help finding a battery replacement? We bought a Watseka XP Cargo Electric Bicycle off amazon back in 2014
recently is hasnt been working and after further inspection we found that one of the batteries has failed (the one pictured below).  However i have been unable to find a replacement.  any suggestions?  its form factor is quite different from the what is standard now (the existing battery is shaped like a cube, where as all of the new ones i see are rectangle).
http://watseka-bikes.com/ seems to be down and has been for a while now so i think the manufacturer is out of business

SLA batteries are all the same, 2V/cell nominal, mostly 6V and 12V batteries. In this case you have a standard 6-DZM-9 6V, 9AH battery. All you need to do is find a replacement 6-DZM-9. The best solution would be find a battery specialist (not just you corner car/truck and motorcyles battereis seller) and see what they have in their catalogue.  Ideally you want a Deep cycle battery desoigned for electric scooters, bikes carts etc, not a Standby power battery. The latter is designed for UPS with the very occational deep discharge and won't last quite as long as one designed for regular discharge/recharge cycles.

With lead acid batteries, do not replace just one battery out of a bank, you will need to replace all the batteries - at 6 years old theyare at the end of there economic life anyway, and replacing just one battery will mean the life of the new battery is significantly reduced.


Need to replace Shimano FD-M191 I need to replace a rusted up Shimano FD-M191 front derailleur.  This is the original equipment on my 2010 Fuji Absolute 3.0, which has 3 gears in front and 8 in back.  Acera SL-M310 rapid fire shifters. Seems like FD-M590 for FD-M360 might work?  So many models.

There are a number of criteria when selecting a front derailleur. The number of gears must match. You need an 8 speed triple with a clamp diameter to match your frame. This is assuming that your derailleur clamps to the seat post. This is where things can get complicated. Some clamps come with an adapter to fit more than one size seat post. The next option is a high or low mount clamp. This is determined by the location of the clamp in relation to the actual part that does the derailing. Another criteria is top pull or bottom cable pull. This is another area where they make units that will work either way depending on how the cable is routed. I have access to an 24 speed Absolute DX. It has a 31.8mm/high mount clamp and uses a bottom pull design.


What's the best strategy to preserve vintage headset life? I recently purchased a complete Dura Ace 7400 set (8 speed, downtube shifters so 7402 parts) with the 7400 headset as well. It's the improved one with the silver race and not the gold one prone to bearing brinneling. So far, I haven't noticed any problems in the races. The headset came with the original bearing retainers  (7400 was races or loose ball, 7410 is cartridge).

When vintage headsets do have brinneling, it's recommended to replace the retainers with loose balls to give the headset a second life. In order to keep my headset races functional for the longest time, should I put new bearings in the retainers and install, and then in many years when I need a headset servicing replace those retainers with new loose bearings; or should I skip right to packing new loose bearings now and potentially a second time in the distant future? (The retainers will live in my toolbox so I can have it be "original.")

I've heard people recommend rotating your headset races as a potential solution to mitigate bearing brinneling. Is this relevant or helpful in this situation?

The frame is made by Stowe in the late 80s. While not very historically significant, it's a vintage piece  I want to preserve and keep in good condition. I will probably not ride it in regular rain or any races. I'm a pretty gentle rider and weigh 145 pounds.

I'm not sure why you're asking this, because as far as I can see the answer is in the question. You want to "keep it functional for the longest time" and then you say "should I discard a part that extends the life"?

Ball bearings without separators/retainers wear out faster, so there's more metal fragments in the race and the whole unit wears out faster. A much better way to extend the working life would be to extract and preserve the original retainer, and use new retainers and bearings. If you replace those more often than strictly necessary you'll minimise wear on the races.

But remember that the headset is very rarely the first part of the bike that wears out. Unless the bike is stored in atrocious conditions or terribly badly adjusted, by the time the headset wears out the derailleurs are normally gone, you're on the fifth to tenth bottom bracket, third or fifth wheelset and so on. A better question might be whether you have a stock of those parts to use as spares in order to maintain your bike in original specification. But note that this only applies if you ride the bike, and since you're asking about keeping it working for time rather than distance, that may not be a factor.

To keep the bike functional for the longest possible time you should dismantle the bike and pack all the metal parts in heavy grease to preserve them. The plastic and leather parts are more problematic, they probably need to be chilled and kept in an oxygen-free environment. That should allow it to be reassembled and used at any time in the next 100 years or more. If you choose a good storage location (a dry cave, for example) and a proper container (a sealed stainless steel case, perhaps), extending the functional life by 1000 years isn't out of the question.


How does one become an official for bicycle races? What's the process? Are there classes? Fees? Do they get paid, or is it voluntary?

Edit based on comments:

I was hoping to get an overview of the process that wasn't based on any given country assuming that the ultimate goal was to eventually officiate at the highest levels, i.e., Olympics, classics, grand tours, etc. As these officials work internationally, there should be quite a number of similarities from between countries.

All of the information that you need is on this page for USA Cycling.

There are three levels for road cycling, starting with C, then B and A. C level I believe is just a clinic that you attend, pass the post test (70% minimum IIRC) and you must be 16. To move up from C to B, there are 11 modules that must be taken and passed, and then to move to Level A, there are requirements for races attended, level of races officiated, and other age requirements. The officials manuals detail these, and are located on this page.

There are different requirements for Mountain and BMX (I believe they skip the B level), and the local contacts for Missouri (If your profile location is still correct) are located on this page.

As far as fees, etc.,  that is going to vary from race to race and with the level of the race. I know at the races that our club puts on and a majority of the races in the region, the officials are compensated.


How are the flat/aero bullhorn handelbars called? I've seen some bikes which look really good (IMHO) with a bullhorn handlebar which is flat and has an aero design.

After some googling I've only found this model which is really expensive:

Do they have some kind of strange name to search them and find something more affordable?

Is it possible to mount normal brake levers in them? (Not in the horns but in the center)

I currently have normal (rounded) bullhorns, but I'd like to get some of this just for aesthetics if I don´t lose functionality.

These are one component of aero bars, used on  time trail and triathlon bars.

These are used in conjunction with elbow pads and bar extensions that mount on top. The attachment points are visible in the pic you provided.

See this article Selecting the Right Aerobars for Triathlon.

Typically brake levers are mounted on the ends of the lower bars, and gear shifters on the ends of the bar extensions.

Aerodynamic bicycle components tent to be expensive because they are predominately used by pros and racers so they also need to be string and light.


Can I use a Sora rear derailleur with my 7 speed shifter? Since the only problems cames from my Tourney rear derailleur. I want to change it to a Shimano Sora derailleur, but, I don't want to change the shifter, I'm ok with 7. Would a Sora rear derailleur work with a Tourney 7 speed shifter?

Yes, despite being from a 9 speed road groupset it will theoretically work. If fact any Shimano road or MTB shifter for 9 speeds or below would theoretically work. The reason is that for 9 speed and below derailleurs, Shimano used the same cable actuation ratio - the ratio of cable length pulled to cage movement.


BSA Bottom Bracket Replacement So I have an old Winora City bike here and I am willing to spend a few hours in maintenance and repair of the bike. However, I am still a novice in the field and would like to gain some experience.

I feel the most urgent part to be replaced is the bottom bracket. The screw which holds the crank to the bracket constantly starts loosening itself on the left side. Loctite helped only temporary.

Concerning the parts I need to buy, I am very confused. First of all, a bike mechanic once told me the threads are BSA. The spindle is a square taper, J.I.S.-like, which can be seen here: Sheldon Brown's Bottom Bracket Glossary. Contrary to most bikes, mine is with an outer thread and the brackets are held in place by a nut (no screw).

On the drive side there is a single gear, type Sugino 48

I am wondering right now how to replace the bottom bracket. But before starting and interrupting half way because I don't know how to proceed, I would like to ask you whether I am on the right track:

I presume that the first step is to disassemble the bottom bracket. For the drive side I found (as can be seen on the picture) that I have to use a pull tool.
Next, I need to precisely measure the length of the shell. It looks to me like a 68mm, but might as well be 70mm.
Then I can select a new set of spindle/bearrings. Am I restricted to those "cup and cone" bearring sets? Should I buy another type? What is a reliable and well-to-maintain solution here?

It seems to me that the thread on either the crank thread or the nut is somewhat damaged.

If this is your daily ride and you are not going to take it for around-the-world-tour, I'd replace the bottom bracket with a cartridge one. It doesn't require any adjusting - great advantage if you are a novice.

Measure the shell width (you can do it without removing the spindle, just flip the bike) and make sure it is 68 (typical BSA).
Get yourself a crank puller (simple tool for couple of bucks), pull the cranks and measure the spindle length (just measure the tapered parts, discard the threads) and check whether the spindle is symmetrical (i.e. the length from the middle of the bottom bracket to the left and to the right of the spindle is the same).
Check what kind of tool you need to remove the drive side cup. When attempting to remove it, remember that at BSA, the driver side has reverse threading (you unscrew it CCW).
Purchase the stuff you need and put it on the bike. The cartridge bottom bracket has its left and right (driver) side marked.

Good luck!


Is an exercise bike good enough for keeping fit in the winter, rather than a turbo trainer I bought a turbo trainer for winter training last year, but the hassle of using it (lugging my bike up the steps and into my narrow apartment, changing the wheel to one with a trainer tyre, setting up something to watch at the same time, getting the bike computer set up right), plus the noise (the NOISE!) whenever I get up to a decent speed, mean I probably won't be using it much.

So I was thinking of getting a standalone exercise bike instead, figuring it will be easier for me to hop on when I feel like it and less noisy.

Edit: (to make it less subjective):
What I'd like to know is what are the drawbacks of using an exercise bike when you're used to riding a road bike?

what are the drawbacks of using an
  exercise bike?

Noise (you mentioned this)
Many quickly get bored riding on an exercise bike
Promotes bad cycling form
Can be large, heavy, expensive

My favorite alternative to riding in the snow in the winter is to ride on rollers. The rollers I have used have several advantages

Not as boring
Amazing for form
Foldable space saving models exist
More like actually riding on the road
No switching out tires
Ride on bicycle

Getting comfortable with riding on the rollers took me about 2 hours and I feel that it has been a great way to stay in shape and in good form while I'm not able or willing to ride out in the weather.

