diference between 170mm 172mm 175mm crank arm length on road bike What is best for which use, advantage, or application, especially for climbing.

Believe it or not in the range of lengths you are looking at there is very little scientific support for there being any real discernible differences in performance (both in absolute power and metabolic efficiency).  For the lengths you are considering I would suggest this is largely a personal preference choice.

Crank length and maximal power

If we are concerned about maximal power output,  there appears to be no significant difference for the crank length range commonly (Martin and Spirduso 2001). The study used 16 male cyclists were tested for maximal power across crank lengths of 120, 145,170,195, and 220mm.  Only the extreme (120, 220mm) showed a significantly lower maximal power, but the effect size is small (around 4%).

Figure 1 - Maximal power as a function of  crank length (reproduced from Martin and Spirduso (2001)).  Be careful of the Y-Axis scale, the effect size is actually small and error bars are large indicating a lot of individual variability.

Choosing a crank length for optimal power

Martin and Spirduso (2001) also attempted to create a formula for optimal crank length based on fitting a 2nd-order polynomial regressions to the subjects best power (response) as a function of the ratio of leg, tibia, and femur lengths to crank ratios (think inverse U cuvrve).  Leg and tibia lengths had support ($R^2$ of 20.5 and 21.1%), but the effect size was small (around  3%) and the relationship had a number of outliers.  That said, the regressions suggested a crank length that is 20% of your leg length or 41% of the tibia length.

As a side note, in terms of effect size, you can gain 5% through gear selection, using larger cogs (see Spicer, 2000).

Crank length and metabolic efficiency

Most cyclists are not producing maximal power on their ride.  Instead we tend to spend most of our time at sub-optimal output levels. In this case we might be more interested in the metabolic cost of cycling, and optimize the setup to be the most metabolically efficient. McDaniel et al 2002, investigated the impact of a number of factors (including crank length) on metabolic cost. 9 cyclists were used in the study.  A smaller number of crank lengths were used (145, 170, 195 mm) compared to Martin and Spirduso (2001).  Pedal rates were also investigated (40, 60, 80, 100 rpm).

Overall, mechanical power strongly predicted metabolic cost (R^2 = 0.95; not surprising) and the authors used the metabolism residuals (left over variability) to investigate the impact of crank lengths, pedal rates, and pedal speed.  The used step-wise regression to attempt to build the best descriptive model (personally I think small-sample sized corrected AIC ranking would have been more appropriate).  They found independently each had some descriptive power, but overall the best descriptor was pedal speed (combination of crank length and pedal rate (cadence)).  Once pedal speed was accounted for the other factors (e.g., crank length) provided little descriptive power. Note that all of these factors will be related (i.e., multicollinearity) so it is not surprising on their own there would be some descriptive power.

In terms of metabolic cost, it would seem your pedal speed is what matters.  To quote the author:

  The main finding of this investigation was that mechanical power
  output and pedal speed accounted for 99% of the variation in metabolic
  cost at intensities below LT.

Note that LT stands for Lactic Threshold (aka maximal aerobic capacity).  More importantly, they follow up and state (emphasis added):

  Mechanical power output alone accounted for 95% of the variation in
  metabolic cost, suggesting that, even with our wide range of
  pedaling rates, pedal speeds, and crank lengths, muscles’ ability to
  convert chemical energy to mechanical work was remarkably stable.

Choosing your length

The take home is our body will adapt to the commonly used crank lengths, so you need to select base on other factors. While some will argue that  performance gains are possible,  these for the most part appear to be small, on the order of small drive train efficiency gains (e.g., using larger rear cog; see Spicer, 2000).  A common theme to me is that individual variability seems to be a much larger effect, therefore you will need to consider your personal situation.

If I had to suggest one potential selection criteria I would suggest considering if you like to spin or mash your gears.  If you like to spin, you will likely want a shorter crank length so you can turn your legs over faster.  If you like to mash, a longer crank length will likely feel better as you have more leverage.   As an aside, spinning can also be more efficient as you tend to use a larger cog in the back, which is known to be more efficient (Spicer, 2000). Why on earth modern cassettes use such small cogs I have no idea! I suspect weight at the cost of efficiency.

Other SE questions covering this subject.

What is the effect of changing length of crank arms?
Why such a tiny difference in crankarm length?

External Reading

A good summary of the science, in a readable format, is available on the Cervelo website:

http://www.cervelo.com/en/engineering/ask-the-engineers/crank-length.html


MTB: choosing trajectory (line) through a turn Consider a 3 meter wide track, the incline is 30 degrees, the terrain is dirt road with some sand, rocks, maybe mud. An at least 90 degree turn is approaching, and you have clear visibility of the whole turn.
How do you choose consciously (and with practice subconsciously) your path through the turn, in order to minimize loss of speed? What factors affect the decision and in what way?

TL;DR
So here is the scenario. The incline is constant 30 degrees. A and B indicate the terrains on both sides of the track.

What effect on the decision has the estimate how much is A and B dangerous? For example, if B is a 100m drop, and A is lush field.

Here is an example of taking the turn entirely on the outer edge. This has the effect of increasing the turning radius. On the other hand, one slip and the bike leaves the track.

On the other extreme, here is an example of taking the turn as tightly as possible.

Further, if there is another turn very near, the exit line of the first turn directly affects the attack line of the second turn. What are the strategies to deal with a double turn?

Cornering is an essential mountain biking technique, regardless of the type of turn you're going into.

Scenario 1: Turn to obstacle
With clear visibility you should make the turn so the exit lines you up for how you plan to ride the upcoming obstacle. Usually this means taking the turn wide (high) so you can pull the bike back into line easier.

Scenario 2: Single turn
A single turn leaves you with only one decision: fast or slow? The lower you go through the turn, the tighter the radius and the more speed you will carry (conservation of momentum). But like any type of riding, maintaining control at speed can be difficult, which may cause you to take a wider line.

Scenario 3: Turn to turn
Consider an S-curve. You'll want to kind of approach it with the idea of slaloming through the turns. This means picking whichever line will bring you into the entrance line of the next turn. Again, this usually means riding further out, then coming back in to the entrance of the next turn.

Lastly, as you mentioned in example 1, there are times when the other side of the berm isn't so pleasant if you happen to overshoot. Here it's about how much courage you have! If you have the skills and want to ride high then go for it, otherwise scrub a little speed and take the tighter line. And really, there's always the ideal situation, then there's what happens on the trail, which is often very different from how the ideal works.


Identify vintage bicycle brand I don't know much about bicycles but I came across one that I want to offer to my nephew since he is into vintage race bikes. I would like to know the original brand of the bicycle/frame since I want to replicate it with the right decals. I was told the frame tubes are Reynolds 531 and from the equipment (Mafac, Simplex, Belleri) I assume the bicycle is probably French from the 70s after several searches enter image description here. Thank you in advance for your help.

Not particularly fine lugwork. Look like Prugnat lugs, but not S4s. Fork crown isn't too finely filed either. Can't tell the brand of ends from the shots. Straight brake bridge with no tangs at the stays. Can't see BB very well at all. Nor chainstay bridge. Is Campag brazeon cable guides? Can't see. Are forks replacements? Does the fork raking look like it's cheaply done? Match the quality of the lugwork? Fork ends match the stay ends? What else could narrow down its country of origin?


Is it 'safe' to use a 700 x 47c tyre on a rim with inner width of 15mm? Looking to upgrade my tyres on an old roadie mash up to something chunkier so I can handle some off road sections on a ride coming up, currently it has a 27 x 1 1/4 front tyre and a 27 x 1 3/8 rear with plenty of clearance all round*.

I've got a set of 700c rims (internal width 15mm) that I am looking at putting on in place of what's already there because the tyres are cheaper for it, so would the wider 47c tyres be suitable for these rims? They have had a set of 32c tyres on them for ages no problems but it still looks like they'd fit a wider tyre quite fine, Just want to make sure first.

Also if wouldn't mind knowing what would be a minimum size tube to use, hoping to avoid having to buy new ones because I am on a $50 budget to get the bike suitable for the ride. At home I already have a number of thinner tubes that I doubt would work (up to 28c I believe) but also a pair of 27 x 1.25" tubes, Would these work for the 700 x 47c tyres? or would I need fatter tubes also?

*should be noted that the tyres already on the 27" rims are slicks or near enough and are falling apart due to being  left out in the weather for many years.

To fit 700c (ISO 622) wheels into a bike built for 27" (ISO 630) you only need to shift the rim brake pads down 4mm. If you're exceptionally lucky your current brakes will have enough reach and you'll just have to adjust the pads. That's the first thing to check, because if that doesn't work there's no way you're going to do this on a $50 budget.

2" wide tyres should be ok on the 700c rims. Not ideal, and probably outside the manufacturers specifications, but it should work. I've done that with 406 wheels before and it's worked pretty well.

The real problem is the tubes. Again, new tubes overstretched like that would work in a pinch, but they're be extra vulnerable to punctures because of the stretch. But usually if you're replacing aged tyres I'd suggest new tubes since they're likely to be in similar condition. Trying to over-stretch old tubes is very likely to fail immediately, and if not will almost certainly fail shortly after you start riding.

If you can get the 700c wheels to work, I'd go with a 38mm tyre rather than 42 or 48, just because I'm really wary of damaging the tubes. I assume on your budget you can't afford to carry a spare. But really, if you're doing a ride of any length I think you should buy at least one spare, unless it's a ride you can bail out of and get someone to carry you and your bike home. Even a cheap, shitty spare tube is better than nothing. personally I would cheap out on the tyres in order to buy a couple of tubes. It's not worth going out on a ride and having to go home because your old tubes give out.

If you can't make the brakes work I suggest buying the fattest 27" tyres that will fit your tubes, which is likely to be 1 3/8". I'm sure I've seen 1 1/2" x 27" tyres but I can't find any now.


