Once the housing exits the bar tape, the bends in the housing should all be very large radius, smooth bends.  

To further reduce cable friction, I've been using Shimano's "Special Grease" inside the housing.  I have a special injector filled with this grease that I use to pre-inject into the housing so when I run the cable through it all gets a nice coating.  This method is less wasteful than simply coating the cable before running through the housing.  

There.  Now you can trick out your Avid BB7 brakes.  Even though this is mainly about the Tektro/Cane Creek levers, this all applies to any other lever.  Look at how the housing exits the lever and make sure the housing has no tight bends under the bar tape.  It might feel okay before you tape the bars, but after taping the bars, the bar tape will force the housing into the tighter bar bends and what feels fine before taping could feel binding after the bar tape.  

(What's playing:  JP Harris & The Tough Choices Return to Sender)

Friday, September 14, 2012

BMC bottles in the wild...

Coming to you from Berlin, Germany, Black Mountain Cycles bottles in the wild.  Some great location shots here.  Thank you, Michael and enjoy!  Those are a couple of very nice bikes you have there. 

In front of Berlin's Reichstag

At the Holocaust Memorial with the U.S. Embassy in the background.  

At what's left of the Berlin Wall that separated East and West Berlin

The full set of photos can be found here:  BMC Bottles in Berlin.

(What's playing: The Pretenders Up The Neck)

Thursday, September 13, 2012

Tom Ritchey...

The guy has done more, ridden more, made more, given more than just about anyone I can think of in the bike industry.  Knowing how much he rides is motivating to get out on the bike.


(What's playing:  Tom Ritchey's 40 Year Ride)

Wednesday, September 12, 2012

38/26, 38/24 whatever it takes...

As much as I prefer Shimano's mountain bike components, they sure make it hard to supply a customer with exactly the desired component.  Take the crankset, for example.  Years ago, crank and chainrings were easily modifiable.  Don't like the stock 26/36/46 ring set up?  Easy, replace the ring you want to change with any by Specialized or Sugino (my all time favorite cranks and rings, by the way).  And without ramps and pins, they shifted great.  However, as six became seven which became eight ... and that became ten, chains got skinnier and shifting suffered so chainrings had to be profiled and ramps and pins were added to move the chain between rings.  

And even that was no problem because you use an appropriate width chain to match how many gears you have and it all works.  This brings me to my frustration with Shimano.  Recently, I built a really nice bike for a customer - custom frame, hand built wheels, Shimano XT...a real dream bike for someone who had been through other bikes and now wanted to treat himself to something really special.  We decided to go with an XT crankset with 38/24 rings instead of the 38/26 because of the 29" wheels.  He's tall, so 180mm cranks were also in order.  He also wanted to go with as many silver components as possible.  No problem.  Shimano's XT crank is available in both black or silver, up to 180mm length, and with 38/24 ring combo.  Okay, that's a problem.  Yes, all those options are available in an XT crank, just not all together.  

Solution:  Bring in the XT 180mm silver 38/26 cranks and swap out the 26t for a 24t.  How difficult could that be.  Maybe not so difficult if Shimano hadn't created different 38t rings based on if they were going to be used in conjunction with a 26t or a 24t.  Okay, small set back.  Time for more research.  Go to the Shimano tech doc page and look up part numbers and check compatibility.  Nope not listed.  At face value, any old Shimano 10 speed 24t ring isn't necessarily compatible as a double with a 38t outer.  They have these pesky two letter codes that need both rings need to have in order to be compatible.  No distributor, and not even Shimano, have a 24t ring that is compatible with the 38t ring from the 38/26 crankset.  

Now, if this was my bike, I would have put on a "non-compliant" 24t Shimano 10s ring and it would have probably shifted fine.  However, this was someone's dream bike and they were spending big bucks on it and I wanted it to be right.  In the end, the only thing I could do to make it exactly right was to bring in another XT crank (175, black) with a 38/24 ring combo and swap rings.  You want your dream bike, I'll make it happen.  

Shimano Mtn Double
Check out the pocketing and ramp profile of the 38t rings:  38/26 on the left, 38/24 on the right.  I'm sure Shimano with all their engineering expertise could have figured out a way to make one 38t ring that worked just as good with either a 26t or a 24t ring.  They are smart that way.  This is the kind of stuff that drives folks to their competitor, SRAM. 

(What's playing:  The Beatles Money)

Tuesday, September 11, 2012

Recent WITS bikes...

There have been some pretty great bikes passing through the stand recently.  With that, here's a quick WITS (What's In The Stand) post for your Tuesday coffee and scone pleasure.  

First up is one of the Black Mountain Cycles cross frames that was built into a Sturmey-Archer 3-speed commuter.  The bike turned out great and is busy tearing up San Francisco's streets.

3-Speed Cross
Sugino's RD-2 crankset with 48t ring.

3-Speed Cross
Cable routing.  The brakes are Tektro's new CR-710 canti brakes.  A really nice, lower profile version of the CR-720.  I like these new Tektro brakes better than the Avid Shorty 6 brakes.  

3-Speed Cross
I set this up with the S-A thumb shifter that has a great retro shifter look.

3-Speed Cross
Another look at the CR-710 brakes.  Note the straddle cable adjuster.  Dig the brakes.  

Speedvagen
A Vanilla Speedvagen came in for fresh bar tape and hub maintenance on the rear DT Swiss 240.

Speedvagen

Speedvagen

Speedvagen

650b
Built up a set of 650b wheels for a retrofit into a Rocky Mountain.  