Photos of my rollers:

  Is an exercise bike good enough for
  keeping fit in the winter

Yes... and no. Completely depends on what level of 'fit' you are trying to attain and how consistent and hard you work on the exercise bike. If you are just trying to keep your blood moving and stay generally fit, then an exercise bike is a great winter workout tool. If you are working towards a 206 mile - 1 day race in the summer then you will probably want to mix your exercise bike workouts with other exercises like weight lifting and yoga.

  Is an exercise bike going to be better than a turbo trainer?

Depends. Exercise bikes tend to be more upright in their posture which may make the exercising more comfortable. Pricing and space will also be something to take into consideration when looking at exercise bikes vs. trainers. If you are wanting to be better trained and acclimated to riding your bike for races or rides, then a turbo trainer will probably better suit your needs.

There is another bicycle stackexchange question and answer similar to what I have said.
I wish to get fit, therefore should I have a heavy bike?


Is mountain bike good for long distances? I am currently living in a plane area. I use an MTB (mountain bike). My work place is 10 to 15 km away from my home. Temperature is around 36 degree in celsius in my region.

Question : Is mountain bicycle good for this purpose?

Edit: See the image of mtb below. One more thing roads are straight but there are few up and downs in my ways.

10-15 km is not a particularly long distance. You can certainly ride and MTB on roads to commute to work. Obviously an MTB will not be as efficient to ride as a bike designed for road use (such as a flat-bar commuter, road oriented hybrid or drop bar road bike).

You can make your MTB more efficient by fitting narrower tires with a road tread (or no tread) and inflating them to the higher end of their pressure range.


Have some new parts on hand but need new frame - frame swap reasonable? or sell and purchase new bike? Purchased my first "decent" bike, a Motobecane 700HT about 5-6 years ago as a 'gateway drug' of sorts for myself to get into XC biking. Ended up using it for commuting for a few years as well.

Over time have upgraded both front and rear discs with Avid BB7 (160/180mm) and tried to keep everything clean and well serviced. Frame got beat up a bit commuting (locking to outside bike racks) but just cosmetic. Bike still runs pretty well, shifts great - front gears can be a little slow but that might just be typical Deore derailleur (I have XT in the back and still run like new). Front fork (Dart 2) lockout is broken and I think the rebound is starting to get sluggish. I've replaced several other minor components over time as well.

I currently have on hand:

A brand new Rockshox Reba RL 120mm TAPERED 15mm Maxle lite (steer tube has been cut down just a little bit, should still be plenty long, but affects resale)
A brand new Mavic Crossride Disc wheelset (15/12mm through axle)

These are of course, utterly useless to me right now. I actually did try to mount the Reba fork to my bike using a specially designed headset from Cane Creek and while the fork "fits", it just barely rubs on the inside of my headtube. No dice.

So my question: Would I be better off liquidating everything I currently own and purchasing a new bike, or would it be a reasonable endeavor to port my current parts to a new frame (waiting for a good deal online)? I am not sure how 'compatible' my entire parts list are for modern frames and considering age whether I would be better off starting from scratch. For consideration, I am confident in my ability to swap components over myself, so I won't be having to tack on cost of LBS to do it for me.

I found a local that is selling Dartmoor Primal frames sub $200, which sounds like it might be a winner for me - being 650b or 26er compatible I like the idea of upgrading to 27.5 wheels as a down the road upgrade. I expect to have to purchase some new minor components to handle this swap - probably new bottom bracket (? I am fairly unfamiliar to the different specs on BBs) and seatpost - not sure if frame comes with headset but I'll assume I'll need a tapered headset as well as all new cable. Is this reasoning sound? Or are there likely more parts that will need to be changed?

Well, it depends…

Would you be happier cleaning a bunch of stuff out and getting a shiny new bike that reflects all you've learned? One that will "just work," or

Would it be a fun project to build up a bike from scratch? Would it feel good to know that you'd "built it yourself?" Do you have the time for the project? Is it ok with you to get stuck and make some mistakes – probably "wasting" some time and/or money?

If you decide to build, there are likely to be some unexpected "gotchas" along the way. So it is worth doing some reading and searching to see if others have run into similar problems. Sheldon Brown has a good piece on Upgrading Older Road Bicycles that may help you start thinking about the possible problems. Overtime the morass of bicycle standards has sorted itself out (a bit) so some of the problems that he mentions may not be issues. If you're looking at a frame you may find that the builder/seller publishes the key specs so that you can buy the correct parts. The specs will help you identify where the problems may lie. Some of the ones that come immediately to mind are:

Frame size and stem type, this decides if you can use your existing stem and the length of the stem you'll need.
Rear dropout spacing. This will decide how easy it is to use your old wheels.
Seat tube diameter (affects seatpost size and the front derailer clamp size).
Brake type and reach (distance from the mounting bolt to the rims, this is mostly an issue for caliper brakes).
Tire clearance.
The bottom bracket. It used to be that frame builders were tending towards 68 mm wide bottom brackets with British threads, but now there is a whole new generation of bottom bracket designs, so you may find that you'll either need to pick a frame to match your old one, or get a new one.

I tend to lean towards the build side, but that's partly because I can't afford the bike I really want…


Cargo bike with steering linkage In Europe, I've seen a common type of utility bike with the cargo basket on the front, and the rider behind it. Sometimes the cargo basket is a seat for children. To make this work, there is some sort of mechanical steering linkage from the handlebars to the front wheel/fork in the front. Is there a name for this type of bike and can you buy them in North America?

What you are thinking of goes by several names:

Front-loader
Long john
Bakfiets

There are a variety of manufacturers of these style bikes available in the USA. Some of the big names are imported from Europe such as Bakfiets, Babboe, Riese & Müller, Urban Arrow, but there is an American brand Yuba that manufacturs them too. There are many other smaller manufacturers as well.

If you expand to trikes with a basket in front, those come in even more names, and even more manufacturers.


Which mountain bike pedal is most suitable for racing? Which kind of mountain bike pedal is most suitable for racing? It needs to be pretty light, but also durable to be able to resist a tough race.

I have had SPDs and eggbeaters, and I love the Crank Bros eggbeater pedals. I've found them to be way better than SPDs. You can clip in on four sides rather than two, and in my experience, they're easier to clip out of in emergency situations than SPDs are.

Also, unlike SPDs, eggbeaters don't have flat surfaces, so you're less likely to slip off if you're trying to get back on after hike-a-bike sections of muddy trails.


Should I avoid hard-packed crusher dust trails with my hybrid? I ride a  Trek FX 7.2, with 35mm Bontrager hard-case lite hybrid tires. I'm still fairly new and inexperienced with cycling, and I've driven  exclusively on roads so far. I'm looking to start increasing my distance and speed, with the goal being to be able to perform a 50K ride  by the end of summer (my longest ride so far was 25k).

To this end, I've started looking for new routes to go cycling on. One route I've found that seems like a great choice is the Rum Runners Trail, which is part of a much larger trail system going across the entire province. Most of the trail is made up of hard-packed crusher dust, which I believe looks like this:

The website above says it's a great surface for hybrid bicycles like mine, but the product page for my tires makes me concerned this isn't the case. Specifically, there's this answer from a Trek employee at the bottom of the page:

  The H2 tires are going to be designed for pavement riding and not really for gravel riding

So essentially right now, I'm not really sure if I should be riding on this trail with my hybrid. I've considered just going on the trail and finding out first hand, but I'm still fairly new to cycling, so I'm worried about damaging the bike (or myself!) due to driving on terrain the bike isn't made for.

Is my bicycle a good choice for this hard-packed crusher dust trail?

The H2 aren't what the bike shipped with. I bought the H2 late last year, after the original tires got a flat.

You are absolutely fine riding the Trek FX 7.2 with the Bontrager tires on that trail. That gravel surface is not any worse than rough, worn tarmac so go ahead and enjoy those trails.

You don't really need much tire tread (or any) on flat crushed gravel trails, 35mm wide tires have plenty of volume.

Be aware that you will have less grip, both in cornering and braking. Try running slightly lower pressure than you would on the road. Avoid big bumps and potholes. Carry a spare tube, tire levers and CO2 inflator or mini pump in case you get a flat.


When do I need the cassette low spacer I want to install a CS-HG800-11 cassette on my Zipp 303s wheelset. The cassette comes with a low spacer (Y4T724000) and I am not sure whether I need it and if so which way should I put it on the freehub body? On side of the spacer is flat the other one is not.
Help would be nice!

You don’t say what size the cassette is but presumably it is a wide range model.
11 speed compatible freehub bodies are 1.8mm longer than 8-10 speed ones. Some wide range 11 speed cassettes can fit on a 10 speed freehub because the the large diameter inner sprockets can overhang the inner end of the freehub body a little and clear the drive side flange and spokes. Such cassettes come with a 1.8mm spacer for installation on a 11 speed freehub.


What is a suitable Gear Range for Biking on Flat Rail Trails My wife and I are 70 and are planning a purchase for relaxed riding exclusively on smooth (packed cinder/crushed stone) rail trails. We’re looking at comfort bikes like the Jamis Hudson Sport and the Giant/Liv Sedona with a preference for 7 speeds. Our area is hilly but the rail trails are not.

Thoughts on the choice of bikes and the preference of 7 speeds instead of 21 for this type of riding?

Comfort oriented hybrid bikes are good for recreational riding on smooth prepared trails without steep hills.

7 speed bikes are simpler, but without a choice of front sprockets you will want to be sure that the gear range they offer suits you. Getting a good test ride on any bike you are considering is recommended.

One thing I would avoid is front suspension. At the price range of the bikes you mention they don't provide much damping but do add weight.


51cm top tube too small for someone who normally cycles frame with 55cm top tube? I'm looking to buy a second bike and have found a really nice frame. The bike I cycle at the moment, which fits me perfectly (I am 5'11" (180cm)), has a 55cm top tube. The frame I'm looking at has a 51cm top tube. Is this difference too much?

There are two lenghts on a bike that are crucial for bike fit:

Seat tube length, which tells you how much of your seatpost will be outside the frame;
Effective top tube length, which is the horizontal distance between the centerlines of seat tube and head tube. This tells about your reach to the handlebars, how much the bike will feel "long" or "short" to you.

