Crono Tech Blog

Cyclesport Travel information meeting

2012-01-13T08:53:00.001-08:00

Cyclesport Travel/Cronometro

Cycling Vacation information night.

Have you ever thought about a cycling vacation in France, how about Italy? Thursday, January 19th is your chance to stop in and check out the great trips

Cyclesport Travel is offering for 2012.

The Pyrenees Playground Trip June 25th to July 7th
This trip include an opportunity to participate in the Ariegeiose Cyclosportive and ride virtually all the important Pyrenees climbs.
Castles, cave paintings, the Tourmalet, Plateau de Beille, Ancizan, Col dAspin, Col d Agnes, the Corniche and the Mamar are all
on the menu for this incredible experience.

This years L'Ariegeoise Cyclosportive will finish atop Plateau de Beille in the L'Ariegeoise 161km and La Mountagnole 117km events.

Tour de France trip July 9th to July 17th
Experience the TDF like the French villages do! We will let the Tour come to us in the our mountain village and ride up the Port de Lers to watch the pros!
Ride every day and come back to your cabin or head down to the local bar to watch the Tour excitement.

You will have the chance to ride the 18 percent grade on the last climb of stage 14 before the tour attacks it.

Italy, Gran Fondo Prosecco and Chianti October 1st -10th
Ride through two beautiful wine producing regions and celebrate by rolling through the Prosecco vineyards during the Gran Fondo on Oct 7th.
LINK TO GRAN FONDO PROSECCO

We will have wine and cheese snacks and lots of pictures of past trips.
Time: 6:00-8:00

We hope to see you then.
Colin, Dave, Mark and Scott

Cyclesport Travel is now able to take credit cards! Just our way of trying to make your trip more convenient.

This is just to good.

2011-04-28T15:54:00.001-07:00

To good not to post.

Published with Blogger-droid v1.6.8

Adventures In Compatibility

2011-01-05T11:50:00.001-08:00

With Cervelo's new "BBright" bottom bracket standard comes new challenges in mating drivetrain parts. The BBright layout is similar to the popular BB30 standard in that the crank spindle is 30mm in diameter, but Cervelo has chosen a BB shell width of 79mm instead of the typical 68mm found on road bikes, even those using the BB30 standard.

Interestingly, the drive side of Cervelo's BBright bottom bracket shell is unchanged from a BB30 shell and the extra 11mm in shell width is added to the non-drive side of the frame.

Partering with Cervelo in the BBright project is Rotor, who makes an impressive crank specifically for BBright frames. Unfortunately, Rotor does not offer a BBright crankset with 180mm crankarms. We therefore chose to outfit Tom's new Cervelo R3 with a Shimano Dura Ace crankset, which is offered in 180mm.

The most obvious challenge in using the Shimano crank is to reduce the bottom bracket opening from 30mm to Shimano's 24mm Hollowtech II spindle diameter. This is fortunately achievable using BB30 adapters currently on the market. The problem, however, is that these adapters are made with a 68mm bottom bracket shell in mind and not the BBright 79mm shell.

Because the drive side of the bike follows the BB30 standard, the adapter works fine on the non-drive side. On the non-drive side, however, Colin had to fire up the lathe and turn this:

Into this:

Tom's crank is now spinning happily along. Stock Q-factor is preserved, and it has ample clearance on both sides.

The appropriate adapters should be commercially available at some point, but I could not find them at the time of this post.

Cyclocross Brake Chatter/Shudder

2010-11-05T11:30:00.001-07:00

Lennard Zinn wrote a great article (HERE) about the common problem of chattering front cantilever brakes on cyclocross bikes. Basically, when the cable housing stops above the top of the steerer tube, as it does on most 'cross bikes, fork and frame flex caused by braking forces can create sharp spikes in cable tension. These spikes lead to increased braking force, to the point where one of the following must happen:

1. The front wheel locks up and skids
2. The rider is thrown over the handlebars
OR 3. The brake pad finally breaks free from the rim surface

The path of least resistance is option number three, and that's precisely what happens. After the pad breaks free however, the cycle begins all over again. This constant sticking and slipping is what causes the shudder that can be truly terrifying.