Which endurance tires for touring? I got a recommendation from an experienced tourer to switch to Schwalbe Marathon Plus endurance tires during summer and Schwalbe Spike something during winter. I like the Marathon Plus tires, despite them being a bit slow, because I don't want to get a flat in locations called no-where. I am not interested about product recommendations but rather how can I know a good endurance tire for a certain touring location? If you know that a road is poor for the next 1000 kms, is it a good idea to switch to wider tires with greater volume? Is there any objective way to test a tire in a random shop? I have noticed that sometimes some LBSs have old tires but time-to-time it is hard to say. So how can I detect a good endurance tires if my favorite tires cannot be found? By it I mean that I want more objective ways to select tires rather than just brand.

It's difficult to judge the quality of a tire hanging on a rack in a bike shop.  Experience (including recommendations) is an important factor, since it takes 1000's of kms to put a tire to the test.  When deciding on a touring tire, buy a set to try out pre-tour.  You'll get an idea how they handle, how fast they wear, how puncture-resistant might be just by using them for everyday riding.  Then when you're ready for the big trip, put a fresh set on the bike and save the worn ones for when you get back.

Certainly wider tires will help on rough roads.  Thicker tires may last longer.  For puncture resistance, stay away from racing tires and look for ones with a kevlar belt (or similar puncture protection layer).

If you know the roads may be bad, plan ahead and get a wider set for the entire tour.  Don't plan to buy wider ones during the trip -- you never know what will be available when you get there.  Conversely, if you find yourself having to replace a tire while on tour, your options will likely be limited.  You'll just have to settle for what you can find.  (I once had to replace a split road bike tire in a small mountain biking town but only one shop carried my size -- an off-road knobby tire. Still better than a split one!)


Brand new single speed bike has a skip in the free wheel motion or make a click noise once every rotation of the tire Just put together a brand new single speed fixie style bike.  There is a skipping or catch motion when the bike is upside down (on the seat and handle bars) and I'm pedalling the crank and then stop and let the back tire spin (free wheel motion).  I'm guessing that in that position once I stop spinning the pedals connected to the crank arm should just be still while the back tire is spinning.

What is happening is that the crank arm/pedal acts like it catches on something and moves and then stops and then catches again, moves and then stops when the back bike tire is spinning.  It doesn't seem normal, especially because it's a new bike.

Also I only took around the block to test drive and it seems when I stop pedalling it hold my feet on the pedals in a 3 o'clock / 9 o'clock position there is a clicking or catching sound happening there as well. When pedalling the bike feels normal.

Here is a short 8 second video of the skipping when the bike is upside down on the seat and handle bars

What do you think may be the issue? Any help would be greatly appreciated!

After a month the the freewheel did not improve so I bought and installed a new Shimano freewheel.  The results were night and day.  Gone was the knock when pedaling and the warble of the back tire was gone as well.

The OEM freewheel was like dog excrement and the new Shimano is like pedaling on butter.


Crankset or chainring replacement I have a Marin Bolinas Ridge 7.1, I am not happy with the front large chain ring size, I mainly ride on the road, and have an extremely limited budget. I would take it to the LBS, however, I believe that would cost at least an hours time just to find out what it is that I have.

More so than anything, I am trying to find out the specs as the ones on their website only list it as forged. I have determined that it is a 110 BCD with a tapered square. An email to the company revealed that they are not sure what is in it, and possibly riveted chain ring(s). (Bolinas Ridge 7.1 ). I also do not have the tools to pull it apart for a better idea of what I should be looking for. If anyone has changed one of these I would like to find out a lot more.

edit- original teeth are 42, i was looking to go either 48 or 50.

p.s.I have since learned that it should be a regular square taper, so I will be getting another crank. At that point, I should be able to figure out the ring.

Thank you for your interest.

Square taper cranksets are common, you can find used ones or new ones fairly cheaply with either mountain (~42t) or road (~48-52t) chainring sizes.
Some Considerations for Switching from Mountain to Road Crankset:
number of gears
Mountain cranksets generally have three gears and road cranksets usually have two. To switch to a road crank with two gears, you can just adjust your front derailleur, including the limit screws, position & cable tension, and only use two gears of your three-speed shifter.
derailleur position
To accommodate the bigger chainring size, you will need to raise the derailleur on the seat tube so that it is still 1-3 mm away from the outer teeth while shifting. You will probably also need to tighten the low limit screw quite a bit, as there is no more very low gear. Finally, you will need to reset the cable tension. Depending on how much you moved the shifter and the condition of the cable, you may need a new front derailleur cable to make this work, but that's a cheap upgrade that is usually worth it just for the sake of reducing friction when you shift.
chainring clearance
One thing you will need to be careful of is that there is enough clearance between the chainstay (the tube parallel to the chain) and the chainring. If it's pretty close to the 42t chainring now, it might not fit the larger chainring (without, that is, extending it with a longer bottom bracket, but that raises additional complications with the chainline, i.e., you want your chain to run as straight as possible). But, it might fit just fine, in which case that would be a pretty easy swap to make.
other considerations
If choosing a used crankset, make sure to find one that does not have any visual wear around the teeth (should not have an asymmetrical tooth shape) or the inside of the square taper. There should be no apparent wear in either of those places or it will lead to problems fairly quickly. Otherwise there are lots of good used options and new options in the sub- $50 range.


Why is this guy blocking the rear wheel? In this video the guy has clearly blocked his rear brake, as we can see the rear wheel is not rolling, but sliding. In this particular context, what has been his intent? Could have he done it for stopping, control/steering, look-cool-move?

No reason at all.

NWD10 is a classic old school movie. You don't see purposeless skidding like that in today's  MTB movies nor do you see it in real life MTB riding. Kirt Voreis (the guy in that scene - legendary rider) is probably doing this for no reason, just for fun, or at least what used to be fun in these old times.


What happened to riding with no hands? I remember, as a kid in the seventies we were able to ride blocks without ever touching the handlebars.
Today, I only see road-bikers riding without hands - and this is rarely.  I almost never see hybrid or mtb bikers go without hands.

What happened? Is it because I got older that I don't have the sense of balance anymore?  Or are bikes made differently in the sense that they're not self-balancing? Or is it the forward positioning??

Nothing happened or changed. It's just your observational bias coupled with different demographics preferring different bike capabilities.

Many children's bikes have relatively relaxed geometry, which makes them stable which has benefits for kids. Bikes built for adults usually aren't as stable, because stability and maneuverability are at odds with each other, and the adult riders want the maneuverability.

Mountain bikers value fast handling over stability, and so do many road cyclists.

However, many triathlons or time trials are events where maneuverability is not important, so many of those frames are much more stable. Touring bikes are also in that group.

I have a bike built up from a nashbar touring frame, that is so stable I can nearly fall asleep while riding. I hop off that bike and hop onto an 80s Bianchi racing bike, and trying to ride no-handed at any speed less than 35 mph (55 km/h) is virtually an instant crash. My surly cross check is in the middle of that range.


How to fit rivnut / nutsert to frame? I have an old steel frame road bike, dating from 1980.  Its not rare or special, but its very like the one I rode to high school in the late 80s.

Problem: There are no bottle cage mounts, so my solution is to drill 4 holes and fit rivnuts to suit the standard bottle mounts.  Rivnuts are also known as nutserts, and look like this:

There's a special rivet tool that compresses the fitting while preserving the thread.  I have one on order, and it looks like this.

So other than drilling the bare minimum diameter holes in the frame, what else do I need to consider?

paint or treat the raw steel edges of the drilled hole?
locate holes properly on the centerline or fractionally left, away from the drivetrain?
use mixed-epoxy on the insert as an insertion lube plus it will be a waterproofing layer when in use
my nutserts are smoothbore, not ribbed as per the example - would this matter?

Job completed - it worked well.  Starting off with the finished product:

Start by measuring accurately.  I put a bottle in each cage and then tested placements, considering the band-on clamp for the FD and the toolbag I have in the front of the frame triangle, which lead to a slightly high seat tube position, and a slightly low downtube bottle.

Then I used a self-powered punch to put a divot in the center of the tube.  Be accurate!

Upper seattube hole is drilled, lower one is part drilled.  I started with a 2mm bit, then stepped straight to a 5mm and finished with a 7mm.  Probably better to go 2mm, 4mm, 6mm, 7mm.  I tried to catch the swarf with grease, which was only moderately successful.  I also tried a magnet, and a greasy paperclip in the hole to fish out swarf and chips.   See painting comment.

Close up of hole.  The edges are slightly raised, and as Mikes pointed out its not a flat contact area.  So (no pic) but I gently filed that lip off, and flattened the edges of the hole at the 12 and 6 oclock position to help the insert sit flatter.  It worked well.

Here's the nutsert / rivnut / insert about to go in.  Its got a light coating of clear epoxy on it, which may not have been needed.

When drilling, it was easy to drive a bit hard and clonk the drill bit into the far side of the tube.   The tapered reamer didn't work for the same reason.   So to protect the bare steel I sprayed some zinc-based paint on the edges, and into the hole to hit the far side.

Finished fitment.  The paint's not great (okay its pretty awful) but the insert sits really close in and has no problem with M5 bolts.

Here's the top-side of the downtube before bolting on the cages.

Last comments

if you're going to buy the tool, don't buy a cheap one.  Mine was $30 and the circlip failed on the last insert. leaving the tool's axle loose.  Aim to spent at least double what the cheapest tool costs.
David points out that its possible to do this with a QR skewer - but I had to use a lot of force on the end of a 250mm arm.  A 30-40mm Quick Release lever wouldn't be capable of this.
Drill the minimum-sized hole possible.  Use vernier calipers to be sure.  I ended up wiggling the drill bit fractionally to get a tight fit without stepping up to the next drill size.


What should I look for when buying rollers? What should I look for when buying rollers?

What sets more expensive models apart from their cheaper alternatives?

What should you look for in a set of rollers?

Price
Resistance if you want it (Kreitler has a nice belt driven 'killer headwind')
Noise level, especially if you live above someone (I am not sure that even Kreitler can solve this problem without some dampening).
Size and weight - if you will be transporting them to races and have limited space.
Susceptibility to corrosion. Unless you don't plan to drip sweat, or plan to wipe them off well after each ride.... get rollers with a good corrosion proof coating.

