The Golden Wrench

A blog about bicycle repair and maintenance by the mechanics at Freewheel Bike.

Saturday, February 27, 2010

Tough Love

Occasionally we have customers come into the shop with antiquarian rigs featuring seized or frozen components. Two dissimilar metals have been duking it out for decades, and eventually they just can't let go of one another. Kind of like the two male mooses who got their antlers stuck together fighting over a particularly virtuous she-moose, or the plot of Romeo and Juliet. Yes, sometimes these conflicts end up messy, and we are called on to mediate.

Our job is to break the wills of taciturn components. And we have turned it into a nuanced art.

This particular customer came in with a very fetching purple Maruishi singled road bike. Japanese steel: very savory! Unfortunately, the seat post was chemical welded into the frame. It's like a chemical snowball fight between an Irishman and a pacifist. The aluminum says "Ya flanny gaet, aeet some SNUUUUUU" and the steel says "Fine, I'll go ahead and keep them" and an electrolyte (salt from toxic sweat or from the road) begins egging on the Irishman from the sidelines. Soon, electrons are zinging across from the aluminum to the steel at a great rate, causing the once-smooth surfaces of both metals to become rough and scratchy. The battle can cause quite a mess, and breaking them up is hard to do.

A couple of themes are involved in a seatpost extraction. The first is leverage. The seatpost stuck in the frame is often made out of aluminum just slightly firmer than mashed potatoes, and therefore putting leverage on it is a delicate proposition. Too much leverage improperly applied tends to smoosh and shred and squarsh the seatpost without actually breaking the bond. Not enough leverage makes the seatpost giggle, and that's just demoralizing. Here is a brief pictorial tour of the clever setup that our chief persuader devised for the task at hand.

Man does not live by torque alone, however. Another aspect, lubrication, plays a crucial role in the operation. Lubrication puts little ball-bearing shaped molecules of oil between the bonded surfaces, making the seatpost and frame lose some interest in the dispute. We leave a penetrating and corrosion-attacking substance in the frame overnight to do its insidious work before reapplying leverage. If this doesn't work (which it didn't in this case), we get out the final step: flame.

MAPP gas torches are not just for heating tepid coffee (just visible in the lower right corner of the picture). They are a powerful tool for unlocking seized components. One might object that aluminum (seatpost) expands faster than steel (frame), so wouldn't that make the situation worse? I would answer "SILENCE!!!" because somehow it just works. The different expansion rates sometimes cause the little aluminum oxide teeth to shift from their little rust detents just enough so that one can wrangle it out. Sometimes it works, other times it just stinks up the neighborhood for a few hours and cooks a frame. Like Romeo and Juliet.

In the present case, the snowball fight ended up with two casualties. The Maruishi gave up the ghost but not the post.

Friday, February 26, 2010

Got Matrix?

An expectant hush falls over the bike shop employees assembled around a work stand in the back of the service area. A new Madone hangs there, newly outfitted with Shimano's electronic Di2 group. A mechanic spins the pedals and lightly presses the front shift button; into the circle of silence steps a robotic hum, like a servo motor coming to life. The front derailleur leaps into motion after just a brief pause, guiding the chain onto the big ring, then readjusts itself so it's not rubbing the chain.


Okay, I'll stop trying to emulate Chris and just tell it like it happened. Here's a shot of the guts of the Di2 system hanging out of the bottom bracket shell:

Now we heat-shrink the waterproofing seals which are necessary for internally routed cables:

Here we are after everything's been crammed back into the frame. Pretty tidy! Note the surprisingly compact battery which powers the whole system tucked away under the bottom bracket:

The revolution is now!

Saturday, February 20, 2010

Contemplating Easton Freehub Compatibility

We are an official dealer (and, unofficially, fans) of Easton wheelsets, and can't wait to see how they perform over the long haul. Word on the street says to expect good things.