This Trek X02 had the worst chattering front brake I had ever seen when equipped with its stock cable hanger (above the head tube). Simply switching the hanger position completely eliminated the chatter. No change in brake pad material or toe-in angle was required.

A very stiff frame and fork should reduce the problem, but I have seen really nasty chattering on newer 'cross bikes with 1.5" oversized lower head tubes that are supposed to be ultra stiff. It seems that any frame and fork, oversized or not, will flex to some degree under hard front braking. If the cable hanger is placed above the head tube, this flex is going to translate into cable tension spikes to some degree. On some bikes, it is minor enough that there's not much of a problem, but a crown-mounted hanger could be the solution if your cyclocross bike shudders badly.

As Zinn states, many carbon fork crowns are not equipped with a bolt hole for mounting a hanger there. Luckily the XO2 above did have a hole. If you're stuck without a bolt hole in your fork crown, you could try Cane Creek's Drop-V lever and using linear pull front brakes instead of cantilevers. The Drop-V is a brake lever only and not a shifter, so you would only be able to run a single chainring on the front.

Stolen!

2010-10-28T13:35:00.000-07:00

Colin rode his Surly Traveler's Check to work yesterday and locked it up outside the back door. Someone managed to steal it in broad daylight despite the visibility and constant traffic of people in and out the door.

The thief must have been a really smart guy, as the genius put it up for sale on Craigslist today. We called him posing as a buyer, but sent Madison's Finest to the meeting instead. Now the bike is back and he's in jail!

Unfortunately he had already stripped it of its Nite Rider light, its fenders and seatpost with Regal saddle. It came back with a crappy suspension post and crummy saddle. All in all a great success though.

One of those days.

2010-09-14T10:24:00.001-07:00

You know you're in for a long day when you've already had to slam a Cherry Coke and cut up the can for shims before noon. I was already jacked up on coffee too.

We got some nice words from pro triathlete Charisa Wernick recently. Her bike was a little bruised up from the airline's henchmen, so I realigned the rear derailleur hanger and replaced the cable. Good as new, and she took 5th place in Sunday's Ironman Wisconsin!

@crono_Madison thanks for fixing my bike!! Awesome bike shop if you need anything before #IMWI http://twitpic.com/2n5h5l

2010-09-03T14:27:00.000-07:00

...and were back!

Ironman Wisconsin is right around the corner, which means life is hectic but also fun because we get visited by professional triathletes from all over the world who have made a habit of bringing their bikes to us for service before the event.

Today I got to get Hillary Biscay's machine ready to do battle. She has won the Wisconsin Ironman before, so be sure to watch for her out on the course. Don't blink because she'll be going by pretty fast.

Blog Revival

2010-05-19T13:37:00.000-07:00

Keeping the blog up to date is tough when the shop is busy...

The Wheels on Willy criterium took place this past Sunday, with excellent weather and a return to the original course that goes right past our front door.

It was quiet in the wheel pit, without a single mishap while I was on duty. A very different experience from the one I had working for Shimano Multi-Service at the Collegiate Nationals Road Race recently. Rain all day made conditions ripe for punctures, and I changed roughly 40 wheels for competitors. A race day mechanical problem is never a good experience, but it's rewarding when they get back on the road and chase back into the peloton.

On Hiatus

2010-01-29T20:58:00.000-08:00

I'll be on the road for the next five weeks with Joe Pug. You won't see any blog posts in that time, but you can follow what I'm up to on twitter:

www.twitter.com/madisonandrewh

Here's where we'll be:

www.joepugmusic.com/tour

Sticky Front Derailleur

2010-01-27T15:54:00.000-08:00

I've mentioned sugar residue and its negative effects on shifting, and today I came across a particularly frozen front derailleur. The sugar had dripped all over the derailleur from a leaky water bottle, and fluid in our parts washer was powerless against the sticky residue. Because the sugar was originally suspended in fluid, it was able to flow deep into every one of the derailleur's moving parts. It occurred to me that the best way to get down into the nooks and crannies would be to soak it. However as I mentioned before, the parts washer fluid was having no effect on the sugar. Instead I used....water!

