How do I adjust the Marzocchi Dirt Jumper 3 (mtb fork)? The fork has no labels on the adjusters. I don't know what's what. I checked their website for manuals, and they always mention removable top caps. But as you can see in the photo that these are not removable. I've tried turning them both ways. They only turn, they don't move up/down.

Sorry to say, but those forks do not have much (if anything) you could adjust.

The dials your are seeing are usually associated with more 'base model' coil forks and you would use them to adjust the preload (SAG).

You would adjust the preload for forks to match the rider weight against the suggested preload value. XC preload is typically 15-20%. DH is more. Preload is the initial value by which the forks are depressed in a standing state. Think of it as the bit that extends when the wheel lifts off the ground (in short).

Anyway, regarding your forks. If those are indeed Marzocchi Dirt Jumper 3's, you would find this user manual much more useful.

If those dials are still working (they typically seize up or break off on the inside) you can expect them to tighten the coil when turned in the '+' direction. However, experience have tough me that the difference in feel is negligible and in most cases those knobs are actually just for looks. You often find them on budget friendly bikes and often the dials have popped off.


Is there anything special to pay attention to when preparing a bicycle for powdercoating? I am thinking of having an old bike powdercoated to spruce it up a bit.

What do I need to do to prepare the frame? Remove all components? What about stickers and decals? Some kind of chemical etching dip?

It is an aluminium MTB frame.

You'll definitely need to remove all components.  For threaded bits you have two choices - leave junk bolts in there that will get powdercoated over and then carefully remove them (leaving a bit of an edge around the bolt hole) or let them get masked but almost certainly somewhat powdercoated into and use a tap and die set to chase them before reassembly.  Be prepared to face/ream/chase the headtube and bottom bracket in any case.

Do make sure you've cleaned it as much as possible, removing any residual grease and road dirt.  I wouldn't worry about the stickers and decals, the media blasting to prepare the frame should take care of that.  With the relatively low cost of media blasting I wouldn't bother trying to strip the paint myself.

Make sure you find a powdercoater that is familiar with bicycle frames; particularly when it comes to media blasting they need to understand how thin the tubing is.


Which brake system is this I have two brake systems I think on my bike. On the front I have a threaded stud and on the back a road brake.
Here is the front and the back (click for large version):

As you can see on the back the highlighted part is way smaller:

So am I right to say that on the front I have a threaded stud and on the back a road brake?

So am I right to say that on the front I have a threaded stud and on the back a road brake?

No
As Andrew says, you have v-brakes on the front and the rear.
Here's a picture from the front

V-brake pads come with a threaded stud and washers to allow you to adjust the angle of the pad and the distance from the arm to the pad.
The "ball and socket" design allows the angle of the pad to be adjusted.
The different thickness of the silver washers allows for two different possible distances between the brake arm and the pad.


Starter Road Bike for Tall Man I'm a marathoner that is interested in mixing in some duathlons and triathlons, but I am having trouble finding a starter bike (< $1500) made for a tall man. I am 6'6". Any brands and models that you can recommend that offer a frame that fits someone around my height?

At 6'6" you're probably going to be looking at the top end of most manufacturers size ranges, road frames of 62cm and above are the range you'll be looking at.

I said "probably" though, you would do best getting yourself to a local shop that knows something about fitting people to frames. Being so far from the average height I'd not risk buying something offline without having tried sitting on anything, particularly as it's your first road bike.


A vintage bike collection Do you know a collection of vintage road-bike, with pictures of their old school style and actual argus price.

I just bought a Mercier and I wonder, how much it can cost nowdays...

Try Old Roads. I don't know how accurate this information is though.

As 'user973810' suggested, try Sheldon Brown's Vintage bike pricing guide  as another reference.  Again, you may question the accuracy of the data.

 Vintage Trek has some original price lists and a lot of information on old trek bikes.  If you happened to be looking for information on treks, then check there as a guide for info about the bike.

If you had a schwinn, I'd recommend checking (maybe even emailing) Bicycle Heaven, a shop and museum, they have a massive collection of vintage schwinn and other bikes. Here's another good guide on finding prices for old schwinn bikes at Schwinn Cruisers. Their site has a lot of info about old schwinn models.

Check recent ebay auctions and see if there are any completed listings for that bike. Try using "completed items only" checkbox. It may still be hard to find results for some bikes. You may be able to compare prices versus their inventory.

Use something like  searchtempest  to search multiple craigslist sites to see if there were any postings for that style bike anywhere. These can vary somewhat wildly from actual value, both above and below, depending on the seller.


New wheelset, spokes losing tension I recently got a new wheelset Reynolds Solitude from a friend. He bought a new bike and it came with these wheels so he sold them as take-offs. They have internal spokes.
I have one problem with them not sure if it is related to the wheel set being new.

Spokes on my rear wheel, non drive side (laced radially) keep losing tension after ride. First time I had 7 spokes loose after 45 miles ride, I didn't feel any problem with the wheel as I was able to ride home. Took it to LBS they have trued the wheel and after that I got them loose again.

