Archive for the ‘Repair’ Category

Continental Gatorskin rear tire lasts 5,400 miles

November 12, 2014

My Continental Gatorskin  tire lasted 5,400 miles. (Continental photo)

My Continental Gatorskin tire lasted 5,400 miles. (Continental photo)

5,400 miles. That’s how long my Continental Gatorskin 700 x 28 rear tire lasted. Not bad. It saw quite a few miles of dirt too.

I paid $52 for the tire, so it had better last that long. A small amount of cord is showing, so you know it’s time for replacement.

Recently I ran over a large staple and, although it jammed into the rear tire, it did not cause a flat. I stopped after about five seconds and removed the staple, which had not gone in far enough to cause a flat.

I credit some of my good fortune to riding a quality tire.

I still have a Michelin Pro Optimum on the front with the same mileage and it will probably last until I decide it’s time for a new one, usually when the sidewall begins to fray [I took it off a month later because it looked ratty].

Front tires require close attention because if one blows on a fast descent, you could be in trouble.

One word of advice from Continental in its instruction sheet, written in 16 languages, says to toss your tire, tube and rim strip after three years, irrespective of miles ridden.

I guess I’m just too cheap. I’m riding a tire that’s nine years old. It’s on my rain bike. I stored a tire for 28 years before using it. Worked great.

I ride inner tubes until they have so many holes they’re not worth patching, but usually I have to replace them because the tube fails at the valve.

I’m trying out a Continental Grand Sport Race Road tire next. The 700 x 28 version has an actual 28 mm cross-section. Amazing! Check back in 10 months for my report.

Floor pump repairs

June 18, 2014

Topeak sells spare parts for their excellent floor pumps.

Topeak sells spare parts for their excellent floor pumps.

I’m not too particular about floor pumps, so when my Topeak Joe Blow Sport finally failed, I looked for a spare part — the head.

The pump head is usually what fails because its lever clamp gets a workout. Mine finally failed. One side screws into the head, allowing access to the interior. That part started popping off.

I glued it down but then the lever that is screwed in started pulling out. Topeak sells a replacement head and hose, complete with parts for all their pumps, for about $20 online.

It was easy to replace. All I had to do was unthread the hose at the pump base using a wrench and then rethread the new hose by hand.

The pump head lasted at least 10 years. I don’t know when I bought the pump but I paid $30 and now it goes for $50. The only other maintenance you need to do is occasionally grease the plunger. It’s easy to access. Just pull back the tabbed plastic seal at the top and twist.

Jobst Brandt invented what he believed to be the best floor pump, a double-action behemoth. It was custom-built. I tried it once and found it hard to use. That was partly because the pump was built for his 6’5″ frame, but also because it was hard to pump. He claimed he could fill a standard road tire in 10 strokes.

While other double-action pumps have been made, the reviews have not been favorable.

My all-time favorite floor pump was Silca, but it had one irritating drawback. There isn’t a clamp at the pump head. You have to rely on the rubber washer inside the head to hold the presta valve. Those washers don’t last long before they lose their grip. They’re still sold online, but at more than $6 apiece, I’ll pass.

So many ways…to mess up a hub

December 23, 2013

Over-tightened hubs will bind and cause pitting in the race. This is a  Shimano 6700 hub with dimpling from being too tight.

Over-tightened hubs will bind and cause pitting in the race. This is a Shimano 6700 hub with dimpling from being too tight.

Well, it has happened again. I messed up a hub, and it can’t be fixed.

It’s one of those lessons learned when switching components. For decades I used Campagnolo. You learn the ins and outs of parts and everything is wonderful.

New parts have new problems and quirks you need to learn. Take the Shimano Ultegra 6700 front hub. I had a squeak that I couldn’t identify, which turned out to be a loose front quick-release. So I cranked it down, hard.

I also repacked the loose-bearing hub (11 3/16″ balls by the way according to Shimano) and when I did so, I may have adjusted it a bit too tight. It’s one of those adjustments that requires finesse and an awareness of what’s right for a particular hub. You want a small amount of play. That’s because when you clamp the quick release, there’s more compression of the threaded bearing race on the clamp side.

All it takes is a bit too much pressure for the bearings to bind. That binding caused the dimples in the hub race. Back in the days of Campagnolo, races were replaceable, but not Shimano’s. I don’t think this hub is toast. It’s probably going to last quite a while, but not as long as it might last with proper treatment.

Service sealed headsets and bottom brackets
While you’re servicing your hubs, note that just because you have a sealed-bearing headset doesn’t mean it needs no maintenance. The bearing cartridges ride on races and they need grease. If not greased, they’ll start making noise or, worse, wear out the headset prematurely. I didn’t service mine for two years and that was probably a year too long.