I don't normally recommend dunking your expensive bike parts in water, but it turned out to be a very effective due to sugar's solubility in water.

If you ever try this method, be sure to thoroughly dry and lubricate the part after you're done!

Sticky and lifeless front derailleur.

Into the dunk tank.

The derailleur is getting cleaner and the water is getting dirtier.

Here's a shot of the water soaking the derailleur for a few hours. Don't drink that.

A little scrubbing with a toothbrush cleaned it right up!

Let's build some wheels.

2010-01-14T09:19:00.000-08:00

We just got in various Edge rims for wheel build projects. The shallowest (25mm)and lightest tubular version weighs in at 213g. We'll add DT Swiss 190 hubs to make an unbeatable climbing wheelset.

The second set will incorporate two different depths of clincher rim: 65mm rear and 45mm front, with respective weights of 450g and 400g. Using DT Swiss 240 hubs keeps the cost down a bit and still yields competitively light wheels.

We plan to have various wheel configurations available for demo use during the coming season. They really have to be ridden to be believed, so we're happy to send you out on them for a real-world test ride.

Bike Swap TOMORROW

2010-01-08T13:28:00.000-08:00

We'll be closed tomorrow, January 9th, for the 19th annual Cronometro Bike Swap. If you haven't been to the swap, it's worth checking out whether your looking for that hard-to-find N.O.S. European part, a winter beater frameset, or just some entertainment.

We'll be there giving some presentations and socializing.

You can find the details HERE.

Cronometro’s 2010 Annual Service Package

2009-12-11T13:24:00.000-08:00

Cap the cost for all the service your bike will need for an entire year!
Pay $300 for the year and receive $430 worth of professional service.

Nice bikes should be overhauled each year and often need a drivetrain tune-up sometime during the season to keep them working at their best. Your bike rides will be more fun when the shifting, braking and handling have been optimized by a professional mechanic.

Included in the Annual Service Package:

-One Complete Bicycle Overhaul ($225 Value) (Must be completed by Feb 28th, 2010)

Bike is stripped down to bare frame and any necessary frame labor covered, including thread chasing, seat tube honing, bottom bracket and head tube facing, head tube reaming, and thorough cleaning.
All parts cleaned in solvent tank, lubricated and reinstalled.
Wheels trued, tensioned and dished.
Hubs, headset and bottom bracket disassembled and cleaned, any ball bearings replaced and packed with fresh grease.
All new cables and housing installed.
Handlebars wrapped with new tape on road bikes, or grips installed on
mountain bikes.

-One Complete Tune-Up ($150 Value)

Drivetrain parts (Chain, Cassette, Derailleurs & Crankset) removed from bike and cleaned in solvent tank. Parts are lubricated and reinstalled.
Wheels trued and tensioned.
Front and rear shifting systems adjusted.
Front and rear braking systems adjusted.
Headset, bottom bracket and hub bearings adjusted.
Torque checked/adjusted on fasteners.
New shift cables and housing
Handlebars wrapped with new tape on road bikes

-Free adjustments as needed throughout the calendar year

Front and rear braking adjustments
Front and rear shifting adjustments
Headset, bottom bracket and hub adjustments
Wheel truing
Chain/cassette replacement labor covered
Tire/tube replacement labor covered (clinchers only)
Brake pad replacement labor covered

A limited number of packages are available for the coming year. The 2010 Annual Service Package must be purchased by Jan 31st, 2010.
The 2010 Annual Service Package will expire on Dec 31st, 2010. All work must be completed prior to this date.

The Cronometro Service Department
Campagnolo Pro Shop, DT Swiss Certified Wheelbuilding
24 hour turnaround on repairs scheduled by appointment.
(Not including work requiring special order parts.)

