The main reason that aerobars may have an advantage over flat or road bars is that they are designed so that your main support mechanism is skeletal, rather than muscular. The longer the distance, the more this will hold true.

This picture is of a top triathlete. Note that the forearms are almost parallel, and the upper arms are at a 90 degree angle. This allows the main support for the upper body to rest on the bone structure, with minimal muscle involvement. (Stadler was an Ironman distance triathlete, bike segment of 112 miles).

While you may see variations on this, it is a general truism that the longer the race, the more comfort trumps aerodynamics, and vice versa (Short races aerodynamics trumps comfort.)

Many of the ultra mountain bike competitors set up their rides similarly, and have "wrap" style aerobars that allow them multiple different hand positions for control, as well as the resting position where their arm muscles don't have to do the work for support.

That all being said, I would point out that many riders go much further than 40 miles with no pain at all. This would suggest to me that your fit is not correct, or that you are not in shape enough for a 40 mile ride yet. Tailbone pain is (usually) a bad saddle and fit, and the rest is also easily attributable to fit. Aerobars will not be a magic cureall for an improperly fitted bike


Sudden loss of air on tubless tyre, and now it won't inflate

Your valve should NOT be depressible into the rim.  You should have a presta ring screwed in it, else nothing is retaining the valve and your air probably leaks from there!

If its not the case, if the tyre is seated correctly on your rim, inflating it with a pump should be easy.  Maybe you have a dent on your rim where your air is leaking.

Yes absolutely, you can get a new valve for tubeless tire.

A good way to find where your air is leaking from is spraying soapy water around and check if an area makes bubbles.  It will tell you exaclty where your leak is from.

Cheers


Tern Spartan (front rack) on Bike Friday NWT

Yes, a Tern Spartan Front Rack does fit on a BikeFriday New World Tourist (and also the Tern Cargo rear rack):

To prevent the rack from interfering with the V-brakes I mounted the upper end of the rack (and the fender) on a 80mm screw. Behind the fork I inserted 4x6mm spacer (the thinner in diameter the better) to mount the rack before the V-brakes (yes, the mount does interfere with the brake's cable but since the surface of the spacer is smooth I do not expect to notice anything when braking):

As of January 2020, Tern offers two versions of the Spartan front rack. 74mm and 100mm. I bought the 74mm version. When mounting the rack to my BikeFriday NWT, I felt like the rack could be slightly wider in order to being able to mount it with less force. However when measuring the rack at the height where the panniers are mounted, I measure roughly 100 mm which I find confusing.

Some may argue that using a 80mm screw with a margin of some 30mm from the fork to attach the rack reduces the stability of the rack and the maximum loading capacity. However, to me this does not seem to be the case considering that I will not mount very high weights to the rack. I do not know if my solution also works with disc brakes rather than V-brakes.


Tire is losing air but inner tube seems to hold air

Just check the tube more carefully, some holes are very hard to spot. Put it into the water and look for bubbles. You must fill the tube and press it. Try hearing any hiss when pressing the tube in the air. There could still be a thorn in your tyre, we have many similar questions. It does not matter if it is an e-bike or not.


Why aren't hub/drum/roller brakes suitable for touring?

Their main problem is your first bullet hypothesis: They can't cope as well with sustained braking on descent, as that is where brakes are challenged the hardest.

Even with the extra cooling fins, on a long descent, the brake may overheat, and may catastrophically fail. Riders using roller brakes have reported the brakes getting hot enough to ignite the internal lubricants inside the hub when making descents on tandems or loaded bikes.

Even if you had cooling fins the size of the wheel, you are generating heat inside the hub, and that heat has to travel out to the fins, which is surprisingly slow. Going down a mountain, you theoretically could have your hub start on fire, while the outer parts of the cooling fins could be cool to the touch. Disc brakes don't have that as the source of the energy is at the caliper which is on the outside of the rotors, but even then those have failed from overheating too.

The weight aspect on its own isn't too big a deal, even with heavy loads,
you can only slow down so much before you are completely stopped. However, when descending, you can drag the brakes and build up heat faster than it can be dissipated, and combining a descent with a heavy load doubles the demands on the brakes.

Ultimately, every bicycle brake system turns kinetic energy into heat, and has a maximum wattage it can operate at continuously. What increases the wattage is greater deceleration or greater loads.

If you were touring across Iowa, you'd be totally fine. Japan is pretty mountainous. If you are going to only be traveling where the terrain is pretty gentle, you'd probably be OK. If you are going into the mountains though, you'll want a different brake system.


What's the deal with compressionless brake cable housing?

I recently upgraded my brake cables with some Jagwire of the compressionless variety. jm2 is correct in saying the steel housing is reinforced with kevlar to prevent the longitudinal wires from buckling. The performance is very good and my brakes are far more responsive than with the old, traditional spiral-wound housing that was there before.

That said, installation is made a bit more tricky because:

The cable is not as flexy (it's a lot thicker than gear housing) so lengths must be cut appropriatly and secured well with the correct ferrules/end caps.
It is very difficult to cut. I tried first with a proper, full-size hack saw to get a smooth cut and it was immediately blunted. They must use very hard steel. I then just used some high-quality wire cutters which just about did the job and I smoothed up the cuts with a file. Make sure you have decent cutters if you're using compressionless.

It's also debatable whether compressionless is needed for brakes. It's needed for gears as they are indexed so need precise cable draw for a given shifter movement. Brakes have no such need, if you need more caliper movement just squeeze the lever a bit more. It probably gives some finer modulation but I reckon most of the improvements I experienced were just due to new cable vs 8-year-old ropey cable.


Rear wheel resistance and vibrations are driving me crazy

Check if the bearings are worn. I know its new but it's worth checking. If there's no grease on the bearings, apply some grease on the bearings and install the wheel back. But before doing that, check if the bearings were screwed in too tight. if that doesn't make any sense to you, I apologize.


What does FSR stand for in mountain bikes?

FSR is the name of a suspension design from Specialized. According to a FAQ, it originally stood for "Future Shock Rear". The Specialized website contains an FSR Suspension page with marketing information about the system.


Mounting the front light on the frame instead of the fork or the handlebar?

The light is better on your handlebars or fork than on your frame - the frame lags and always points at some tangent to where you're going while turning, so either you need a really wide beam, or you have to ride into the dark.
Fortunately there are solutions, and some of them are pretty vintage.

Steerer mount.   In the days of threaded headsets, there was a stack of anti-rotation washers needed.  It was common for one of these to be extended out the front and upward, to support a "bicycle lantern"
As time went on these changed from oil lanterns to battery powered by two D cells.

this last one is a particularly vintage unit, but shows how it is mounted on the bike, below the threaded stem's retainer nut.

A variation on the above is to mount the lamp from the front wheel's brake bolt.
 Downside of this is its getting quite low and can be obscured by wires.  Also many brakes don't have bolts long enough to go through more thickness.  However if your bike has a cantilever, V, or disk brake, then this hole is either spare or used only for a mudguard/fender.  Worth considering.

There are a ton of options for mounting things under the bars too, which helps clean up your working area.  Risk here is that some lights are built with a certain intentional beam pattern, and flipping them will light up other road users in an non-legal manner.

If you have to mount your light to your frame, there are two ways to do it.

Secure a longer flashlight/torch to the side of your top tube, such the front lens area is forward of the head tube.  Downside, a torch makes for a bad headlight because the beam pattern is wrong.

Get a gopro handlebar mount, and put it around your headtube with the clamp between the top and downtubes.  This will let you use some kind of gopro to your-light adapter.
I use this for my gopro on an older road bike, and the footage is really directional, makes me look quite pro while riding.


How to true 16 spokes front Campagnolo scirocco 35

I guess you have an aluminium/aluminum rim, which doesn't take kindly to rebending.  Steel is generally okay to bend, but I have no experience with CF wheel rims.

Tool for rim tweaks is Vice Grips - with layers of padding in the jaws.  If you can find the ones with ~50mm wide clamping surface, that distributes the pressure better and reduces the localised "bottle lid" effect.

As for bending the whole rim back to approximately flat, lay a broomstick on a flat concrete floor, then stand on the high bits.

Kind-of like this but not using the axle, since its a bare rim you will want to overbend it so it ends up straight.  Use the flat concrete floor and look for wobble.

If the wheel is this bad, its dead.  Straightening this wheel is a get-home fix only  Notice in the middle where the join has wrenched, and now the braking surfaces will have a lip?  Also the whole join is stressed and may give way anytime.

Regardless, once you have your rim straight, examine it closely, both sides, for cracking.  Spend at least 10 minutes on this and even use a loupe or magnifying glass on anything suspicious.  Check in the braking surfaces, the spoke side, and in the tyre valley.

Alloy does not bend back very well, so you might be best off replacing the rim rather than rebuilding it.

Aside - don't misplace any spokes or nipples!  On my 20 spoke shimano front wheel, the oversized nipples go at the hub and are $14 each to buy, and the spokes have to be hand made.


Reach is the distance between the center of the brake bolt and the middle of the brake shoe. Generally, brakes are sold with a range of reach (usually written on the brake; this is because you have some adjustment with the pads), like 40 mm - 50 mm or whatever and are termed as short, normal, long and extra long reach (but the actual reach lengths vary based on the manufacturer and time period of manufacturing, so you need to look at the range of reach for the particular brake you're using; for example, a long reach brake today may have been a normal reach brake in the 1960s). People also use drop bolts to use shorter reach brakes when longer reach brakes are required.

Most brakes are probably 40-50 mm ish reach these days, though you need to check the particular brakes you're working with.

To measure the reach needed, take the wheel (ideally, without a tire), and remove the existing brake. Then, use a ruler to measure from the center of the brake hole to the center of where the brake should hit the outside of the rim. If this is 45 mm, pick a brake such that the reach range contains 45 mm (e.g. a 40-50 mm reach brake).


Can I replace my Shimano outer chain ring with a SRAM?

You can use the chainring, but each brand (Shimano, SRAM, etc...) aligns the shifting ramps and pins to work best with their own brands inner rings. So the indexed shifting will not be as fast/smooth as when you would use the same brand of rings together.