I can not afford to go to LBS any time I have problem with my wheels so I am taking different approach. I would like to learn how to do it on my own so I bought ParkTool TM-1 for that purpose and a truing stand.

Now I have a question : What is the process for fixing this particular problem, retensioning the radial side and truing the wheel? If anybody can point out things that I should do/don't do in order not to destroy the wheel?

If you are looking to learn about wheel building, google search Sheldon Brown. He has a website that is phenomenal. I highly recommend it. I learned everything I know about wheel building from a couple hours of youtube videos, the park tool bike mechanics book, and his website.

As for your specific question, I think overall the spoke tension throughout the wheel sounds like it is not enough and after tightening and truing whichever side it is that you are having trouble with I would do a quarter turn on each spoke in the wheel and ride. If it loosens up do another quarter turn on each spoke. With a properly laced and trued wheel with spokes at the proper tension you should never have issues with the spokes loosening.


Do hardened chains cause more chainring and cassette wear? I was reading the Sept 2016 issue of Bicycling where they were reviewing the SRAM NX series. The blurb for the SRAM chain (below) states that "The PC-1110 chain SRAM recommends for NX ... has performed its duties as well as SRAM's higher -end stuff. And because it hasn't had premium hardening treatments, it actually  may be gentler on your cassette and ring than a more expensive chain."

Any truth to this or is this just advertising-speak that snuck its way into the review? This is Bicycling magazine, after all.

Do hardened chains cause more wear?

There are two sides to this question, for the two places chains contact chainrings and cogs with force: the outer plates and the rollers.

There is probably a grain of truth to the statement in question regarding the hardness of outer plates. Sometimes you do see chainring ramping get worn to the point of not performing as well as a result of the rider, usually a racer, habitually shifting under load. Every once in a while you see it somewhat in advance of the teeth being worn. I don't see why this effect wouldn't be exacerbated the harder the outer links are. (That being said, I'm not sure which if any chains, expensive or not, have outer links that are any harder than other ones, since you don't really gain anything by it, and I'll bet the writer has no data on this either.)

For all the other parts of a chain - pin, roller, and inner link (or the bushing in the case of a traditional 5-piece chain) - you want it as hard as you can get it as long as the other mechanical properties (ductility being the big design counterbalance to hardness here I think) are what they need to be. That's how you get a chain that resists elongation the best and in turn keeps cogs and rings going longer, which is what most cyclists are interested in.

So basically the statement is misleading.


Please help me identify this bicycle (Peugot) I recently finished a renovation project on a classic Peugeot road/touring bike and was wondering what the model and production year of this bicycle is.

I tried but could not find anything myself. Perhaps one of you more knowledgable in classic bikes could help me identify the model/production year. I've attached a number of photos.

Some additonal info:

Simplex derailleurs
Frame number: y71210232
Atom hubs
Rigida rims

Here is a link to the rest of the images:
https://drive.google.com/drive/folders/1vWegk_w2W92iAWccGJoYzEkW7v3aPSQz?usp=sharing

Thank you very much!

It looks a lot like this 1976 UE-8, except for the front rack.


Replace V-Brakes with Caliper Brakes on a Flat Bar Road bike I own an Fuji Absolute 1.4, a flat-bar road bike, 2013 model with 700x28c Tires and a carbon fork. The bike is really smooth but I am not happy with the braking power. I want to replace the existing V-Brakes with Caliper Brakes. I have searched all over the net, and found few relevant answers but they were not satisfactory. Now I have few questions in mind.
1. My Bike front Fork is Carbon and it has a hole probably for a fender mount or Calipers. Is it possible to mount Calipers on it. If so what type of Calipers do i need to get (Short or Long Reach Ones).
2. I don't want to use Cantilever brakes as i am not a fan of them.
3. If I have mounted calipers successfully, do I need to change the brake levers to pull the brakes as i know caliper brakes require short pull with increased tension.
I want to convert as i want to change the bike into a touring one in future with good amount of braking power.
Thank you

Generally, V brakes have much better stopping power than calipers. And I'm guessing that your frame will require calipers with a pretty long reach, which makes it even worse. Forget about caliper brakes - concentrate on making your existing brakes work better.

First thing you should do is to check if anything's malfunctioning: are the cables sliding freely? Are any of the moving parts binding? Are the pads contacting the rim squarely? Next step is to upgrade the brake pads.

If you do switch, then yes, you'll need new levers. Caliper and cantilever brakes: short pull, V brakes: long pull.


Where can I find my serial number I recently bought a bike online and I wanted to make sure it was the bike I paid for. I looked for the serial number on the bottom of the bike and couldn't find it. Where else would they put the serial number on a 24 inch Haro?

This image from the City of Portland police shows the common places for bicycle serial numbers. Note that they are usually stamped and aren't very visible.

Note that one area not shown on this image is the head-tube. That's where my latest bike had it. Otherwise, my bikes all have it in location #4 (bottom of the bottom bracket) or behind the seat post.

