Category: Drivetrain

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Fenders Touring Bike Tires

Tire and Fender Considerations for Snow and Mud

The temperature is going to be well below freezing this New Year’s Eve day and several inches of snow have fallen in the last 48 hours. A combination of de-icer, sand spread by the highway district and traffic has left the busiest roads mostly bare and dry. But driveways and side streets are covered with (one after another, or all at the same time) patches of snow, ice, slush and gravel. I’m not riding the bike today.

Ice on the street
Would even studded tires help here?

This morning I looked in a supplier’s catalog at tires with 400 or so carbide steel studs in the tread. I’m tempted to buy a pair but I’m not sure if even that would keep me upright on the ice. And the use for such tires is limited…I don’t really want to be taking them off and putting them back on every time it snows. If I had a bike with disc brakes I could try the old zip-tie snow chain trick.

Photo: Dutch Bike Co.

Earlier this month, before the snow was sticking, we went on a day trip from Three Horse Winery north of Eagle, ID to Montour, ID where we ate lunch before riding back. Scott and Aileen scouted this route prior and they were going to show us the fabled passage between Eagle and Montour which we had been unable to discover on our overnight trip last year. This turned into sort of an epic slog through mud and water and emphasized the importance of the right bike for the job… those of us with fenders spent quite a bit of time digging packed mud from between the tires and fenders. We even ended up taking Sky King’s front fender off when her front wheel completely bound up and stopped turning. For those on bikes without fenders and using disc brakes the going was relatively easier.

Here is a map of the route for those who might want to repeat it.

Even with the mud everybody had a great time and there was more smiling taking place than cursing although there was some of both. That is partly a testament to the cohesiveness and the great attitude of our fledgling bike touring group wherein everybody is quick to help others and nobody complains. Plus, every rider is competent and able to take care of themselves on and off the bike.

A touring bike continues to open my eyes to the scenic and solitary places within an hour or two of where we live. Places I never visited in the previous two decades of living here and probably would not have experienced in another 20 years, but which are suddenly accessible on my country bike. Not to mention a new group of friends….a group of thinking, entertaining and interesting people who make this hermit happy to be a part of it.

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Drivetrain The Touring Bicycle Wheel Touring Bike Components

A Bike Touring Wheelset

A hub is laced to a rim with spokes and nipples in order to create a wheel. Elementary I know but semantics are important if the aspiring bike tourist is to make him/her self understood.

I don’t want to go into how to build a bicycle wheel because there are hundreds of YouTube videos and several good books available on how to do it. (Jobst Brandt’s The Bicycle Wheel being the paradigm for books)

I will say there are a couple of elements that make a good, strong touring wheel, and these things may not be intuitive. Here is a good touring wheelset:

A durable inexpensive wheelset for loaded touring.

Shimano Deore hubs laced to Mavic A319 rims with 36 DT Swiss double butted spokes.

Notice there are a lot of spokes…36 per wheel to be exact. Each spoke crosses 3 other spokes on the way from the hub to the rim, creating a structure of amazing grace, elegance and stability. Some recently popular wheel designs with as few as 18 spokes per wheel rely on the strength of the rim for stability of the wheels which results in a heavier rim. (unless the rim is carbon fiber) Spokes actually are made in various gauges or thicknesses and a visceral reaction might be to assume that thicker spokes will result in a stronger wheel….but not so fast. The spokes flex with every revolution of the wheel, no way around it. So making the middle sections of the spokes thinner than the ends (called “double butting”) allows the spokes to flex and adds strength where they are most likely to fail; at the ends. Get Mr. Brandt’s book if you want to know the excruciating details.

In my experience, based on building dozens of wheelsets, there are only two companies that consistently make high quality rims: Mavic and Velocity. The Mavic A319 rims are a super solid choice for a touring wheelset. For hubs it would be hard to beat the Shimano Deore hubs for value. Steel axles and loose ball bearings make a durable, user friendly combination.

Mavic A319 36 hole.

Eyelets provide a wider and smoother bearing surface for the spoke nipple, distributing the load and mitigating galling or cold welding of the rim by the spoke nipple.

A good box section rim will have an outer wall and an inner wall creating the “box section”. The eyelets on the Mavic A319 distribute spoke loads to both the inner and outer walls of the rim.