Inner rings frequently have individual teeth shaped so that the chain will lift off and drop down faster in certain positions. These teeth are lined up with the ramps and pins on the outer ring, to facilitate faster/smoother shifting. If you pair a SRAM outer with your Shimano inner, these teeth will not line up correctly. It won't make the shifting not work, but it will just not work as well. The X-Glide road rings are also designed for 11-speed, Yaw front shifting; your're paying for tech/features that your bike can't fully utilize.

Also, you are right, X-glide rings do not come in 50T, 130BCD combinations. You'd have to go with a 53 or larger size.

chainringsramyawcompatibility


No you would either have to use a 2x11 speed drivetrain or a 3x10 speed drive train. You can't pick and choose and any hacks would reduce reliability.

Using the 10 speed 30/28 is the same gearing as 34/32 on the 11 speed so no advantage on the change.

For remote touring maintenance is as important or more important than gear selection.

For long distance touring 10 speed would likely be more available on the road as 9 speed is being gradually phased out and 11 speed still quite new so would factor in what stock bike shops held.


You can't directly convert because you need the distance and beam angle. Lumen is a measure of output while lux is how much light is falling on an object. 5 lux is very dim indeed, less than a sliver of moonlight on a dark street.

I should ask, though, are you sure it said lux and not lumens? If it's a single led run from AAA or CR2032 batteries, then you're most likely looking at maybe about 5 lumens.

This would be an example of a light driven by CR2032 watch batteries that would illuminate at around 5 lux at a diffuse 15 meters. Essentially worthless as a bike light but it is better than nothing in terms of preventing cars from running you over.

Update: You included the advertising copy for the light which indeed said it had "4 lux" and "2 bright LEDs." Obviously, the person who wrote the blurb doesn't know what they're talking about since not only is lux is the amount of light falling on an object and is a function of distance, output, and output angle but 4 lux is below moonlight in terms of level of illuminance. So yes, that light would be about the same as the little light I linked above -- just two 5mm LEDs and fairly worthless -- or even worse than worthless as @David Richerby points out, if it gives you a false sense of security. You should think of it as a glorified front reflector rather than as a light.

One way to look at how bright a light is, is to see its running time. LEDs are extremely efficient -- and getting even better -- but their running times still does give a gauge to how bright they are. Your light is advertised as running for 50 hours on 3 AAs. Assuming they are alkaline AAs, that is roughly 2000 mAh at 4.5 volts. So that would be 2000 mAh / 50 hours = 40 milliamperes @ 4.5v. That's enough to drive the two 5mm LEDs very dimly @ 20 mA each. This is a typical LED that would be driven at that current:

  Specifications

  Model: WC301-08 – White
  Color Frequency: .31 x .32 (White)
  Luminous Intensity: 17,000mcd
  Viewing Angle: 30°
  Forward Voltage: 2.9V–3.4V
  Typical Voltage: 3.1V
  Typical Forward Current: 20mA
  Style: Round 5mm – T1 3/4

We finally get a useful spec. 17,000 mcd. Plugging that into a lumens calculator, we get a smashing 3.6 lumens. With two LEDs, we get 7.2 lumens total.  This is with fresh batteries, the light is unlikely to have a booster circuit so it will get dimmer as the battery capacity diminishes.

Rant: Note that manufacturers (especially Chinese no-name ones found on TaoBao or Amazon) are notorious for fake lumen ratings. A "1000 lumen" flashlight is often just 200 lumens in real life.  The best way to figure out what the flashlight is really putting out is to go to a good review site that measures the lumens independently. I like Bike Light Database but there are others.


The law says

  Q3: Can I modify my e-bike so it can go faster than 32 km/h?
  No. Modifying your e-bike to increase its speed beyond 32 km/h will no longer qualify it as an e-bike.

Which means that it's no longer a bicycle, it is a moped, scooter, or motorbike. Note that the bike can go faster, you just can't have a motor that operates while the bike is going faster. It's an interesting thing to police.

The exact penalties that will be applied depend on the discretion of the law enforcement process you experience. A Police Officer might just ticket you for, say, "1. Drive motor vehicle, no permit" which is $85. Or they might be persuaded that you should attend court and explain your behaviour to a magistrate, in which case

  Dealing with vehicle not conforming to standard

Which is "no set fine" offence and you could face quite a lot of excitement, starting with "we will give your bike only to an approved mechanic who has agreed to modify it so that it is in conformance with the standard, and who will release it to you only once it does". If you are exceptionally lucky they will agree that turning it back into an e-bike is acceptable, but they could easily say "must be a conformant motorbike", and good luck with that.  If the legal system wants to make your life unpleasant, they can. The trick is not to make any of them want to do that.

This "getting away with riding an illegal e-bike" is only partly humorous, there is good advice.

  Obey traffic laws. Do not do tricks. Do not ride like a jackass.  Avoid congested roads. Do not endanger others when you ride.

Viz, pick the law you want to break (fast e-bike), and obey the rest.


The part that popped out is one of the pistons.
There should always be a bleed block in place between the pistons when bleeding the brake. Immobilizing them this way is what prevents overfill and also prevents the pistons from popping out if you go to squeeze the lever as part of part of the bleed procedure, both of which happened here.
Excessively narrow pad gap is the main symptom of overfill.
Bleed them again with the block in place and everything should be good.
The piston that came out probably went back in clean and lubricated, while the other one remained however it was. That kind of thing can cause uneven pad wear and adjustment weirdness, as one piston moves more readily than the other. You could try addressing it by intentionally overextending each piston in turn and then cleaning them with a cotton swab and alcohol. Removing them all the way isn't necessary.


First of all, try changing the distance and vertical alignment between the sensor and the wheel-mounted magnet.

If that doesn’t help, the sensor (or its cable) mounted to the fork is probably broken. Check the cable for any visible damage. I think the sensors are usually cheap&simple reed switches to detect the magnet. If you have a multimeter you could try measuring the resistance between the two contacts of the cycle computer’s mount. It should toggle between zero and infinity when you pass the magnet in front of the sensor. If it doesn’t do that it confirms a sensor or cable defect.

Your best choice is a replacement part, but if you are handy you could try replacing the cable and/or the reed contact.


Where can I find out more about this bike with a spoke-less back wheel?

The "Lunartic Cycle"
Here you go:
http://www.yankodesign.com/2010/08/13/no-spokes-cycle/
Complete with movie.
As for your extra reading material:
http://bicycledesign.net/
Hope that helps!


I trust you used the search function and read "How do you carry a dog on a bike"?

I haven't ridden with a big dog since I was a child, but I have a friend who had one. My experience was that when the dog weighed about the same as I did my ability to ride was entirely dependent on the co-operation of the dog. In my case that was not usually a problem, but when he leaned out to have a look I had to stop. In that respect it's much like riding a tandem.

The main thing is how disciplined the dog is. If your dog will stay in sit or lie when there's a dogfight going on or some other strong distraction, the only question is how you carry the weight. And the Soma Tradesman will do that.

The problem is that you won't be able to effectively strap a dog onto that front rack - it's too small, and you can't fit a deep enough basket to it, so any attachment is going to require a full harness on the dog, and tying the harness to the rack between the dog's front legs. I can't imagine any dog liking that. Otherwise you'd get (at best) strangulation issues when the dog tries to sit up or jump off, and more likely you and the dog will end up in a heap on the ground. At whatever speed you were travelling.

The cheap option that will work is a trailer. Either a second hand on (probably a kiddy trailer since they're more common), or a new one, and ideally one of the ones designed to carry a dog. That way you can enclose the dog so it's not tied in one place, but it can't get out and run amok. A two wheel trailer is also more stable, so the dog moving about won't throw you off the bike (as easily). This article discusses trailers in detail and recommends the Croozer. I have seen decent size dogs carried this way, and one that the owner was happy to leave loose with the trailer open so the dog could jump out and run when it wanted to. I've never owned a dog that I was willing to see killed, so I haven't done that.

If you want to go touring, the trailer will not be ideal and the consensus is that to reduce air and rolling resistance you want a low, single wheel trailer (one vs two wheel trailer)... which will not work with a dog.

My dog-owning friend ended up with a load bike for his dog. Something like a long john will be ok for touring and very handy for carrying loads around town. As with kids, the dog will probably appreciate being able to see something other than your butt. Those are increasingly common in Oz, and I suspect the USA too. They've been common in Europe for going on 100 years.

Other load carriers will also work, but you will need to do your own research and balance load capacity, ease of pedalling, cost and availablity.


Whenever I am asked a question like yours, I invariably ask back: "what are you going to do with that bike?".

As 90% of the time the answer is "dunno", the obvious suggestion is "go for an economical model that fares decently in most situations, then when you have found out what your cup of tea is and you still love biking, go for a more expensive choice".

And this advice is based on my own experience: in the times where having a mountain bike was cool, I rode an old 3 speed, steel frame from the '60s, my father's legacy. It was not cool maybe (nowadays we would call it vintage), but served my purpose.

Then for my first chosen bike in the early 2000s I went for a BSO city bike, sub brand of a major brand. Again, it was not fancy or cool, but I rode about 15 thousand km on it (including a holiday in the central Italy Apennines), discovering that what I like to do with bikes is commuting and touring.

Then my first serious bike was, and still is, a touring bike. I also own a cheap city bike, just because I don't trust leaving my touring model in an unguarded garage for thieves to pick up.

A friend who asked my advice in the past ignored it and went for a cool, expensive, full suspension off road model  (where we live the max rise is about 40 m and the only off road, except BMX tracks, is gravel roads in the countryside). He admittedly rode it for a bare 40 km and then sold it after 10 years to make room in his garage.


Diamondback Sorrento for first starter bike?

You're an exceptionally experienced programmer, you know by now that life is a series of compromises and trade offs. Yes the diamondback is a good bike for that price, but you get what you pay for. If you really want a bicycle you'll enjoy, go to a family owned local bike shop and trade a little extra money for an experienced employee to fit you to a bike that's just right for you.


Why does my bicycle steer funny and feel unstable when I have a heavy load in my Bob Yak trailer?