Some time ago, almost all the bikes had an horizontal top-tube, and due to manufacturing constraints (lugged frames using lugs with fixed angles) they tended to have a certain proportion between frame "height" and "length" in order to fit the average rider with a certain height.

Today we have a widespread adoption of welded frames, sloped top-tubes, mirabolant geometry designs, and we should always consider variations in leg-torso proportion for people with the same height.

That's why I think is safer not to consider the relation between  one of length/height of two frames to have a correspondent variation of the other measure. In other words, is perfectly plausible to have two frames with same seat tube lenght and significantly different effective top tube length, and vice versa.

So, to answer your question: Yes, you can ride a frame with a 51cm seat tube lenght, achieving a similar fit, IF the effective top tube length of the frame is similar to the corresponding measure of the former 54cm frame.

EDIT: Unfortunately, since the frame you are looking at is a 51cm top tube, it is unlikely to be a good fit.

(EDIT: I thank Zenbike for editing my question, because I had mistaken top tube for seat tube and didn't even notice. Usually only the seat tube length is informed, and end up being considered as "THE" frame size).


From Trek to Surly - advice on frame size I have a Trek FX7.3, frame size 22.5 inches. I'm looking to swap the frame out for a Surly Cross Check. Has anyone done a similar build? Also, what frame size would you recommend that I go for?

Just an idea at the moment - I'm not too sure how compatible more of my parts would be with the Cross Check frame.

Cheers!

You could compare the geometries of the FX and the Cross Check. Matching the standover, 56cm matches. Comparing the effective top tube lengths, between 58cm and 60cm match.

Bottom line the geometries are different.

On another note, the FX doesn't seem to be a particularly high-end bike, so purchasing a complete Surly could possibly provide more economical than moving the parts to a new frame.


Bike wheel help for newbie I was wondering if someone could help me? I have recently bought a Specialized Allez Sport road bike (61cm frame) and due to my weight I’m looking to upgrade the wheel set straight away due to my weight 140kg. Having researched I have found that either Velocity Deep V or H Plus Son SL42 wheel sets would be suitable for my weight, but how do I know if they are suitable for my bike? Will they fit? Any help or advice would be greatly appreciated.

Thanks in advance!

There are a few questions and answers on this site about wheel compatibility, but here is what you need to know in your situation.

Obviously you need ISO 622 / 700c rim brake wheels.

Dropout spacing on the Allez Sport is standard road bike 130mm rear, 100mm front.

Rim bead seat width should be compatible with the tires you have, or intend to run. A beefier wheelset may have wider rims than those on the Allez. Note that rim width refers to the inner width of the rim where the tire bead engages. Searching on this site or the Internet will yield a chart of rim width to tire width compatibility.

As a heavier rider you may want to run slightly wider tires than the original 25mm. The Allez will probably accommodate 28mm tires. You can check by looking at the clearance between the current tires and frame.

Lastly, the freehub body that the rear sprocket cassette fits on only needs to be compatible with 9 or 10 speed cassettes. (11 speed cassettes require a wider freehub. 9 and 10 speed cassettes can be fitted with spacers, but 11 speed wheels will likely be more expensive.)

You actually have a massive choice of wheels available to you. Search this site for advice for wheels for heavier riders. Wheels aimed at touring bikes with high spoke counts (32 or more) seem to be what heavier riders go for.


Derailler clearance on ERTO 406 wheels i have a Cannondale Hooligan I on which I plan to remove the Shimano Nexus 3spd IGH and replace it with a derailleur gear system. This bike has ETRTO 406 aka 20 inch wheels.

I want to use an 11 speed XTR M9000 medium cage RD

My question is: what is the maximum number of teeth I can have on the cassette? I see there is a 11-46 or 11-42 and 11-40.

The question isn't about the capacity of the derailleur but about whether there will be enough clearance between the derailleur and the ground.

thanks!

Rough estimate of distance of tip of derailleur cage from axle center:

I assume top pulley wheel is just touching sprocket, and pulley centers lie on a radius line from wheel axle center.

The radius through chain pin centers of a sprocket is approximated by n * s / 2 pi. n is number of teeth, s is chain pitch: 12.75mm in this case (see here).

Add say 5mm to pin center radius to get approximate total radius of sprocket.

40 teeth: 86mm

42 teeth: 90mm

46 teeth: 98mm

XTR RD-M9000 derailleurs have 11 tooth pulleys (I think)

11 teeth: 27mm

The distance of the tip of the lower pulley wheel from the wheel axle center is sprocket radius + (2 * pulley radius) + cage pulley center to pulley center distance.

Guessing the pulley center to pulley center distance is 80mm:

40 teeth: 220mm

42 teeth: 224mm

46 teeth: 232mm

How much clearance between the axle center and road do you have? An ETRTO 406 rim is obviously 203mm radius, plus say 25mm tire depth for a 35mm wide tire: 228mm.

There are plenty of 20" wheel folding bikes with derailleurs available, but I assume these use ~30 tooth largest sprockets. Browsing through google images of folding bikes I see their derailleur cages are very close to the ground anyway.


How does weight influence your speed when descending? I have recently bought a road bike and went on a little trip with a friend who is also a novice.

We have approximately the same height but he weighs a lot more (I weigh 67-68kg for 1m81 and he weighs around 80-85kg).

While descending a road, he outclassed me easily. It made me wonder :

Suppose that two people have exactly the same characteristics (same bike, same height, same equipment,...) but a different weight and a corresponding different shape (one is fit and the other overweight or more muscular). If they both ride perfectly (i.e. in an optimal manner), who is going to go faster ?

If the road and tires were perfectly smooth and there was no air, physics tells us that these two people would go at the exact same speed.

Theoretically, the heavier person has a less aerodynamic shape if his/her additional weight is the result of fat and not muscle, so if the road and tires are still perfectly smooth and if there is air, the lighter person should be faster (assuming that the "aerodynamic theory" is right).

Now, add the fact that the road and tires are not perfectly smooth and that I have probably forgotten important factors, how to know which one will be faster ?

I could have asked this question in the Physics community but I bet it is something known in the bicycles one.

The heavier person will present more area to the wind, but this is mitigated by two factors: The bicycle presents a fixed area to the wind and the area presented by the heavier person is not proportional because of the 2/3 power law. If you just scale up a rider by a factor in mass, the volume increases in proportion, but the frontal area scales up as the 2/3 power of the weight ratio because the dimension along the direction of travel does not contribute.  Both of these mean a heavy rider on a bike with a constant grade will descend faster with no power input besides the hill.


Harsh Winters bike - Steel vs aluminum frame? I am looking to a buy a single speed commuter bike which I can also use through the harsh winters here. I have narrowed it down to two bikes -
One has a 6061 Aluminium frame while the other has a hi-ten steel frame.

So my question is, given that I will use the bike through winter and have to park it outside in heavy snow with all the salt and grime on it (for about 5-6 months), is having a steel frame bike a bad idea or is it not a big issue?

Specifically this question is about Sweden, where temperatures range -5 degrees C up to 23 degrees C  (23F to 74F) in Stockholm, but further north the temperature has been recorded below -42 degrees C (-52 degrees F) (from https://en.wikipedia.org/wiki/List_of_extreme_temperatures_in_Sweden)

I've ridden quite a few different bikes on salted roads for over three decades, and it's more a case of preferences than objective benefits.

The steel bike will get chips in the paint, then rust and look really ugly after a season or two.  It will probably take decades until it's rusted enough to make much of a structural difference, but it'll be really ugly quite fast.  Ugly bikes get stolen less, so this may be a positive if you don't care about looks.

Aluminium bikes in salt will stay rather good looking, but the steel bolts will react with the salt and aluminium and seize quite properly unless you change them all to stainless.  If you don't change them, make sure you get good at drilling out bolts and re-threading if you plan to do your own maintenance.


How long should a road tyre hold its pressure? How long should a road tyre be able to maintain a pressure of around 100psi, and what factors are likely to reduce this time?

Background:

My tyre pressures are consistently dropping to around 60psi after about a week (three commutes, total ~50 miles), which makes the bike feel sluggish and less responsive.

I've only recently got a road bike, but I've always had mountain bikes - they've always held around 30 psi for weeks and weeks with no problems. I'm wondering if it's the higher pressure that's causing my tyres to need inflating more frequently, or something else?

This answer to another question, and some other answers I've seen suggest that you should check your tyre pressure every day, but is this to be cautious or are you likely to actually have to inflate your tyres every day?

Do yourself a huge favor, inflate them daily.

As they are high pressure and low volume they tend to lose air quicker than that of a tube that is low pressure and high volume (MTB).

With daily inflation checks you will vastly reduce the instances of pinch flats, which IMO are typically the result of too low pressure. Butyl tubes, the typical tube, retain their pressure better than their Latex counterpart but still ... check regularly.

This touches on why your tyres leak down (solubility etc):
Is there a difference in having tires filled with CO₂ vs air?


Good wind-screen for a bicycle? I recently constructed my own windshield for my bicycle using Lexan and wood. It works great but it is hand-made thing and I might be willing to buy a premade one that is curved (mine has a 90 degree angle).

But is there a good one available?

Zzipper makes fairings for upright bikes.

I haven't used a Zzipper or Windwrap fairing myself, but they're well regarded by the people in the forums at bentrideronline.com , who I've gotten good advice from about 2 recumbents I've owned.

Windwrap is sold by t-cycle.com/collections/windwrap-fairings and they're made for recumbents, but the smaller XT and XT mini might fit an upright. It looks like most of of the mounts are being redesigned at the moment.


How to prevent my bike from tipping over when using just one pannier? I often carry gear in a pannier on my bike rack, as in the photo below (not my bike, but same pannier design. My actual bike frame is very different; I'll upload my own picture tomrrow):

I have two panniers, but typically only use one because I usually have to carry the bag around with me at my destination, and carrying more than one bag becomes cumbersome.

The problem I run into is that when fully loaded (not beyond capacity, but close to it), my bike tips over when I prop it up with the kickstand. I always put the pannier on the same side as my kickstand, as I've learned that it tips over easier when on the opposite side.

What can I do to prevent my bike from tipping over when the pannier is too full? The easiest solution would be to distribute the load between two panniers, but that's impractical because of the challenges with lugging around two bags once I'm at my destination.

Do there exist kickstands with some sort of platform on the bottom to help stabilize them? Is my kickstand not positioned/attached correctly? Or is there some better way to balance things out so that my bike won't tip over?