Note this posting from Bike Forum which shows the Haro serial number stamped on the bottom bracket.

http://www.bikeforums.net/bmx/1089833-haro-identification-serial-number.html

There is also a registry of Haro bmx serial numbers, which might also help in identifying your bicycle:

http://bmxmuseum.com/forums/viewtopic.php?id=206889

This latter registry is particularly useful because it has user-submitted photographs of serial numbers. While the majority are on the bottom bracket, some are stamped very faintly into the rear dropouts.


Threaded post V brake pads Looking to replace my Shimano brake pads. What is the difference between M65/T3 and M70/T3 threaded V brake pads?

As you have mentioned yourself, the M70T3 uses a threaded post, while the M65T3 uses a knurled post that requires a screw on the V-brake or, more commonly, on a cantilever brake. In fact, the M65T3 is sold as a cantilever brake, and it is shorter and chubbier than the M70T3. If you have a V brake, you shold buy the M70T3.


Road positioning when stopping at an intersection with stationary traffic When the light is red and there are cars in a line. Since bicycles ride on the very right do we go ahead to the stop light or stay behind the cars? I live in British Columbia, Canada.

I'm from BC, you have the option of taking the centre of the lane and waiting like a vehicle, or you can stay to the right if there is room (at least 1.5m or 5ft). If you stay to the right, basically you ride in an imaginary bike lane if there isn't one painted on the road, so you ride all the way up to the light on the right hand side of a line of cars at a red light. I do this pretty much every single day on my way home from work. Some intersections even have a button for cyclists to push, like the kind pedestrians push when they want to cross, but for cyclists waiting at the intersection.

When you stop however, do not stop beside the car at the front to the line, you never want to be in a vehicles blind spot. Pull up just ahead of it and make eye contact with the driver so he knows you're there. If the first car in line is signalling to turn right, then stop just behind them and wait for them to turn in front of you before proceeding to the front of the line.

Motorists are supposed to shoulder check when turning right at intersections to check for cyclists, but it's my experience that most motorists don't even know that bikes are allowed to ride on the road, so always drive defensively.

Rights and Duties of Cycle Operators - Section 183 Motor Vehicle Act
Passing on the Right - Section 158 Motor Vehicle Act
The British Columbia Bicycle Operator's Manual


Is there anything similar to motorbike roadbook holders for bicycles? Does anybody know if there may be in commerce anything similar to the roadbook holders they use on offroad motorbikes, but for use on bicycles?

I know there are some electronic versions in commerce that include a GPS system, but I was looking for a cheaper solution (possibly smaller than the one below).

Here's a sample:

An installed roadbook:

Personally I just use the map case on a handlebar bag (needs to be oriented properly to work), but here's a clever DIY solution by Raymond Parker:

Basically it's a piece of wire bent to prop the cue sheet at the right angle.  Put your sheet in a waterproof case or ziplock and a couple of binder clips hold it in place.  A shock cord keeps the whole assembly in place.  Full instructions here:  http://veloweb.ca/garagepages/sheetholder.html


Replace a double ultegra crankset for a triple ultegra crankset. Is that possible? I would like to exchange a triple Ultegra crankset on one road bicycle to another bicycle with a double Ultegra crankset.

Is that possible?

Most people go the other way. Many new bikes now only come with double chain rings. And compact crank sets give almost the same gear range as triples.

But it should be possible. The distance the front derailleur travels is about the same. You may need to adjust your limit screws though. And of course you need to change the front shifter to a 3 speed version.


What are the advantages of having a road bicycle frame with lower tyre clearance? Say, I won't ever put tyres above 28mm and the frame allows upto 30mm vs a frame that has an allowance of upto 35mm.
So, what are the advantages with a frame with lower tyre clearance or the advantages with higher tyre clearance (apart from tyre size)?
Also, what difference will either of them cause while riding?
I am getting myself a custom built road bike frame - with geometry close to Merida Scultura 8000-E Disc, with slight tweaks according to my body dimensions.

It could allow for slightly better aerodynamics and a slightly lighter frame. It allows for a shorter wheel base and you don’t have to worry about toe strikes (toe overlap) too much. It also looks better.
I can’t think of any other advantages. It’s obviously possible to build frames with huge tire clearance without running into great trouble, so it stands to reason that there are very few disadvantages in ample tire clearance.
With very wide tire clearance you run into problems regarding chain line and the front derailleur (hence why most fat bikes don’t have a front derailleur or need some very awkward solutions).


Sticking points in the pedal stroke During a stroke, I encounter one or two (not always in the same pedal position) where the resistance is high. If I spin the crank freely (on the bike, wheel off ground), it will quickly come to a stop at one of these points. So, part of the stroke is fine. At these points, spinning the cranks backwards, the chain seem to collapse at the top. I feel like maybe the back cassette isn't spinning as free as it should.
Does anyone have any idea of what this could be?
I feel I take good care of my bike. Cleaning it from dirt about once per week and degreasing/greasing the chain typically twice per month.
I'm fairly new to bike repairs so any help and pointers are appreciated.  Note:  The bike is fairly new; only about a month old. I've ridden about 2500 km.