FULL DISCLOSURE:
I built these wheels for a customer who reminded me he has disc brakes. Disc brakes require a disc specific hub onto which the brake rotor is bolted. These wheels don’t have a disc specific hub. That’s right, I’m a professional and an expert. I’ll be selling this wheelset and the customers new wheels are on the way.

Categories
Touring Bike Tires

More About the Best Touring Tire

Schwalbe Marathon Dureme
The Schwalbe Marathon Dureme

I enjoy reading the posts and looking at the pictures on the Pondero blog. The latest post happens to be a review of the Schwalbe Marathon Dureme tire. Check it out and look at some of his other articles while you’re at it. Good stuff.

I copied the following from the Road Bike Rider website. While not normally a great source of information for the touring bicycler I think the question and the reply at least provide a starting point for a reasoned decision about tire selection.

Are 25mm Tires Better than 23mm Tires?
Question:

I found out yesterday from my LBS owner that I’m apparently late to the party moving up to 25mm tire width. I’m told all the pros have switched. Is this why I’ve been able to buy 700X23 tires on-line so reasonably? – Seth S.

Coach Fred Matheny Replies:

Yes, there has definitely been a move toward wider road tires, and I suspect that’s why shops and websites are putting 23s on sale.

A number of studies, most notably by Jan Heine in Bicycle Quarterly (www.bicyclequarterly.com), have shown that wider tires roll faster on all but the smoothest pavement if the tires have supple casings.

Wider tires also tend to be more comfortable because of the increased air volume and because they don’t have to be inflated as much to avoid pinch flats. They corner on bumpy pavement better because they don’t bounce around on the rough asphalt like narrow tires tend to do if they are inflated hard.

The weight difference between the same tire in a 23 and a 25 — or even 28 — is minimal. The extra few grams are more than compensated for by increased comfort and performance.

The only drawback is that many race-oriented frames won’t accept anything larger than a 25, or in some cases a 23. Manufacturers are remedying this, in large part because pro racers in events like Paris-Roubaix that features rough pavement and cobblestones are going to wider rubber. A good example of a carbon race-oriented bike that can handle a 28 is the Specialized Roubaix.

I’m a convert. I’m running Michelin Pro Race 25s (which are more like 28s) and Conti 4Season Grand Prix 28s on all my bikes except my old Litespeed Vortex, which will only handle 25s. I made the switch some years ago due to the extremely rough pavement here in western Colorado. We have a variety of chip seal, potholes, convex patches and grass-filled cracks, but while narrow tires beat me up, 28s smooth things out considerably.

I haven’t noticed any difference in speed — maybe a slight increase — but the added comfort is what sold me. I used the Conti 28s on the Pacific Crest Tour this summer and even on the relatively smooth pavement of Washington and Oregon, they made a significant difference in efficiency over the two-week event.

And while we’re at it the Schwalbe tire company has a page about tire size and rolling resistance. It’s interesting to note that, at a given pressure, a wider tire has less rolling resistance than a skinny tire. Obviously a skinny tire can be inflated to a higher pressure but the trade off is a less comfortable ride.
a rolling resistanc graph

So don’t just assume that replacing the tires on your mountain bike or touring bike with some skinny, punishing race tires will make your commute better. Might want to consider the construction and tread pattern too. Maybe a little wider tire will still allow you to punk the other commuters on your route and yet not beat you up before you even get to work!

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Bottom Brackets and Crank Sets Drivetrain

Some Square Taper Bottom Brackets

Second in a series on bottom brackets. Numero uno is here.

The newest (2012) Long Haul Trucker complete bikes come with the Shimano UN55 square taper bottom bracket which is an improvement over the UN-P.O.S. used in earlier years, but when asked what I might upgrade on a stock Long Haul Trucker I am likely to recommend a new bottom bracket. Don’t get me wrong, the bottom bracket that comes standard on the stock LHT is perfectly adequate. But there are bottom brackets that will last longer.

With bottom brackets, one gets what one pays for. In this case more money buys better bearing seals, higher quality bearings made to stricter tolerances, and better materials throughout.