You have a few options here.

You can get a two-legged kickstand. These are primarily used with heavy touring loads, but they will help stabilize the bike when parking with an uneven load. The two legs fold up into each other when you disengage the kickstand. You generally cut these with a hacksaw to shorten them to the appropriate length. I used one for a while:

However, that may be overkill. You might look into what's sometimes called a brake-band by the maker of the Click-Stand, an add-on for a parking stand for touring bikes. (The stand itself - a kind of tent-pole-like thing with a rest on the end that the bike leans into - would likely be overkill for am everyday use like this.)

This'll hold the brakes on while the bike is parked, and stop the bike from rolling while parked. (You can purchase them from the click-stand site, or just make your own with pieces of velcro.) Here they are, hanging on the side of my bike in between uses:

Finally, if you're not too picky about your paint job, you can simply decide to go without a kickstand and just lean your bike against a wall or a pole, or lay it on the ground.


Can early 2000 era frame use the latest group sets I have a Schwinn Peloton LTD from early 2000 with a 10 speed DuraAce crank.
The label on the bottom bracket says BC1.37x24 ROAD.

Can I get the latest Shimano group sets to work with this frame?

Yes, you should be able to run the current range of groupsets. All the mount points are the same as 20 years ago, except for 11/12 speed freehub body, so you might need to change the rear hub or wheel. Your BB shell is a regular threaded 68mm, should be absolutely no trouble to find suitable BB cups.


How can I tell if my tire is equipped with a tube? I have a puncture on my MTB tire. It says tubeless ready, but how do I know if it has a tube in it? Rims are sealed, it is a new bike around 6 months old.

First you may check whether sealant fluid came out of the punctured tyre. It could indicate a tubeless tyre, though it is not always the case. The sure way to tell is by checking the valve.
If your valve is held by a thin screw-on collar that you can screw off with two finger or no collar at all and that you can easily push back into the rim-bed your tyres have inner tubes. Same if your valves have no threaded shaft,
Tubeless valves will look like those in the picture.
They are tightly screwed on and require tools for removal. And as you also see in the picture, the core, the silvery bit comes out. Although this my also be be the case with traditional tubes but not always.


Would a swivel wheel trailer work with a bicycle? I want to use a trailer with my bike but it's extremely dangerous in winter conditions due to black ice and slush.

I'm looking for a trailer that acts like 2 extra wheels for stability than just something to drag. So imagine a trailer box that is hard bolted to the bike frame so the trailer always keeps the same angle of the bike frame. The 2 wheels on the trailer pivot.

Have you ever seen this done?
Do you think it can be done with a bike?

Would it work? Sure, technically. You'd have to fashion one yourself (or have it made for you). If you want the frame to stay fixed and just the wheels to swivel, unlike a chariot, then you'll likely need to weld the frame to your bike, making a strong commitment to winter weather (and permanently increasing its footprint in your garage).

Will it be comfortable or beneficial to your ride? No. In order to turn a bicycle, the vehicle leans. Without leaning, your inertia will play a big part in the direction that you go; i.e. you're going to have to take it slow around corners to avoid falling over. You'll need to slow down to a speed where you'd be unlikely to fall on black ice, provided you have appropriate tires, making your trailer redundant.

In my experience, riding year-round in all weather from freezing rain to a foot of snow to a tornado (oops), well-treaded tires are usually good enough, provided you pay attention to the road conditions. At times, it turns the activity into something more akin to skiing. If you wanted to really make sure you don't get surprised by ice, studded tires are the easiest answer, though if you're cycling in all kinds of weather, it can be a PITA to have to switch between studded tires and treaded tires once the ice clears.

To summarize: yes, you could do it, but it's not worth it.


How to properly attach a "tag-along" bicycle I have a tag-along for my son that wants to join me on some rides. It's a great way for father-son bonding. He's 7yo.
I've attached the collar of the tag-along to my seat post, and tightened the four bolts. However, without instructions (2nd hand tag-along), I only tightened them hard enough so I cannot move the pinion by hand that's attached to the seat post.

When I connected the tag-along itself, I had to align the holes with the pinion so that I can slide in the quick-release pressure lever and hold everything in place.

However, when we went riding and I started to turn left or right, the whole tag-along "bent" downwards throwing my son off it!

The pinion attached to my seat post was simply not tight enough, and it would turn left or right in the direction we were going, but this caused the other moving parts of the tag-along to follow it, resulting in the tag-along turning on it's side and throwing my son off!

Obviously I've made it tighter, but it may loosen over time.

Any recommendations or tips on how to properly secure a tag-along to the bike itself? I am tempted to drill a 10mm hole through my seat post and the pinion to tighten the lot, with a proper bolt.

Thanks

You mention four bolts, does your seatpost hitch look something like this:

By design, these can cinch up pretty tight against all size seatposts, in contrast to two bolt models which need the proper size shims:

However, with the four-bolt there are some caveats:

Do you have a carbon or aluminum seatpost? With both, you have to be careful as it's possible to crush the seatpost if you tighten the bolts too much. In these cases, you might want to ask the help of a bike store - they might give you some carbon fiber seatpost compound that will help with friction, as well as tighten the bolts using a torque wrench to prevent seatpost collapse.
If you have a steel seatpost, it's next to impossible for you to tighten the bolts too tight. If the bolt heads are stripped, get new bolts at your hardware store and get good quality steel ones (note: bolts with socket cap heads are stronger than the bolts with the button cap shown in the photo). Be sure to tighten in an X-pattern, just as if you were tightening the lug nuts on a car tire or the bolts on a head gasket. Rather than an allen key, you might want to use a hex bit in a socket wrench, you can get much more torque:

With the proper amount of torque on the bolts, it really shouldn't twist under normal circumstances. You could drill a hole to pin it, but that would weaken your seatpost.  Instead, you may try using some blue loctite on the bolts to make sure your bolts are not backing themselves out and a bit of the same friction compound used in carbon fiber bikes on the seatpost to add just a tad more friction.

p.s. When buying second-hand, always make sure your product isn't subject to a CPSC recall such as this one: https://www.cpsc.gov/Recalls/1998/CPSC-Riteway-Products-Announce-Recall-of-Bicycle-Trailers


Amount of spacers below the stem for steel 1 inch steel steerer I have a steel bike with 1 inch steerer tube made out of steel. I have about 55mm of spacers below the stem and above the top of headset. Is is safe to run my bike with that many spacers below the stem? I use it for mixed terrain riding, mostly road with occasional gravel mixed in.

Common threadless steel steerers have essentially no practical limit for this in either 1" or 1-1/8". There of course is a theoretical limit, but it's going to be a very large number, way over 12"/300mm. There have been a few companies over the years to make thinwall fancy alloy steel steerers (Alpha Q/Reynolds was a fairly popular one) that do have limits, which was published info.


Bent Peugeot Carbolite 103 Frame I have a vintage Peugeot carbolite 103 frame which is really bent. The rear triangle is bent in the direction of the drive side to such an extent that the drive side crank arm is blocked by the frame and cannot spin a full circle.
When I look at it from the back it is very noticeable.

Is there any way it can be cheaply fixed and will be safe to ride?

Thanks

It can be fixed. I can't guess how much your local bike shop will charge but any good shop should give you an estimate plus or minus 10% of what they will charge so you will know what to expect.

Here is an article at Park Tool explaining how to align a frame. It is possible to align a frame at home and get it kind of close even without shop tools if you have some skill. Some have used a string to measure alignment instead of the shop tool.

Once it is fixed it should be safe to ride assuming the rest of the bike is safe (see my note below).
From Sheldon Brown

  A steel frame can be straightened (within limits) if bent, and still remain safe and strong.

NOTE: I am saying that a steel frame that has been straightened is safe to ride assuming the rest of the bike is safe.
Since I can't assess the over-all condition of your bike I'm not saying that your bike is safe. Your local bike shop can make this assessment and would be able to speak to the over-all safety of your bike.


New Park Tool truing stand doesn't seem to be calibrated, calibration seems off out of box I recently purchased a Park Tool TS-2.2 truing stand, however I feel that the calibration is off. I have a wheel that was recently trued at my LBS and there is a significant gap between the rim and the caliper on the right side.

Assuming a trued wheel is on the stand, shouldn't BOTH calipers be set so that they meet the rim at the same time? I assume the point to having calipers on both sides is so that you can true both sides of the rim at the same time, right? Is it most likely the calipers are off or the arms that hold the wheel off?

Has anyone came up with a cheaper way to calibrate these things? I think it is ridiculous how much Park Tool wants for their centering tool...

The 2.2 is not for directly measuring dish, a shop will use a proper dish measuring tool(for time and repeatability) and there are techniques for the home gamer that lacks a dish tool that involve flipping the wheel over in the stand and noting the difference. The caliper is for measuring lateral warp or wobble and radial eccentricity(wheel hop) Only one side of the caliper is needed at any one time, the reason the 2.2 has two sides is that it is sometimes more convenient to adjust to the left and other times to the right especially if you want to improve a slight dish issue while straightening a wobble. Also some folks like to work from the high spot side and others prefer the low spot side. In the high production shop I worked (I'd do about 40 rims per shift, and there were 4 wheel stations) we often bungeed, or jammed with a small wrench/stick, one side of the caliper wide open to make inserting the wheels faster.


What makes a good floor pump? There are so many options, mainly because of the own-brand alternatives. So how do I choose a good floor pump? What should I look for?

I'd say it must have a good sturdy build and should be stable.

It must have a good pressure control and display; it should have a proper pressure range.

It should have a good connector with detachable/replacable plugs.

It should have a long hose, so you're not too close to the bike and make full control strokes on it.


COSMOS road bike? Identify my frame it is a vintage Cosmos World Champion road bike.
Frame height is 57 cm / 22.44 inches (measured from the center of the crankshaft to the seatpost).

Frame uses Columbus tubing. Components:

Selle Italia Turbo 1985 WC  "World Championship" leather saddle.
3ttt "3T" Triple T  Super Competizione / Racing Team Service  steerer.
Brev. Campagnolo Front dropout.
Columbus rear dropout.
Weinmann Carrera 1st generation brakes (Red emblem).
Gipiemme Sprint Pedals.
1st generation Dura-Ace front derailleur.
Shimano RD-6401 , 600 Ultegra rear derailleur.
Shimano FC-1050, 105 crankset.
Shimano SL-1055, 105SC (7sp) shifters. (Band On / Clamp on)
Shimano BL-1055 / 105SC  brake levers.
Mavic MA 2 rims.
Ciclolinea 80's bar end plugs.