I suspect Chris H is on the right track with his weight distribution question.
You may have too little weight on the front wheel. An easy way to test too little weight on the front wheel is by shifting your body weight forward when the bike feels unstable.
Experiment with the trailer load to find the best handling.
You may find that adding front panniers with some weight helps.
It's all about experimenting until you find the right distribution.
Looking for other people who are having problems with stability using a Bob Yak trailer has led me to some advice that might help.
In a thread on campfirecycling.com Jacob says:

I’ve been a bike messenger (in The Netherlands) for some time, using a Bob Yak professionally. Since my positive experiences with this handy one-wheeled-trailer I own one myself now, mainly for use as a vacation trailer.
When loading a Bob Yak/Ibex trailer you should keep a few things in mind. 1. Always distibute the load evenly along its length-axis 2. place the heaviest load nearest to the trailer’s wheel 3. When you overload a Bob trailer (which is fairly possible), never make the load ‘top heavy’.
I’ ve handled loads of over 50 kilograms with the Bob Yak and have had no stability or handling problems with it.
Tip: A bike without shockabsorbtion is most ideal (in terms of handling/control) for towing a one-wheeled-trailer like the Bob Yak.

Another problem some people had with the Bob Yak is high speed stability wobbles. cara2u posted this warning on forums.adventurecycling.org:

Please be very careful if you decide on a one wheel Bob. If they are not loaded correctly they can cause your bike to completely lose control
at the most inopportune time, downhill.
On our last TA tour we met an Aussie gal that had that very thing happen to her on a downhill. She was unconscious for two hours down in a drainage ditch until someone found her. She had to fly home to convalesce for two months before she could continue her tour. She was East to West and the accident happened the first week or so of her trip.

There is a lot more conversation about stability at speed in this thread.


Staying in the middle is the worst thing to do as you can get boxed in unable to sprint your way out of trouble and the riders at the back can come around the top of you and drop you. You are reasonably safe at the front until there are fairly few riders left as it will be difficult for the whole group to come around you and you can sprint your way out of trouble. You are also ok at the back as you are in the slip stream of the group and can use that to slingshot the person in front at the crucial moment and sprint for the line. What you don't want to do is stay in the middle.


9.4mm major diameter means you have a 3/8" axle, which is sometimes even called 9.5mm. The thread on it should be 3/8x26tpi, which again is sometimes called 9.5mm x 26tpi.

All Shimano hubs have the Shimano name and a Shimano-esque part number on them, which for normal front hubs (non-generator etc) will start with "HB-". Shimano doesn't do rebrands. Also all Shimano threaded axle hubs use metric axle threads unless there's a prevailing standard otherwise, as in 3/8"x24tpi internally geared hubs, low-end generator hubs for shopping bikes, etc. So from the sound of it, it's not Shimano.

Things I will say straight off:

Some shops specialize in Dahon and might be able to make this very easy for you. If you had access to such a place, that could be a good way of cutting to the chase.
If you insist on matching a replacement yourself there are technical aspects to getting it right that are a little outside the scope of an SE type answer (or at least one I'm willing to write I guess.) There's a second edition copy of Barnett's floating around the internet. I'm not really sure of the legality so I won't link. I believe it was compiled from sample chapters and it's largely outdated at any rate. However, it does have their chapter on replacement cone matching, the principles of which haven't changed. Every other writing on the subject I've ever seen on the subject is overly pithy and misses some aspects.
One of the key steps in replacement cone matching is testing that the ball track is occurring on the new cone in an appropriate spot. Usually this means nestled neatly in the curvature of the cone, not too high or too low. Barnett's covers this in depth. Any good mechanic will do this test when installing a non-factory replacement cone and not make any promises beforehand. The point is that ordering generic replacement cones online is pretty dicey.
If one really wanted to try ordering them online anyway, you need to find a way to match curvatures. What I would probably do is use a scanner to create a good side view profile of the existing cone and overlay it properly scaled in a graphics app with the side view product images of the various Wheels Mfg 3/8"/9.5mm generic front cones (which they call "Taiwan cones" since several of the dominant OEM hub firms are Taiwanese) I'd be looking at as initial candidates to choose from.

To answer your questions:

Cup and cone hubs typically have no real ability to handle different ball sizes or different numbers of balls, the exception to the latter being most hubs can either have loose balls or retainers with the same size but a lesser number of balls. You need a  front cone. All generic replacement front cones are for 3/16" balls.
The color of the axle is irrelevant. Some have a black oxide finish and some have different kinds of raw or polished finishes. Well kept axles have grease on them and good chromoly ones are very corrosion resistant anyway, so it doesn't really matter.
3/8" axles are one of the sizes where the same size axle is used on front and rear hubs in some applications. So it's not true that 3/8" cones are categorically supposed to go with 7x1/4" balls. 7x1/4" would typically imply a rear hub with a bearing retainer, and in such a hub 9 1/4" balls would typically work without a retainer. You need a front 3/8" cone, which basically all are going to be sized to work with ten 3/16" balls. One of the confusing things about this may be that the metric sized axle standards, which depending on where you look have become more common, use different diameter axles front and rear.

The practical thing to do is one of two things:

Read the Barnett's chapter, then find a shop that has the full range of Wheels Mfg 3/8" front cones and take what you have to go try to find a match. The Barnett's chapter will get into the sealing and length matching considerations, as well as how to transplant pressed seals etc. Wheels Mfg used to make a 3/8" Taiwan Cone kit that I believe is no longer available in kit form, but a lot of shops still have it, and the cones that it came with are all still available.
Fix your existing cones by grinding them with a drill and sandpaper. I've come to have a high regard for this approach since it can usually be made to work acceptably unless the cone is devastated, and replacement cones can be harder to obtain than they used to be. There are questions here about this approach.


Update:

Based on your other question: Possible to identify sprocket without taking the bike apart? - you have a Nexus internally geared hub, which would mean you may need a single speed chain.

For derailleur gear equipped bicycles you just need to get a chain compatible with the number of gears ('speeds') on the rear sprocket cassette. More gears require a chain with a narrower outer width because the sprockets are closer together.

Generally speaking derailleur chains are available in  6, 7 and 8 speeds; 9 speeds; 10 speeds and 11 speeds.

Just for completeness and to address the 1/2" x 3/32" measurements on your current chain:

All bicycle chains have 0.5 inch pitch (distance between center of the pins)
All chains for derailleur gear equipped bicycles measure 3⁄32 inch between the inner plates. (Single speed chains use a wider 1⁄8 inch inner width.)


To convert to a rigid fork consider

1) Fork length - to maintain head angle geometry
This depends on the travel of your existing suspension fork and the wheel size.
ie For older 26inch wheels - an 80mm Suspension fork was a 420mm rigid fork and 100mm suspension fork 440mm etc.,

2) Brake mounts - whether your disc brakes are post-mount, IS Mount or flat mount.
Adaptors can be bought to convert between them.

3) Disc rotor size - some rigid forks will have a maximum rotor size clearance.

4) Tyre clearance - though you are using it for commuting - bear in mind if you use an MTB tyre in the fork - determine the maximum tyre clearance.

5) Fork steerer length - if you are buying secondhand (especially). New forks will have an ample length of steerer to cut down. But secondhand forks, you must check and measure to make sure there is enough for your frame.

6) Fork steerer width / profile - unlikely to be anything other than a straight 1.125inch on your bike - but with tapered head-tubes you may have to change the lower crown race.


Why do deep section front wheels get pushed around in crosswinds?

The answer to your title question is "moving air exerts a force on obstacles", and deep section front wheels have more area affected by side winds so there's more force.

In any crosswind there will be some side force that applies a turning torque on the front wheel of almost any bike (viz, zero rake bikes have been made, but they have less trail than is common today). The diagram below shows the normal design, somewhat exxaggerated as was the style in the 1960's:

(via the esteemed Dave Moulton whose post I got the image from contains an interesting discussion about why we have trail)

Note that the centre of drag/centre of the wheel is forward of the pivot axis. Thus, wind force from the side will tend to turn the wheel downwind, in the same direction that the wind is pushing the bike. So the rider will tend to stay upright, unless the turn makes them crash into something.

The bike you have pictured has the opposite design - as the wind pushes the bike and rider away, the drag behind the steering axis will turn the steering into the wind. I predict that in many cases the centre of mass will move downwind while the support moves upwind, resulting in a fall. But note that the front wheel design pictured is at best going to require clean, dry conditions to operate, and those are normally only found on indoor velodromes, making side winds a non-issue.

The OP asks about airfoil effects: More streamlined shapes can generate lateral forces due to airfoil effects, as often helping propel the bike as slowing it down - this is why speed records must be set in zero wind conditions.

Ignoring drag just for this example, the direction of the force from the wind is affected by movement for a streamlined shape, but not for a round shape. The apparent wind direction changes, but the vector components are still just movement + wind. But because drag is nonlinear the total drag force will be greater on the sum (that's why headwinds are so annoying), but the side force will not change by a huge amount.

The key point, though, is that the side force is still present regardless of the shape of the section. You could have a perfectly flat plane and it would still experience the side force.

And what matters to the rider is that the side force exists. Once you have that force, the above discussions of geometry applies. Where the force impacts and how that changes the balance and steering of the bike is what makes the wind hard to deal with. Whether there's a force-aft component to that force doesn't affect balance or handling.

It's definitely possible that turbulence from the fork will mean that there's less lateral force on the wheel behind the fork. But the more streamlined the fork the less true that will be. For the bike you've pictured above there is no effect at all, since the "fork" is merged into the trailing edge of the wheel. Instead that bike will have the opposite effect - there will be more lateral force on the rear of the wheel because there is so much more surface area behind the pivot axis of the wheel (the head tube).


There don't seem to be many (or any?) carbon wheels for 9 speed bikes

Any Shimano compatible 10-speed wheel, other than a very few with special deep-splined aluminum freehubs such as WH-7800, can take any 9 speed Shimano cassette without additional spacers.

Shimano 11 speed road freehub bodies are longer and require a common 1.8mm conversion spacer to put a 10/9/8 speed cassette on. Many wheels come with this spacer, or a generic one can be used. 11-speed road cassettes do not fit on 8/9/10 speed freehub bodies, although some machining hacks can allow it in some cases.