Either the rear wheel or the crank bearings are binding at some point in their revolution, or (or possibly there's something going on with the chain). The first thing to do is track down where the problem is.
Check first for obvious stuff, like is the rear wheel out of true and rubbing the brake blocks?
The next easiest thing to do first is take the rear wheel out, remove the quick release skewer and check the bearings. Turn the axle with you fingers, does the axle have a tight spot, do you feel excessive resistance or 'notchiness'? Push and pull the axle about to check for play, if you can feel the axle moving more than a tiny bit there is excessive play.
If the wheel bearings are is OK, check the crank. Most front derailleur cages have a small screw that allow them to be opened and the chain removed. Get the chain out of the cage and off the chainrings (it's awkward but possible). Spin the cranks by hand, again checking for a tight spot, excessive resistance, 'notchiness' and play.
The wheel is the problem fixing it depends on the type of bearings. Some hubs have 'serviceable' bearings that can be disassembled, some have pressed in cartridge bearings. If the crank is the issue, a new bottom bracket is required.


Wobbling Topeak QuickTrack rack bag I have a Topeak Super Tourist DX rack and an MTX TrunkBag DX bag, which fit together using Topeak's QuickTrack system - a dovetailed plastic foot on the bag slides into a metal channel on the rack.

Both are several years old. Recently, the combination has developed a wobble, where the bag seems to be able to move from side to side in the rack. The bag doesn't fall off, but the noise is annoying!

What causes this? Is the plastic foot worn, or is the metal channel bent?

Is there a cure for it, apart from replacing one or both parts?

As an interim answer, it sounds like the plastic track has been wallered out and now has play between it and the metal track.

  Topeak UNI Super Tourist DX Disc Carrier stock photo showing rail in the middle

Topeak MTX Trunk Dry Bag stock photo showing underside.

First guess is that the grey plastic foot has worn through insertion/removal over time.  I doubt the metal has worn, but it may have unfolded a little.

You need to look at your bike and see which is the cause.

Your options are:

Check that the foot is not wobbling on the bag - as ChrisH points out they're only rivetted together, so it may be sloppy there.  Drill out the old rivets and install some small bolts with washers, and nyloc nuts to stop them coming apart.
Pack the gap between plastic and metal using a strip of additional plastic.  I hear sugru is the bee's knees for this kind of repair but it probably wears even faster than the original.  Or you could use a long thin piece of brass or aluminium, which would wear faster than the steel, but may need one on each side.  This might be called a "Gib" in the machining world.
If the metal runners are bent outward, you may be able to bent them back in with pliers or a vise or a big clamp.  Risk is snapping the steel, or potentially weakening it.  I doubt this part is available as a service item.
Replace the plastic foot completely.  I do not see this as a service item to purchase, which is somewhat surprising.   You might try to 3D Print a replacement, after taking careful measurements of your existing one and of the rack track.  Or if you lean more to woodworking, a hardwood rail with the right dimensions could bolt on in place of the worn plastic one.  You could mill the new foot out of aluminium too, depending on what access you have to tools.


Gearing preferences of men vs. women on road bikes Is there evidence that men and women prefer the same or different gearing when riding a road bike? In other words, in the same conditions, would both men and women generally ride in the same gear or does one group statistically prefer to ride in a higher or lower gear?

I understand that the question is quite academic as everyone is free to pick their preferred gear.

Really this question is far too broad, but I'll mention some things that dictate gearing, ultimately, non have anything to do with sex or gender.

Strength - Stronger people can push heavier gears
Cadence preference - someone who prefers a higher cadence might choose gearing for quicker pedaling
Terrain - Hillier = easier gearing, flatter = bigger front and smaller back
Type of road cycling - TT will use harder gearing, endurance racing lower
Compete vs training - Some people have different bikes for training and competing

There's other factors too, and as most sports, there is a difference between top male and top female competitors and I'm sure it will be something like top males might have larger front rings than top females. Although the difference within the male and female groups might be of more interest than just the difference between avg male and female.


Jamis Commuter 4 conversion to derailleur geared I'm trying to convert my Jamis Commuter bike with an IGH to a 10 speed derailleur setup.

I've got a bit stuck on the project with the rear derailleur.  Here's what I want to verify.  Looking at the attached picture, there's definitely a hole for a derailleur hanger right?

From my research thus far I just need to find a compatible derailleur hanger.  I assume my best bet (since this model never had a hanger) is to look for other Jamis compatible hangers and see if I can find a match.

I don't see any holes designed for a derailleur hanger. You should be able to use this type though. It clamps into the horizontal dropout. I've heard them called claw hangers. Don't know if there's a better name for them.


How to tell if this light's bulb is blown? And what kind of light is it? See photo. Is this a normal LED? I'm trying to troubleshoot it and can't tell if the bulb\diode is fine.