2009-11-12T11:44:00.001-08:00

Packing bikes for travel or shipping is not the most glamorous part of this line of work, but it is fun when the bike is going to an event like the Ultraman World Championships in Hawaii. Think of Ultraman as a race that exists for those who don't find the Ironman challenging enough.

Here are the bios for this year's competitors, including Madison's own Ann Heaslett. Good luck Ann!

Sticky Shifting

2009-10-27T14:29:00.000-07:00

On longer rides, calorie intake is a necessity. However, the sugars contained in many sports drinks pose a hazard to the function of your bikes shift cables. If your bottles leak the fluid, gravity will eventually pull it down to the lowest spot on the frame, which is the underside of the bottom bracket shell. This spot also happens to be where both shift cables run over the plastic cable guide which leads them to their respective derailleurs. The extra friction caused by dried sugar on the cable guide inevitably leads to poor shifting and possibly broken shift cables.

The underside of this bike has been coated by dirt and debris that only stuck to the frame because of the sugar residue. If you look closely you can even see the red tint of the energy drink. The easiest solution to this problem is to make sure you close the valve on your bottle after taking a drink, as this is the most common cause of leaks. Also make sure the bottle lids are fully tightened but not overtightened to the point of damaging them.
If you find that your bike does have a coating of sugar residue, Pedro's Green Fizz does an excellent job of removing it without damage to your bike or the planet.

Blogging About Blogging

2009-10-23T09:29:00.000-07:00

The Tech Blog was featured in this article from InBusiness magazine as an example of how blogging can facilitate making connections with existing and potential customers. Pretty cool, despite their comment on my infrequent posting, which is fair considering that I do in fact post infrequently.

Tufo's Elite Pulse Tire

2009-10-21T10:42:00.000-07:00

Just a quick note about the straightest and roundest tubular tire I've ever seen. It's Tufo's new Elite Pulse tire. It is also, however, a bit on the expensive side.

New Seven

2009-09-18T10:33:00.000-07:00

Now that Ironman Wisconsin is over, I might have some time to contribute to the blog occasionally.
Today we received a new Seven Axiom with custom paint.

Here is a link to Seven's amazing finish options.

We're building the bike with Shimano's new Ultegra 6700 group, which has inherited much of the technology originally developed for Dura Ace 7900.

2009-07-31T08:29:00.001-07:00

Here's a very cool custom wheel I've just finished for a Cervelo P4.
It's an Edge Composites 68mm rim with a PowerTap SL+ Wireless hub in black.

2009-06-04T14:20:00.001-07:00

Here's a pair of wheels I just finished for a friend of ours at Saris Cycling group, makers of the impressive PowerTap hub. He requested Marwi's "Ti-Dye" Titanium spokes, which sure do have some bling when laced to Velocity Fusion rims in gold!

2009-06-02T11:10:00.000-07:00

I've just begun building our second coupling Titanium tandem from Seven Cycles. It's an Axiom, which is constructed of Seven's Argen butted Ti. The frame can be broken into three pieces for easy transport, thanks to frame couplers from S&S Machine.

The rear disc brake mount is new from Seven. It positions the caliper inside the frame's rear triangle, making the traditional mounting locations for fenders and a rack fully accessible.

Chain lube is good, but...

2009-05-26T11:15:00.000-07:00

Don't overdo it.

If you apply a heavy coat of chain lube and do not wipe off the excess, your drivetrain will pick up lots of grit and grime. All this gunk will not only slow your bike down, but it will also accelerate the wear on parts like your chain and cassette.

The proper way to apply chain lube is to put a light coat on the chain, spin the crank a few times to work it in, and then wipe away any excess lube still on the surface of the chain. The main goal in lubing the chain is to get the lube into the moving parts and remove anything left on the outside. It's this extra lube on the outside of the chain that causes gunk to stick to it and build up.