Cosmos is a South African manufacturer. I believe they hand built good quality road and track frames but have long been out of business. You will probably find an enthusiast to tell you more on http://bikehub.co.za/  Nice bike!


1980's bike vs New(er) Models? (Should one stay with an ancient bike?) I have been cycling on a Centurion Pro Tour that was constructed sometimes in the 1980's - probably late 1980's, but still.

It works great.  It coasts downhill far faster than my hybrid, it doesn't weigh very much and I have definitely gotten perfomance results from riding it.

But, it is still from the 1980s.

It kind of forces you to ride in an areo position.  Once, I felt a pull in my back when I was riding up a hill (the topographic lines are very close together on that thing), and it took me days before I could ride again.  Sometimes, I feel it a little in my elbows.

It is worth it to look at a new bike?  My budget is really only 500USD or so.  Or am I just not adjusting it properly?

I know it's a narrow question on the fact of it, but I can't be the only guy with a decent ancient bike who would like some opinions one acquiring a new one.

My bike shop told me to I'd benefit from a new one, but hey - they are trying to sell bikes.

Thanks!

I suggest that you go to your local bike shop and see if you can test ride a modern bike.

As Daniel says $500 will not get you far. A test ride of a couple of bikes at different price points will help you decide. You may find that your "retro" bike is OK after all. Or maybe that it never did fit you properly. But a new bike could be 5kg lighter than what you have!

Now is a good time to do it, because it's Spring there and the shops will have a good range. If you decide to buy, then you can save for the next six months :-)


How to bleed rear SRAM Force 1 brake I'm having a hard time bleeding the rear brake of my Specialized Diverge. Following closely the instructions provided by SRAM (and other sources like GCN and other people from YouTube) only works for the front brake, the rear one always end up full of air in the system. It's funny all videos shows the bleeding procedure using the front brake, but none for the rear one.

Following SRAM official guide, after finishing the step of removing the caliper syringe, I always get lots of fluid coming out. All videos are edited on this part, so I can't know for sure if its normal or not to have so much fluid leak. After that, following all other instructions, the lever feel is mushy and touches the handlebar without any pressure.

Any tips on how to properly bleed a rear brake? What I could possible doing wrong?

On SRAM/Avid brake bleeds it's not normal to have fluid come out when disconnecting the caliper syringe beyond about what you'd expect the bleed screw to displace, or some drops in other words.

When you're doing that, is the lever syringe clamped still clamped shut? (It should be.)

Does each syringe connector have an o-ring and each bleed screw have an o-ring? If any are missing at any point, that's a way air can be introduced.

Have you visually checked the hose for damage? Checked banjo bolt for tightness? Checked the barb/olive/nut assemblies are as they should be? Losing a ton of fluid at the caliper end when you disconnect the syringe raises the question of whether there's a leak somewhere.

When you do the step where you push the caliper syringe while you hold the lever syringe upright, are you applying gentle downwards pressure on the lever syringe plunger, and being sensitive that it is indeed moving up in correspondence with the pressure you're applying at the caliper? If the lever syringe wasn't moving freely during that step, the fluid could get pressurized and maybe spill out that way. Sometimes syringes can get sticky and you can fix it by taking the plunger out and lubricating their seals with brake fluid.

There aren't really any differences between the front and rear procedures. With SRAM brakes it's not supposed to make a difference how the ends of the system are positioned (unlike some systems where you want the lever to be the highest point and the caliper drain plug to be the lowest.)

Doing the actual air bleeding steps, where you push the plunger hard then pull up to coax out air, is a bit of a skill that takes practice. Importantly, you have to get a sense for when you're not seeing anything further because you've actually gotten all the air out versus because you haven't tried hard enough. It's a good idea to tap all throughout the caliper and lever with the back of a screwdriver or similar during these steps, to loosen any pockets of air that might be present.


How is "correct" tire pressure related to tire volume? I have a unicycle with a Surly Endomorph 26"x3.7" tire, and I've discovered that this tire rides best at significantly lower pressure than smaller tires.

Even though I weigh ~110 kilos, I can ride this 3.7" tire at 12psi without pinch flats.

Previously I rode a 24"x2" Nokian tire that required at least 40psi.

Is there some known relationship where higher tire volume encourages lower tire pressure?

If you ignore the strength in the tire walls (pretty much zero for bike tires) then the pressure (which = force / area ) multiplied by the contact area of the tire on the road must be the force you are putting on the road (ie. the weight of you and the bike).

So for a large tire contact patch you need a lower pressure to support your weight, for a small area narrow tire you need a much higher pressure


Picking a crankset for a 107mm BB on a downhill bike I bought a downhill frame (Commencal DH Supreme 2012) that I want to build up with parts myself.
Now I'm trying to pick a suitable crankset for the 107mm bottom bracket. Having a hard time finding anything. It seems like not even the Saint group supports 107mm BBs. Where should I start searching? I'm not looking for specific advice but I need to find a place start or maybe I'm not getting it right with the specs.

According to the tech sheet at http://www.commencal-store.co.uk/PBSCProduct.asp?ItmID=12450127 you need a Press-fit BB.

PF107 should have 41mm diameter cups, have the same overall width as an External-bearing BB in an 83mm shell, and be compatible with the same cranks as "normal" external-83mm BBs.

SM-BB71 should work in your frame, and allow you to fit FC-M815 cranks. The cups will be the same as the "73mm" pressfit BBs, but the inner cover (aka spacer tube) is longer for "83mm".


Replacing a groupset in step purchases At the moment, on my road bike, I have Shimano Tiagra groupset. I would like to upgrade it to Sram Red, but I cannot afford to pay for the whole groupset at one time and would like to buy them in steps. I am wondering if this would be possible to do. If yes which components would I need to buy first?

Thank you.

If you want to upgrade gradually you need to follow the compatibility of the groupsets.

If your Tiagra groupset is the 4600 series of 2012, the 10 speed components should be compatible with other Shimano 10 speed road components, so you can use Dura Ace 7800 and 7900, Ultegra 6600 and 6700, and "105" 5600 and 5700.

The amount of cable pull per gear is different between Shimano 10sp road and Shimano 10sp mtb. SRAM 10sp doesn't use the same cable pull as Shimano 10sp road or mtb.


Changing cassette, can I change ratios Not sure if I'm using the right terminology here. Last night I changed the chain on my cheap road bike (2008 Specialized Allez Triple), and then took it for a quick test drive but the chain was skipping under any load at all. Figured the cassette is well done as well.

The problem is it's very hard to find a 12-26T where I am for some reason, but there are stores with 11-26T in stock. Would this cause big issues? Anything I should check for before I buy and install?

Also, I am sure I've seen people do this, but right now everything is Shimano, but the only cassette's I can get are SRAM, shouldn't be an issue correct?

This would be completely fine. You only really have to worry when going to a much wider range. Smaller road derailleurs cannot deal well with big differences between the largest and smallest gear, but they can all handle a 15 tooth difference. Things only start to get compatible once you move beyond 11-28.  Shimano/SRAM are compatible for 8-9-10 speed cassettes. Things aren't compatible at the 11 speed level. According to this chart, Shimano and SRAM mountain Cassettes are compatible at 11 speed, but for the road there is a small difference in sprocket pitch.


What to put on or inside winter-SPD-boots to keep toes warm? Where I live we have very cold winds blowing in from Russia's Siberia. It is freezing despite the fact that I have all kinds of extra winter clothing like commando balaclava, SPD winter shoes, ESS goggles -- but my toes are still freezing.

So what would you suggest I wear to keep my toes warm?

MEC advise, on their web site, that the cheapest way to keep your shoes dry is a plastic bag.

They also sell shoe covers: some for rain and some (with neoprene and microfleece) for winter.


Can I convert hybrid to mountain bike. Tyres and tubes? I have a mountain bike looking frame with wheels that currently have road tyres. The bike is classified as a hybrid.

My tyres state: 28" x 1.6 (42-622)
The rim: ETRTO 622 x 18

I am having difficulty locating any mountain bike tyres for size 28".
Can I use size 29"?
Would I need a different set of rims?
Also, do I need a different tube for these tyres?

My goal is to do some dry trail mountain biking.

Lots of question. Thank you

There's a bunch of weird standards for naming the size of tires and rims, and there's an actual ISO standard.

The best thing to do is ignore the big letter printed names that have inconsistent conventions, and look for the ISO standard stuff, like "42-622".

The ISO standard size of your tires and rims is 622.  (18mm wide rim and 42mm wide tire)

ISO 622 is the same as "700c" (common road size) and 29er (new larger mountain tire).

In other words: yes, a 29" tire should work fine, as long as it's not too wide.

Try to stick with something close to the same width and they'll work fine with your existing rims. Mountain (off-road) tires with their knobs can require more clearance at the same size.

As long as you keep to about the same size tire, your existing tubes should be fine.


Tubeless tyres deflating - serious problem or just because I don't have sealant? Both the (new) tyres I have bought deflate overnight: I have to pump them up again every time I want to ride them.

This happened before I even rode them for the first time, so no punctures.

Is this just because I haven't got around to adding sealant yet, or is it a serious problem with the rim/tyre? The wheel is Shimano Ultegra 6800.

Is this just because I haven't got around to adding sealant yet...?

Yup.

The sealant plugs the very small air leaks in the casing and between the rim and bead. The tire will leak down substantially faster without it.

Despite the fact that it's not the subject at hand, it's worth reinforcing what brendan said: make sure you're running tubeless specific road tires for road tubeless. Standard beads- both steel and kevlar- stretch, and without a tube to bind them in place they will stretch enough to climb over the rim and blow off suddenly and catastrophically. You can get away with non-tubeless specific tires at the lower pressures used by mountain bikes- Stan's made their initial mark on the industry by providing conversion kits for non-tubeless rims and tires. But you cannot get away with that at road bike tire pressures. Road tubeless tires use a carbon bead that doesn't stretch, and therefore doesn't blow off the rim. That is the critical innovation that took so long to come around and make road tubeless possible.