It's an LED.

Easiest way to see if it is damaged is to connect it to a battery and see if it lights up.

The difficulty is that you can't disassemble the the white plastic unit, so if the LED does not light, the connection  wires, resistor or LED itself may be damaged.

If you have a voltmeter you could measure the resistance across the terminals. It should be infinite one way, tens of ohms the other. If it's infinite both ways or zero either way it's trash.

Good news is that decent quality rechargeable LED lights are now inexpensive and ubiquitous.


Tyre Has Randomly Deflated Day off work so I didn't use my bike today, left it in my garage with nothing there to cause any damage.  However later today I walked into my garage to collect some supplies and a loud bang followed by a hissing sound (air going out) came from inside. When I checked my back tyre had lost all air in it. Does anyone know why this may have occurred?

Likely something under tension failed which compromised support of the tube leading to the explosion.

Three main culprits come to mind:

Rim Tape - Rim tape can fail as it gets old. Usually what happens is that it can no longer keep the tube out of the spoke nipple wells.  When this happens the tube will expand into the spoke nipple wells where there are all sorts of sharp bits that can lead to a puncture. Look for a slit in the rim tape over one of the spoke nipple well holes.  The tube will have a puncture on the side facing the rim.
Compromised Tire Structure - Your tire carcass may have become partially compromised (e.g., damaged side wall) and over time this slowly broke until the tube exited the compromised area and ruptured. The tube will typically have a large slit.
Temperature related blowout - Is our garage hot?  If so this will increase the pressure in the tire.  If you were already at the upper end of allowable pressures (or the tire/rim combination is not good) then this could lead to and over-pressure blowout where the tube escapes at the tire/rim interface. The tube will typically have a large slit on the side (as it would have escaped at the tire/rim interface.

Inspecting the tube will give a lot of forensic information. Make sure you note the orientation of the wheel and tube as you disassemble this will make it easy to trace back to the source of the puncture.  A puncture on the inner diameter of the tube (i.e., the side that faces the rim) will point towards (1).  Large slits in the tube are suggestive of (2) or (3).  If you inspect the tire and find no damage then this is suggestive of (3).


Minimal gear for dry winter riding in the city New bike owner here. I ride everyday in the city for errands and eating out as long as it doesn't rain (I don't like riding in rain). As winter is approaching, I'd like to find a bag of some sort that would pack the following as I stroll the streets, or linger in coffee shops, in between commutes:

Helmet (clip from outside?)
Wind/Winter jacket (if it gets hotter and less windy, I can put it in the bag and ride)
iPad
Keys, Wallet, misc items

I don't intend to carry anymore things. A backpack could work (provided it doesn't make me sweaty), but is there one where the helmet can be securely clipped on?

Essentially, I want a single bag to carry all essential accessories, so I can just put 'em all in, and carry it with me between the rides, while freeing the hands from carrying anything else.

What are my options?

Update: I live in Victoria, BC, Canada - nearly always above zero degrees. Lots of sunshine. Windy. I don't intend to ride in even mild rain.

Update 2: I carry an U-lock that is attached to the frame, and I just realized that I can lock the helmet to the lock (helmets are unlikely to be stolen I guess), so I don't need to carry the helmet with me. That increases my options.

For such light weight I suggest a handlebar bag:

Advantages:

They don't get dirty from spray from the wheels unlike panniers (which transfer dirt to your clothes)
Your phone is handy if you want to check e.g. a map (I mean stop but don't get off).
They've typically got a shoulder strap and quick release mounting so they're easy to take indoors.
They've got slightly more capacity than you say you need -- you'll soon use it.
Unlike a backpack they won't make you sweaty
You can always add a backpack for shopping

Disadvantages:

They're quite small
Cheaper ones soon start to let water in (true of any bag though)
(This is the big one for me) they get in the way of handlebar mounted lights.  This may or may not be an issue for you, but don't ignore it.

Even a wedge bag would hold all your stuff except the helmet.

Whatever you go for either clip the helmet on the outside or get a mesh helmet bag - helmets can do with some fresh air and a bag that will hold a helmet is quite bulky.

I've got an Altura dryline -- not the cheapest option but it has a mapcase to go over the top and can keep a netbook and change of clothes dry.  It would take a helmet for a small head, but not mine. I recently switched back to using it because of a baby seat.

There are much cheaper options (example) out there as well, and most come with a shoulder strap.


Chain line adjustment when replacing triple crankset with single I have an old Univega MTB with a triple 28-38-48 crankset and 6-speed freewheel. The bottom bracket is square taper with cup and bearings. I want to remove the front derailleur and convert to 48T crank, keep the freewheel and rear derailler. The final setup will be 1x6. What adjustments do I have to make to the chain line (priority item) and the bottom bracket, if any. The fixed crankset will be 48T so I expect that chain line adjustment should be minimal, if any, on a bike with a rear derailleur.