The best way to get a drivetrain clean after it's been overlubed and gunked up is to have the parts removed and cleaned in the parts washer. The solvent can get into the small openings in your bike's drivetrain parts that cannot be reached by hand.

Our Complete Tune up includes a full drivetrain cleaning (chain, cassette, rear derailleur, front derailleur and chainrings) as part of the package.

Sweat can destroy your bike.

2009-04-03T09:49:00.001-07:00

The flow of air past your body tends to dry most of your sweat before it can drip onto your bike, but some of the sweat (and the salts suspended in it) will inevitably come into contact with the bicycle and its components. This is of particular importance when the bike is on a stationary trainer, as the wind is no longer there to evaporate the sweat.

Here we see the clamping area of an aluminum handlebar that has been eaten completely through by salt deposits and moisture from sweat. See the two dark spots? Those are where the entire wall of the handlebar has been consumed by corrosion. There is also a great deal of visible salt left over after the moisture has evaporated. This is a particularly dangerous example, as there was very little material preventing the handlebar from simply snapping off below this spot. The forces generated by a rider sprinting in the drop position of the handlebar could quite possibly have broken this handlebar off, likely resulting in a serious crash.

Solutions to this problem include regular wiping down of the bike, and the use of a sweat cover when it's on the trainer. Regular replacement of the handlebar tape can help cut down the contact of salt with the handlebar as well. Some people just have naturally more corrosive sweat than others, so be sure to stay on top of it if you are one of the people who sweat battery acid.

It's Spring

2009-03-21T14:09:00.000-07:00

...and that means it's time again for people to bring really strange things into the bike shop.

This poor bike was out for its first ride of the season when tragedy struck. Its owner had stored her gloves and arm warmers under the saddle in case she needed them on her ride. When the gloves and arm warmers fell out, one of the gloves got caught in the rear derailleur and cassette. This instantly stopped all motion in the drivetrain, probably causing her to backpedal in an attempt to free things up. The chain slack that resulted allowed the chain itself to be sucked into the rear wheel, thereby destroying not only the chain, but also the rear derailleur hanger and probably the derailleur as well. The wheel and even the frame are also damaged, and may not be salvageable.

Yikes.

Headset Shenanigans

2009-03-20T14:48:00.000-07:00

I didn't think of taking a picture of this at the time, but an experience I had in the shop today was certainly blogworthy.

A fellow came in with some major stickiness in the Campagnolo "Hiddenset" headset on his Bianchi road bike, which he bought used. After removing the fork to take a look, I found that the top bearings were completely non functioning. Removing the parts from the headset cup, I discovered that there was a grand total of ZERO ball bearings inside. The bearing race was just sitting in the headset cup, as well as an unrelated fork crown race thrown in to take up enough space to fit the top bearing cover back on and make the bike look normal. This was an extremely dangerous condition. Installing the appropriate ball bearings and steerer tube compression ring, as well as removing the extraneous crown race got him back on the road. He will still need to get to a Bianchi dealer to have the headset replaced, as it has been subjected to some pitting.

Did you get your bike used? Have it checked out by a professional mechanic!

Wheelchair Project

2009-03-06T14:12:00.000-08:00

I officially suck at blogging, but here's a custom project we just completed to keep the blog alive. It's 8, count 'em, 8 wheelchair wheels. They're built to take the abuse of playing basketball and other sports where the chairs can take a beating.
The rims are Velocity Deep-V MTB's, laced to Cronometro's very own hourglass wheelchair hub using direct pull Wheelsmith spokes. Also included are Velocity Veloplugs instead of rim tape to cover the spoke holes. The Veloplugs are lighter, can withstand up to 400psi and make tire mounting easier because they take up less space on the rim than traditional rim tape.

Dreaming of custom wheels? We would be happy to work with you on the project. We can create anything from the lightest carbon race wheelset to extremely durable wheels for touring, mountain, cyclocross or BMX bikes.