Why would I choose a bike trainer over a stationary bike? I was planning to buy a stationary bike to use it at home during the pandemic, but I thought it might be better to buy a bike with a trainer at home.
Do you think it is a good idea? I don't know about how much resistance the trainer provides and if it can be a replacement for the stationary bike?
I don't have any bike right now, and I am thinking to buy a Giant Talon 2/3 (hardtail MTB) to use it in summer and with a trainer, it is possible to use it at home. But, I have never used a trainer and I don't know if it is a good option.
Edit
I bought a Giant Talon 3 (hardtail MTB), and I would thankful if you can recommend some budget trainers.

The main difference is cost, both money and space.  If you already own a bicycle then it is using up space whether you can ride it or not.
If you want to use the existing bike on a trainer then that may end up cheaper overall.  And you can still unhook the trainer and go ride normally, giving you dual-service.
By comparison, a stationary bike is a fixed item and can't be used to ride outside.  Its a single-purpose tool, and takes just as much space as your normal bike.
Other points to consider

Noise - I'm not sure which is going to be louder, and this may not be an issue in your environment.
Wear on bike - adding mileage to your real bike is hard to track when its not moving.  For a stationary bike, its total distance travelled is unimportant.
Training effect - I can't really speak to this, but there's a significant difference between any indoor bike and riding for real.  The "crank inertial load" drops off much quicker on any indoor bike compared to an outdoor ride.  That is, you stop pedalling and coast much longer for real.  Expensive trainers can duplicate that better, but its still not ideal.
BORING I find any static bike to be mind-numbingly boring after a while.    But I've never bought into the virtual options like zwift, so that is an additional cost to consider.   Turning the pedals over while reading a book or watching a movie feels quite pointless to me, you're not concentrating on the ride.

Ultimately its up to you - Do you want a bike that you can ride for real when conditions improve?  Or do you want a piece of inside exercise equipment that risks being left unused after a while?
At least the bike can be used outside.  The stationary bike means you still need to buy a bike for normal outside usage.

I've just realised the suggested bike is a hardtail MTB, and presume that you intend to ride off-road with it.  So there's a sub-question here about

whether the kind of bike you intend on riding, and how/where you want to ride affects the choice between stationary bike vs a bike on rollers/trainer.

I can't give a definitive answer on this point; anyone with experience is welcome to add their own answer.


will Shimano Shimano Dura Ace 7700 STI Flight Deck work with Rear Derailleur Shimano XT RD-M771 I thinking to change my Long Haul Trucker set up. Have both Dura Ace 7700 / 7703 STI Flight Deck 3x9. Will it be compatible with the LHT stock Front Derailleur Shimano Sora FD-3403 n Rear Derailleur Shimano XT RD-M771.

I'm changing over to Paul Touring Canti's brakes too. Just wondering what other issues might come up

Sorry if these questions are redundant.
Thanks for your time and consideration.

Yes, all nominally 9-speed Shimano mountain RDs will work with ST-7700, and all pre-11-speed road FDs will work with ST-7703, except for FD-4700 at present and any future 10-or-fewer groups that use the 11-speed actuation ratio.


Rear derailleur has trouble switching gears on the way up, but works perfectly on the way down? I noticed an issue with my gears switching recently so I decided to try indexing them. I've gotten to the point where going from the smallest cog to the largest works perfectly, but in the other direction it doesn't want to move from gear 1 to 2. If I keep shifting up it shifts normally, only a gear behind, until it gets to gear 8 and the chain skips the 7th cog. Does this point to an issue with the derailleur itself?

This sounds like classic derailleur cable friction. The cable gets stuck inside the housing and stops or delays the derailleur moving to smaller sprockets. This is caused by dirt contaminating the housing, or perhaps corrosion of the cable.

The fix is to remove, clean, re-lube and re-install the cable, or replace the cable and housing altogether.


Good way to stop electrolyte tabs from turning into powder? I carry electrolyte tabs on multi-day bike rides, especially in hot weather. I use a container like this (though not necessarily this brand — the picture is just for illustration):

What I find is that after a few days on rough terrain the tablets turn into powder (from rubbing against each other and, to a lesser extent, against the container.)

This is a bit inconvenient, so I'm wondering if anyone has any tricks for how to solve this?

I've got a few individually wrapped tablets (and equivalent powders) that came as samples.  I never use them when starting from home instead saving them for carrying with me.  This works for long hot days, but on a multi-day trip would soon run out, and the packaging is wasteful.

The tubes protect the tablets from crushing, though they add bulk compared to decanting into a small resealable bag and packing that carefully into your luggage.

Assuming you want to carry on using the original tube, you need to fill the empty space.  You could use something as simple as paper or cotton wool, or even the wrappers from cereal bars, screwed up.  I wouldn't use gel wrappers as they'll make the tablets damp. If touring with the ability to make hot drinks you could even use tea bags as padding. Some of the tubes of tablets have a sort of plastic spring that takes up the space when only a few have gone.  This seems effective for as long as it lasts, so I suggest filling the space under the tablets.  For that you could even use a few sweets (making assumptions about what else you carry).  Under the tablets, enclosed in a bag, would be a good place to carry some emergency cash, making good use of the space.


What kind of dyno is this? Can anyone help me out. Just pick this dyno up and have no idea what kind it is.

The high spoke-count wheels look nice but are mostly for show rather than increased load capacity.  Notice the front wheel is laced radially and the rear is laced crossed.  As such this front wheel would not suit a brake.

At least one tyre has been replaced because of the colour and tread difference.

Otherwise its a fairly neutral BMX, not intended for stunts or trials.  If you like it, just ride it and maintain it.

Since you've "just picked it up"  try asking the person selling it.  If they're the original owner they will know the most.  Original paperwork is always a selling point for a bike too, and a service history.  I know exactly how many km are in my chain and cassette.


Caliper drop for bike conversion I'm trying to work out if my current brakes are long enough to work with 700C wheels (ie 622mm rim), rather than 630 (27").  The question I have is, will the wheel sit at the same point in the dropout? Do I need to factor in a different diameter quick release bolt? Or do they have the same diamater?

Will the frame spread make a difference?

Thanks

Tom

I will use 27" to describe ISO 630 in the remainder.

You need to be able to move your brake pads down by about 4mm. If you can do this, you should be OK. Velo-Orange has a nice page describing the process (if you don't have the sufficient brake adjustment, put in a 700c wheel which has appropriate hub spacing (probably 126 mm - Velo Orange (among others) are also willing to sell you a prebuilt wheel for this purpose), and measure from the center of the caliper bolt hole to the center of the rim, and that is the reach required for a replacement caliper (then, you can buy a cheap replacement caliper) ). If you're spreading the frame to take a 130 mm hub (you shouldn't need to do cold setting for this with a cup-and-cone hub), the angle change is tiny (you can work out the trigonometry for it), so you will need a little less range of adjustment. The QR is irrelevant. The wheel can sit slightly further back in the drop out (maybe about 2-4 mm) to match the angle exactly of the brakes hitting the wheel, but I don't think this is necessary (once again, you can measure the angle from the dropout center line and the brakes with the vertex being center of the axle, and use a little math or adjustment to match it for the brakes with the new wheel, but it should be tiny). In other words, you'll figure it out when you put in the new wheel and adjust the brakes.

For completeness, people using Canti's often have to swap to something else, like PlanetX's Frog Bollox for the additional adjustment range. Velo-Orange does point out that most original brakes for 27" bicycles are not very good even compared to cheap brakes today, so you may want to get new brakes anyway.

Also, note that you can still buy 27" wheels (see here) and tires from brands like continental or whatever, though there is certainly more expense and less selection.


How to clean a rear derailleur? This has always bugged me. At the end of the season I'm breaking down my bikes and cleaning every inch of them and I get to the derailleur and can't seem to ever get all the junk out of the middle of it! Anyone have any good strategies for getting in by the springs and around the moving parts?

I'm fine with removing the cage and doing jockey wheels, etc., but would prefer to keep the main body together.

Lean the bike slightly against something with the derailer facing out.  Slide a section of newspaper up behind the derailer and large cog and let it drape down over the tire and onto the ground.  (This protects the tire and absorbs most of the solvent.)

Get an old toothbrush and a spray can of (no shouting now!) WD40 or some other similar solvent.  Alternately spray the derailer (and cluster, if you're so inclined) with WD40 and work it with the toothbrush.

When it's sufficiently clean (ie, no longer caked with congealed crud) wipe it dry and lubricate with chain oil.  (Since this is usually done in tandem with a chain cleaning, simply oiling the chain will usually oil the derailer sufficiently.)

You may want to hit it with another shot of oil after a day or two, since the small amount of remaining solvent may prevent the oil from reaching all surfaces at first.


Professional Rider Database I'm looking for a downloadable database of professional (road) riders, containing age, height, weight, etc. The only thing I've found so far is http://www.sports-reference.com/olympics/sports/CYC/mens-road-race-individual.html which seems to have a good amount of information, but is not easily downloadable, as I would have to go to each rider page individually go obtain the data. Any other sources out there?

It's unlikely that anyone who has compiled that data would allow you download it.

Cycling News has a really good database at http://www.cyclingnews.com/teams

You can download rankings that include all the riders with name, country and age at http://www.cqranking.com/men/asp/gen/downloads.asp

Other than that I would try the UCI or each country's governing body, but it's unlikely they would have height and weight stats.


Quick release saddle bolts? I need to find a way to easily remove the saddle on my folding bike.

Solutions from Zefal (Lock & Roll) or Pitlock/PinheadComponents/AntiVandale aren't usable because they're meant for regular bikes, where adjusting the saddle is uncommon once set, while folders require adjustment every time the bike is folded/unfolded.

I was wondering if some company made a quick-release saddle bolt, so that I could easily take the saddle with me and leave the seat post.

That doesn't prevent some ass*e to take the seatpost just "for fun", but it reduces the risk and it's a lighter alternative (seat posts on folders are bigger and heavier than on standard bikes).

Thank you.

Replace your hex seatbolt with a knobbed or winged bolt of the same strength and sizing specifications.

Clamping knob:

Wing screw:

(I happened to see these at http://www.jwwinco.com/products/section8/, but do not know if they are up to spec. @WTHarper mentioned the McMaster-Carr site that has lots of options.)