Assuming the chainline is spot on as it is now, you could remove the inner and middle chainrings, and place your 48t outer ring in the middle ring position. This will most likely require new chainring bolts intended for single ring use (they are shorter).
This will only work if the middle and outer ring share the same bolt circle diameter - BCD (most triple cranks work like that, but I've come across a few where the inner and middle rings both had a smaller BCD than the outer ring.)

If above solution doesnt provide the chainline you want, you could replace the bottom bracket. Shimano makes a cheap and (in my experience) reliable bottom bracket for square taper interface: The BB-UN26. It comes in various spindle lengths and for both 68mm and 73mm shells.


What is the cable pull of Tiagra 4700 10 speed? What is the actuation ratio? It is well documented that Tiagra 4700 is not compatible with other 10 speed parts, and uses a different set of ratios. But what are those ratios?

What is the cable pull of a Tiagra 4700 10 speed shifter (ST-4700-R)?
What is the actuation ratio of a Tiagra 4700 rear derailleur (RD-4700)?

The 4700 cassettes do appear to be compatible with other 10 speed components.

Shimano provide a compatibility chart, but that is only useful within the Shimano product line.

Here is my attempt.

Cable pull * Derailleur shift ratio = Cog pitch

(Supposedly) 4700 uses 11-speed cable pull, which is 2.7
The cog pitch for Shimano 10 speed cassettes is 3.95
So 2.7 * Derailleur shift ratio = 3.95
And we get 1.46296

According to this YouTube video, you can combine:

Shimano Tiagra 4700 shifters
Shimano GRX 812 11 speed rear derailleur
11-34t 10 speed cassette

This implies that a Tiagra 4700 rear derailleur has the same actuation ratio as Shimano 11 speed road rear derailleurs, as suggested by Argenti Apparatus. This is a ratio of 1.4. 3

Plugging these numbers into the equation we get:

Cable pull * Derailleur shift ratio = Cog pitch
Cable pull * 1.4 = 3.95
Cable pull = 3.95 / 1.4
Cable pull ≈ 2.82

So, to answer the question:

Tiagra 4700 10 speed shifters have a cable pull of 2.82
Tiagra 4700 rear derailleurs have an actuation ratio of 1.4


Can a hub casing be warped/bent? For a couple weeks now, my commuter bike has been creaking ominously while I pedal, and just the other day, the rear wheel began to wobble up to a full centimeter to either side (rubbing the frame) during a longer ride.  At first, I assumed that the cone assembly in the wheel wasn't tightened well enough on this new bike, and it had taken a couple hundred miles to come loose.

So I sat down and adjusted the cone and nut assembly and perfected the spin: the axle isn't bent, the internal bearings are fine, plenty of grease, no scoring.  So I put it back on my bike and was astounded to find it still wobbled like crazy!

I've just spent the better part of two hours messing with the hub, and was on the verge of giving up when I noticed that the outer shell of the hub seems to be warped as if someone had twisted the two ends towards each other.  The wheel's wobble lines up with this warping perfectly, and the axle pokes out of the drive-side of the hub slightly off-center.

I can accept that the manufacturer might have installed a hub that wasn't parallel (it's a cheap commuter bike) but how would it have taken so long to show up?  Should I just replace the wheel?

Addition: A pertinent picture and some information.  You can clearly see the bulging on the axle, along with the skewed cassette.

Hub shells with pressed flanges, as opposed to being one solid piece, can do things like this. In such a case the press fit wasn't tight/solid enough to resist all the considerable forces on the shell, and it gradually came loose.

The bearing cups that most hubs have pressed into them can also come loose and cause a similar set of issues to what you describe.

Both are rare problems, although it's probably true that most or many pressed flange hubs can self-destruct like this if ridden hard or long enough.

If it's not one of the above, then I have no idea, other than maybe something went wrong with the machining and it didn't have proper wall thickness or something. But this would be a very weird failure from a one-piece hub shell.

Getting a new wheel is the only reasonable fix.


Are carbon fiber rims susceptible to fatigue? While reading this question's take on the wearing out of aluminum rims used on bikes with disc brake systems, the inquiry was projected further to include carbon fiber, disc brake rims.  Do carbon fiber disc brake rims ever wear out through fatigue?

Also, do the nipples have any additional support (from material other than carbon fiber) at the rim to deal with the concentrated forces there?

The answer seems to be that material engineers don't have a good understanding of carbon fiber composite fatigue I'm guessing because there is a wide spectrum of CFC layups using different epoxy formulations, fiber weaves and fiber/epoxy ratios. The article quoted below also says there are many failure modes for CFC whereas metal has just one: cracking.

From https://www.quora.com/How-does-carbon-fiber-CFRP-behave-in-fatigue

  technically they are pretty good, better than most metals. However their fatigue
  resistant properties are not used by the Aerospace industry. The issue is that
  composite fatigue is extremely hard to predict, with results having a very wide
  scatter. Basically we know they are really good, but cannot confidently quantify how
  good.