I took off the bottom bracket on the Shimano 6700 and while it doesn’t look like it needs any maintenance, it’s always a good idea to grease the threads and clean the parts. Sealed-bearings are designed to emit a bit of grease. They’ll dry out, eventually, and need replacing.

Addendum: As I look at the photo, it occurs to me that the dimples are low on the race. I’m wondering how it could dimple so low? Are the bearings really riding there? Odd.

Addendum 2: I was using 7/32″ bearings (Campy on my mind) rather than 6/32,” and that could explain why the bearings rode low in the hub. I’ll replace them with the correct count and size and see what happens.

WD-40 quells the last creak

May 20, 2013

WD-40 silenced my creaking shoes.

WD-40 silenced my creaking shoes.

This weekend was a milestone celebrated in silence. Nothing squeaked or creaked on my ride. That means my shoes didn’t creak the way they often do, especially when I ride in dirt.

I had tried oiling the cleats, but that didn’t work. It may have made it worse.

What happens is microscopic grit gets between the metal holding plate, shoe sole and cleat. You can clean out the grit but it comes right back.

I decided to try WD-40. WD-40 is strange stuff. It’s mostly a solvent of hydrocarbons that work by transporting a little Vaseline and mineral oil into tiny crevasses.

So unlike a heavy oil, which gums up the cleat and attracts dirt, the WD-40 penetrates inside the shoe cleat and works where it’s needed. No residue and no creaking. At least that’s my experience.

One of the perks from buying WD-40 — it’s made in San Diego.

Freakish Squeaks Keep on Coming

April 25, 2013
Old saddles on new seatposts can rub and cause squeaking.

Old saddles on new seatposts can rub and cause squeaking.

Here's how it used to look. Campagnolo seatposts offered plenty of clearance.

Here’s how it used to look. Campagnolo seatposts offered plenty of clearance.

When will it end? How many more squeaks and creaks do I have to live through?

I blame it on the transition from old, reliable technology to new, reliable technology. I have to learn all over the ins and outs of today’s bike parts and what makes them tick, and squeak.

This time it’s a case of old parts not meshing with new parts.

I purchased a new old stock Avocet Racing II saddle and slapped it onto my new technology seatpost. It’s one of those generic posts with the standard seat clamp I see on most run-of-the-mill posts.

It turns out that the clamp is wider than the Campagnolo Super Record seatpost that used to hold my Avocet saddles, so the inside of the saddle rubs against the clamp. If not lubricated, it squeaks like hell.

Who knew? Today’s saddles don’t have the long sides that characterized the seats of yore. When you think about it, you don’t need the long sides. It was probably a fashion decision to cover the seatpost. Modern saddles have gone the opposite direction.

A Link to Chains

March 25, 2013

Here’s a chain measurement. At 12 inches (13 shown here because I started at 1 inch) a worn chain will be 1/16 inch beyond center to center. This one is about 1/32 inch so it has more wear.

When I shifted to Shimano Ultegra, minor matters, like the cost of a chain, suddenly took on new meaning. $40-$90 for a chain?

I purchased a Park CC-3.2 chain wear-indicator tool and started cleaning my chain with Simple Green more often. I also purchased a second chain so I’d be more inclined to clean my chain, some KMC master chain links and Park MLP-1 master pliers. I read up on the best way to clean a chain as described by Sheldon Brown. I especially like putting the chain in a container with Simple Green and shaking well.

I’m pleased to report that the chain is wearing longer than I expected. Worn chains will more rapidly wear freewheel sprockets, adding to the cost of maintenance.

The Shimano CN-6600 has about 4,000 miles, but it won’t last much longer. Park has two settings, .5(%) and .75(%). It’s at .5 but being the cheapskate that I am, I’ll let it go to .75, which is about 1/16 inch and the recommended wear point for chain replacement according to the experts.

While Pardo and others mention that most chain-wear indicator tools push the rollers apart and are therefore “inaccurate” it’s easy enough to measure your chain when the chain-wear tool indicates it’s worn, just to confirm. Of course, measuring with a ruler is subject to error as well.

Park no doubt accounted for the roller spread when making the tool and from what I can tell it’s spot-on accurate. Now back to your regularly scheduled bike riding.

Follow Up (April 30, 2013)
About 550 miles later the chain wore down to the 0.75 setting. Your mileage may vary.

Park chain wear tool makes it easy to judge chain wear. When the tool easily fits into the .75 setting it's time for a  new chain.

Park chain wear tool makes it easy to judge chain wear. When the tool easily fits into the .75 setting it’s time for a new chain.

Bikes hanging from rafters

December 15, 2012
Lowering hooks makes for easy bike storage in the garage.

Lowering hooks makes for easy bike storage in the garage.