These wheels are as snazzy as fruit bread, but their freehub system can be somewhat mystifying. Rather than just playing it safe and offering "Shimano" and "Campagnolo," Easton custom-machines their freehub splines to interface magically with specific cassettes from specific manufacturers. That way, they can use the metal that you don't need on your freehub for baseball bats, hunting arrows, snowshoes, and time travel devices (that may be dealer only information: if it is, forget that you read it here). So you have specific interfaces for SRAM Red, Dura-Ace 10sp., Campagnolo, and Sturmey-Archer 3sp. internally-geared with drum brake. For some reason, the Sturmey model wasn't in the catalog when I just checked, so you may have to contact the dealer directly to work out a special deal.

Here's some pertinent info:

For starters, any Easton freehub works on any Easton wheel. Since "all cassette bodies fit on any R4, R4SL, XC One, or Havoc hub," this opens up a whole new world of possibility: You could have a freeride bike with Easton Havoc wheels and Campy Chorus 10sp. if you wanted to! However nifty this may be, and it's pretty nifty, there are some tricky things to keep in mind.

If you get a Campagnolo-splined wheel, it will be compatible with 9, 10, or 11sp. Campagnolo cassettes. It will also cook you breakfast on Saturday mornings and sing Italian love songs at you in Italian, and will become jealous and pine away if you ride other bikes. It's quite a commitment in other words, but if you're a Campy sort of dude, you know that already.

The standard freehub that comes on the Easton EC70 and EA70 wheels is compatible with all Shimano-splined 8, 9 and 10sp. cassettes. So you can run anything from HG50 to Dura-Ace 10 (with a spacer, naturally), and SRAM PG-850 up to Red. You could probably run some fly-by-night, snake-oil, aftermarket special if you wanted to--as long as it has standard Shimano splines. Yay, versatility!

The mountain bike freehubs are the same as the ones on the EA70 wheels, and are compatible with everything except fixie cogs and Havarti cheese: they break out in hives for some reason. Muenster is fine, which is a mystery all unto itself. We did not test them with Velveeta, Brie, Barry Manilow, or Jarlsberg Swiss, so proceed with caution.

EA70/EC70/XC One/Havoc. Recognize those splines?

The standard freehub that comes with EA90 SL, EA90 Aero, EA90 TT, and EC90 TT is compatible with any Shimano 10 speed cassette except certain sizes of Ultegra 6600 (including 13-25, 14-25, 15-25, and 16-27--basically, no Junior gearing). It's a fetching blue color, too. My picture didn't turn out, so you'll have to close your eyes and imagine it.

The freehub that comes on EC90 SLX, EC90 SL, EC90 Aero, and EA90 SLX wheels is only compatible with Shimano 7800 and 7900 Dura-Ace cassettes. I heard that and went, "Naaaawwwwww!" and tried to cram an Ultegra 10 sp. on a new EC90 SLX wheel. It was ugly: the carrier that holds the three largest cogs slopped around like a hula hoop, and the rest of the cogs wouldn't slide onto the splines without significant effort. OK, apparently they weren't joking.

Ultegra fits ugly.

But this doesn't make any sense! It's not fair! I'm writing to my congressman and Easton is going to jail! The Ultegra 10sp. cassette fits on a Dura Ace 10sp. hub, and the Dura Ace 10sp. cassette fits on an Ultegra 10sp. hub (Pete checked). Pete determined by lots of measurement that Shimano and Easton are using different standards for compatibility. Picture in your mind a splined freehub body. It has "peaks" (the high points) and "valleys" (the low points). Shimano standardizes by the diameter of the valleys; Easton standardizes by the diameter at the peaks. So when Easton measured a 7900 cassette, they made their freehub body to mate perfectly with the splines and paid less attention to the diameter of the body itself. Huh? Right. We could have just read the sticker and took their word for it, but Pete's an empiricist and I'm an idealist, so "easy way" just isn't in our lexicon.

Another thing that can go wrong with the EC90 and EA90 freehubs: you can get your cassette out of phase. There are three different ways that a cog or carrier can line up on the freehub, but only one will bring you fame and glory. Recently they have started putting an anodized stripe on the freehub to idiot-proof the operation (because we all have our days!) and slow down the nasty-grams in the tech service inbox. Check out these pictures marked "right" and "wrong."