Buy or rent a bike in Europe for 2 week backpacking trip My wife, daughter and I will be traveling to Germany, Switzerland, Amsterdam and a few other areas in late July of 2018.  We will be traveling with what we can carry on our backs. I'm looking for suggestions on whether it is better to buy or rent some bikes that we can use and travel on the trains with while we are there.  I'm not against buying to have a better quality bike if necessary.  We are avid bikers currently so definitely want some decent quality bikes.

Traveling with bikes on international trains, specially in combination with quite a bit of luggage, is not easy.

In most cities you can rent reasonably bikes and going that way will make travel arrangements easier but you can not be sure of getting decent quality bikes that fit you.

For a two week three or more locations trip, I think buying or renting long distance bikes is not going to be worth the effort.
You better decide whether you want a bike holiday, in which you cycle from one place to an other, maybe across country borders or a multiple location holiday for which you use trains to get where you want to go and rent bikes for one or more days in one or more locations.

If you know you want to buy bikes which are available in one of your chosen locations, you might order them to be there when you arrive.
And take them home with you at the end of your travel.
But plan on taking the slower regional trains, with changing trains more often as the fast and long distance trains do not have many or even no bike transport options.
Late July is summer school holiday in big parts of Europe and all long distance trains are likely to be full, needing booking ahead and also the longer runs of the regional trains are likely full and the limited bike space very popular.


What is a Q-LOC axle? Is it compatible with Quick Release? So what is a Q-LOC axle? If I decide to install a fork with such an axle, do I need another front wheel or is is it possible that my current QR hub is compatible. What do a Q-LOC wheel look like and how much do they cost?

It appers that Q-LOC is the name SR SunTour gives to  through-hole axes, such as this one. In this question, the advantages are explained. They are not compatible with traditional QR, because of the difference in the diameter.


Is it normal that the Abus Bordo folding lock rattles? I have the latest Abus Bordo Granite X-Plus 6500 folding lock:

It is cased inside a rubberized pouch that attaches to one of the bottle-cage locations:

Very convenient, but sadly, it rattles while riding on an uneven surface, which can get quite annoying, and does not make for a smooth ride.

Firstly, is that normal, or is something wrong? (Has one of the bolts come looser than it should be?)

Secondly, how do I prevent this from happening?

This is a late answer I know, but I've found a solution to the rattling problem. I've had an Abus 6500 for nearly 3 years now and the rattling always annoyed me. I used to wrap a kind of nylon strap between the lock as I folded it and that partly solved it, although most of the rattle was coming from the joints themselves. It was only just today when I thought of this: I sprayed some chain oil, the type that comes in a spray can, into the joints, between the bars. As you may know, this oil is very liquid when sprayed but soon solidifies as the solvent evaporates. This allows it to get right into the joint and GREATLY reduce rattle. There is inevitably some that runs onto the parts you need to touch so a bit of cleaning up afterwards is necessary but the result for me is just astounding. I just wish I'd thought of it 3 years ago!


Opening a Shimano Alfine 8 hub (large dust cover) I’m dismantling my Shimano Alfine 8 hub to service the internals. I’m at the stage in the photograph but can’t turn the large black plastic dust cover, with <-tighten loosen-> on it.
The hub has been sat idle for a couple of years but is only three years old and from instructions I was expecting the dust cover to be removed by hand. Attempting to tap it round with a screwdriver only put the notch in the soft plastic visible at the six o’clock spot. (Won’t be repeating that).
If it won’t turn by hand, how can I remove this dust cover? Have I missed anything?
I see there’s a tool, the TL AF10 but it seems expensive for a one trick pony. Is there another way? With any more common tool, to try while I wait for the right one in the post of course.

For the same cost as having the correct tool delivered, I bought a selection of cheap tools to trial:

L-R: Strap wrenches, oil filter plier, oil filter loop wrench and waterpump pliers 12”. These are tools readers are more likely to already have in the home or garage, or available to borrow from a friend or neighbour. These ones came from a glamourised “dollar store” type of shop for cheapness but also available at DIY shops or automotive shops.

Firstly, the strap wrench and the waterpump plier are no good. The strap wrench slips off as the surface is too narrow, meanwhile even the large 12” pliers are not suited to the size of the dust cover and don’t grip sufficiently.

Both of the oil filter tools are about the right size to do the job and worth a try. The plier version works best.

The ring tool needs a little care to get a good grip and must be turned over the right way to tighten or loosen.

Like this to loosen clockwise:

For completeness, this is the orientation for tightening (spot the difference), if deemed necessary to use a tool at all:

Finally, the recommended tool is the oil filter pliers, seen here.  They grip really well but you have fine control over the grip (cover is only plastic) and good leverage:

As I said, these are tools you might already have or can access easily for occasional jobs (proper tool is available from Shimano). Gentle force should be needed, maybe even by hand. In my case the cover was seized tightly and needed some extra help, now I have a couple of tools to do it and may find other uses for them, especially the pliers.