Also make sure to read these two questions:

Should I buy a pvc or aluminum roller?
What are the advantages and disadvantages of turbo-trainers and rollers?

What sets the more expensive models apart?
Kreitler rollers are well known as the gold standard in rollers, and they cost two to three times as much as the more economical brands. Are they worth the investment? If you have the money, yes. Not only are they nicer, but they will last longer than other rollers. There are a few small shops that make rollers of similar quality at a similar or higher price. Kreitler makes a wide range of roller styles, and they are all of similar high quality.
Most of my roller time has been on a set of Cycle-Ops that I bought second hand for $50, and they were worth more than that. These are a great product, and I have logged about 90% of my hundreds of roller-hours on this set of rollers. They certainly can do the trick, but riding on Kreitler rollers is always a distinct pleasure. Kreitler rollers are luxurious to ride on and are definitely worth their cost.
Some specific differences:

Kreitler rollers are lathe turned alloy drums "to within 0.002" tolerance". This makes them evenly balanced and roll smoothly and evenly. I have not compared the weights of drums from different manufacturers, but Kreitler drums certainly feel like they have more inertia. Cheap rollers are often made of plastic. Even though CycleOps also uses lathe-turned alloy, they are not as smooth  (I would expect that the design has improved since my set was made 10 years ago). Kreitler drums are solid, including where the bands sit, whereas other alloy drums have plastic disks on the ends for the bands.
The frame on Kreitler rollers is sturdy and keeps the rollers parallel, which helps make the ride smooth. Of course all rollers have three parallel drums, but the sturdy construction of Kreitlers keeps the drums aligned during hard riding and over time.
High quality bearings and other parts
All of the above gives a butter-smooth, quiet, luxurious ride.


Can I do brevets (long distance rides) on my hybrid bike? If yes, how to start? I have a hybrid bike with 27" large frame,  700c wheels and 35mm tires. Can I do brevets (long distance ride) on this bike? If yes, what are the points I should start working on to achieve this? Currently I am a beginner and riding around 40 minutes per day and little more on weekends.

This question gets asked quite often. The short answer is that you can do long distance rides on basically any bicycle as long as it’s comfortable for you.

There are a few things you can do to your bicycle to make it more efficient and easier:

Make sure your seating position is good. Especially that your saddle is high enough. This will improve power output and reduce risk of knee pain/injuries.
Reduce air resistance by lowering the handlebar.
If you have front suspension, lock it (or get a rigid fork).
Wear tight fitting bicycle clothes.
Keep it well maintained.
Get road bike tires with low rolling resistance.
Get clipless pedals and shoes.

In the end the most important part will still be training. Training for long distance rides basically boils down to riding a lot. During long rides nutrition (and of course hydration) is also very important.


New Bike + Disc Brake Shuddering: Cause and Fix? I recently bought a new bike (cx steel frame, carbon fork, disc brakes) that I am using as a commuter/all-rounder bike.

My question is similar to questions that have already been asked concerning disc brake shuddering/pulsing (here and here), but subtly different: Will skipping the bedding in process lead to shuddering when braking? If so, will attempting the bedding in process now fix the issue?

I am new to the world of disc brakes and foolishly didn't learn about bedding the pads until searching for resolutions to my issue. I have ridden my bike for ~200 miles so far, and the past 50 miles is when the shuddering in the front brake became noticeable.

Brake Details: I have Hayes CX Expert mechanical disc brakes and a carbon fork.

Skipping the "proper" bedding in process can do this yes. Bedding in brake pads impregnates the rotor surface with material. There is a particular process to do it because you want a good even layer. If skipped, the will still get "bedded in" but possibly unevenly, causing vibrations and ultimately a shudder like you have described as the pads skip over these slightly thicker portions of the rotor. The proper method has guidelines of how fast and how hard to brake which has been proven to help keep the bedded layer smooth. Also if not bedded in and then ridden EXTREMELY hard brand new, meaning some downhill action,it is possible (but unlikely) to get hot spots much like car brake rotors can get when super heated beyond their intended use.

Their are several ways to handle this situation, there is a resurfacing paste product called Squeeel Out that works decent, or you can resurface them yourself which generally works pretty well. To do so you will sand both the pads and the rotor surface, and then follow the initial bed in procedure.

When sanding the pads, it is easiest to lay a piece of sandpaper on a hard flat surface and drag the pad around in circular motions. Sand the pad directly doesn't work as well because you don't get an even sanding. The rotor can be done a similar way, or by laying the rotor on a flat surface and hand sanding with a sanding block. You don't have to take a ton of material off, just remove the surface contaminants. After sanding the rotor clean with alcohol and allow to dry.

Some people would recommend buy a new rotor and/or set of pads but i have had good luck with saving them the ways mentioned above. While you have the rotor off you can also check that it is true, but that shouldn't be an issue with it being new, but then again i have seen them come out of the package slightly bent.


Semi-integrated / external headset compatibility Mechanics at a repair place told me that my bike needs a new headset. For the moment, I have a semi-integrated / zero-stack Cane Creek VP-A45AC. I went afterwards directly to a bike shop asking for a new headset, and they sold me an external Massi headset. I am no expert in headsets, and I don't know if 1) the shop sold me this external headset because it's interchangeable with a semi-integrated one 2) they made a mistake and I need to go back.
I didn't find much on external / semi-integrated headsets compatibility, does someone now if I can use this external one on my bike (provided the dimensions are correct, which seems to be the case) ? Thanks.

No, there are no external headsets that are directly interchangeable with an internal one. There are external headset lowers for tapered forks that use the same bore dimension as internal for non-tapered, which might have been the source of confusion.
If you have the pictured headset, those are probably a standard bearing that can be replaced without needing a whole new headset, providing there's nothing wrong with the other parts.


Gravel and MTB: What film to use to protect for rocky riding? and what parts? What do the parts of the carbon frame need to be protected for rocky trail?
And, what do you use to protect the carbon down tube for rocky riding?
EDIT:
Some people used to install "Paint Protective Film" (PPF) for cars' paint protection and some bicycles, do you think it is practical? If ans is Yes, what is the suggestive film to use to protect for rocky riding.
Thanks.

Helicopter tape. Underside of down tube and bottom bracket shell, plus anywhere your bags or housings rub.


I'm worried about my derailleur snapping. The chain isn't running around the bottom pulley, it's running next to it I'm worried about my derailleur snapping. The chain isn't running around the bottom pulley, it's running next to it, scraping against the bottom pulley and the frame.  When I change gears it makes a horrific noise and the bike has ground to a halt without me touching my brakes. This has happened 3 times.

I am doing the London to Brighton charity bike ride in 29 hours. I don't have time to get it into a shop and I have a 54 mile ride to do and I am worried about my derailleur snapping.

What should I do?

I wouldn't recommend riding your bike at all until you have a professional look at it. Otherwise you're taking the risk of physically injuring yourself and the people around you, especially on a big ride.


Rohloff twist shifter is too slippery when sweating My Rohloff Speedhub is pretty slick, but unfortunately so is the twist shifter when I'm sweaty.  In southern Florida, riding my trike, that's pretty much all the time.  Switching gears already has higher resistance than your standard derailleur; when under a bit of load it takes even more effort, and there are times when I literally cannot shift gears because my grip slips.  I don't have many options to change out the shifter (it's custom to Rohloff) and it's irregularly shaped so I don't think I could use bike tape or anything on it.  I'm hoping someone can give me a solution that will give me a good grip even when sweaty or wet that isn't going to look ridiculous or be unwieldy.

Cycling gloves are designed for comfort and to improve grip by absorbing sweat and providing a contact material that provides grip even when damp or wet.  Typically, hands do not sweat much so most cycling gloves will help in this regards.


Struggling with bottom bracket installation This is the first bike build I've attempted, so far the process has been pretty difficult but I'm especially struggling with the Bottom Bracket installation.

Firstly, I have a frame with a threaded BB shell, so I bought a threaded bottom bracket, like this one: Threaded Borrom Bracket. This went horribly though, I wasn't sure what to expect in terms of force when screwing it in, I think I ended up with it misaligned and forced it, destroying the threads on my new frame in the process...

To work around that, I bought a BB that doesn't engage with the threads on the frame but threads together instead. Here it is: Bottom bracket number 2.

I have 2x 16 notch tools I can use for installation (1 to hold the other side) but I can't even get it in the shell all the way.

Do I need something to press it in, or is this just a case of my second bottom bracket being not suitable for a frame with a threaded shell?

Any help with this would be appreciated, despite a lot of niggly issues and incorrect part selection on my part, I'm quite enjoying the whole process.

Here's an extra picture of the empty shell which is threaded (well, crossthreaded now...)

Each side of the BB is fitted with a silver notched cup, that I can remove. If I take this off, the BB does fit into the shell and I can thread it into the other half. I just can't seem to get it tight enough to stop the BB from spinning in the shell.

I also noticed that when I full tighten the BB, the square pegs won't spin anymore.

Thanks!

ADDITIONAL INFO

As requested in the comments, here is a close up of the original threaded bottom bracket I purchased originally (Link at the top) and a picture of the side of the shell that it won't screw into. It looks very neatly cross threaded to me, I was really angry at myself for doing that...

** Hopefully the final edit **

So I've managed to screw in the Tange BB, it actually went in 99% of the way by hand very easily. I tightened it with reasonable force at the end using a Torque wrench but I didn't want to over do it. I notice the non-drive side I can still see 1 thread but it doesn't seem to want to go in any further easily. The drive side is all the way in and flush to the shell. Does this look correct and as expected? I consulted a few video guides from ParkTool but not much was mentioned on expected "flushness" of the cup on that side.

Here are some pictures:

Drive side:

Non-drive:

Threadless cartridge BBs have their place, and that place is where the threads are destroyed. Thankfully you're not there yet. They are a compromise because they tend to have creak issues sooner or later no matter what.