Help Identify This Bike This bike was given to me from a elderly lady who no longer wished to own it. Other than a columbia I have no idea what year or model. There seems to be no serial numbers from which I can see on the frame itself.

Too bad the first picture is so backlit. I can't zoom in very well- amazed you have determined its a Columbia! The chain guard is by Wald, purchased sometime in the distant past from an IBD. The fork has most certainly been damaged from a frontal impact. The pedals were most likely installed after 1973; the year the CPSC mandated pedal reflectors. The frame itself is so weird- it looks as though the spot-welded dropout attachment had failed (common failure) and was repaired with bolts and nuts (common "field repair"). The rack, if "homegrown", it ingenious, if a little raw. The surviving decals, if original, suggest an homage to the popular Schwinn American of the early '60's, but also remind me of the mass market Columbia 10 speed bikes marketed about 1975. The more I look at it- the bizarre rear dropout, which stands incongruous to the rest of the bike- and the way the rear rack braces were installed (one "out", one "in")-I suspect the bike was damaged and repaired "at home" by a good lay mechanic. He did the best he could with what he had, and kudos to him. I suspect the bike may have stared life about 1973-1977 as a lifestyle model. Cool bike!


What causes uneven wear on cleats? I find my right cleat is wearing a lot quicker than my left one.

Usually I start with the left cleat in the pedal and then click the right one in while pushing off. Is the action of inserting the cleat that damaging? or is it the standing on the right foot while waiting?

Of course the more the cleat interacts with other surfaces, the more it wears.

My experience with SPD-SL cleats is the "primary unclipping foot" wears down a bit quicker, although I usually replace both at the same time (partly for convenience, plus I find the yellow "walking grips" wearing out more evenly, so are worth replacing as a pair)

Similarly, the pedal on the primary-unclipping side will likely wear quicker - for example, after around 15,000km:

The SPD-SL pedals show wear nice and clearly; you can see I primarily unclip my left foot. The left pedal had significant vertical movement, and was overdue for replacement.

  Is the action of inserting the cleat that damaging? or is it the standing on the right foot while waiting?

These will cause different kinds of wear, typically.. What is causing the wear should be pretty obviously if you look closely at how the cleat attaches to the pedal, or what contacts the ground when you stand (easily done if you take of the shoe, and clip in with your hands!)

For example, with the SPD-SL cleat:

The yellow bits (1.) will wear from standing, whereas the area that rubs (2.) will wear from unclipping.

Different types of cleats will be different, e.g the SPD "mountain biking" shoes have a recessed cleat, so standing will not wear the cleat.


Tire won't fit on the CR-18 Sun rim I can't fit a Kenda tire (28-622  700 x 28c-28 x15/8 x 1 1/8) on my SUNRIM CR-18 rim.  Is there an alternate size that will work?

My immediate thought was that you have ISO/ETRTO 630 rims (what used to be known as '27 inch' on older road bikes) which are of course a bit bigger than but sometimes confused with 622 '700c' rims. According to the CR18 page on the Sun Ringle site those rims only come in 622 and smaller. Perhaps 27" versions of these rims were made in the past so you should confirm what size you rims are. 630 and 622 are the bead diameters in mm so it's easy to check by measurement.

if you so have 622 rims, so what you probably have is a slightly oversize rim and slightly undersize tire. Some tires are known to be undersize and hard to get on.

You may just need more force to get the tire on. Make sure the bead is sitting in the deepest part of the rim 'valley' as you try to get the last part over the edge.


Avid juicy three piston popped out when bleeding without block So, First time bleeding juicy three brakes. I bought a cheap bleeding kit, didn't use a bleed block and the piston was pushed out.Feel a little stupid now.

Pushed piston back in and let the excess fluid out but now there is no reaction from the brakes. The lever goes to the bar. Are the brakes useless? They are about five years old avid juicy threes.

Thank you.

You should just need to re-bleed them. Happened to me a few weeks back late at night before an Enduro the next morning. Bled them and they were good as new.


What Schwalbe Nobby Nic should I buy? I recently bought a Swissbike X5 (same as the Montague Paratrooper, but labeled Swissbike and matte black).

It came with Kenda Kinetics 26" x 1.95" (front and rear)  that I'd like to replace.

Due to good experiences with Schwalbe, I'd like to buy the Nobby Nic, but there are many different Nobby Nic models, as well as widths.

I'm going to use the bike mainly for fun riding in the forest.

I would go with something in the 26x2.25 range with the Double-Defense protection.  The 2.25 will give you nice volume to allow lower pressures while still being narrow enough to fit most frames (you might have to go narrower if your frame won't allow the 2.25).

Double defense will give you the maximum protection, it weighs more, but I doubt you would notice unless racing.

Unless you are well versed in running tubeless, I would just stick with tubes.

Hope this helps.


Upright bicycle efficiency & seat movement The Kwiggle is folding bike that has been around for a while now (even though doesn't seem to be for sale yet): https://kwiggle.odoo.com/en_US/startseite

Apart from it's folding capabilities I was interested in the more upright riding positions which they seem to claim that "You ride faster and your quadriceps have to work less." (https://kwiggle.odoo.com/en_US/home-kwiggle-vorteile)

I find this a quite interesting claim in terms of efficiency. Is there more evidence of this, and if yes, why aren't more "city bikes" doing this?
Another interesting "city efficiency" aspect seems to be the movable seat which is highlighted more in this video and they claim "The movable saddle follows your natural hip movement.":

Personally I think the combination of the movable seat with a more upright riding style (which is what race riders do to increase speed) is a quite interesting combination!
So my question is about general efficiency of this approach. Is it an entire waste of energy compared to regular diamond shaped bikes or is there something to the combination of upright riding + movable saddle?
EDIT
Personally I think most answers are addressed by non-european cyclist. In Europe (Netherlands and Denmark) an upright "dutch" bike is the norm for urban cycling and has showed several postural and efficiency advantages.
A dutch bike posture seems to be very similar to the one presented in this Kwiggle prototype:

With regards to the "swinging saddle" there's very little evidence showing how efficient this system can be. Personally it does sound interesting as the pedal stroke is leveraged by the hip moving towards the direction of the stroke.
Regarding the rest of the features of the bike, there's many things left to be desired, but the question is mainly about the "upright posture" (already established in Europe) and the "swinging saddle".
I'd be curious if there are any other "swinging saddle" prototypes out there since that seems to be the novelty of this approach.

When I consider all the claims made, I believe they are probably true and verifiable... Not once do they tell you what they are comparing their product to, they lead the reader to presume...
"You ride faster and your quadriceps have to work less." - compared to what?  Walking
"- If you have a Kwiggle with you, you will explore cities and landscapes faster, further, more independent and more flexible."  - Key is is the first word - "If" followed by faster/further/more independent than what? Obviously, if you have their product with you, you almost certainly won't have a competitors product with you.
"The standing position is also unique in the world. You get more force onto the pedal." - More force than doing what on what? If you stand on a regular bike, you have the same position and same advantages, but you set the saddle up for more efficiency - by pedaling faster with less force (i.e. spinning - which is more efficient when trained)
Every one of the claims falls into the same kind of questionable claim. Probably spend a fortune on legal fees ensuring they don't breach various consumer protections laws around the world.
Note - this is a essay on the sales claims of the product and makes no assessment of the product itself.


With a 700c X whatever tire, does the other number really matter? I'm trying to buy a new tire off of a website but they offer 700cX32c and others like that but are they all the same size or not?

700c (ISO 622) is the wheel size (other common wheel sizes are 26 inch (ISO 559), 29 inch (which is really the same as 700c), 650b, etc). The second number determines the tire size (via width-ishness).

See this page on tire sizing - there is some variance even among tires marked the same thing (and strangely enough, numbers mean different things when written as decimals or fractions), even if the tires are of the same style (say, slicks; Obviously if one tire is knobby and the other is slick, you can't reasonably expect them to have the same tire clearance when mounted in the same bike). Generally, the bigger the second number, the bigger the tire  (knobs can cause this to be violated) and typically more cushioning. However, if its too big, it won't clear the brakes or the fork/frame.

Typically, your tire should between 1.5x and 2x the inner rim width - too narrow and the rim can take some hits. Too fat and the brakes drag on the tire/handling can be compromised.

If you haven't bought a tire before, take the bike to your LBS and try on some tires so you're sure they'll clear the frame and are not too wide for your rims.


What is mysteriously slicing the inside of my tubes? For about the last year, I've had a problem keeping my bike on the road. Originally, my rear tube went flat when the tire was punctured by an office staple (don't ask me how a regular office staple could have been positioned properly on the road and puncture all the way through the tire while I was riding, I can't figure that out either). Since then, every time I replace the tube, it lasts for maybe two weeks and then goes flat again. Each time, the tube gets this mysterious slice along the inner side. Here is a picture of one of these slices. It's very faint; only deep enough to puncture fully through the tube in a few places.

This is a picture of the inner side of the tube. The slice is almost halfway down from the seam and runs across the length of the tube shown here. My patch is covering the largest hole, but doesn't solve the problem.

The first time I saw this, I figured it was something to do with the rim. However, this slice (which is usually about 20cm long) appears in different locations relative to the valve on every new tube. So if it is something to do with the rim, it isn't anything that would be in a fixed location on the rim.

I also thought it could be due to installation error, so I made sure a few times I had professionals at the shop do the installing. Same thing; about two weeks later it would be flat with a slice like this through it.

Obviously, this has nothing to do with the tire itself, since no part of the tire is in contact with this part of the tube. Given the time it takes to form, it looks like something is gradually cutting into the tube and, after about two weeks, finally manages to wear through it. I've washed the rim thoroughly and run my fingers along it to check for slivers. Nothing. I thought maybe it was the rim strip, the edge of which contacts the tube. That's still my number 1 guess, but if that's it, why is this slice only along a ~20cm section of the tube (I've checked the rest, no slice) and always in a different place along the rim? Why wouldn't it either be in the same place or along the entire tube if it were the strip?

Anyway, this mystery has me stumped and has cost me a fortune in tubes and bus fare (what with a bike no longer being my commute option). To try to mitigate it, I've tried using self-sealing tubes, which obviously didn't work perfectly (lasted an extra few days though) because they are more suited for punctures on the outer side of the tube. My next thought is trying puncture-proof tubes. If I can't figure out how to stop these slices, I figure puncture-proof tubes would be thick enough to give me a few extra weeks per tube.