Potts 29er
And finally, this custom Potts 29er built for a rider in New Mexico with a no nonsense XT build with White Industries hubs and WTB Frequency i23 rims.  The owner happens to be my same height and rides with my same seat height.  The bike fit me like it was made for me.

Potts 29er

Potts 29er

Potts 29er
Custom frame, stem, and bars.  The bars were custom bent to match my favorite old flat bar, the Titec Flat Tracker.  Such a comfy bar and perfect on this Type II equipped rigid 29er.

(What's playing:  The Replacements Alex Chilton)

Monday, September 10, 2012

Road discs are coming...

Road discs are coming.  Just not on my road frames and I'll tell you why.  First, yes, road discs are coming.  Are they a good thing?  Sure, for certain applications.  Key phrase there.  Disc brakes make a ton of sense on bikes where your riding has miles and mile of descending with a lot of heavy braking and you:
A.  Ride in the rain
B.  Ride in the extreme heat
C.  Ride with carbon rims (clinchers or sew-ups, but especially clinchers)
D.  Are a big dude (or dudette)
E.  Ride the brakes down descents
F.  Want the latest thing
G.  All of the above

Now, I'm not down on road discs.  Really.  However, I think the bicycle industry has a lot of things coming out that are not necessarily consumer driven.  There's a lot that is being pushed out because bike and part manufacturers need to keep it new and fresh.  They rely on selling "new" bikes and parts year after year.  They are caught in a cycle that demands they create new bikes, parts, and niches. 

This cycle seems to be happening at an accelerated rate with more new stuff coming out than you can shake a stick at.  "Shake a stick at."  What the hell does that mean?  It's an all out war for bike companies to one-up one another in their effort to gain market share.  The piece of the pie isn't really growing so they have to make something that consumers want more than another companies something.  My widget is better than their widget and if you buy it, you'll be better/faster than your buddy who buys those other guy's widget.  

Okay, back to disc brakes.  They are coming on road bikes.  The good news is rim brakes will still be the overwhelming majority of brake options available on road bikes for quite a while.  I'm glad about this because I simply do not need disc brakes on my road bike.  At least, based on where I live.  Where I live, there are no stop lights.  There are only a handful of stop signs.  What there is is a lot of open road where I am not even touching the brakes for as long as an hour sometimes.  There are a few descents that require brake modulation, but there are also a lot of wide open, shortish, descents that can be taken at full speed, with no brakes.  Why would I need disc brakes for these types of rides?  I can ride out to the Pt. Reyes lighthouse and probably hit my brakes no more than 5 times in the 40 miles.  Your situations may vary.

One of the reasons I was skeptical about discs on road bikes was due to the tire's small contact patch and the power the disc brake offered.  My thought was that the power of the brake would over-power the traction of the tire.  Not the case as confirmed by a friend who shared my same concern and ended up on a vacation only able to ride the road on his disc brake mountain bike which he shod with road tires and had no problem controlling his speed.  

My biggest concern about road discs is the noise.  It's everyone's goal to have their mountain bike disc brakes run drag free, but we know that's not the case once the bike is out of the work stand.  Wheels, hubs, forks, stays, dropouts...all flex under load and when they flex, the rotor will touch the brake pads making that sound that is barely perceptible when combined with knobby tires in the dirt.  Now take that sound and put it on a road bike where things are much quieter.  How many times have you chased a tick or a click on your road bike that drives you crazy?  Now add in rotor scrape noise and that peaceful road ride is now fraught with unwelcome noise.  Your rotor heats up and warps slightly because you 'E' and you aren't going to be able to fix that out on the road so the rest of your ride is ridden with a 'ch, ch, ch' sound with each wheel revolution.  

On a road bike with rim brakes, if your wheel goes a bit out of true, you can reach down and without stopping either flip open the brake's qr or reduce cable tension with the barrel adjuster.  Brake rub sound goes away.  It's all good.  On a disc brake equipped bike, if your rim, er rotor, goes out of true, you've got nothing.  You might be able to back out the pads in the case of an Avid BB7 brake, but chances are, you'll be hearing that 'ch, ch, ch, ch, ch, ch...' the rest of your ride and it's going to drive you crazy.  And you're going to bring it to your mechanic and say "HELP!"  You'll get back on your bike and it will be quiet again until you get out of the saddle and rock back and forth up a hill and there's that sound again. 

So, road discs are coming and I have no plans in the immediate future to have disc brakes on my road frames.  Cross frames, however...  Ah hell, I'm still not personally in a tizzy to get disc brakes on my cross frames, but it's going to happen.  I just need to get more excited about them.

IMG_0002
Yes, this is an exageration, but the gap between pad and rotor is less than a business card.

IMG_0003
Ah, that's more like it.

One final thought on road discs:  I find it interesting that road discs are coming, yet there really are not any new disc brakes, or rather, new road disc technology coming out yet from the major component manufacturers.  I don't count what I would consider kludged together pieces to force the issue.  Road discs are coming with disc brakes that have been around for almost a decade.  Not bad technology, but one would think that while creating a new niche, manufacturers would want to introduce road disc bikes with new disc brakes, developed specifically for road use.  I think this points to bike manufacturers pushing road discs through the system without enough demand and a bit before manufacturers have a chance to supply disc brakes developed specifically for road use.

Post Script:  And as if on cue, this bit of news pops up regarding SRAM lightening their cable disc brake for road naming it the BB7 Road SL

(What's playing:  Dwight Yoakam Take Hold of My Hand)