I think the mounting points are for fenders only.

If you have the rim brake version you could use a pannier rack with Quick Release Axle adapter. For example this one directly from Trek or this adapter from Tubus with a Tubus Fly Classic rack.

Considering the relatively lightweight wheels, the road rim brakes, the carbon frame and the frame geometry I’d try to keep the weight low. More than 12kg of luggage (including panniers) is probably a bad idea.


Using an LED torch as a helmet light, will I blind oncoming drivers?

I have a helmet mount very similar, and yes its totally possible to dazzle and annoy any other road user, from pedestrians to other cyclists to motorised vehicle drivers.

Benefits to a helmet light

Its high up above the ground and higher than handlebar lights, so other road users can see it over cars.
The beam follows your head, so you can light up the thing you want to see.
Retro-reflectors everywhere!  Since the light source is near your eyeballs, retro-reflectors work really well and from a very long way away.  A sweep across a dark road will illuminate all those car bumpers and street signs and mailboxes and jogger's jackets and sports shoes.

Disadvantages of and risks due to a helmet light

Drivers might get dazzled.   I've had a bus driver yell at me from his rolling bus because of my head light.  Admittedly he was more annoyed by the flashing, so after some research I decided to leave it on solid.
Retro-reflectors can be dazzlingly bright when lit up at close range, destroying your own night-sight.
Snaggage risk - your torch/flashlight is a fairly respectable-sized hook and can catch on low hanging branches.  I've caught mine on a washing line at low speed and basically "clotheslined" myself with the chinstrap.
Helmet Function may be compromised by the holder.   Michael Schumacher's skiing accident was exacerbated by the gopro camera mount that focused impact forces on one point rather than spreading them over the head like a helmet is supposed to.  If you were crashing, then the mount should snap off.  What if it didn't snap, or if you impacted vertically onto it?
Weight - torch batteries are dense and the added weight can be noticeable.

Comments

I have mine mounted fairly far back on the helmet, so the torch front barely clears the top.  This reduces snag risk.

The mount is held on by a minimum of velcro, and there's a separate hand strap used as a second line to stop it getting lost.

As mentioned, I use it on solid mode now, however the focus is set fairly tight.  At night my normal posture puts the lights on the road surface around 4-5 metres in front of my wheel.  I tend to look up with my eyeballs rather than my neck.

However, if a car presents in a manner that crosses my path and may require them to give way (to yeild) then I will point the beam below the driver's door.  If I'm passing a parked car that has a person moving in the drivers seat I might light up their wing mirror.

I'd rather annoy someone than get doored by their inattention.
While I won't deliberately dazzle anyone or anything, my priority is everyone using the road arrives home safe.

EDIT Here's a pic showing what I do, for clarity.


Tyre liner causing a slow puncture -- am I doing something stupid

I've never seen this exact flat, but I can see how it can happen.  It's why some brands of liners now have rubber tips at the ends of them.  a little filing just to be sure it's smooth there with an emery board should take care of it.  Or as suggested in the comments, a piece of electrical tape should help.


Solid, yes. Worth it? Probably not.

Unless it has been kept in perfect running condition, a 30+ year old bike is going to need lots of maintenance. IT will also have really outdated parts. Finding spares will be difficult, newer parts might not fit at all. All this boils down to maintenance nightmare.

Even if you find bike that's perfect to ride, it will still be an old bike. It will be heavier and its' gears and brakes won't be as good as in newer models. Unless you get a kick from riding vintage bike (nothing wrong with that), I'd go for more modern one.

This site has 1980 Schwinn Traveler specifications: http://schwinncruisers.com/catalogs/1980.html.

At least the 27" wheels that the Traveler has are going to be trouble. 27" size is not used much these days. Finding new tyres/inner tubes in case of flats will be tricky.


What are the conditions for removing training wheels?

Consensus seems to be more and more this:

  Do not use training wheels.

The most important part of cycling is not the pedaling, but balancing and steering. Steering is mostly done by leaning (therefore balance) and not by turning the handle bar.
Training wheels do not help in learning to balance the bike and actively prevent leaning.

Therefore it might be better to start with a balance bike (no training wheels, no pedals) to learn the essentials and add the easy part of pedaling afterwards.


Am I using the crank extractor correctly?

I don't know about this this particular crank extractor, but the one I have came with two different end caps, one for ISIS/Octalink and one for square taper. Check that the end cap you are using fits inside the square hole in the crank, otherwise you will just strip the threads.

After you are sure you have the right tool, use more torque. If you have a piece of metal pipe at hand, use it for extra leverage, or get a longer wrench. Turning clockwise is correct.


As usual, Sheldon's got the answers.

ISO 622 is the unambiguous way of referring to the following rim sizes:

700c (you see this marketing on road, hybrids; this is from the French system; the c is often dropped, but there are rare a,b sizes)
29"x decimal (you see this on mountain bikes; usually only applied to wide rims)
28"x decimal (particularly in Germany)
28" x some fractions (seems to be a rare Canadian / northern European thing).

700 mm is roughly 27.5 inches, so if you mounted a reasonable tire on it, you'd get around 28 inches (hence the name 28"). For mountain bikes, you'd get a bigger tire giving an outside diameter of 29"+.

In theory, any tire which can be mounted to a rim marked as any above sizes can be mounted to the others, but in practice you want the rim width to be appropriate to the tire size you're mounting.

In terms of which way you should refer to this wheel size, ISO 622 is unambiguous. If its being used on a road bike or hybrid, 700c is also a good way to refer to it. If its being used on a mountain bike with a big tire, 29" is also a good way to refer to it.


Is it possible to construct an overnight shelter using a bike as the upright?

Yes, its been done before, there are various configurations.
Google for 'Bikepacking tarp shelter' for many ideas.

Good resources for this type of thing are
bikepacking.net forums and in the UK Bear bones bikepacking.

Here are some examples:


Repair Marin Hawk Hill (cracked frame) or get new bike?

A new similar bike would cost ~1500 €/$/GBP, right?
For half the price, you get a new frame, a new shock, all your old&used parts (in which conditions are they)?
No brainer:
If you think your parts are worth at least 750$ and you can sell them for more than 750$, sell them and then buy a complete new bike.
If you think your parts are worth less than 750$, accept their offer (or find a better deal on a compatible set frame+fork)


You absolutely should not have let fluid out of the system. If the brake was working before there was not too much fluid in the system. You will need to bleed the brake to remove air bubbles and restore the fluid level. (If the back brake has not been bled in eight years you should do that one too.) Dirty pistons and seals are usually to blame for non-retracting pistons. In extreme cases the whole caliper has to be disassembled and cleaned.

You can try to find the manual for Avid brakes by searching on the SRAM website. There is a 2006 manual which may apply.

Check out this Park Tool video for how to clean hydraulic brake calipers. It also explains how piston retraction and advancement works.


Really deep dents or cracks are a cause for concern, but not little dimples and such.

Also, the "work hardening" of aluminum is considerably less than industry types would make out....I've worked on numbers of aluminum frames that are at least 20 years old with no sign whatever of any structural problems.
Kind of depends what you're doing.  The average roadster isn't subject to much in the way of severe shocks; not so with a mountain bike being used to bounce off boulders and do 10-foot vertical drops.


There is no real problems other than things getting scratched or broken being shuffled around, derailleurs easily get caught on seat belts etc. There is however a very easy and affordable option to avoid this. (Assuming you have QR skewers)

Install a 2x4 or similar piece of wood. Then mount QR truck mounts to said 2x4. If you are going to be using your SUV to carry your bike very often this is the way to go if you don't want to spend the money on a roof or trunk rack. Generally, and depending on SUV make and model you can easily fit more than one bike using this method.


Long post v-brake (or canti) shoes? (Canti studs not sufficiently inboard)

A rear wheel with a wider rim could make up the gap, depending on what you have in there now. There are a wider selection of wide rims available now, although I do not know if this extends to smaller wheel sizes. Wider rims will likely mean running a larger volume tire, but there is plenty of room.


Will any Avid brake bleed kit work with my Promax brakes?

The only specific piece that you need to worry about is the threaded hose fitting that screws the tube from the syringe into the reservior port, everything else is identical.

Unfortunately I believe that the Promax Hornet use two different types of threads for their reservoir ports on the lever and caliper whereas Avid only use a single type (if someone can confirm otherwise, you are good to go). So you may only have one fitting that works instead of the required two.

There are many generic sets that come with multiple fittings that are cheaper than the Avid kit and will have the fitting you need. They don't ususally come with DOT 4/5.1 but you can buy this at any automotive store.


Tandem team with large height disparity - possible?

I think this should be possible, as long as your wife is happy in the navigator position and you are OK with being the bug-shield. Having the larger person on the back is difficult, but may be possible with unusual designs.

I'm always banging on about how important bike fit is and a tandem is no different. Do make sure you try as many as possible before buying as it's a big investment. If you are in or are visiting the UK, you can try the Tandem Experience, which we found very helpful. We visited a (fairly) local bike shop and they found us a bike which fitted us and gave us some tips on a harmonious ride. It would be worth calling to discuss sizing in advance.

SJS Cycles/Thorn make popular touring tandems and they do a L/Xxs size frame which might fit you both (I couldn't see precise numbers).

Note that it's very likely you'll need different crank lengths, or you may argue over gear selection.

There are any number of frame builders who could build something to fit you both, but that's a big investment, especially if you haven't had a chance to ride a tandem together properly. It's not just the bike fit that counts, you need to have at least a day out to get used to it and ensure you can both enjoy it and the compromises involved.

However, don't let that put you off. One of the best things about tandeming is the easy conversation on a long ride. The next best thing is long, gentle down hills. Have fun.


Is Ultegra 6800 GS compatible with an HG800 11 speed 11-34 cassette?

As for clearing a 34, there is no universal answer because it's slightly dependent on where the dropout puts the RD mounting bolt relative to the axle center, which despite Shimano having a standard spec for does have some variance bike to bike. So it's a little bit of an experiment every time. Generally speaking this can be made to work on RDs, including the one in question, with a max cog spec of 32t by running the B-tension screw in reverse or subbing in a longer one. It's also common for it to barely work and/or be a little grindier than desirable in the low gear but basically work. And remember that when you do this, something is lost in shifting performance on the rest of the cassette, so it's not all upside.