You should take the frame to a shop with a proper piloted BB tap set. One side of your shell looks fine. The fix is to install the pilot into that side all the way and use it to start the other side. At that point one can use some force to confidently get through the cross-threaded section. (One shouldn't necessarily go all the way through with the second tap without partially removing the first, because referencing one side to the other isn't really how the tools are intended to work, but that's a tangent.)

You have enough good thread in there remaining that things should be fine at that point. The risk is continuing to mess with it and starting to lose threads completely, which could happen from the spot you're in now.

In the scheme of things, bike bottom brackets use a fairly long section of very fine threads. Its pretty common for low end cartridges such as Sunrace to not get things right and have problems with starting rough, going in rough, etc. It may work fine after chasing the threads, but if it doesn't, there's a lot to be said for just getting a Shimano UN-55. It will go in right and last a ton longer, and they've gotten really cheap.


Steering tube turning inside fork crown I need some help. I can't seem to find an answer to my particular problem.

Recently, I was riding my bike on a sidewalk since it was getting dark, and I went through a patch of weeds. It seemed fairly safe to do since I could see through them. I was trying to avoid braking and turning. There was a piece of rebar sticking out of the ground about 12-16 inches. I hit it straight on, flipped over, I may have fractured ribs or bruised them very badly. Anyhow that's how my issue started.

I have a fat tire mountain bike 26 inch tires. At the time of the wreck my handlebars turned so I loosened them to straighten them from the stem. After a few weeks of not riding, I rode my bike again and noticed when I hit the brakes my tire turned. I came home, loosened the stem and tightened the top cap, and then tightened the stem. I tested it and had the same problem. I removed the Fork and reassembled. Everything was tight. Then I noticed that the steering tube was actually spinning inside the fork when I held the front wheel straight and turned the handlebars.

Is it broken and I need a new fork? I tried reassembling multiple times, the bearings are good. I'm at a loss for ideas aside from taking it to the shop. Any help would be appreciated. Thank you

There are some MTB forks that have replaceable steerers that are attached via binder bolts. Here's a Marzocchi and an RST one, respectively:

If your fork is like this you may be able to get it fixed by just tightening the bolts. You should probably take them out and re-loctite them first if so. However, look through the crown area carefully for any other damage that might have occurred from the crash, such as cracking or deformation, either of which could produce the steerer spinning as a symptom (and it would seem kind of likely there's something like this going on, given the timing).
If your fork doesn't have a steerer attachment like this, as most don't, it's more or less a goner. If it was bonded or retaining-compounded in to begin with, you maybe could fix it by re-bonding it, but I'm not saying this is necessarily a good idea.


How do I install this Ribble endurance SLR headset? I've installed the bearings and now I'm struggling with which order to stack things. I can't find any documentation or manual of any description. I've attached a few photos. Does anyone have any idea?

In my experience I believe you should start with items in https://i.stack.imgur.com/so4gwm.jpg initially. Starting with the thinnest one first, in the direction facing down as you have them in your hand.
Lastly using this on the top: https://i.stack.imgur.com/cT9ppm.jpg
I would recommend using the Parktool Youtube page for more detail on Headset installation:
https://www.youtube.com/channel/UCzaZ1sPWEuZN-I8_XT6AH8g


Strangeness with gears I searched the internet and this forum and couldn't find anything about this. I recently took off my rear wheel to change the tire and tube. Upon returning it, it shifts fine (no falloff or skip) however it's backwards from what I remember. The last person to do anything to my bike was a very experienced friend. He tuned it up and replaced a rear axle and returned it, I haven't done anything since. I distinctly remember the most resistance being when I had 3 on the left (front gears/crank) and 7 on the right (rear cogs) for a very long time. And when gearing down to ride up hill, visually I would see the chain on the smallest of the rear cogs. Now the smallest rear has the most resistance and reads out as 7, but the internet and other bikes tell me this is perfectly normal. I can't understand how this is mechanically possible and I'm starting to think I fooled myself somehow, or it's an alternate dimension paradox. Genuinely curious if anything like this is possible, not trolling you. It's a 2007 Norco Scrambler with stock shimano shifters and cassette

I'm starting to think I fooled myself somehow

And you are correct.

Smaller sprockets on the front or larger sprockets on the back give lower gear ratios (easier to pedal, but you go slower).


What would you upgrade first on a road bike? I have a Decathlon Triban RC500 with all stock components which I'm quite happy with. Since I have cash to burn (actually not, this question is hypothetical :)) what component should I upgrade first to make it faster/lighter? What would give me most bang for my bucks?

Honestly?  Nothing.   Assuming your bike functions correctly and is not yet worn out?  I'd not change anything on the bike mechanically.

Perhaps think about comfort, what would allow you to spend longer on the bike, or to go harder?  What hurts at the end of a long ride, and how can you improve that?

Changing Contact points can help, so better gloves/bartape.  Perhaps shoes and cleated pedals, but there's nothing wrong with flats (its really hard to walk around the shops in cleats)

If you do night riding, then some decent lights can be wise, two front and two rear (so a primary and a backup in each direction)

Clothes make the ride more enjoyable too.  Close fitting fabric is faster than loose baggy clothing, and it often weighs less too.  So a riding top and tights/leg warmers might be of interest.

As for progress - if you're data-driven then using a service like Strava or mapmyride or similar can help you know that you're improving.  They offer free levels, and more for a subscription.  These services may work on a standard smart phone, or you might choose a fancy bike computer.

But seriously, wear parts of your bike out before upgrading.  That's fiscally responsible.

When your tires wear to the point they get a lot more punctures, then replace them with something nice like GP5000 or similar race tyres.  But not earlier.


Riding in single line Is it safest for a group of cyclists to ride in a single line?  Is it required for cyclists to ride in a single line in a narrow bike lane, or can they pass on the left in open traffic?

In general it depends on the road or trail, how wide it is, how straight or twisty, how visible the trail ahead is etc.

On a wide trail without tight turns and plenty of forward visibility riding two-abreast is fine.

On a narrower trail with tighter turns or less visibility, riders should ride single-file and stay on their side of the trail. Common sense applies to overtaking, i.e., don't try to pass if you can't see far enough ahead.

There may be laws that apply to cyclists in different locations of course.


Question about Shifters I have a bike with lever/downtube shifters. I hate them, feel like they don't stay in gear for more than 10 minutes at a time, and would prefer a bike that has preset gears. Is there a way to get the shifting mechanism on my bike replaced to something like a thumb shifter?

I'm not looking for opinions about the best kind of gears.

There is a nice instruction video from RJ The Bike Guy on youtube on how to convert from downtube shifters to brifters. Perhaps that can be some idea for you.

In case the video is taken down, I'm posting a written answer.
Yes, it is possible to convert from downtube shifters to brifters. Here's what you need:

brifters compatible with the cassette and front chainrings on crank you already have, or
brifters, cassette, front chainrings with crank, probably derailleurs in case your current are not compatible with new cassette and front chainrings
new brake cables with housing, new shifter cable housing (shifter cables are delivered with the brifters usually)
"downtube cable stops" (can be found in the internet) - the cable stops that allow the shifter cable to go pass the current shifter bosses to the steering bar and the brifters.

The procedure is pretty straightforward:

you remove the components you need to remove (at least the bar wrap, current brake handles, cables, downtube shifters),
install the new components,
install the cables,
adjust and finetune everything,
and enjoy your upgraded bike.


With a garmin edge touring can I just ride or do I have to do a route? I'm thinking of getting a garmin edge touring but I want to use it as a map rather than a satnav. Can I just ride and it will show where I am? Or will it always want me to take a pre-determined route? Thanks.

The map screen will show you your location, you aren't required to choose a route, routes are just big feature of the edge touring that Garmin focused on for that line.


Identifying 1970s-80s Motobecane Special Sport I'm trying to identify the exact year/model of a Motobecane called the "Special Sport", which was bought in France. I don't know if the parts are all original, however: It has a Huret Svelto rear derailleur, but I can't tell what model the Huret front derailleur is. It has Motobecane-branded center-pull brakes. Lastly, it has a Maillard Helicomatic rear hub, which would suggest to me that it's an early-'80s model, but the rest of the bike doesn't look very '80s at all.

The frame is a 70-73 motobecane. This head badge was used during this year. in 74 it was changed to the round version
I however dont see a frame in their catalogs called a super sport, so not to sure about that. however you seem to have matching components to the Grand Touring from this time period.Here are some old catalog scans


Effect of salt on bike chain I have seen other questions on this forum where preventive measures against salt water on bike chain are discussed. I have seen them in context to rusting.

What I want to ask is that, rusting will be caused by water, then what is so special about salt water ? What effect does salt specifically have on bike chains ?

what is so special about salt water

Pure water when it dries is gone, there's no residue.

With salt water when it dries you get salt crystals, which are hydroscopic (they suck up water from the air). This means that even if the air is dry where you are now, the salt will attract water as soon as you put the bike somewhere more humid. And the water will form rust in contact with steel, since steel reacts more vigorously with water than salt does. In other words, the salt sucks water out of the air, then exposed steel sucks water out of the salt.

There's a second problem that salt water gets sticky as it dries, and that attracts dust. It's like an oily chain lube in that regard, fine as long as you clean it off frequently. But that grit grinds away any protective coating on the steel, and any protective layer of rust as it forms. Then the salty water makes more rust.

Chains are especially vulnerable to this as water wicks more easily than chain lube (especially in cold weather). So it will be drawn into the inner workings of the chain. Then when the chain dries a bit the salt is already in the middle of the chain and ready to soak up more water and keep the wear surfaces of the chain links wet. So they'll rust faster.

Solid salt spread on icy roads will work the same way as salt water, but probably more so since the lumps of salt will be saltier than actual salt water.


Extending range on SRAM PG-1130 cassette / cassette specification I'm considering buying a Kona Rove ST bike with a 1x drivetrain setup. However, one concern I have is a limited range of higher gears (40:11 ratio for the highest gear). I would like to have some more range there, and would consider replacing the front chainring for a bigger one. Of course that would present a new problem in lower gears.

That could be solved with replacing the whole cassette or installing an expander sprocket, and I prefer the latter because of the costs.