Phil Wood Company designs, manufactures and assembles precision bike parts in San Jose, CA. USA. Their bottom bracket uses two adjustable cups to hold the bearings and spindle in place which makes it possible to achieve the perfect chain line, since the bottom bracket can be positioned within a 5 mm band of “normal” centered position. The cartridge bearings are plainly visible when the unit is installed, which might make one wonder about the durability when used in extreme conditions, but Phil Wood Co. uses “seals which are as good or better than those found in the highest quality submersible motor and pump bearings”. I have only seen one Phil Wood bottom bracket that needed servicing though, and even that was straightforward….the unit can be sent back to the company for new bearings at a reasonable cost.

phil wood bottom bracket
Phil Wood cartridge bottom bracket
bottom bracket cups for phil wood
The left and right cups use an interference fit with the bottom bracket and require the use of the Phil Wood bottom bracket tool

SKF is a German company (Correction: Thomas K. correctly points out that SKF headquarters are in Gothenburg, Sweden) which has been a leader in bearing technology since 1907 and today is the largest bearing company in the world. Their approach to bottom bracket design strives to incorporate the best of old and modern technology. Rather than using cartridge bearings pressed onto the spindle and into the bottom bracket cartridge they use bearings which are received by races which are part of the spindle and the shell. Custom seals are used to keep contaminants away from the assembly. This way they can use roller bearings on the drive side and over-sized bearings on the non-drive side increasing durability and strength. This design has some appeal to the retro-grouchy Bike Hermit, and SKF is proud of it too….they offer a 10 year or 65,000 mile warranty (just be sure to keep track of your miles) 😉

SKF bottom bracket. The little bit of bling afforded by the red cup is not undesirable.

 

The mechanical seal designed to keep the bearings cozy and happy in the most inclement weather
Categories
Bottom Brackets and Crank Sets Drivetrain Touring Bicycles

Bottom Brackets

At the risk of talking down to some readers and over the head of others I feel the need to explain the term “bottom bracket”. According to Sheldon Brown’s Bicycle Glossary a bottom bracket is:
The part of the frame around which the pedal cranks revolve, also the bearings and axle assembly that runs through the bottom bracket shell of the frame.

SKF Bottom Bracket
This is an SKF brand bottom bracket. The red cup slips off to allow the unit to be threaded into the bottom bracket shell.

Looking at the late Mr. Brown’s page I realized I am opening a bona fide can of worms. There are several bottom bracket “standards”, and bottom bracket/crankset interfaces. We won’t even get into “outboard bearing” and “BB30” and other new standards which are mostly calculated to keep the buying public buying, while claiming to add some performance advantage…not performance related to the durability or function of the piece… but of the rider/bike.

“Square taper” bottom brackets are made to work with “square taper” cranksets and cranksets with suitable chain ring sizes for touring generally are of the square taper variety. Clink this link for a discussion of gears and gearing. So this series of pieces will be about square taper bottom brackets.There are still compatibility issues to think about though. The taper on Italian (Campagnolo) cranks and bottom brackets are different from the taper on cranks and bottom brackets made anyplace else in the known Universe, which actually is typical of Campy parts. And bottom brackets come with different spindle lengths. The correct spindle length for a given bicycle will be a function of the width of the bottom bracket shell, the shape of the chain stays and of the shape of the crank. For example: with a Sugino XD500 (XD2) triple crank set on a Surly Long Haul Trucker, a 107mm to 110mm spindle length works well.

Before the widespread use of cartridge bearings, bottom brackets were designed with loose balls or caged balls running on races inside the cups and races shaped into the spindle. Mechanical seals or o-rings were used to keep out water and dirt. Nowadays the spindle is held inside a case by means of sealed cartridge bearings pressed onto the spindle. The only seals being those on the bearings themselves. A less than ideal state of affairs for the part of the bicycle in a location that will be sprayed from time to time with a slurry of water, grease, oil, de-icer, sand and grit.

So, what’s the dyed-in-the-wool bike tourist to do? In the following posts we will explore some of the available options for touring bike bottom brackets. If the idea of reading about that titillates you, you should think about getting a life.