Exceeding the printed large cog spec by two whole teeth without any B-tension hacks usually doesn't work. I've tried it with various of the 11-speed road RDs, probably including this one but I can't be sure.

As for exceeding the total capacity, there are many answers here on this topic but basically the bike will be rideable but will have chain slack in some number of the small/small combinations. Total capacity numbers can basically be taken at face value (in other words they're reasonably honest), so you can do the math to see which ones will be slack, again with a very slight bit of wiggle room due to variance in dropout geometry. Here 18t of the total capacity is being used up front, leaving 19t in back. 34-19=15, so once the chain is long enough to wrap around the 52t ring, 34t cog combo, it can be tensioned on a 15t or above, and below that it will be sagging/floppy. Riding in the floppy gears carries some risk of derailment/jamming.


Is there difference in quality for disc brake rotors?

One of the most advanced designs is the "floating rotor", made of two different materials connected together. They look like this:

These are exceptional brake rotors. They are very rigid and won't bend sideways easily. Overheating is much less of a problem for these. If they are getting overheated, they don't bend that much because of the material expansion. Usually the spider in the middle is made of aluminium alloy, but you can get rotors with carbon core. Carbon ones weigh less, but cost a lot more than with alloy spider.

Also you can get a full carbon rotor:

These are very expensive. Marketing materials for these say they are perfect, but you can easily spend a lot of money only on one rotor. I have never tried a carbon rotor or even seen one in flesh, only on pictures. You can also get a combination of carbon with ceramic spider and other space-tech materials. kettlecycles.com provide with examples of these. (Thanks @J-unior for the link)

One of the extremes I've seen is combination of carbon and ceramic in a disk brake rotor. Don't really think these are available in shops, but interesting to know.

If you go for single piece cheaper rotor, then you don't have such a big variation in materials: they are generally made of stainless steel. And here the shape is making a big difference.

If you get one of these:

You'd be able to stop on a dime, but you don't get a lot of modulation. These things will be like an on/off switch if combined with good pads. These are Hope trials rotors and I would not recommend using them for anything other than trials. (If you are doing trials, you should already know this)

Then you have middle ground rotors with a lot of variations on patterns:

These are the most common and most affordable with prices from £12 to £25. I do believe that in this category there is really not much difference in quality. But make sure that the pattern has overlapping holes: when the disk is dragged through the pads, there should not be a continuous line of solid material. Pads should have a way to clean themselves and if in a section of a rotor there is no gap, the pads will not self-clean, decreasing the overall performance. In this category choose the ones you like most.

And the last in the category are cheap and nasty rotors you get on bikes from Wal-Mart or Asda. They are usually heavy, easy to bend, with poor pattern. They look like this:

Apart from the material and type of construction don't forget that you have different diameters of the rotors: 145mm, 160mm, 180mm, 203mm and 205mm. The bigger the rotor, the more braking power you get and better heat distribution, but also the greater the weight. Usually downhillers go for 205mm rotors on the front and 180 on the rear. For more calm disciplines like XC 160mm rotors are more common.

The size of the rotor must match your current one, but you can buy an adapter to place you disk brake caliper in the right position for the size of the rotor.

And you can get different types of mounts to the hub. The most popular is 6 hole international standard - on all of the rotors above. But you also get Shimano Centre Lock:

For this type of mount you need to have a hub with the same mount or use adapters from 6-bolt to Centre lock. 8-10 years ago there used to be rotors with 5 and 4 holes for mounting, but you can't get them now.


A good place to start is looking up the specifications of your current Suntour fork: http://www.srsuntour-cycling.com/components/fork/XCM-27-5-5617.html

The important points are:

Straight 1 1/8" diameter steerer tube
Post type brake caliper mount for 160mm rotor
9mm quick-release wheel attachment

You will also need the axle to crown length to be the same or at least close. The Suntour page does not give it but you can measure it easily. I'm not particularly knowledgeable about MTBs but I am  guessing that most 120mm travel forks for 27.5" wheels will have about the same length.


Assuming that the cabling is clean, that the derailleur is nicely indexed and well alligned, the derailleur hanger not bent, and the chain correctly moves lateraly +/- 4mm for each gear up or down, then I would have a look at the distance between the upper jockey pulley and the sprockets.

The distance should be on all sprockets less than 25 mm and more than 12 mm.
I suspect that your distance is slightly too high, meaning that the chain has too much room and can flex.

The way to adjust this is by loosening the B screw, as described on this page.

I had the same problem on a 105 derailleur on one of my bikes. B screw was loosened to the max, and I was still too far from the sprockets compared to my other bikes. I managed to file the part of the derailleur hanger touching the support of the derailleur where the B-screw is, to shorten this distance even more. Now it shifts very well.


What are the advantages and disadvantages of turbo trainers and rollers?

Turbo trainers allow you to alter the resistance, so they are good for interval style workouts. They don't require any skill to use as you're locked in place. But as most people will tell you, riding a turbo trainer gets very dull very quickly, and unless you really concentrate they don't do much for your "souplesse" (spinning smooth circles at a high cadence, the most efficient way to pedal) - it's easy to just stomp up and down on the pedals.

Rollers require you to balance and it takes a little to get used to them. On some models you can't alter the resistance, although you can of course shift into a higher gear to work harder. It's generally accepted that they are very good for your souplesse, in part because pedalling smoothly makes it easier to balance. They are also a lot less dull than a trainer - you can even get fancy sets of rollers that allow you to stand up and pedal.

Ideally you'd want both - a turbo trainer for shorter, intense interval style workouts against resistance to build speed and power, and rollers for spinning smoothly for longer periods of time to get in the miles and build endurance.


How do I make my bicycle as ugly as possible without affecting the riding qualities?

popular techniques in approximately increasing order of cost include:

dirt: mud, road grime, let them cover any shiny parts
stickers
pad bits of the frame with old inner tubes held on with duck or gaffer tape
apply spray-paint in ugly or mismatched colours (optionally after keying or stripping the original paint). Then put stickers over the top
cover any desirable decals or etched logos with paint or stickers
strip some of the paint off entirely and re-paint in mismatched colours
even more stickers
strip some of the paint off entirely and, if steel, allow to rust a bit before clear-coating over the rust

you can also clear-coat over stickers if they're not that weatherproof
cosmetic damage to non-functional parts (scuff or cut the saddle, scuff
levers or bars, choose the brightest bar tape you can and get it really dirty looking)


Help selecting between wire/folding tires

For most of us it makes little difference.

Kevlar beads are supposed to be harder to fit but the hardest job I've had fitting tyres has been with wire. Some tyres are available in both (there's normally a little difference in the compound as well). The kevlar version is nominally more expensive, but can be cheaper if it's stocked in more competitive places. I found this with my winter tyres. As the kevlar version folds it can be cheaper to ship as well.

The weight saving of kevlar is real but small enough that you're not going to notice unless you're racing at a high level.


I'm a fairly new mountain bike rider. Doing a mix of on and off trail. What is your opinion on handle bar extensions for new riders

There are several types of extensions available. One type is molded into the handgrip, these tend to be on the  shorter side. Another type tend to extend out and turn toward the centerline. The finish can be bare metal with a knurled finish or a rubber grip installed. The advantage of the inward turn is it prevents the end from becoming a bayonet in the event of a crash or fall. One of the purposes of handlebar extensions is to allow multiple points to hold the bars to eliminate fatigue. Another purpose on earlier mountain bike was to increase stability when climbing. In my opinion on most modern bikes this is no longer necessary as the changes in gearing and geometry have eliminated the need. There are several downsides. If you have your hands on the extensions they aren't near the brakes. A pretty important criteria for a novice rider. The other minus is the extensions move the shifters and brakes inboard. This can have the affect of a slight change in handling, similar to riding with narrower bars.


There are two standards to mount disc brake calipers that are relevant to you:

flat mount
post mount

Have a look at Nathan Knudson's explanation to identify what your bike has. Its specs sheet might also help.

These are industry wide standards. A Shimano flat mount will fit, for example, on a bike that came with SRAM flat mount.

There are adapters for flat to post mount available. However, it is better to avoid these. In particular post mount calipers on flat mount frames are quite a bodge.

All rotors and calipers are cross compatible (at least all that are relevant to your case). It will be enough to align the new calipers for existing rotors. However, one needs to check brake pad compatibility. Some (mostly very cheap) rotors must not be used with sintered pads.


Mavic crossmax freehub doing strange noise at high speed coasting

There's a few different Crossmax/Crossride/Crosswhatever iterations for how you get to the freehub guts to service it. For the one you have, I think your probably just pull off the endcaps, or take them off with a 5mm wrench on each end if there are such wrench flats there. You don't have to take the cassette off; I always do anyway, but it's fine not to if you don't have the tools.
When you take it apart, your chief concern is the pawls or springs flying somewhere and getting lost. It's good to do this operation suspended over a tub or similar so they have nowhere to fly to. The symptoms you're having mean there's some possibility one of the sets is out of place or otherwise unhappy.
Clean everything, and then lubricate it. Mavic freehubs are pretty insensitive to what you use, but typically go with a medium to heavy weight oil. Mavic neutral support mechanics are known to favor Shimano mineral oil. Make sure to keep track of the washer you'll find in there.


New chain skips when old chain was replaced at 0.75% mark

To me, that looks pretty worn.  My guess is that as the chain elongates, it grinds further into the gear valleys, making the "flattened" profile.  The chain and cassette become mechanically paired, wearing together until the chain breaks.  The cassette longs for its lost chain and will not take another mate... er, is mechanically incompatible with other chains.   The wider profile probably leads to periodic instances of 2 rollers in the same gear valley, sort of riding the top of the valley and unable to lower a single roller.
So, options...  1)  Clean frequently, and maybe consider a different lube.  Lube minimally, just on the rollers.  I use Muc-Off dry ceramic for our gritty trails, but it's very dry here.  I have no idea how it'll handle your wet grit.  2)  Replace the chain sooner.
For comparison:


Stripped thread on steerer. Who is at fault - me or LBS?