Fender Mounting on the Karate Monkey

2009-01-27T08:36:00.000-08:00

I thought I'd share a solution I've come up with for mounting fenders on a bike equipped with disc brakes. If you've tried such a setup before, you likely know how much of a headache it can be. The problem lies in the fact that the disc caliper sits exactly where your mounting strut wants to be in order to connect the fender to the eyelet on the fork or rear dropout.

To make matters worse, on my Surly Karate Monkey I need to be able to access the rear caliper mounting bolts in order to swing the caliper out of the way if I have to remove the rear wheel in the event of a flat or other mechanical problem. The disc adapters supplied with my Axiom Rainrunner fenders compeltely block access to one of these bolts.

To solve this problem, I used the upper caliper bolt to secure one of the fender struts, like this:

The lower strut mounts in its stock location.

The front fender was a little more tricky. Because the Karate Monkey fork is suspension corrected, there is a large gap between the fork crown and the tire. Using the stock bracket to mount the fender to the fork crown leaves a giant gap between the fender and the tire. In addition, the upper strut on the disc side faces the same problem of interference with the disc caliper.

I shortened the struts and anchored them to the cantilever brake studs, which were not being used as it is a disc brake setup. To make sure the strut lays flat, I used some chainring bolt spacers that came with my Salsa chainring guard:

As you can see, the fender has been rotated forward a bit, leaving the stock bracket in front of the fork crown. I don't see this as a problem, since the fender still provides good coverage on the rear of the tire. It also makes a convenient mounting point for a light or reflector. You'll notice also that the bike does not have a disc front wheel on it yet. I'm still waiting for my Shimano Alfine Dynamo front hub to show up! I plan to use it in order to power a Supernova E3 headlight and possibly a taillight if I can come up with a mounting solution for it.

Crono's First Dura Ace 7900 Build

2009-01-07T07:46:00.000-08:00

I just finished up building our first bike outfitted with Shimano's new Dura Ace 7900 parts group, a fully custom Parlee Z1. The build went extremely well and the bike weighs in at 15.6lbs (without pedals).

Shimano's crankset engineering is simply amazing. Their forged aluminum crankarms are lighter and stiffer than many carbon cranksets on the market, and I applaud them for resisting the pressure to switch to carbon simply for its exotic appearance. The new 7900 crank boasts a 20% increase in stiffness, a lightweight hollow big ring, and chainring bolts that thread in from the back for aerodynamics.

The 7900 brake calipers are not all that different from the previous generation, but one change that I'm particularly fond of is the introduction of a new cable tension adjuster. The new adjuster has a lower profile and stands the cable housing in a more vertical position than the previous model, making it less likely to interfere with other cables when turing the handlebars. It also no longer has a tiny circlip inside the adjuster that is often lost on previous generations of brake caliper.
One important note is that these calipers have a higher mechanical advantage than the 7800's, and therefore require more cable pull. See the description of the shift/brake levers for more information on this.

Front shifting is much lighter with the 7900 group. It's quite impressive how fast one can shift to the big chainring with such a light throw of the lever. There is also no trim necessary when in the big chainring due to a redesign of the cage profile.

I wouldn't say rear shifting is much quicker with the 7900 group, but they did lighten the rear derailleur with a carbon outer pulley plate and tweaks to the materials engineering in the derailleur body. Small weight savings were made in the cassette with a lighter and stiffer aluminum sprocket carrier. Modifications were also made to the tooth profile here to improve shifting, although again I have not noticed a great difference. I should note, however, that the comparison I'm making is against the already snappy shifting of the 7800 group.

Each 7900 chain is supplied with a quick link for easy removal and reinstallation. This is convenient if you prefer to remove your chain for thorough cleaning. The previous method of installing a special breakaway pin seems a bit primitive compared to this elegant solution. Note that the 7900 chain is directional. The links with the engraved logos should face out when properly installed. The link is also directional and should be installed as pictured here.