The problem I have is with the specification, or lack thereof, for the SRAM PG-1130 cassette on the Kona. If I understand correctly, it fits a Shimano HG hub standard (?) and differs from the SRAM XG line.

In that case I should be looking at extender cogs designed for Shimano 11 speed cassettes?

SRAM PG-1130 cassettes fit on a Shimano HG freehub body, not the SRAM proprietary XD driver body.

If you see 11-42t cassette fits 10 and 11-speed non-XD™ driver bodies in the description on the SRAM page that means HG.


How to build a lugged fork I have an idea to build a carbon fork with aluminium joints. I don't have any experience in frame building but I want to read about it somewhere. Is there any good literature about how to build a bike from scratch?

I've found a couple of books on Amazon, like "Construction of Lugged Bicycle Forks". I think this is the book that I'm looking for. I have a good machinist guy with two turning and one miling big industrial machines.

What I need is to buy two awesome pieces of TAPPERED carbon tubes and then mill a head and dropouts to fit the carbon tubes.

I have some experience with Solidworks and I think I can make a model with all the loads which head should take. I can test all the loads of the carbon tubes and then calculate the head and drop-outs. What do you think, guys?

There are some decent websites where people talk about building composite bikes, and even a couple of answers here. But those are mostly either very simple complete bikes, or aimed at people who know a reasonable amount about framebuilding. The book you found is about steel forks, and has only one chapter that seems relevant to what you're doing, and that chapter is marked "optional" in the ToC.

That design stage is critical though. Bicycles are surprisingly hard to analyse using modelling tools, and the front fork is far from the easiest part of the bike to work on. It's also a part where failures are very likely to result in injury. Those two factors mean that it's not a great part to start experimenting on, especially "start toying with framebuilding".

These days with cheap sensors and high-rate portable data collection units it's not impossible to get at least an approximation of the major forces on a diamond frame bike (because you only need 30 or so channels - 8-10 tubes for the frame, maybe  four for the fork, with tension and torque for each), but you're only getting an approximation. I don't know of public data like this, unfortunately.

Your design is also relatively unusual as far as carbon forks go, it's more an MTB fork with carbon blades. That doesn't mean it can't work, just that no-one else makes one and there may be a reason why (bast case it might be unprofitable, worst case it has bad failure modes). If you're just going to combine OTS tubes with machined lugs it should be simple enough to build one and see, though. That will also avoid most of the mess and complexity of working with composites, and that's good.

In your position I would be very tempted to make another part first and test that to destruction. That way you get to run through the process and get an idea of your abilities and limits, and you get a part to test. Seatstays, for example. When they fail you tend to end up sitting on the ground, rather than using your face as a digging implement. If you threw together an inverted 4 frame with single bar seat/chain stays you'd have a part similar to a front fork, but with safer failure modes.


How to measure pedal axle/spindle size? How do you measure pedal axle/spindle size?

Replacement pedals and accessories specify a size like 9/16" or 1/2".  How do I measure my current pedal to see what I need?  Is it just a matter of putting the pedal threads in a caliper and measuring the outer diameter of the threads across the axle/spindle?  Or do you need to measure the solid part, excluding the threads?

They're standardized between different types of cranksets.

One piece cranksets use 1/2" x 20 tpi. Three piece cranksets (most bikes) use 9/16" x 20 tpi. Old French things use something else, but these are rare (and instead of being marked with R and L for which pedal is which on the spindle, it will be D and G).

If you want, you can measure it like any other bolt. Or, take the pedals to a bike shop and compare them to another pedal.

You find one piece cranksets on some BSO's (i.e. bikes you get from places like Walmart), children's bikes and very old American bikes. Otherwise, you should have a 3 piece crankset and use a 9/16".


Can you fix a tube with a lighter? I was thinking about a patching tiny puncture I got from a metal sliver in the road.  I usually don't even attempt to patch tubes, I always carry a spare, put that on and recycle the tube and forget about it.

I was wondering if it would be feasible to fix a small hole in the tube by applying heat from a lighter until some of the material melted and fused back together.  Or even dripping some molten plastic or rubber over the whole if it were larger.

Has anyone ever done this successfully? I'm curious about butyl and latex tubes.

No, that won't work because first and foremost tube rubber isn't going to liquefy and re-solidify and be fine; it's going to burn and be weak.

Traditional vulcanizing patches do more or less what you're talking about. The vulcanizing fluid acts on the rubber to permanently fuse the patch and make the tube as good as new. It's easy and gives predictable results.


The chemistry of mixing sealants It's become a fairly common occurrence in shops to be faced with a tubeless wheel that was doing fine, slowly started having issues, and hasn't had a sealant re-up in a while or ever, but what sealant was used is either lost information or one you don't have handy. If unknown, maybe you could figure it out if you pull the tire, but that's sometimes easier said than done these days, and you can always clean out what's in there and start over,  but what you really want to do if possible is just shoot some fresh sealant into the valve and move on.

Every sealant manufacturers says not to mix brands, yet experience bears out that usually if you just do it, it's fine. But what possible exceptions are there, and why? Are there any sealants out there that are particularly bad for the purpose of possibly mixing with unknown prior sealants? Any that are particularly good? Any hidden compatibility rules that might allow a shop to responsibly only have a small number of bottles around yet still be able to handle anything that comes in the door?

If your tire has begun to lose air slowly (loses 10 PSI over 2 days), it has lost the liquid carrier in your sealant. The remainder of the sealant is dry or lumpy and can't travel to the new thorn. It was ammonia or environmentally friendly antifreeze (not ethelene glycol) that evaporated. Like the original liquid is pretty much gone.

Our riding club carries Orange seal and Stan's in portable 3 ounce bottles. We use it interchangeably any time a member gets a low tire on the trail. Never had an issue.


Ask for Recommendation for Biking Outfits I am thinking about start cycling other than just riding it around school. I want to make myself look professional. Do you have any advice for me? I don't really know what kind of outfit is suitable for college students. I think I would love to get a shirt or a tank and a bicycle shorts. Thank you in advance. Does bikers have special shoes, too?

It's not really clear what you mean by look professional.

If you mean a professional cyclist, then a cycling outfit is the way to go. They are designed to be comfortable for cycling, and to keep your leg muscles warm.

But if you mean professional as in office worker professional, then that's a problem that many of us struggle with.

Firstly, how far do you ride? The further you ride, the more likely it is that your clothes will be sweaty and you'll want to change. If it's not that far, in warm weather many biking students here wear long baggy shorts and matching tops, like skateboarders. But you wouldn't say they look professional.

The other way to go is to change clothes. Depending on the size of your campus and how modern it is, it likely has a decent gym with showers, and maybe locker facilities. Many students take gym membership to access those facilities; you can keep a change of clothes, and a towel there, and shower and change before classes.


How long should I expect handlebar tape to last? I assume that if handlebar tape is grimy, torn, or peeling, it should be replaced. How long should I expect handlebar tape to last before it needs to be replaced? How often do most cyclists replace handlebar tape?

Anywhere from a month or two to years and years; how long handlebar tape lasts depends on too many factors to really answer this with a number. Of course, how often you cycle is a factor, but how good the tape is and how well it's applied also makes a difference.

For example, gel tape is notorious for wearing quickly, as the gel gets pushed away from where you lean your hands. Good-quality cork tape without a lot of padding can be kept around nearly forever, unless you rip it or it starts to stink. Tape that's wrapped way too tightly can develop rips and cracks. And if you have cables routed under your tape, that can subtly move the tape around a little bit as you shift, causing you to need to rewrap or replace more often.

How much weight you put on the bars, how tightly (or loosely) you wind the tape, how good the tape is - all these will change how long it'll take until you have to change the tape or simply rewrap it.

One thing that's worth noting is that if you're wearing through the tape itself, you're probably putting too much weight on your hands or gripping the bars far too tightly. And cork or plastic bar tape that simply comes loose over time can be rewound.


What is causing phantom shifting on front chainring? I have a steel cyclocross bike which doubles as my weekend bike and my daily commuter. About a month ago I got in a wreck and bent the rear derailleur hanger and the rear derailleur. Got the hanger re-aligned and put on a new derailleur.  Chain was not all that worn (checked it) so didn't replace it.

Fast-forward about three weeks. I was noticing significant "phantom shifting" which was primarily when putting a lot of torque on the pedals (I have 220mm cranks and go up a 10% grade on the way to work). Everything seemed to be lined up on the stand, but on inspection the chain had multiple links with cracks in them. New chain=problem solved... for about 3 days. Now it's started acting the same way. It frequently "skips" and occasionally tries to shift from the middle chainring to the small chainring if I'm riding uphill, which threatened to unhorse me once. It can also do this on the large chainring. I checked visually and there's no snaggletooth. The chainring does seem to have a very minor wobble -- less than 1mm left/right, but I've noticed that the phantom shift/skip is indepenendent of where my feet are (ie can happen with left foot up, right foot up, etc)

Any ideas on what else could be causing this / what should I check?

One thing to check is whether the crank integrity is intact -- the shaft could be bent, there could be a cracked cup, or the axle/cartridge could simply be loose.  Also, the crank arm may be bent or loose.  If the crank shifts under load (due either to the axle shifting or a loose arm) it could easily account for your phantom shifts.

Next is the rings.  You imply that one ring has a "slight wobble", which may indicate a bent arm or may indicate the ring needs replacing.  Also, the rings may simply be worn to end of life -- from experience this can cause phantom shifting.

Another possibility is a "galloping" rear derailer.  If for some reason the rear derailer is not taking up chain smoothly it can cause front ring phantom shifts.


I am looking at buying a tacx turbo trainer however I am only putting out about 200w on a bike Is this enough for a turbo trainer and if so, which tacx should I buy?I am looking at a tacx blue or satori as these are in my budget however will the satori be to hard to ride as it has a max output of about 1000watt?

I got a Tacx Flow two or three years ago, so my answer is based on this. Also I don't use it all that much...