Absolutely.
If they actually put anything but a French headset on a French fork, it should be 100% on them.
Hopefully they will fess up and cover the whole thing.

Just to be clear, measuring the difference between a French fork and the more common ISO/British is super easy. The OD of a French steerer is 25mm, and common 1" is 25.4. The thread pitch is also different. The parts just don't fit right together. Making this mistake and sending it out the door without noticing anything amiss is implausible.

Also, if you did have a French fork and it's being replaced with ISO, they owe you a new stem too because the quill OD/steerer ID is .2mm less on French than ISO.


Can I replace steel bearings with ceramic bearings?

Yes, you can. You just need to get the right size of loose ceramic ball bearings as that's what shimano wheels use. They are available from various vendors, like here for instance.

You didn't ask this, but I'll answer it for you anyway: would I recommend replacing the bearings on a pair of WH-R550's with ceramic bearings? No, and neither would many others. Ceramic bearings are expensive and can end up costing nearly as much as your particular wheelset. There are better places on your bike to spend that money and get more bang for your buck. A lighter, more aerodynamic wheelset would be a great place to start.


Hybrid bike stolen, trying to weigh factors for how to replace

I know you say you're not comfortable buying a used bike, but…

A used bike will get you so much closer to what you say you want in a bike, and can be so much better a value for your money. Here's my pitch for a used bike:

Look for a brand name "vintage" mountain bike – one without suspension, but with tons of clearance for fenders and wide tires. If I were looking, I be hunting for something like a Trek 850 from the '90s. I think Bridgestone also made some nice bikes of similar vintage.
The wide tires will let you run wide street tires (something like a Schwalbe Big Apple) at a relatively low pressure that will give you a comfortable ride with relatively low rolling resistance.
No suspension means lower weight, complexity, and for equivalent quality lower cost. Eliminating the suspension also makes it easier to fit fenders and racks.
An old used bike will have lower perceived value, especially a steel bike with skinny tubes. Steel is nice in a used bike because it is much less likely to fail suddenly as a result of mistreatment by a former owner and it is also out of vogue which may help with the thieves.

So the big question, I think, is why not a used bike?

If it's because you don't feel qualified to check out a used bike, I can understand that. Perhaps your LBS sells used bikes, or can recommend someone who refurbishes them in your area. I'd also encourage you to consider that bikes aren't like cars. They are much closer to "what you see is what you get." If you test ride the bike and like it and all of the basic functions work – brakes, shifting, adjusting the seat and bars – then you're probably good. You could also factor in the cost of having your LBS do a tune up.


There are a few reasons that might cause the jumping of chains.

Chain or sprocket is worn out (Buy new ones).
The derailleur is misaligned (Needs adjustment).
The wheels are not fitted properly making it a bit slanted (clean the crevices
and fit the wheel properly).

Check all of these and comment back if all are good.


"Chain binding" occurs when the chain is really tight around the sprockets.  No set of sprockets is perfectly round and centered (especially if worn a bit), and if the chain is tight at one spot in the rotation it likely will become too tight with another half-turn or so.  The pressure of the chain on the sprockets makes the crank more difficult to turn, or, if the sprockets are really off-centered (though likely not visibly so) the crank may lock up entirely simply because the chain isn't long enough to reach all the way around.

Even if the sprockets are perfectly uniform and centered, the friction of the chain links against the teeth will contribute to a sort of "drag", if the chain is too tight.

Note that this is different from having a "frozen link", which is a defect in the joining of an individual pair of links in the chain.


Problems with front derailleur shifting on an inexpensive bike

I'm sure you're a better judge of how effective your LBS employees are than people on an Internet forum, but in my experience it isn't uncommon to find some LBS employees are not very enthusiastic about working on bikes they view unfavorably for whatever reason: too old, too inexpensive, and so forth. Some think that working on an inexpensive bike is like polishing a turd, and I have run into more than a few who view it that way.

If the bicycle is similar to this one, I would encourage you to check out some YouTube videos regarding derailleur tuning:

Tuning a front derailleur
Tuning a rear derailleur


Why are derailleur jockey wheels commonly made of nylon?

Caveat: I've only seen two or three sets of metal pulleys in my life. There are several reasons:

cost: plastic parts are cheaper to make than metal ones
weight: it's easier to make a lightweight plastic part than a metal one (this is also related to cost, "easier" usually means "cheaper")
durability/resilience: somewhat counter-intuitively, plastic cogs are less likely to fail completely. When the plain bearing locks up the plastic wheel is likely to slip on the metal bearing (and many people don't even notice that this has happened), or the teeth with abrade off to form a smooth surface that the chain will run on (it's very hard not to notice this). A metal pulley does not do this, if they stick for some reason generally the bike isn't rideable, and it's unlikely that the aluminium pulley will slip nicely on the steel bearing.

The latter is somewhat hard to get experience with, since metal pulleys are sufficiently rare and expensive that few people use them. Also, people who pay extra for them tend to maintain them so I haven't seen them fail other than via "full of mud, not going round". In that case, though, the chain will not go through the rear derailleur at all, so the bike needs to be converted to single speed before you can ride it. Which is an ugly thing to have to do when you're out on a bike ride.

Note that recumbent idler pulleys have the same concerns but often they're on the drive side of the chain so the forces are larger. So are the pulleys to reduce chain bend angles and thus losses. In that case metal cogs are usually also lighter and quieter but significantly more expensive (more than double the cost). Derailleur pulleys would also benefit from being larger, but that's relatively rare, I suspect because weight and air resistance also increase with size (and a larger cog would mean extra chain, further increasing weight)


Need to know what type of bike frame this is

I've emailed Scott USA and here's the answer:

  We have searched high and low.
  No one can find any info on this bike
  at all! It’s that old. Sorry we couldn’t help..

My own search did not bring up anything useful either. I think this is either some other bike with Scott decals or an one-off prototype, given frame finish and configurable linkage.

Update: This is Scott FX DH 1996. Confirmation link.


Can I use a road bike stem on my mountain bike?

For XC and trail use it'll be fine.

It's really only downhill bikes that require especially strong stems, I think (and in that case you'd likely be using a shorter stem anyway for handling reasons).


How to eat properly when cycling in extreme heat?

It is extremely important that you eat and drink properly when cycling in extremes of temperature.

In Dubai, where riding in the summer means riding regularly in 50c temperatures, this is a major problem.

Eating is less of a concern than hydration, but you want to avoid dehydrators, like alcohol, in your food. You also want to watch what spices and additives are present in your food, like high salt content, but your standard diet as noted (High protein  the night before, and carbs after a ride and assuming unsalted nuts and trail mix) should be fine to ensure energy. (Too much salt in one go can upset the stomach by drawing water into the gut, especially if you're already dehydrated. So it needs to be in small doses.)

Avoid sugary drinks, stick mainly with water, and electrolyte replacement drinks with low sugar content.

Desert survival expert Marjorie Woodruff recommends drinking a few ounces of water every 1o minutes if water is limited, and a minimum of 1 liter every 45 minutes if water is readily available. Electrolyte replacement s fairly essential, but can be accomplished far more inexpensively using a product like Elete Water because it can be carried easily, and a very small container is an effective add in to about 25 liters of water. It's mostly tasteless, but in our experience here in Dubai, very useful.

Proper clothing is essential. Cover your skin. Do not rely solely on sunscreens, as they do not prevent dehydration, although they are better than nothing. Better yet, do both.

Another essential in hot weather cycling, especially while touring, and deadly essential if touring unsupported is the ability to recognize and understand what is happening when you are affected by heat, and what it feels like.

This article from the Mayo Clinic has a pretty thorough examination of exercise in hot weather, and what the dangers and effect are.

  How to avoid heat-related illnesses

  When you exercise in hot weather, keep these precautions in mind:

  Watch the temperature. Pay attention to weather forecasts and heat
  alerts. Know what the temperature is expected to be for the duration
  of your planned outdoor activity.

  Get acclimated. If you're used to exercising indoors or in cooler
  weather, take it easy at first when you exercise in the heat. As your
  body adapts to the heat over the course of one to two weeks, gradually
  increase the length and intensity of your workouts.

  Know your fitness level. If you're unfit or new to exercise, be extra
  cautious when working out in the heat. Your body may have a lower
  tolerance to the heat. Reduce your exercise intensity and take
  frequent breaks.

  Drink plenty of fluids. Dehydration is a key factor in heat illness.
  Help your body sweat and cool down by staying well hydrated with
  water.

  Don't wait until you're thirsty to drink. If you plan to exercise
  intensely or for longer than one hour, consider a sports drink instead
  of water.

  Sports drinks can replace the sodium, chloride and potassium you lose
  through sweating. Avoid  alcoholic drinks because they can actually
  promote fluid loss.

  Dress appropriately. Lightweight, loosefitting clothing helps sweat
  evaporate and keeps you cooler. Avoid dark colors, which can absorb
  heat. If possible, wear a light-colored, wide-brimmed hat.

  Avoid midday sun. Exercise in the morning or evening, when it's likely
  to be cooler outdoors.

  If possible, exercise in shady areas — or do a water workout in a
  pool.

  Wear sunscreen. A sunburn decreases your body's ability to cool
  itself.

  Have a backup plan. If you're concerned about the heat or humidity,
  stay indoors. Work out at the gym, walk laps inside the mall or climb
  stairs inside an air-conditioned building. Understand your medical
  risks. Certain medical conditions or medications can increase your
  risk of a heat-related illness. If you plan to exercise in the heat,
  talk to your doctor about precautions.

  Heat-related illnesses are largely preventable.

  By taking some basic precautions, your exercise routine doesn't have
  to be sidelined when the heat is on.


What caused this seat clamp / frame failure?

It looks like plain old metal fatigue. Most probably there was a hairline crack, then water got into it and rusted it out.

Note that when you extend the seat height, you increase the lever arm of the seat post and put a considerable amount of stress on the frame precisely at that location. It doesn't help that the design of that seat clamp has no reinforcing material and is high-up, further increasing the leverage on it. Poor design.

The good news is that it's a steel frame. You could take it to an auto body welder and they could easily fix it for less than an hour of labor. Since they can't weld from both sides (the seat tube wouldn't go in), it'd still be weak and susceptible to damage. Or you could try rebrazing it yourself.