The Dura Ace shift levers have undergone an extensive redesign for the 7900 series. Here are some shots:

Most important to us in the fit process is the contour of the new lever hoods. They are much flatter than the previous model, which should help achieve a comfortable hand position. They also feature adjustable brake lever reach, which will help fit those with smaller hands. The shifter's attachment bolt is a bit harder to get at, as the hood must be peeled back from the front end of the lever, but it's no more difficult than attaching a Campagnolo Ergo shifter.

Because the new brake lever & caliper are designed for more cable pull than the 7800 parts, they are not recommended to be interchanged. The longer cable pull of the 7900 lever used with the 7800 caliper would result in a stiff lever feel, but actually a loss of braking power. A 7800 lever's short cable pull with a 7900 caliper would give you lots of braking power, but a squishy lever feel. This is due to an increase in the mechanical advantage of the new brake caliper. Length of cable pull is a function of the caliper's mechanical advantage.

The late, great Sheldon Brown's site has an informative page on mechanical advantage as it applies to the differences in cantilever vs. linear pull brakes. Although this is a new application, the physical principles are exactly the same.

Galvanic Corrosion

2008-12-15T08:33:00.000-08:00

Aluminum is generally considered a "corrosion-proof" material for building bicycle frames, and it certainly resists corrosion in the sense that it does not rust like steel does. What is common with aluminum frames, however, is the process of galvanic corrosion. The problem with aluminum frames is that the frame is often in contact with a dissimilar metal, such as steel or even different aluminum alloys. The two metals have two different electric potentials, with the possibility of a tiny electrical current flowing between them. The presence of water and an electrolyte (both of which are found in the rider's sweat) facilitates this current flow, and ions begin to flow between the metals. The problem lies in the fact that the metal which loses ions begins to corrode much more quickly that it otherwise would.

Below are two examples of galvanic corrosion occuring on the same frame. The first photo shows a steel ferrule that has been in contact with the aluminum frame for a very long period of time, and has also been exposed to a lot of sweat. The steel ferrule has corroded and gotten stuck in the frame. Luckily, this is an example where the frame has not been affected, only the ferrule.

The second photo shows an area of the frame that has been in contact with another aluminum part, and also has been exposed to the rider's sweat for some time. In this example, the frame is the part that has been corroded by the process. You can see that the edge of the cable exit hole in the frame has begun to be eaten away. The other part involved is not pictured, but has not been affected.

The solution to the problem of galvanic corrosion lies partly in proper preparation of the parts before assembly, and partly in rider maintenance. A layer of grease between to dissimilar metals will act as an insulator, and is very effective at preventing the problem. However, it is not a substitute for regular cleaning of the bike. This is especially true in the off season when the bike is on a trainer. Because the rider does not have wind current to aid in evaporation of sweat, more of it ends up in contact with the bike. This makes it especially important to try to keep the bike covered when riding on a trainer (we can get you the Safe-T-Net from Minoura or other similar models) and one must remember to clean the bike after workouts. Replacement of cables and housing once a year will also ensure that the insulating layer of grease between parts is there to insulate the two parts.

Rim Wear

2008-12-01T09:54:00.000-08:00

The friction forces involved in slowing your bike down are enormous. The effect this can have on your rim’s braking surface is quite impressive, as the wear can be accelerated by grit picked up on the road and small aluminum shards that are shed from the rim and embedded into your brake pads. This can make your pads quite abrasive, resulting in serious weakening of your rims. The example above is of a front rim that has been worn down by braking, which has caused a concave shape in the braking surface. The rim wall is much thinner at the center and can eventually be worn completely through and make dangerous rim failure possible. In addition, this rim has some dents from various impacts over its lifespan, making it an ideal candidate for a wheel rebuild.

The wheel’s hub can typically be reused, although it may need an overhaul (like this one does). Parts replaced are the rim, spokes and nipples. A typical wheel rebuild will cost about $170 total, and hub overhauls will vary in cost with different models. Unless otherwise specified, we use stainless steel double butted spokes from Wheelsmith, DT Swiss brass nipples and a quality rim from a manufacturer like Velocity.

If you have any concerns about the condition of your rims, please give us a call or stop by the shop for an inspection.