We'll be stocking all available Easton freehubs, including the SRAM Red specific unit and Campagnolo, as well as the 8/9/10sp. Shimano unit so you can upgrade your new TT wheels to Sora 8sp. like you've always dreamed!

We expect good things from Easton wheels. Some of the employees will be pummeling demos at various local events and will be able to give a report on their serviceability, durability and performance, as well as how they wheelie and stuff.

Edit: 2/22/10 10:20am
After all that talk about cheese I think it's time to give a way $10 worth of gift cards to our Midtown Bike Center cafe. The first person to e-mail the correct answer to wins. What is the maximum cooking temperature used for making Brie cheese? Hint: I usually get my trivia question information from Wikipedia.

Click here for more info about Easton freehub body compatibilities.

We have a winner. The answer is 37C (98.6F).

Thursday, February 18, 2010

Tuesday, February 16, 2010

Lectric Lube In Stock Again

Sorry for running out of Moringstar Lectrcic lube, I did not anticipate such high demand. We now have more in stock at both locations for service and for sale.

Wednesday, February 10, 2010

No, Tyson. THIS Makes You Go Faster.

Recently we got to fiddle around with a bike decorated with Sram's new XX group, which is supposed to give the legendary XTR a run for its money in terms of light weight, performance, and getting your bike stolen quickly. From direct observations of both groups, it looks like it's going to be a war. Being an ambassador for the bike industry, I am adopting the stance of Switzerland in this skirmish: I prefer one, but cannot afford either, and therefore will referee the debate and poke fun at both groups as evenly as I can, in light of the above limitations.

In the little bit of fiddling I did on the XX bike, I noticed something right away. See if you can guess what it is from the following picture:

If you guessed, "It slants the wood grain of your workbench about 45 degrees to the widdershins!" you would be incorrect: the direction of the rotation is clockwise. Actually, the correct answer is that everything uses Torx bolts (hence the green Park folding tool). This is a thoughtful feature because all the fasteners on XX are made of titanium, aluminum, Gorgonzola, black pepper, fresh basil, capers, pine nuts, and balsamic vinegar. Torx is one of those great innovations that is just now catching on as people realize that Allen bolts tend to round out rather easily if you're a stout yeoman with an elitist disdain for torque specs. It was designed to NOT deform or cam out under pressure, unlike the venerable Phillips head, so it's a great choice for lightweight fasteners.

Another observation: That cassette looks awfully fragile.

Here's a better picture of it on the SRAM site. Yep, it's pretty much hollow. It looks like it could dent or deform rather easily, and since 8 of 10 gears are machined from one tender-me-hunka-burnin' steel, wear and tear in the typical gear ranges will be an expensive proposition.

On the other hand, if you're a fan of minimalist clamps cluttering your handlebars, you'll like this:

One clamp around the handlebar gives you brake, fork lockout switch, and shifter. Remember when 31.8 handlebars first came out and you wanted to put a brake lever, fork lockout switch, and shifter all on the same side of the bar? There wasn't quite enough room for all that plus your computer, HRM, bell, commuting light, and Sumo-Guy horn. You fought it for days and ended up cutting your grips down to 2" so it would all fit, didn't you? And that's when you started on those gray hairs. Been there. SRAM has done us all a favor in streamlining the mounting system. "But," they reasoned, "why stop here? We could put lots more stuff on the handlebars since we saved so much room!" SRAM has plans for that extra handlebar room: XX accessories rumored to be on the drawing board for next year may include a searchlight, Sidewinder missiles, aero bars, an abacus, and wind chimes. It's all rumors until Interbike, as they say.

We certainly don't want to be prognosticators of certain doom and gloom, but this was kinda weird:

Hopefully this was an anomaly. Hopefully this is not a precedent. Hopefully the owner was mistaken when he vouchsafed that "Oh yes, everything was torqued properly and working as smooth as a Maytag brand dishwasher with very low actual miles!" Especially since this particular owner may or may not be slightly the SRAM rep. That may or may not be some sort of rumor, and he may or may not have mildly bragged up the front shifting before handing me a bike with a whacked front derailleur.