Is a Vittoria Randonneur 28- or 32-622 on a hook-less 23 mm rim feasible?

Hookless is getting more commonly seen and will probably become pretty normal. More analysis here: http://www.bikeradar.com/us/mtb/gear/article/trail-tech-off-the-hook-40749/ . Basically, the bead lock area of modern tubeless compatible rims diminishes the need for it. For this kind of rim (very short sidewalls, center mounting groove, bead lock), lack of hooks shouldn't be a factor in figuring out what width to run.

What will actually get you in trouble, or keep you out of it, when determining how narrow you can go is how much tire you have overhanging the outer sides of the rim, which protects the rim from dings and scrapes. A reasonable minimum is 1-2mm per side, and never a tire whose inflated width is narrower than the rim. (There are some trends in the racing world to break this rule, but rims suffer as a result.) Internal width is a relevant consideration, especially in gaging how wide you can or should go, but it's not the end-all factor that it's sometimes made out as these days.


Pletscher and Greenfield both make decent kickstands. The most common kickstand is a single leg model that attaches just behind the bottom bracket. Pletscher also makes a double leg kickstand that mounts in the same place and Greenfield makes a kickstand they call the Stabilizer that attaches near the rear dropout on the non-drive side.

The double leg kickstand is nice if you need the bike to be stable while you load cargo or if you use a single-wheel trailer like the B.o.B Yak or Ibex. On the other hand it is a, small, bit more trouble to use since you have to lift the bike a bit to all the legs to fold down.

Most kickstands seem to come in a size that is too long. The leg(s) need to be cut to a length that is appropriate for your bike. It's easy as long as you have a hacksaw – on the Pletscher you just measure from the ground to the center of the bottom bracket and then find that dimension on the where it is marked on the kickstand and cut it off.

Depending on where you park the bike you might want to get a foot for the kickstand either to protect a floor or to provide some resistance to sinking into soft surfaces.


If I replace the cassette on my road bike, should I replace the whole drivetrain?

If the new cassette has the same gears (# teeth) as the old one, you may not need to. If your chain is worn or in bad shape, this would be the time to replace it. If the new cassette has a different number of teeth in the larger cogs, you may need to lengthen or shorten the chain.


What is the best way to protect frame from dents during crashes?

Your bicycle is probably as protected as its going to get when it comes out of the factory, so I'd suggest doing nothing (well, maybe crash less).

Protective Film -- Cosmetic protection (possibly structural in some cases for things like cable rub as pointed out by Nathan in the comments). If you're worried about keeping your bike shiny and scratch free I suppose. Be careful with Carbon Fiber depending on adhesive. Won't protect from dents.
Derailleur guards are a terrible idea -- the force transmitted in a crash will be applied in a way not in line with design and damage the frame, whereas if the derailleur is installed as normal, the hanger will bend (or break) and is usually easily replaceable or reparable (align with something like the Park Tool DAG). If the derailleur is damaged, it's a heck of a lot cheaper than repairing the frame damage caused by a derailleur guard. You could spec an internal gear hub or single speed instead, if you want to avoid derailleur damage depending on the frame.
Bumpers -- See point 1. I see these as likely less useful than the film.
Crash Guard -- See point 2. Plus, there aren't as many nice mounting points as on a motorcycle since you have to pedal on a bicycle for it not getting in the way, whereas you only shift+brake with foot movement on a motorcycle.


Car headlights are more complex than bike lights. The beam is 'shaped' to throw light away from oncoming drivers and has a sharp cutoff on dipped beam. therefore bike lights will always cause a greater degree of glare (for relative brightness) than car lights.

Point the beam so its shining at the ground about 10-20meters in front, and slightly towards the curb. The faster you go, the higher it needs to be. Curb side is where you need most light, as that is where the glass and rubbish is, and it avoids blinding oncoming motorists. As far as being seen, add a non-directional flashing light and hi-vis gear.


A quick Google search suggests it's a BB386Evo. Do you see that number, or maybe just a "386" stamped anywhere on it?

Further confirmation:

https://machiine.com/2017/the-wilier-triestina-zero-9/

https://www.racycles.com/product/detail/5707

That last link makes it sound like it's a custom BB:

"The bottom bracket standard is the Wilier co-designed BB386EVO, designed for 30mm diameter thru-axles and 86mm wide bottom bracket shells"


Most fork manufacturers will actually suggest service based on Hours on the fork, I know Fox will suggest you breakdown and clean all seals and replace open bath oil systems every 30 hours ridden.  Also most sealed gas dampers suggest you send them back to the manufacturer every X number of hours to have them rebuilt by the factory.


Consider you are not finding what you are looking for for a reason.

A larger tire does not necessarily have a lower rolling resistance.
A the same pressure a larger tire actually has a lower rolling resistance.

Over city terrain I would take a 28 mm or 30 mm over a 23 mm for rolling resistance.

For ride and flat resistance I would definitely take a 28 mm + over a smaller tire.

Racers go with a narrow tires more for wind resistance. On a hybrid you don't have nearly the aerodynamics of a road bike - you are taller and wider.  What you pick up on a small tire on hybrid is just not worth it.  You already have the wider fork and rear hub.  Putting smaller tires on it is just not going to change the aerodynamics much - especially on the rear.

I would stay in the right sizing for your rims and go with a low resistance road type tire.

You probably have like a 20 mm that will take 28 mm tire fine.
If you are bigger than 20 mm you can find CX 135mm wheels as low as 20 mm.

On the front you if you are dead set then you could find a road wheel for the front.
But I still don't think 23 mm is going to make you faster than a 28 mm on that bike.

If you really want speed then I would put that money into a road bike rather than a custom wheel build.


Chain with master link / quick connect link doesn't clear rear derailleur

That chain connector is not only for single speed, but I believe it is for 1/8" chains as well, so you may have a track chain, which is not meant for multi-speed drivetrains.

If it's not an 1/8" chain, and is instead a 3/32" chain, and your drive train is 8 speed or less, you can just replace the master link and you should be good to go. The master links only cost a few dollars so it can be a lot cheaper than swapping out the whole chain.

Master links for multi speed chains look more like this:

Or, if you have a chain tool, you could just remove a full link from the chain, skip the whole master link business entirely and ride today and let future Leeroy deal with it. Being short one link shouldn't be very problematic. This is also the only option if you have a 1/8" chain as mentioned above, and don't want to replace it.


Need help identifying year of Ultegra rear derailleur

I believe that is an Ultegra 6600, made from 2005 to 2008 (according to Wikipedia). Not sure you will be able to narrow it down to the exact year.


Will my rear wheel with an internally-geared hub shift forward when pedalling steep uphill?

Wheels in horizontal dropouts have been reported to shift. You may or may not have a problem depending on how strong you are and how well your wheel clamps in your frame.

There are devices that fit in horizontal dropouts that hold the wheel in place and remove the need for re-adjustment after removing the wheel, such as Surly Tugnuts (example only, not a product recommendation).

There is no need to use a chain tensioner if you have dropouts suitable for adjusting the chain tension. It will only add friction and will not stop nor deal with the the wheel moving in the dropouts.

Worn chains can not slip on non-derailleur drivetrains. A worn chain only elongates by 0.5-0.75%. When your chain becomes worn you should replace it as it will accelerate wear on the sprocket and chainring, as we'll as becoming inefficient.


Excepting the hubs, are the front and back wheel in OEM road bikes or in Road Bike wheelsets manufactured differently?

Yes - they're totally different for a number of reasons.

The rear hub has a cassette on the right side, so the wheel has to be assembled dished.  So the right side spokes are slightly shorter than the left-side spokes.

Right image shows something that MTBs have tried - having the right chainstay further from the bike's centerline than the left chainstay.  This is not common on road bikes.

Rim profile can vary too.  A front wheel can be flipped and used the other way around, (with the possible exception of directional tread on a tyre, and disk brakes.)  So front wheels are built symmetrical.   Rear wheels are dished, and as a side effect the nipples can be at different angles as they leave the rim.

Here's a cross-section of a MTB wheel that shows it nicely.

The tyre is centered in its track about 2-4 millimetres to one side of where the spokes would be centered.  You can see the hole where the spokes go through, and its part-way out of the valley.  This is ONLY practical on the rear wheel and lets the builder use slightly more even spokes but still have effectively a "dished wheel"

In addition, the power of drive comes through the cassette, so the rear wheel might be laced with a variety of patterns.  Most common is 3-cross, where each spoke crosses with three other spokes on its way to the rim.  2-cross would be slightly shorter spokes.  Combinations like radial lacing on the non drive side and 2 or 3 cross are not as rare as they used to be.

Front wheel lacing seems to be favouring radial spoke design for simplicity, but that's at odds with front wheel disk brakes.  So rim-brake road bikes will move to fewer spokes radially, but disk brake road bikes will drive it back to 3-cross and add spokes.

Left wheel is radially spoked, and right wheel is 3-cross.

Spoke count matters too - the front wheel carries less load, so can "cope" with fewer spokes.  The downside is a weaker wheel, which translates to a heavier rim.

Spokes might be bladed on the front and plain old round ones on the back.  The front wheel runs in cleaner air, with more predictable aerodynamic effects.  The rear wheel is in much choppier air, so bladed spokes have less beneficial effect.

So yes the front and rear can be assembled differently.  The method to assemble them would be pretty much the same, as long as the wheelbuilder gets the crossing correct while adding spokes.  Bladed spokes provide extra challenges, but nothing a wheelbuilder can't handle.


Shimano sora 9 Speed rear derailleur capacity Rd-3500 SS

Max 32T here refers to the largest rear sprocket, not the total capacity. So with an 11-28 you'll have no problem.


How big are pull ratios in Shimano 9-speed front derailleurs in MTB and road bikes?

I've had something like this on two road bikes - the big-front and small-rear combo means the chain is running as far to the right as possible as it hits the front derailleur.

One was fixed by using proper-sized 9 speed chain, not the mystery chain that was already installed.

Since the limit screw is not the problem, you may need to shim the derailleur so the whole thing stands to the right a tiny bit more.  If its a braze-on mount this won't help.