As regards power output, I have never measured mine when riding on the open road. I have only ever got power readings when using the turbo. I generally get readings from the headunit in the 200W range (probably anything between 150 and 400 depending on effort) but the flow itself is plenty easy enough to ride. Now how closely my turbo-calculated 200W will tally with your 200W is anybody's guess, but my gut feel is that there won't be a problem with them being too hard to ride.

If you're stuck between the Blue or Sartori I can't help much there. But what I would say is that if you can afford to go up to the Flow, then although out-of-the-box it is "just" a trainer, you have the possibility to upgrade to use the Tacx VR software at a later date. I do not believe that anything beneath the Flow gives you this option, and this was my reason for settling on the Flow.

So if that's something you might want to do in the future.... well buying the VR upgrade for the Flow will be cheaper than buying a new VR turbo.


How much does an impact reduce helmet's ability to protect? I read the answers to "When or how often should I replace my bike helmet?", but unfortunately none of the answers there cites any references.

Have there been any studies quantifying the claim of reduced protection after single impact, e.g. in terms of increased risk of injury?

It's easy to see reasons why manufacturers would want you to believe any impact kills the helmet - it's hard to set limits on potential damage, and buying a new helmet means additional profit.

Horse riding helmets come with similar warnings, but my first one seemed to survive several years while I was learning show jumping - including way more falls than I could have afforded new helmets.

There is a lot of good information about this here. One paragraph from the article outlines the basic idea of this:

  Crushing the cell walls destroys the impact management ability for most stiff foams, so the helmet has to be replaced after a single impact. The crushing is not always visible and can be hidden by the outer shell. The foam can also recover some of its thickness over a period of hours, but not its ability to manage impact. Crushed and partially recovered one-use foam will feel rubbery and soft. Experts measure the foam thickness carefully for crush, but for consumers the recommendation has to be "replace after every impact." Often the damage is not apparent in a casual inspection, even when there are cracks in the foam. And the rider often underestimates the impact because crushing of the foam dampened the shock.

It goes on to explain the different types of technologies (with some links to scientific information) used in bike helmets. While your helmet survived all the falls, it was most likely offering you less and less protection from the falls.


How to choose brake cables I've decided to change a number of brake cables on my family's fleet of bikes. I'm overwhelmed by the number of possible inners and outers.

What features should I prioritize? Stainless? Teflon-lined? Cost?

If it matters, I commute (ride ~five miles, daily, all weathers, urban), live in the UK, and have (or will buy) all relevant tools.

I usually get the cheapest stainless steel cables and housings from a reputable manufacturer like Shimano, SRAM, BBB, Jagwire, Avid etc.

I very much doubt that expensive cables for >10€/piece will significantly improve braking performance. Especially if you are already happy with braking performance.

Proper cable installation&routing, matching brake lever to brake arm ratios and high quality brake pads will have a greater impact than SuperUltraSlick™ cables.

Edit: As Rider_X points out in the comments, some brakes work better with stiff cable housings. In such a case stiff housing like Shimano SLR or even Nokons (expensive) are a good idea.


Crank pedal spindle hole thread stripped I'm attempting to reassemble my bicycle after it was shipped across the US. All is well; except one pedal cannot be screwed back in because the thread in the crank is stripped. The pedal itself seems to be fine thread wise, but I cannot screw it into the crank. I don't drive, and I live much closer to a home depot then a bicycle shop; I'm wondering if anyone has any repair suggestions? I bought a wrench to take the crank and arms off, but apparently I need additional tool too get it off; this was just an attempt at having more leverage to try and and screw the pedal in from the top. Anyone have any DIY suggestions? WD40, thread repair of sorts?

It turns out that the thread isn't completely stripped: just the first three or four threads at the entry point. I picked up some EPX cyle grease this evening, which I'll try tomorrow.

You can get parts to fix this, like the helicoil that work by cutting a new, larger thread into the crank then adding a spacer to bring it back to the correct size. They parts are relatively cheap, but the tool to cut the new thread is expensive. Which means that if you can find a bike shop with the tools it's going to cost quite a bit to have them do the work.

It's almost always going to be cheaper to simply find a second hand crank that fits, or if that fails buy a new crank.

As far as the rest of the tools, it might be worth buying a cheap bicycle tool kit rather than buying one tool at a time or travelling long distances to a bike shop. There are a number of specialised tools needed if you you're going to completely strip down a bike, and buying them one at a time adds up. My suggestion is buy the cheap-but-reasonable-quality set, then as you wear out the tools replace them with decent ones. That way the tools you barely use or where the cheap tool works well enough never get replaced.


Is it OK to have a single front chainring paired with 7 speed at the back? I'm planning to have a single front chain ring to be paired with my 7 speed at the back. I'm still saving up for a 10 speed.

Without taking into account whether it's a good idea or not; yes it's possible, with a few caveats.

You have two issues:

Chain line i.e., alignment between the front rings and rear cassette.

The single ring needs to be aligned with the center of the cassette so you minimize the lateral deflection on the chain and avoid excessive wear on the chain and sprockets.

With a 7 speed rear its likely that you have a triple set of rings. If so just us the middle position for the single front ring as it's aligned with the middle of the cassette. If you have a double, things are trickier but you may be able mount the ring on the inboard side of the spider.

Dropping the chain

The front derailleur helps to keep the chain on the front rings. Outer rings help keep the chain on inner rings. With an unaided single front ring there is a greater chance of dropping the chain from it.

1x11 setups feature a narrow-wide chainring that have alternating narrow and wide teeth that fit between the inner and outer chain connecting plates to more firmly hold on to the chain. If you are looking to do this conversion as cheaply as possible you probably don't want to get a new chainring. Leave the front derailleur in place to act as a chainguide.

You don't say whether you are saving for a whole 1x11 bike, or or planning to replace the drivetrain on you current bike. In either case this article may be of use to you. If the latter, bear in mind you will need to check compatibility between your freehub body and an 11 speed cassette.


Shifter not changing gear cable tension I'm a beginner and I'm working on a bike. I'm trying to fix the shifting gears. I'm holding the shifter cable where it comes out of the housing by the front derailleur and I feel no change in tension from gears 3-5. At 1 and 2 I do feel a change and it is difficult to shift to those positions.  It's a shimano grip shifter. I'm following Park Tools "How to adjust a derailleur" but am hitting a problem shifting from 5 to 4. It doesn't shift and no amount of rotations of the barrel adjuster seems to resolve. I just noticed that if I hold the brake cable where it comes out of the shift I do feel the tension change.

Is this a problem in the grip shifter? It seems backwards, shouldn't 4-5 be difficult to shift, as that should tighten the shift cable? I did take the shifter off to inspect so maybe I didn't put it back on right. It seems kind of dummy proof as I only saw one way to put it back together.

I've added a pic of the inside of the grip shifter. Here is another noob question. There are only 3 teeth, how do three teeth make for five gears?

Thanks for any help!

You probably need to check that the shifter is working properly, then set up the derailleur. The problem might be that the cable head is not quite seated in the shifter.

Disconnect the cable from the derailleur. Find a place to grab the cable where it is exposed - the downtube is usually a good spot. Tension the cable manually and work the shifter, you should feel it moving the cable for all gear shifts. If it's hard to feel the cable moving, stick a 'flag' of tape on it and a marker of tape on the frame so you can see the relative movement.

Once you are convinced the cable is being moved by the shifter properly, check the cable/housing run. Everything needs to be firmly seated in place.

Something else to check at this point is that the derailleur limit screws are adjusted properly and that the derailleur can make it onto all sprockets. Manually push the derailleur while pedaling the crank by hand (be careful not to catch your fingers though). If the derailleur will not go onto all sprockets adjust the limit screws - the Park Tool process should tell you how to do that.

When you re-attach the cable to the derailleur:

Make sure the shifter is in the highest gear (assuming 'high normal' derailleur) or has let out the maximum amount of cable
Barrel adjusters are screwed all the way (or at least 90%) in
Pull the cable tight to get rid of any slack

You should find the shifter moves the cable nearly immediately as you select the second higher gear. You can then go through the Park Tool derailleur setup process.


"Racing bikes" with fenders and a rack I'm new to the sport of cycling, although I have been biking as transportation for a few years. I'm a poor college student in possession of a hybrid bike, a Mongoose Crossway. I went into a local bikeshop and tried out the Trek Domane and was amazed by the feeling, which was like flying. I would love to bike something like the Seattle to Portland. Mostly I would like a bike with drop down handles and decent gears to help climb up hills.

My Dad (an immigrant from Europe) biked as his main source of transportation until his late twenties. When he was my age, a cyclist friend gave him a racing training bike (aluminum or possibly steel), which he used for all his practical and recreational purposes. He's adamant that I should have a similar experience.

He has offered my monetary assistance on two conditions.

1.) A road bike that is a 'racing bike'. He refuses to fund any sort of 'touring bike', such as the Trek 520.

2.) The bike must have fenders and a rack.

Having some trouble finding a racing bike with fenders and a rack. So far a bike I have found that matches the requirements is the Jamis Xenith Endura Elite Di2, but since I am new to the sport any guidance would be greatly appreciated!

The problem with nostagia is the n+1 rule. Bikes manufacturers have been on a never ending quest to make bikes more and more task specific. This means most "racing" bikes are not well suited to everyday transportation riding.

Modern "Race" Road Bikes

Mixing fenders and a rack with a modern road race bikes is like trying to get oil and water to mix. The frames often lack any sort of eyelets and depending on the material are largely incompatible with any sort of clamp, so adding a rack is largely out of the question. Carbon frames should not be clamped at all, and a race frame made of aluminium will be quite thin in parts now due to all the hydro-forming now used in modern frames making it incompatible to clamping as well.  Modern steel racing bikes are pretty rare now and usually custom built or frame only options.

Modern race bikes also have very aggressive postures compared to older "racing"  road bikes like your father likely rode. Even if you can add a rack, they will become unhinged with little added luggage weight and the aggressive position is not particularly comfortable for more moderate pacing.  (An aggressive position is typically only comfortable when you continually riding at a hard effort.)