I finally got around to lowering my bikes hanging from a garage rafter. It’s no easy thing to lift a steel bike and hook it three feet above your head. I found a spare 2×4 and some left-over hinges, made a few measurements, and now I only have to lift the bike a couple inches for storage.

A Christmas wish come true

December 13, 2012

Bike-assembly elves had a busy night preparing for Christmas day.

Bike-assembly elves had a busy night preparing for Christmas day.

I never was much of a wrench, and I have not gotten better with time, as I proved last night while assembling bikes for families in need.

It took about one minute to recall why I didn’t enjoy working in the repair shop at Palo Alto Bicycles back in 1979. I’m like a beginner violinist. Lacking coordination, unpracticed. No mechanic worth his weight in Phil Wood grease would need five minutes to adjust a front brake.

I once hired a Toyota dealership moonlighting mechanic to work on my car and he let me watch. It was like cellist Yo-Yo Ma making beautiful music. He could troubleshoot like no other, and there was nothing he couldn’t fix.

But I digress. Fortunately I broke my wrist in a bike crash on Mt. Hamilton and that put me in mail order. Much better. I could sort and pack, process returns.

Target bike quality
While working on the bikes sold by Target I learned a few things. Magna mountain bikes, retail $100, aren’t bad. They would be fine for around-town riding. Just don’t take them on a trail with serious jumps. They’ll snap like a dry twig.

How Target can make a profit on a bike costing so little is a mystery. It’s not like they’ll get rich from return customers buying bike accessories. Tubes? Tires? Give me a break.

Quality is decent. Sure there was a glaring gap in one of the robot-welded frames, but all in all the parts work. I was especially impressed with the gears. Nice shifting.

A few pointers. These bikes need tuning by a pro. The bottom brackets barely turned on some bikes. Fortunately I had the tools. Brakes are hard to adjust. It was a combination of poor alignment, cheap parts, lack of lubrication, and incompetence.

Headsets were tight, some so bad the forks barely turned. That’s an easy fix when you have the right tools. But what of the poor person buying this bike and trying to assemble with no experience? It’s a frightening thought.

Fortunately some local agencies have the best interest of the less fortunate in mind. They relied on experienced bike riders to put them together and then they took those bikes to a shop for further inspection. So for someone’s Christmas morning it’s going to be a smooth ride on a shiny new bike. It was a pleasure to help.

Creaky Bike Seat

November 15, 2012

Creaky saddle? Oil it here with Liquid Wrench penetrant oil.

I’ve had not one but two creaky bike seats in recent weeks. They’re both Avocet, a NOS Racing II and an ancient Gelflex. It just so happened they had the same issue, common with older saddles running a lot of miles.

The seat rails just need a squirt of oil where they fit in the saddle. It dries up in there. Not just any oil. I found Liquid Wrench penetrant oil works best. Other oils may be too thick to soak in. Be sure to tip the saddle vertical as shown in the photo.

The saddle creak symptom only happens when you’re sitting in the saddle, usually while climbing. It won’t creak when you’re riding out of the saddle.

Easy and Not So Easy Tire Mounting

June 7, 2012

After more experimenting on tire mounting, I’m changing my thoughts about what’s more relevant to a good fit.

I thought it was the tire, but now I’m beginning to think it’s more the rim than the tire that matters. I mounted all sorts of tires on the modern Mavic Open Pro rim and they went on with ease, even the Nashbar tire, although that was not my original experience (Good Tire, Bad Tire).

However, mounting tires on the old Mavic MA2, MA40 and Rigida rims was much harder than the Open Pro for the same tire. After looking carefully at the two rims, the deeper channel on the Open Pro appears to give the tire more adjustability for an easier fit. I can’t think of any other explanation.

The Open Pro has a 19 mm vertical profile, while the MA2 is only 13 mm.

I’m not an expert though, so I’d like to know more.

I still believe the tire plays a role. Some tires go on easier than others, but I’m not finding anything on the Open Pro rim that’s an issue, yet.

Considering how much easier it is to mount tires on the Open Pro, my love affair with the MA2 is over. I’d certainly never shell out $300 for a NOS pair on eBay.

A brief video above shows how incredibly easy it is to mount tires on the Open Pro, versus mounting a tire on an older French rim.

Tire Size Actual width
Bontrager Select 700×28 27 mm
Bontrager All Weather 700×28 27 mm
Continental Ultra 2000 700×28 25 mm
Continental Grand Prix 4 season 700×28 26 mm
Continental Gator Hardshell 700×28 26.5 mm
Michelin Optimum Pro   700×25 26 mm
Michelin Speedium 2 700×25 25.5 mm
Nashbar Prima 700×25 25 mm
Continental Ultra (modern) 700×28 25 mm


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