What's the big deal? If the front derailleur WAS tightened to its torque spec, and the clamp has sharp edges (which it does)...

It may dig through the clear coat on your carbon frame if it slips. We'll keep an eye on it.

In short: XX is feather-light, engineered to the hilt, full of practical genius, and of questionable durability. We like what we see from the shop perspective for no-compromise race bikes. It's easy to adjust, intuitive, and well-engineered. Will it dethrone XTR? Why not have two thrones?

Be the first person to answer the following trivia questions and win a Park Tool TWS-2.
What is the generic name for TORX?
What is the typical torque range in Newton Meters for a TORX T-25 fastener?
Send your answers to

2/10/10 6:59pm, We have a winner. The answers are "Hexalobuler Internal Driving Feature" from here, and "15.9NM - 19NM" from here. Thanks for playing.

Here's thw trivia winner, Phil, with his new TWS-2 TORX multi-wrench. Thanks for playing Phil.

Monday, February 8, 2010

Does falling down make you faster?

A handful of folks from the shop took part in the Loppet ice bike race on Saturday, which is in its second year as part of the City of Lakes Loppet weekend. After considering several options for bike setup, I decided to try my hand at homemade studded tires.

Most if the intel I was receiving suggested that, for pure ice conditions (as opposed to icy pavement or icy singletrack), homemade tires were the way to go. My Nokians are great for commuting and last forever, but longevity is less of a concern in racing, where performance is paramount. And, as this was my first attempt at ice racing, I was interested in keeping costs down.

Since I already had a big pile of old MTB tires in my basement, I had some opportunity to experiment. A quick trip to my local hardware store yielded a couple boxes of 3/8" sheet metal screws, and after a couple hours of drilling, screwdrivering and duct-taping, I had a pair of serviceable ice racing tires. Or so I hoped.

I took them for a quick test ride on a skating rink near my house just to see if they worked at all, and after a couple laps I decided they were worth a shot. Besides, at that point the race was two days away and I was scheduled to work all day in between. That's what I get for procrastinating.

But in the end they worked pretty damn well. And the gearing on my Surly 1x1 (I had it at 36x17) was perfect for the race. If I had it to do over again I'd probably add another row of studs to each tire--the guys standing at the top of the podium were able to lean over a bit more than I could. In any case, it was a fun midwinter project.

p.s. I found this photo the day after the race, and now I can't remember where--apologies to the photographer.

Saturday, February 6, 2010

We Have The Shimano Di2 Digital Diagnostic Tool

This tool is used to diagnose problems with the Di2 system and to program the shifters to your preferences. Learn all about it here.

Wednesday, February 3, 2010

Trek Suspension Training Day

Ken from Trek Bikes came to our shop today to show us a few cool things about Trek full suspension bikes.

This was a unique training session at Freewheel because it was open to employees of all Trek dealers. We had mechanics from multiple shops from around the area including Redwing and Hudson.

We got to take a look inside the new Fox DRCV rear shock.

Ken explained how the plunger works.

In this cut away you can see the two separate air chambers and the plunger. This animation shows exactly what is going on as the shock moves through it's travel.

Things came to a stand still when Mario brought coffee and pastries from the Midtown Bike Center Cafe.

Then it was back to work. Ken did a great job explaining why Trek's ABP design works so well.

Then we tried a little demonstration so that we could fell what he was talking about. If you put the front wheel of a non-ABP full suspension bike against a wall and compress the rear shock it compresses normally. Then if you grab the rear brake and try to compress the rear shock you can feel that it becomes much firmer. This firming up of the rear shock did not happen on the bike with ABP.

The first three people with the correct answer to the following trivia questions will win one of these hats. Send your answers to

What does DRCV stand for and what is it's performance advantage (how does it make the bike ride better)?
What does ABP stand for and what are it's performance advantages?

Update: 2/10/10 5:55pm Still have one hat left for the next person with the correct answers.
2/12/10 We finally have a third and final winner. Thanks to everyone for playing.