Categories
Drivetrain Touring Bicycles Touring Bike Components

A Trio of Tough, Top-Notch Tires

We travel, in a week, to the high desert south of Boise for a three day ride on mostly unpaved roads. For the rough, loose surfaces we have outfitted our bikes with wider tires. More air volume at lower pressures is going to make for a smoother ride and a wide footprint will float over the loose sections.
On the Long Haul Trucker I am running the Schwalbe Big Apple 29 x 2 tires. I have always been impressed with the way the Big Apple tires transform the ride on any bike and I’m looking forward to this test of their toughness.
Sky King will be riding the Grand Bois Hetre tires from Compass Bicycles. So far she is liking the way the Hetres perform on her 650b Rivendell Bleriot.
Julie opted for the Schwalbe Marathon Mondial in 26 x 2. The beefiest tire of the three the Mondial also has a more aggressive tread pattern.

line up of three tires
Left to right: Schwalbe Big Apple, Grand Bois Hetre, Schwalbe Marathon Mondial
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three tires
Tableau of Thickset Treads

riding in the Boise foothills
Sky King and Sky putting the Grand Bois Hetres through the paces.

A rare Bike Hermit sighting

Notice that none of the bikes have fenders. We removed them because, even on the Surlys where “fatties fit fine” there was no room for fenders with the new big tires. And anyway, after my experience with tumbleweeds on my recent two day trip down to Swan Falls, I might infer fenders to be dispensable and even unsuitable for off road touring. Stay tuned for updates… same bat time, same bat station.

Categories
Drivetrain Touring Bike Components

More on Touring Pedals

The Bike Hermit has a pair of MKS Unique pedals purchased in 1972 for the then princely sum of $25.00. The Mikashima Industrial Company, LTD in Japan has been making pedals since 1946 and is obviously doing something right. What follows is an overview of two of the dozens of pedal models the company offers today, the Sylvan Touring and the RMX Sneaker pedals.

pedals
MKS Unique

two MKS brand pedals, side by side
The MKS Sylvan Touring pedal is on the left, the MKS RMX Sneaker pedal is on the right

mks touring and sneaker pedals
The MKS Sylvan Touring pedal in front of the MKS RMX Sneaker pedal.

The RMX pedals weigh just under 400 grams for the pair. Same as the Sylvan Touring pedals. Both pedal models use a cone and loose ball bearing system so they are user serviceable. The Touring model has a larger diameter axle and larger ball bearings which may make it more durable than the RMX pedal.

end view of pedals with dustcaps removed
Removing the dust caps reveals the larger axle and bearings of the Touring model on the top.

Aside from the apparent difference in size and shape, there are some functional aspects to consider as well. The RMX Sneaker pedal, because of the way the cages are made, will not accept any sort of toe clips or straps, but the Sylvan Touring model will. Either traditional toeclips with straps or the Power Grip system will work.

power grip strap kit
The Power Grip strap kit comes with all the pieces needed to bolt them onto a set of pedals.

power grip strap adapter bolted onto a pedal
Pedals with flat sides to the cage and two bolt holes will accept the angled adapter plate which comes with the Power Grip Strap kit.

Some people prefer to not be attached to the pedal in any way, and they are entitled to their wrong headed opinions. (just kidding) For those people either the RMX or the Touring pedals will work. For those who want a little bit of added security and who, like the Bike Hermit, are not coordinated enough to keep their feet on the pedals in all conditions, the Sylvan Touring model with toeclips or Power grip straps would be a good choice. Based on past experience, either set of pedals should give years of dependable performance.

Categories
Drivetrain Touring Bike Components

The Bicycle Wheel

What makes a good wheelset for loaded bicycle touring? Durability will probably rate high in any list of desirable attributes. So, what makes a bicycle wheel durable?
Rims:
An extruded aluminum double wall rim with a box section for strength. Drilled for 32 or 36 spokes with eyelets in the spoke holes. Eyelets can help distribute stresses and prevent galling of the metal where the spoke nipples rest. My personal favorite rims are Mavic CXP33 because they have a socket attached to the eyelet which distributes load to both walls of the rim. Another consideration when choosing a rim should be the width of the tire to be used. Schwalbe, the tire manufacturer addresses that on their website.

cross section of aluminum rim
A double wall, box section rim. Photo from Wikipedia

Spokes:
Spokes are normally made of stainless steel and are of uniform thickness the entire length (straight gauge) or are swaged to be skinnier in the middle (double or triple butted). Counterintuitively, double butted spokes are a better choice for durable wheels for a number of reasons. The skinny part is made skinny by drawing that section of the spoke through a reducing die which increases it’s strength by work hardening. The swaged spoke is more elastic and absorbs the stresses in the mid section rather than concentrating it in the elbows and threads. The third advantage requires a discussion of lacing patterns.