Do test if you can move the cage far enough with your fingers (be careful!)

Another possible fix might be to distort the front mech's cage, but that may cause problems with other gears.


Lifting a road bike by one of the seat stays ok?

If it can hold your weight while sitting on it, then it should definitely be OK to lift the bike from it.


Is there a ulock mount that uses the bottle cage openings?

This isn't a ulock, but it's the same idea.

It's a 0.9 lb bike lock made from Titanium. They cost $99 and come with a water bottle cage mount as shown.

TiGr® mini Bike Lock
enter link description here


Will an MTB hydraulic brake lever be compatible with road hydraulic brake caliper?

Whats wrong with XTR caliper - they fit a 140mm disc (Shimano have a compatibility guide here).  The weight Ultegra is 123gr, of XTR M9000 is 91gr

Disclaimer: Brakes are a safety critical component, I do not recommend mixing road and MTB parts.

According to the link above, all MTB calipers/levers are compatible, as are all road lever/calipers combinations, but the guide does not mention cross compatibility.  Many people on the net (I have never tried it) claim they are interoperable. Apart from bleeding, if the piston diameter is the same I see no reason why they would not work.  If the piston diameter is different between the road and MTB setups then there will be differences in performance as the amount of fluid to move the pads the same distance is different.

With some of the newer discs Shimano has changed the bleeding systems. Its possible a lever/caliper mix might be hard, or impossible, to bleed.

The hoses used for these brake components are the same (BH90) so there will be no problem connecting them. (Even if tone was BH59 and the other BH90, the outer diameter and olive is the same  so they can be mixed and matched). The only thing to watch is if the caliper end of the hose is a different fitting you may need new hoses.


Well, you'd have a spider on both sides is one odd and annoying thing. Sheldon Brown has run the cranks in reverse on regular (non-bmx) bikes [In BMX, there is a reasonable set of options going both ways].

You'd also probably get a strange Q-factor as well given that the insertion depths are different for the right and left crankarms. This could be compounded if you happen to have a non-symmetrical spindle length bottom bracket.

(It should work in theory - why you'd want to do this in practice unless you were in the odd situation of having two good right crank arms and no good left crank arms is a mystery...)


Are all skewers compatible with all bikes?

Generally speaking, the answer is no. Not all skewers are compatible with all quick release wheels. There are different diameters and widths of skewers. Notably, many downhill bikes have beefier skewers that are built with a much larger diameter to be more durable. Bikes with wider and narrower axles will have less standard skewers too.

In your case, it is likely that the skewers will be compatible. Even if the skewer isn't quite long enough to have threads protruding from the nut, it will still be okay if the difference is less than 2mm.

See this forum post for more info:

  True, the standard nowadays is 100mm up front and 130mm in the rear, BUT

  When you start talking about different types of bikes, you get into different width hubs.

  Tandems have a standard rear spacing of 140 or 145mm, some downhill/freeride bikes have a whopping 150mm rear spacing and 110mm front hub spacing and monstrous 20mm through bolt skewers, older bikes with French or Italian standards can have wacky sizes from 91mm 96mm, the list goes on.

  But you are correct in saying the "standard" size for skewers is 100mm up front and 130mm in the rear.


Generally, why Bicycle tires are thinner and Motorcycle tires thick?

With the exception of fatbikes, the widest bike tyres are narrower than the narrowest motorbike tyres.  I'll ignore fatbikes as somewhere between too specialised and a novelty.

You'll also notice that all motorbikes have significant amounts of suspension.  Fat tyres and suspension both absorb energy from vertical motion.  This can be a good thing, for example if you ride over a pothole, or a bad thing, if the vertical motion is from pedalling hard.  Motorbikes aren't propelled by pedalling so don't have to worry about this.  They also go much faster so the consequences of hitting a pothole are more severe, or would be without something to absorb the hit.

Motorbike tyres are likely to have higher rolling resistance. With the rims to support them they also have much higher weight and rotational inertia, meaning bigger brakes -- but you need those anyway given the speed.  The rolling resistance is significant in terms of human power output, but given that even a 125cc motorbike can put out 11kW continuously and a pro cyclist more like 500W it's not significant in motorbike power terms.  This higher power (and higher braking force) has to be coupled to the road somehow, and that's through the contact patch.  Typical bike tyres wouldn't last long until even modest motorbike acceleration, or give enough grip for hard acceleration/braking.

In summary: motorbikes can have bigger tyres because they've got more power, and they need to because they're faster and more powerful.


Rusty Front Derailleur – Replace or Repair?

It looks like a cheap enough derailleur that replacing it shouldn't cost too much, and the rust is severe enough that if the derailleur has stopped shifting I'd replace it.

If you can force the derailleur to move with your hand it's very likely to can repair it just by pouring sufficient oil on it and working it backwards and forwards for a while.

But whatever has caused it to rust will still exist afterwards, so unless you fix that problem the new/repaired derailleur will just rust again. If you buy a slightly more expensive one it will use better steel so will rust less readily, but the real solution is to stop leaving it out in the rain, or at least cover it. If the problem is salt spray, all you can really do is put a coating of grease on everything and reapply that every few months. Which is a good idea with derailleurs anyway, especially cheap ones.

Use chain lube that's grease-plus-solvent and put a few drops of that on to the derailleurs when you oil your chain. You can save money by doing this, as $5 worth of chain lube will double the life of the chain, and probably the derailleurs too.

For bikes like this a half-decent chain lube is often a miracle cure. Run it into the brake and gear cables, put it on all the pivot points you can find, coat the corroded metal with it, go a bit wild. But 3-in-1 oil and a top coat of grease will work better on the derailleur spring - you want thick and gooey for that. I use "TriFlow" but any of them will work (with the caveat that WD40 and so on are degreasers, not lubricants)


Can you put disc brakes on road forks originally intended for calipers?

To install disk brake, you need brake mount tabs on your fork/frame. Like this:

Original Image

And hub with mounts for brake rotor:

I've seen a few attempts to create an adaptor for fork/frame to install disk brakev tabs. But none were good enough for real life.

So your best route is to replace your fork and front wheel/hub.
But sometimes it is easier to get a whole new bike.


It appears that there are several products under this name, a general-purpose solvent/protectant and a dedicated bike chain lube.
Reviews on Amazon are rather mixed... One fellow claims no better than WD-40, others appear to like it.
Chain lubes are always controversial and seldom tested in a rigorous manner.

WD-40 is essentially a cleaner/solvent and has no  more lubricating ability than say...Kerosene.
The best chain lube I ever tried is sadly not being made any more... Schwinn Factory Wax.

Clean-running, persistent, and according to testing by Bicycling magazine, among the top for wear and abrasion resistance.

To my way of thinking, keeping the chain clean and free of built-up crud and goo is as/more important than what sort of lube used.


As you asked for an explanation, why this skipping is happening, here it is:

For the beginning let's consider an unused chain on an unused sprocket. In this case the distance between the teeth of the sprocket is the same as the length of the chain links. Therefore, if you apply a force to the sprocket via the chain, the load is equally distributed over all teeth that are in contact with the chain. Due to the force the chain lengthens over time (not much, about 1-2% is enough to make the chain unuseable) which means that the chain links no longer fit the sprocket's teeth distance and also the load distribution isn't equal any more.

Instead, the tooth that is closest to the direction where the force comes from (the last one on the sprocket where the chain leaves towards the chain-blade and the first one one the chain-blade where the chain comes from the sprockets) gets the most load and therefore is wearing out a bit more than the other ones. As everything goes round and round and every tooth is in the position to wear out more than the others, the teeth will slightly adapt the valleys between them to fit the length of the chain.

If you replace now the chain by a new one while keeping the cassette the same (it would be the same if you replaced the cassette keeping the chain), then the chain doesn't fit any more to the cassette that has adapted to the length of the used chain links. If the length difference between old and new chain links is too much (as already said, some 1 or 2% are enough) the chain will slide up the shoulders of the teeth and skip into the next (or even the next-nearest) valley as soon as the applied force gets too high. One can make the components last somewhat longer by changing the chain early enough, but as both, chain and cassette are wearable parts they have to be replaced sooner or later.

It depends on different factors how fast this wear-out process will be:

Dirt and lubrication: Dust, rust, sand etc. act like grinding media which increase the friction between the chain and the sprocket and therefore accelerate the wear-out. A well cleaned and lubed drive train therefore lasts longer.
Load per tooth: The higher the force working on the sprocket and the lower the number of teeth over which this force is distributed, the faster the teeth are wearing out. Therefore it is usually the smallest sprockets on your cassette that at first show the skipping as they get quite a high load and have not much teeth which have to take this load.
Usage frequency of the sprocket or chain-blade: of course, a sprocket that is used more often wears out faster. This is the reason why for most people the middle sized chain-blade at their cranks will show skipping (if they ever come that far within the lifetime of their bike ;-).

This means that a road bike, where you normally don't have much dust and try to pedal rather smoothly without any rapid changes in force, can go several thousands of kilometers on one chain. With mountainbikes where you have the exact opposite (lots of dirt, often sharp load peaks when you go to rough terrain) the rule of thumb that I learned some years ago is to replace the chain every 2000km. Even then you will need a new cassette every second or third chain.


Ever seen a locking bag that could be locked to the bike?

Do you mean something like this from PacSafe it's got a secure steel mesh inside:

I remember using one of their bigger backpack bags when travelling to New Zealand a few years ago, and the only complaints I had were from the TSA when we went through the US.

Alternatively if you have a rack on the back, then it may be possible to attach a lockable box to that in some secure way. Although my worry would be that anyone who noticed such a box, would immediately wonder what was locked up inside and decide to break it open.


How to assemble bike chain with no Master link?

You could try using a simple chain breaking/Rivet tool to break the chain at one point (while still keeping the pin in the link) and then put the chain on and use the tool again to push the pin in and join the chain like that. That's the way I always do it. Here's a couple of tools that you could try:

TRIXES Rivet Tool (Very Low Cost): http://amzn.to/1X9NWXI
Topeak Super Chain Tool (Branded Tool): http://amzn.to/1MDggwF

Best of Luck,
Robert