Other Types of Modern Road Bikes

If a touring bike is what ever reason not an option, then try looking for other road categories often referred to as "road sport", "endurance road" or now "all road". These bikes will have a more upright position, which will make them more comfortable for everyday riding, and depending on the brand will likely have more tire clearance (good for running fenders) and eyelets mounting fenders and may also have an eyelet on the seat stay for mounting a rack (make sure to check, as some brands skip this feature). To the untrained eye these bikes will look very virtually identical to a racing bike.

Vintage

The other option is getting an older "racing bikes" like what your father had.  These tended to have fender eyelets (which can also be used for racks) to have more tire clearance for running fenders.  They were also largely steel which means the frame can be clamped for adding a rack when no eyelets exist. The shifting is robust but not as responsive as modern systems and the brakes tend to be subpar compared to modern brakes (rim/caliper or disc).

Components on a older bike can of course be updated.


Wired or Wireless bike computer? I have bought a new pair of road bikes.

I am a triathlete (Sprint mostly) and I am interested to know, what computer should I buy now? wired or wireless?

I mainly do not like wireless things (I don't do wireless accessories - they tend to fail on you when you most need them).

The reasons I may consider which type to buy will be:
- Price (wired usually lower)
- accountability - (wired will less fail)

I can only think of why NOT to buy a wireless computer, and would like to know your inputs as well please.

I've only ever used wired computers because they seemed more reliable. However, I have a friend who uses a wireless computer.

The biggest problem I've observed is that when he starts riding after a rest he has to make sure he 'wakes up' his computer otherwise it won't track the ride until he does. He's forgotten (and lost ride data) often enough that this is a big dealbreaker for me.


How do I put a lower seat clamp on my Alinker walking aid? I have a walking aid called an Alinker http://www.thealinker.com/

It looks like a bicycle but it has no pedals and any bike shop can service it.

My issue is the seat it's a older style so has 2 bolts under the seat  mounted on the rails and I accidentally unscrewed all the bolts and the triangle shaped piece came out. I have the piece flipped upwards and its on the bottom of the rails. Can anyone here explain how to put this piece in the correct way. I am attaching a picture of my Alinker and the part in question.

I don't know much about bikes so please explain in easy terms.

OK, now I see what you're talking about.  I suspect the piece you have should go beneath the seat rails, with the cylindrical section pointing down and nesting in a matching half-cylinder depression in the base of the assembly.  The two ends of the piece have grooves (on the opposite side from the cylindrical face) that should accept the rails from the seat.

Then the top piece is bolted down over the rails (with bolts from the bottom).

The purpose of the cylindrical side of the piece you're wondering about is so that that piece can "rock" in the "cradle" created by the base, allowing forward/backward tilt of the seat to be adjusted.


Reassembling Shimano FH-M150 rear hub First time servicing a rear hub for me.
I disassembled and cleaned my Shimano FH-M510 rear hub, removing the nut, washers and cone only from the left side of the axle.
When I went to insert new bearings and grease I noticed a silver ring, and i don't understand where i have to put it (you can see it near the old freehub body).

Did I put that ring with axle's parts by mistake? I just remember to have cleaned it from grease.
Can someone help me? Thanks

Ok, maybe it's the left side dust cover

Nice picture. But you installed the dust cover (the silver ring) upside down. They way it works is that the bearings sit underneath it (but do not make contact) and are protected from all sorts of insults and wear. It keeps the grease in, and the bearings in place while servicing it.

The way it is now it will not allow for the race to be adjusted against the bearings. It's got to come out.

In the future, buy a small magnetic pick tool from a parts store. It makes digging out the bearings much easier and you won't be tempted to take it out. It's kind of a pain to get in there just right.

Good luck!


Are all Cannondale Slice forks compatible with a Cannondale Slice 105 frame? I recently bought a Cannondale Slice 105 (2015) off of Craigslist, and the fork was cut way too short, so I need a new one. I tried going through the local Cannondale dealer, but they couldn't help me, so I'm looking for used ones online.

I'm finding quite a few Slice variants: Premium, Coda, and Ultra, to name a few.
Assuming they are the correct size (1 1/8"), will they automatically fit, or are there any other variables I need to consider?

Doesn't need to be a cannondale fork, just needs to be the right diameter(s) and long enough to get out the top of the frame and be clamped by the stem.

Check wheel mounting tech and brake mounts too, but you can use any fork that fits.


Brooks B17 saddle tension? I've been using my Brooks saddle for about 1 year and at first it was really comfortable but less and less I think. It's my first leather saddle so I might do something wrong here :)

I bought the care kit from Brooks and have applied it twice. First time on both bottom and top and second time only on top.

It feels like the saddle is a bit too loose but I'm really uncertain. In my kit I have the tool to tighten it but when searching online for how much tension I should but on it I didn't get any answer. So how hard should I stretch it?

I also see a bump on the front part of the saddle. Normal? Or is that due to too little tension?

Any tips?

Leather saddles start to sag unless you add tension due to the leather stretching over time. How much tension depends on your body weight and how slack the saddle has become. Try adding enough tension that the saddle feels somewhat taught, but you can still depress the center of the saddle a bit with your thumbs. Ride it then add adjust the tension 1/2 turn at a time until you find the sweet spot.

Note that too much tension can cause the leather to tear starting at the rivets. So watch the leather around the rivets, you can usually see signs in the leather before it tears, let off some tension in this case.

Brooks leather saddles are suspended at two points, the front and back. What you are seeing is the leather bending over the forward contact point, likely caused by the sagging from too little tension.


Do I need a bike bag / box to put my bike on the Eurostar? The Eurostar website has a page that really should say but doesn't:

http://www.eurostar.com/UK/uk/leisure/travel_information/at_the_station/bicycles.jsp

I'm guessing I don't?

Would also be interested in any other experiences/hints/tips anyone has for transporting bikes on the Eurostar.

Thanks!

That page actually lays it out pretty well. You have three options: box/bag your bike, pay £30 for a reserved bike space, or pay £22 to ship your bike such that it will arrive within 24 hours of you.

The reserved bike spaces and shipping don't require you to box or bag your bike.

When I traveled on EuroStar and on French trains, I had a friend handy with a sewing machine make me a housse out of lightweight ripstop nylon. By turning the handlebars sideways and removing the pedals and wheels I was able to get it mostly within the size restrictions - it was bulky but fit in the luggage area, which is all that matters. It was slightly longer and wider than allowed but no one checked.


Safely Switch Bicycles before a Century? I did an unsupported century last year on my 30 pound "shop" mountain bike.  The first 55 miles were easy but the last 45 or so were pretty horrible.

This year, I want to try it again but with more hills. I really don't want to lug my 30 pound mountain bike up the hills, but I don't have the money for a decent road bike.

If I follow a reasonable training plan on my 30 pound mountain bike this year, will I be "safe" moving into high-dollar 15 pound rental road bike 24 hours before an unsupported century?

WARNING: This question was edited from its original version. It originally used the term "homemade" century to denote an unsupported century.  Also, the question originally asked if it would be okay to switch to a road bike the day of the mentioned century.  Now, the question asks if it is safe to switch 24 hours before the mentioned century.

I would strongly advise against that. Your legs are not going to be the problem, and neither is your overall conditioning/strength.

If you are going to be around other riders, you need to be able to stop and start and steer safely. Road bikes steer with your butt while MTB steer with handlebars.  This is a big deal when you are tired and running on instincts. You don't want to crash or cause a crash.

Your core and arms are probably not going to be strong enough to hold you up for a century on a road bike unless you've trained on one. A spin bike could help if you can get a road-bike-position. Also doing lots and lots of planks. Think of riding a road bike in a century like a 4-5hr plank. If you can't hold it that long, you'll start to sit which causes pain in your rump and arms/hands.

Short story:

Ride what you trained to ride, in this case the MTB. I often feel 'whiny' at the 45 mile point and again around 60 miles and again at around 90 or so. Usually eating something fixes it (power bar in my case). Almost like someone lubed my knees or something and I'm raring to go again.  I usually only stop long enough to refill water bottles and carry all my food on the bike.


COVID bike build 2020 first timer I am building my first road bike. I have been an avid biker rider for quite sometime and always thought about getting a road bike, just never got around to it.

Fast forward to now, my neighbor (pro rider) threw his Scott CR1 carbon fiber frame in the dumpster along with a MOST carbon handlebar and Cosmic wheel set.  Now that I acquired all this stuff for free, time to finally build a bike!

My point of this post is first to get some advice on ... where to start? How do I find out what is compatible to this bike from a component group, to putting everything together etc.

I know I won't be able to do everything but I know I can get pretty far then I am planning on taking it to a local guy to do a tuneup before I get her out on the road.

I want to build as tough and reliable as possible on a budget (don't want to spend a ton but want a quality bike). Let me know if anyone can help out with where to get started, also if you have parts for sale or anything or want to trade for something, I am wide open to that as well. Picture is attached, let me know what year as well if anyone knows.

Thanks David

Before you commit to putting money and effort into a build ask yourself is this really the bike you want? Doing your own bike build can be fun and fulfilling but you want to end up with a bike you actually want and will enjoy riding

Is the frame actually the right size for you. You obviously can't sit on it do try it out in its current condition. What size is it and how tall are you? How tall is your neighbor? Look on Scott's web site for size guidance perhaps. Is the cockpit geometry right for you? The CR1 probably has a fairly aggressive low handlebar position. I note that the steerer is cut so you cannot raise the stem. What I would do in your position is measure the CR1's stack and reach geometry, then compare that with some other road bikes that you can test ride at local bike stores. That's not really an option during the current situation.

You also need to address safety issues. If the bike was owned by a pro it probably has done a lot of miles. There may be a reason it ended up in the trash (carbon is cracked) or perhaps your neighbor is getting a new bike for free or for a good deal an could not be bothered to sell this frame and get a couple of hundred bucks (if that) for it. Check the frame and fork carefully all over for signs of damage, impacts, paint cracks etc. Same for the seatpost, stem, handlebar. Take the fork out and inspect the steerer tube as well.