A “3-cross” lacing pattern means that any one spoke will cross over three other spokes on it’s way from the rim to the hub. Actually it will cross over two and under one. Without going into a lot of detail (mostly because I would probably get it wrong) the stresses induced in a spoke when the wheel goes around under the rider and load are in that way shared by more spokes. Swaged or double butted spokes do a better job of sharing this stress than straight gauge spokes by their virtue of being more resilient – they flex more.

a front bicycle wheel
A 3-cross spoke pattern. Photo from Wikipedia

Hubs:
Hubs must carry the individual spokes and be strong enough for the combined force of all the spokes in a finished wheel, a force that can equal a half ton in a 36 spoke wheel. Hubs can use loose bearings or cartridge bearings with benefits and drawbacks to both. An oversize and/or steel axle can be stronger for load carrying than a smaller alloy axle. As a generalization, most manufacturers will turn to aluminum or other exotic materials in their quest for lightweight in the upper end range, so it might be better for the touring cyclist to actually buy the less expensive models if they use more robust and durable materials.

Wheels can fail from sudden loads, such as in a crash, or running into an immovable object, or from fatigue. Rims can be abraded by sand and road grit imbedded in the brake pads, and can eventually fail when the force of the inflated tire breaks the wall of the rim. Rear wheels carry more weight and receive more stress because of the rigidity of the rear triangle.

Most spokes will fail at the elbow where they enter the hub due to fatigue. A properly built and tensioned wheel laced in a three cross pattern can reduce the risk of fatigue failure.

Many new bikes come with original equipment wheels that look light and fast because they only have a few spokes and aerodynamic rims. However, semi-aerodynamic and aerodynamic wheelsets tend to be heavier than more traditional spoked wheelsets due to the extra shapings of the rims and spokes. More important, the rims must be heavier when there are fewer spokes, as the unsupported span between spokes is greater.

I borrowed heavily for this post from the book The Bicycle Wheel by Jobst Brandt. If you want more about the theory behind the spoked bicycle wheel and want to have a go at building your own wheels, this book is a must.

The late, great Sheldon Brown’s site is an encyclopedia of all thing bikey, and this page tells how to lace a wheel.

 

 

Categories
Drivetrain Touring Bike Components

Schwalbe Marathon Mondial

(Update 2/20/2012 – The Bike Touring News store now has the Schwalbe Marathon Mondial tires in stock in 700 x 35c and 700 x 40c sizes in the folding version. The 26 x 2″ folding tire is due to hit North America in March,2012.)

Marathon Mondial 622
The new (2012) Schwalbe Marathon Mondial touring tire

The Schwalbe Marathon XR is frequently hailed as the best expedition/long lasting touring tire out there. The ‘XR’ was synonymous with ‘Schwalbe’, in fact, along with the regular Marathon, some think the XR helped build Schwalbe a good name and customer base. Unfortunately, in 2009 Schwalbe decided to discontinue the model. Other tires stepped in to fill the void, namely the Dureme and Extreme and the Plus Tour, but none of those had all the features that made the XR so popular.

Recently I read about a new tire- the Marathon Mondial. According to Sean at Schwalbe North America:
“……the Mondial is not a direct replacement to the Marathon XR, more of the next step in the evolution of the tire. Compared to the XR the Mondial will have the SnakeSkin sidewall which is an additional rubber coated aramid layer which helping to prevent sidewall cuts and abrasions. The Mondial also gets a modified triple rubber compound which we call TravelStar, the compound will increase road performance while also increasing the durability.”
For more information I went to the global Schwalbe website and found this about the TravelStar compound:
The Marathon Mondial has “State of the Art” TravelStar Triple Compound. Under the tread centre lies an elastic mixture for easy rolling, while there is a grippy rubber compound, for cornering traction on the tyre´s shoulder. In the middle of the tread an abrasion-resistant, harder compound offers low rolling resistance for thousands of miles.
Unpredictable gravel roads and potholes, acacia thorns: these are the treacherous tyre killers. Protection may come down to the smallest of margins such as the durability of the rubber mixture. The lightweight extremely densely woven High Density puncture protection belt reliably protects against punctures and ruptures. The light but sturdy “Snakeskin” protection provides maximum reinforcement against sharp objects that would otherwise cut the sidewall.