For the record, the bike is a Trek 3700 with 26X2 wheels and I usually pump the rear wheel up to about 45-50 psi.

TL;DR: What's causing these slices in my tubes? How can I prevent it?

I agree with your diagnosis: it must be related to the rim tape.

Take it off and inspect it and the rim below. If you don't find anything obvious, buy new, good quality rim tapes, check there are no sharp edges, and reinstall.


I find that I'm always in my highest gear. What options to I have to re-distribute the ratios to a more useful range I have three gears in the front and 8 in the back, but I always use the highest gear (I live in a flat place) I might drop down one or two gears occationally but this is only a small fraction of the time.

I want to buy new gears and re-center this distribution around something I find useful, I probably only need the top three ratios from my current setup, and I would like to have maybe 5 more ratios above that. Is this type of modification ever performed?

Sorry I don't know any of the relevant cycling vocabulary.
Also, what are power ratios measured in and how do I determine the ratio of my current highest gear?

Where should I buy these parts?
Can I make this modification for under $100?

To get higher gearing, you'll need either a chainring (front gear) with more teeth or a sprocket with fewer teeth. Mountain bikes usually have smaller chainrings because off-road speeds are generally slower. For example, a mountain bike with a triple crankset with 24, 34, and 42-teeth chainrings would be limited in its top speed by the largest (42-teeth) chainring. In constrast, the largest chainring on a road bike may have 50 or 53 teeth, giving 19% or 26% higher gearing respectively.

Unfortunately, upgrading probably won't be as cheap or easy as you hope. You can't just replace a single chainring, so you would need to get a whole new crankset (the crank arm plus chainrings) and also a new front derailleur. Depending on how much your bike is worth, it may be better to get a new bike.


Should I ask for my money back - crack in Titanium frame About 2 years ago I got my new bike - an Enigma Ti bike. The frame was customised for Di2 and I had hydraulic disk brakes fitted. An expensive bit of kit that was supposed to last forever and make my commutes a pleasure.
I love the bike, it's fantastic but yesterday I found this:

When the guy at the bike shop (not the one I bought it from) saw it he said I was very lucky it hadn't given way. I had been hearing very worrying noises when applying power. My 18 mile ride home through London was done VERY carefully.

So my question is should I accept a replacement frame or should I ask for my money back? This bike was about £5500 and I've done around 9,500 miles on it in 2 years.
What is to say that this won't happen again and I'll end up under a bus?

I am a heavy guy - hovering between about 16 and 18 stone over the last 2 years but surely a Ti frame should be able to cope with that?

If I do decide to get a replacement what should I reasonably expect the bike shop to do about me not having a bike in the meantime. It's likely to be several weeks if not months to get me a new bike. In that time I expect to have a bike to do 180 miles (290 km) commuting on a week and I have long rides like the Ride London 100.

I do have my old £500 bike but I'm probably going to have to spend a fair amount of money servicing it to get it usable again.

As you're in the UK, the Consumer Rights Act applies. It would seem that a £5,500 bike that lasts less than two years isn't of "satisfactory quality", but I would be surprised if the shop simply gave you a refund. I think you have to give them at least one attempt at repairing the frame (I don't know how feasible that is for titanium), and take it from there. If you can, I'd talk to the Citizens Advice Bureau and/or Trading Standards if the shop gets difficult. All this will be easier if you have proof of purchase, of course.

If I were you, I would want a refund, but would settle for a high-quality repair (and if it failed again in less than several years, I'd want the cash back).


Is it possible to replace this quick release part on a Motiv Rockpoint? My son has been using this bike, and the other day he came home with a bolt that had come off. I checked it out, and it looks like there's also another part missing—the other end of the quick wheel release. I assume it's the same as this one on the front.

Is there any way I can get a replacement? I think it's maybe just called a "quick release nut", but are they at all standard? It doesn't look like this bike is even sold anymore, so could I just buy a generic one (or even the whole quick release assembly if necessary)?

Quick releases are standard parts. You can replace the whole unit with a new one. Normally you buy them in pairs, front and rear together.

All you need to know is whether it is for a mountain bike or a road bike since the size of the rear one varies due to different rear axle lengths.

What is more worrying is the fact that the nut came off first place. This can only happen if the QR isn't properly fitted which is a potentially dangerous and even lethal situation. Check this video:


Fluid trainer works with quick release rear axles, I have a standard nut fixie I have no experience with bike trainers.

I bought a fluid bike trainer to use with my fixie.

The trainer is for a quick release rear wheel, and comes with a special quick release skewer.

My fixie has standard track nuts. Any ideas on how to solve this?

Assuming you have the Cycle Ops Fluid 2 trainer, which is what I have, you can use it with nutted wheels.  The skewer that comes with it is just for bikes with fancy quick release skewers that don't fit into the trainer or if you have nice skewers that you don't want to scratch up.
For nutted wheels, the retaining mechanism should fit fine over top of the nuts.
Update
Thanks for the picture.
That isn't the Cycle Ops Fluid Trainer, so it looks like my previous info isn't really applicable.  Some trainers aren't designed to work with nutted wheels.  Looks like it's not only a problem with the way it mounts, but that your hub is too narrow.  The mechanism looks like it's screwed all the way in, but it's still too loose.  How much axle/bolt do you have sticking out from the nut? It looks like the part that's supposed go around the nut/skewer isn't very deep, and is probably meeting up with the end of the axle.  You could probably cut it shorter to alleviate this problem, but that's probably not an optimal solution.
There's a couple different adapters that I was able to find for using nutted axles in trainers linked below. It's difficult to tell if either one would work with your specific trainer.
Forza Bolt Axle Adapter
TACX axle nuts
Even if you do manage to get it mounted properly, it might not work that well. I mounted my fixie on my trainer once, and there wasn't enough resistance. Fluid trainers generally don't have adjustable resistance (maybe yours does) and required that you change gears to adjust the resistance. I found that the gear on my fixie (46x15, which is higher than most) wasn't hard enough to give me a decent workout on my trainer.


Screw cap stuck in adjustable stem connection, how to remove or reattach? I was trying to detach my handlebar, because lowering was insufficient to make my bicycle fit in my box.  I detached the long screw going connecting two lids thereby fastening the stem-handlebar connection, but the lid of the left side is stuck:

Can I use some gentle violence here, or do I need to unstuck the lid in a different way?  I'm not sure if there is a thread inside the hole, and I'm not quite sure why the cap has ripples.  I don't want to destroy anything.

Note: I'm not sure if my terminology is correct overall

This is your stem.

As you can see, it is the whole unit from the bars to the top of the fork, including the adjustable bit in the middle. Most dan't have this and I think this is where the confusion is coming from.

To remove your bars for packing, it is usual to remove the 4 bolts on the face plate on the stem. That is the part immediately touching the bars.

After you've removed the bars, you'll want to tape or strap them to the frame somehow so they're not dangling and pulling on the cables. You shouldn't need to remove anything else.

Do not remove the bars by undoing the 1 bolt that adjusts the angle, as you have already, I can't find any diagrams of how it all works.

Do not remove the bars by undoing the 2 bolts that hold the stem onto the fork as this will remove the forks as well.


Does ideal cadence depend on a rider's weight/size at all? As in the question,  do heavier riders tend to have higher/lower cadence and should there be any difference?

Individual "ideal cadence" is probably more closely related to muscle composition and comfort than it is to size.  While someone could probably "maths out" an ideal cadence for a rider based on all the variables necessary (height, weight, power, muscle composition, etc), that won't matter one whit if the rider has spent the 2500 hours over the last 3 months practicing at a different cadence that they are now comfortable at.  Riding is largely a practiced unconscious act (spinning) that is developed over time.  Making major (or even minor) changes has the potential to ruin the whole unconscious part, making the act tedious and draining and overall less efficient for an individual.  Developing the unconscious act of riding with pedal drills or cadence drills is a difficult task that most recreational riders don't have the time or patience for.


How much is a mass production aluminium road bike frame worth? I was just curious, how much is a frame in a entry level road bicycle worth?

In total, what is the cost of a frame per unit in a bicycle built using i.e. a Shimano Sora groupset, white-labelled brakes rims, tubes and tires?

There is no specific way to calculate the worth of a frame when taken from a complete bicycle.  The market will tell you how much it wants to pay for such a frame, but the theoretical calculation of "The frame is worth the complete bike price minus the price of all other components'" is wrong.  Firstly it's wrong because it ignores assembly and value-add pricing.  Secondly it's wrong because it ignores the steep discount you get when buying a complete bike.

Imagine asking how much the chassis of a Ford Explorer is worth.  If you try to buy all the other parts separately, the total will be more than double what a complete vehicle would cost.  Bikes are a bit like that.


Need derailleur hanger I have what I believe is a 1994 Cannondale.  I need a derailleur hanger and I’m tired of thinking I’m ordering the right one and it’s not.  Can somebody please tell me how to find out what my bike is? I have the serial number and all that but I’m a bit confused on how to figure it out...

Here's a link to the to a website that discusses how to determine from the serial number what year your Cannondale was made.
http://vintagecannondale.com/info/serial_numbers/
Then you can  cross reference that year's catalog, determine the model you have and then be able to get a list of parts/part numbers. The relevant letters and numbers should be stamped on the underside of the bottom bracket shell. Between 1993 & 1999, a two letter code stamped in one corner of the underside of the BB shell represents the year and month of manufacture. The letter F happens to represent 1994. See website.
Once you've determined the year made, a Google search (example: "1994 Cannondale catalog")  will turn up hits that link to a PDF file of that years catalog. Utilizing color scheme and component clues, you then locate the correct model.  With this knowledge you can call up the correct part and part numbers. This may sound convoluted but in just a couple minutes, I had a catalog downloaded and was ready to find a match. Bear in mind that the bike may be manufactured in the year prior to it's model year (the first 2019 bikes were being produced as early as last summer). So one may have to look at, 4say, a 1995 catalog for the correct bike despite sporting a "born on" date of 1994.
Here's another helpful link on the subject:
https://derailleurhangerstore.co.uk/pages/how-to-identify-your-derailleur-hanger
Good luck!