Check the wheels are true, check spoke tension by pinching pairs of spokes together - you are looking for ones that are loose. Check the wear on the brake track (there should be a wear indicator groove. Check the rims for dings or scrapes.

if the bike has lot of miles the the bearings may be worn out. Turn the bars and check for play, excessive friction, roughness or 'notchiness', do the same with the wheel axles. Put a finger in the BB bearings and turn them them looking for the same issues.

Next step is to do your homework and start learning all about bike components and compatibility and how to install everything properly and all the tools you'll need. There are lots of resources online that are not hard to find with Google. My personal favourite is Park Tool which as has tons of great repair articles and videos. You should be able to find some full bike build up videos on YouTube which will get you started. If you have a particular problem or issue look for existing questions with answers on this site. Be aware that in component installation and adjustment details are really important. Do stuff right, don't take shortcuts.

The good news is that road bikes are pretty standardized. A Shimano rim brake groupset will probably bolt right on. There are only a few options to deal with such as the front derailleur mount type and the bottom bracket type.

There are many online bike component stores the are easy to find via Google. I'd go with a bike specific store rather than Amazon etc. as you get better guidance and access to specs and data. Ebay is great for used parts but you do have to know what you are looking for.


Cross Training routines for longer rides I am trying to build up to longer rides (75 - 100 miles). I usually only have time for one long ride a week. I can squeeze in one or two shorter rides of 20 miles or so. How can I build mileage under those kinds of time constraints?

The obvious answer is to go out and ride a little longer each ride, and I'm doing that. I am really looking for supplemental workouts or cross training ideas. My legs and lungs are doing well with the increases but my shoulders, back and arms are not. Frankly even ways to get used to being on the saddle that long would help.

What other aerobic exercises are best? (running, swimming, etc.)
What other strength/flexibility exercises will help? (yoga, back/shoulder exercises, etc.)

One of the best ways to build up to longer rides is through interval training.

The best book I've found on the subject is: The Time-Crunched Cyclist: Fit, Fast, and Powerful in 6 Hours a Week by Chris Carmichael. The book includes a lot of info on lactate threshold, energy metabolism, nutrition, race and century training plans, etc. I first tried out his methods after reading one of his articles in Bicycling on century training.

Basically, Carmichael's methods are a form of interval training where you are doing things like hill-repeats, power intervals, fast pace intervals, etc. There's a lot of info out there on interval training. One of the more common is called HIIT (High Intensity Interval Training).

FWIW - I've made interval training my primary method of training for long distance training. I did 3 centuries this summer and never did a training ride over 60 miles. Prior to 4 years ago, my mode of training for long distance was a gradual distance build-up and had mixed results. With interval training, my performance on long distance rides has improved significantly in both speed and how I feel afterwards.

"What other strength/flexibility exercises will help? (yoga, back/shoulder exercises, etc.)"

The upper back and neck can be a real problem on long rides. For this I use a regimen that I got from T-Nation called Deconstructing the Computer Guy. I've found that the exercises to alleviate insufficiencies related to sitting at a computer all day, also translate quite well to cycling.

Revisiting...

I'm between projects at the moment so thought I'd add to this a bit more.

You asked what other aerobic exercises are best. Probably the best is something that you have accessible and will actually do. Swimming, running, walking, rowing, elliptical machines, etc are all good aerobic exercises, but you actually have to like it enough to be regular about it.

For strength and flexibility there are plenty of options. Yoga is one; as well as things like martial arts, tai chi, etc. For strength, weight training is fine; but not a "body builder" type program.

You specifically mentioned that you are having issues with shoulders, back and arms on your increasing distance. I mentioned an article from T-Nation above that has some great techniques for alleviating these kind of issues. (I must note that T-Nation is a rather obnoxious web site, but the advice I referenced is quite good.) For myself, I had postural and muscular imbalance problems due to cycling and too much time at the computer; and found a lot of relief in following a program very similar to the one described in Deconstructing the Computer Guy. (Four years ago I was on a century and could barely turn my head in the last 30 miles due to neck/upper back pain.) It definitely worked for me and my cycling buddy as well.

Hope this helps.


Tyre loosing air pressure despite having no puncture The front tyre on my bike looses air pressure despite there being no punctures. There is no leak via the Schrader valve either. If I fill up the tyre, it looses a considerable amount of pressure by day 3. What could be causing this?

A puncture
The tire lining along the valve is faulty.
The seam in the tire is faulty somewhere around the tire.

The best way to find out is put some soap in a bucket/tray of water and cover the tire. Fill it up as much as you can and the bubbles are where the leak is!


How can I learn to take care of an old (70s era) road bike/get it back to working condition? I found my mom's old road bike from the 70s tucked away in a corner of our attic. It's not in great condition and is pretty rusty. I don't know a lot about bikes from a mechanical or upkeep point of view but would love to use this bike as an opportunity to really understand them and work on my bike mechanics skills.

It's doable although it doesn't make sense from a cost perspective. Only do it if you have an emotional investment in the bike or want a fun project that will teach you a lot about bike mechanics.

To give you an idea, I bought a 1975 Peugeot UO18 Mixte (a woman's road bike, perhaps similar to your mom's) that had been stored in a barn and turned it into my commuter bike. In order to do this, I had to (in order of simple to complex):

Replaced the brake pads which had oxidized.

Easy. You just need an adjustable wrench or set of open-ended wrenches (maybe a screw-driver). There are different styles of brake pads, it's best to remove the old ones and bring them to your local bike shop so they can give you the right replacement.

Replace all of the brake lines and derailleur lines, which had seized.

Easy-to-moderate. You need to get your brake/shifter housings cut to length which your bike shop will do for you. Replacing brake lines is fairly easy although you need to readjust your brakes after you do this. Rather than cutting the brake line to length (which needs a special tool), you can have the bike shop cut and crimp it after you're done. No special tools needed except screwdrivers, wrenches, and the aforementioned cable-cutter which is optional. Having a brake "third hand" will make your life a bit easier although asking a family member for their physical third hand also works.   Replacing derrailleur lines is a little bit more tricky and not recommended until later on as you'll need to readjust the derailleurs after replacing the cable.

Replaced the old steel front and rear wheels (rims, cassettes, sprockets) with 700c rims with a nice modern cassette in the back and a nice dynamo in front. New tires and tubes too, of course, as the old ones had rotted away.

I could have kept the rims but they were steel and not very "grippy" in the rain; in addition, the old size limited my tire options. I knew that I wanted a dynohub and so it was just cheaper in the long run to just go straight to buying new wheels front and rear. It also allowed me to go from 5 speeds in the rear to 9 speeds.
Easy to moderate. Even if you don't replace the rims, you'll likely need to replace the tires and tubes.  Replacing the front tire is fairly easy. You do have to get a new tire on the bead, which will require tire tools (get the Pedro levers). Replacing the rear is also pretty easy, just watch how to snake the chain around the rear sprockets. You'll also need a pump too, of course.

Replaced the chain with a 8/9 compatible chain

Moderate. You'll need to get a chain-breaker tool and replacement pins.

Replaced the front stem (the old French AVA stem is prone to snapping) and bars with contemporary Velo Orange components.

Easy. Just needed a set of hex wrenches.

These were the "basic" mods. In addition, I also changed out the rear derailleur with a nice Campy one and changed out the shifters to a nicer set of vintage Shimanos.  But these are optional.

Now the overall cost for my bike was much more than if I had bought a decent used bike (I estimate more than ~$300 in parts and several hours of labor) but less than what a new, steel-frame commuter might be (~$800). The advantage in my case is that I live in a high-theft city and this commuter doesn't look too fancy but rides like a dream. And I like fixing things.

If you're a beginner, the only real "essentials" would be to make sure that your tires have air, the cranks work, and that you can brake. After that, everything else can be a slow upgrade as you learn more skills as a mechanic.

In terms of resources, I'd recommend Sheldon Brown's site, the Zinn book on maintenance, and the Park "Blue" book. And of course, a lot of hanging around at your local bike shop.

It might also help if you can find someone to mentor you as a fledgling bike mechanic. I know it's hard as a gal who loves to get my hard hands dirty to find any respect, but it's possible to find community. See if there are any community bike clinics offered at your local bike shops or in the area.

Here is the bill of materials / notes from my repair notebook:

Front wheel
700c  vuelta rim  622x18
Stainless steel spokes 36h
Sanyo 6vac hub dynamo NH27

Rear wheel
SRAM PG950 9-speed Cassette  SR-PG950-34      11X34 $18.39
2012.11.21  Dimension Road Rear Wheel 700c 36h Shimano 2200 Silver / Freedom Ryder 23 (622-17)Black

Front sprocket (original), crankset original, pedals original
52-38

Rear Sprocket
SRAM PG950 9-speed Cassette  SR-PG950-34 (was 14-26) 382g
11-13-15-17-20-23-26-30-34

Derailleur
Campagnolo Mirage (used/vintage)
Chain wrap  = (52-38) + (34-11) = 14 + 23 = 37

Stem and bars
Velo Orange Threadless Stem Adapter ST-0001 $16
VO Porteur Handlebar $32

Upgrade Schedule
2012.09.26: Front Suntour derailler. Put new chain on (7.96mm outside width)
2012.10.09: Replaced front wheel with Dynohub + 700c 622x18 (36h) $85
2012.10.09:  Continental Gator Hardshell Urban Bicycle Tire with Duraskin (700x28, Wire Beaded) $48.79
2012.10.18: Rear Campagnolo (8-9) derailler
2012.10.24: All new brake lines and derailleur lines (Jagwire L3)
2012.10.24: 15.6kg w rack and dynohub and lights, front sun tour derailleur, rear campy derailleur.
2012.11.28 sks mud guards
2012.11.21  SRAM PG950 9-speed Cassette  SR-PG950-34      11X34 $18.39
2012.11.21  Dimension Road Rear Wheel 700c 36h Shimano 2200 Silver / Freedom Ryder 23 (622-17)Black
2012.12.01  Rear wheel => Continental Gatorskin ($49.99)