According to the catalog cuts I have seen, the folding version of this tire will have the TravelStar compound and the Snakeskin casing while the wire bead versions will have Schwalbe’s “Endurance” compound and their RaceGuard casing which is a double layer of nylon fabric.

Look for the folding tire in sizes 26×2, 26×2.15, 700×35 and 700×40. The wire bead tires will come in 26×2, 700×35 and 700×40 sizes. Availability in the US will be October 2011 for  limited sizes and 2012 for the complete lineup. Prices will range from $48.00 to $90.00 depending on size and version.

This thread at crazyguyonabike gets a little out of hand, but in a good, funny way.

 

Categories
Drivetrain Touring Bike Components

Fears of Gears,Gear Inches, Gear Development

Photo of Shimano 10 speed cassette
This is a "10 speed" cassette

“ Hey baby, what kind of gearing you got on that thing?”

What kind indeed.  I guess I got gears in the front and gears in the back. But how do I know what my “gearing” is?  One way to measure mechanical advantage on a bicycle is to use a concept called “gear inches”. Gear Inches? Huh? Gears have inches? What about gear development? What? Are gears reaching puberty? What’s a gear? On a bicycle we use toothed wheels (the front chainring and the rear cogs) to give us mechanical advantage. That means we can make our legs go around really fast compared to how fast the rear wheel is going around…..like when we are climbing a hill. Or we can make the wheel go around really fast with relatively little motion from our legs…..like when we’re going downhill with a tailwind, just by changing the combination of front and rear chainrings/cogs.

Photo of a double crankset ie,one with two chainrings
A double crankset.
Photo of a triple crankset, one with 3 chainrings
The triple crankset

Really, “gear inches” are just a way to quantify the mechanical advantage offered when the chain is engaged on a particular size of front chainring and a particular size of rear cog. A gear inch is not a real unit of measure –                   “Why are women bad at estimating lengths? Because they have always been told “this is 8 gear inches.””

But it is a useful way to compare different combinations of gears to achieve the riders goal. If I know how many teeth are on each of my front chainrings and on each of my rear cogs I can figure out the gear inches for every combination and plot them on a chart.

Snapshot of a chart showing gear inches for 46,36,26 crankset and 12-27 rear cassette
Chief's current gear range in "gear inches"

The late Sheldon Brown has an online gear calculator that makes figuring gear inches snap like. This chart shows the gearing setup on Chief, my touring bike. I’m using a crankset with chainrings of 46, 36 and 26 teeth and a rear cassette which ranges from a small cog of 12 teeth to a large cog of 27 teeth. Giving me a top gear of 103.5 gear inches when the chain is on the big ring in the front and the small cog in the back…. for those high speed descents, and a climbing gear of 26. If I had a larger big cog in the back and/or a smaller small chainring I would have a lower number for my climbing gear and hence a little more mechanical advantage. Some touring bikes, for example, the Surly Long Haul Trucker come stock with a low gear of 21 -22. The 103.5 top gear has been adequate for my purposes.

Comparing the values on the chart, it becomes apparent that their is some overlap, some redundant gears. Noticeably, the 46/27 (46 tooth cog in the front and 27 tooth cog in the back) and the 36/21. It’s entertaining to play with different gear combinations to try to get the best range with little redundancy. The most important thing though for the touring cyclist is to have a low gear that provides enough mechanical advantage to get them over the hills on their planned route. Knowing that  number will only come from experience but  21 to 22 gear inches should work for most people on most routes. For mountainous, off road touring a low gear of 18 to 19 might be more suitable.

The number of teeth on a chainring are marked.
Most chainrings will have the number of teeth marked on either the front or back of the ring.
The number of teeth on each cog in the cassette is marked on the back
The number of teeth on each cog of the cassette is usually marked on the front. Not always easy to see, especially on dirty cogs.