Swapping chainrings on old ultegra crank I have a 2002 Ultegra 9-speed triple with 52/39/30(?) chainrings. I swapped out the inner two chainrings twice and kept the original crank and 52-tooth ring. The 52t ring only gets used going downhill and weighing in at 134#, I don't put much pressure on it.

Are there ultegra quality replacements available, or do I need to update the crank+rings?

Your model number for the crank is most likely fc-6700 (EDIT: FC-6500). Double check on the inside of the end of the crankarm for this ID. If this is the correct number, just search 'fc-6700 chainring' in your favorite search engine and plenty of product results will show up.


What causes tire sealant to seal? I've heard from others that air is what causes sealant to seal. People have said they've read that "somewhere" but I never seem to be able to find those articles.

The reason I think air can't be the sole factor is that there is air inside the tires—in mountain bike tires there is a lot of it. Why wouldn't it just coagulate there? And if you say, well, over time it dries out, that's true—but a puncture doesn't take months to seal.

On top of that, I've accidentally left a bottle of orange sealant with the cap off literally for months, and there was only the barest trace of "rubbery" sealant on the threads of the cap neck.

I imagine this must have something to do with either

the cold produced by the expanding gas coming out of a puncture, or
the low pressure caused by the expanding gas moving rapidly (see
Bernoulli's Principle)
some other unexplained factor.

The reason I want to know is because if I knew the principle behind sealant sealing I might be able to figure out a way to prevent undetectable slow leaks, which I've been getting off and on since I switched to tubeless on my road bike.

Here's a photo of sealant failing inside a tyre.  These are the latex molecules lumping up together rather than staying in suspension in the carrier liquid which is glycol-based but varies by brand.

These have the glorious name of "boogers" and are a sign the sealant is not going to work very well.  This tyre should be cleaned out completely and a new serve of sealant added.

This is what should happen at the hole when a tyre punctures.

The carrier is either a water-based glycol/propylene with cellulose and thickener agents like aramid/ceramic fibres, or non-water based latex mix which doesn't need extra thickeners but does have a limited effective life.  Latex also has some level of Ammonia which can contribute to corrosion.
Either product will distribute around the inside of the tyre while you ride.  This leaves a thin layer waiting just inside the area where the puncture forms.

The lighter-weight carrier fluids exit the hole along with the escaping air.  This leaves a visible wet spot on the outside.

As the carrier flows through the hole with the air, the heavier/larger suspended particles get stuck and form a blockage, which slows the air leakage and eventually seals.   In theory, the plug will flex and more air will leak, but the sealant will do the same, continuously packing into the weak spots and stopping the leak.

This only works if the sealant is liquid.  The carrier is volatile and will bleed out through your tyre over time anyway, leaving a dried mess in the tyre.  If your bike is not ridden much, the sealant will pool at the bottom and that's not a lot of use plus it will unbalance the tyre.

Many sealants can be re-energised by adding more fresh product, but mixing brands is an unknown because the chemistry will vary between brands.  Best to dismount the tyre and do a complete clean before changing brands.  Some riders recommend changing tyres every 12 months regardless of wear.


Need to identify this Frame Please Need help identifying this frame, year and original spec please. It's a Giant TCR carbon frame. Frame number is GH1B037. Stickers in down tube Giant 3 but that's all I can get at the moment. Any help gratefully received. Want to return it to original spec

Bike paint schemes are usually different for each component level and often change from year-year. I did a Google image search for 'Giant TCR Carbon' and looked through the results until I saw the exact match for the paint scheme on your bike.

It seems to be 2012 Giant TCR Advanced 3 as sold in the UK.

https://www.giant-bicycles.com/gb/tcr-advanced-3-2012

http://road.cc/content/review/58922-giant-tcr-advanced-3-2012

You will probably have trouble returning it to the exact component spec it was originally configured with as Giant used many in-house brand components (wheels, bars, post, stem in this instance; although you have the latter two) and the 2012 Shimano groupsets will not available, you will be able to outfit it with comparable level components of course.


Is there any way to save disk brake pads once they've gotten even a little bit of mineral oil on them? I did a frame swap recently and my front brakes are now screeching loud and not as powerful as they were on the other frame. This leads me to believe that I must have gotten some mineral oil or other contaminant on them during the frame swap process.

The problem is that the pads are expensive and they still have a lot of life left on them. But just wondering if it's a lost cause this point to try to clean or salvage them

The best approach I've seen in terms of producing non-mediocore results is heat them up with a heat gun until you can see the oil smoking up and maintain that heat until the smoke stops. You want to heat it through and minimize peak temperature, so let that inform your setting and distance.

This can work pretty well but I make no promises what the metallurgical side effects may be. It's an at your own risk thing only. That said it's a pretty common trick and I doubt there's much risk. And of course do this with good ventilation and with the pads in a vise, hanging on a cable, or some other way where they won't need to be handled until cool.

Things like sanding, degreasing etc really don't work because the whole problem is the material has some porosity.


Most effective > 200 mile ride training On the 17th of August I'm doing a 250 mile ride in the UK in one day. I'm no stranger to longer rides often completing 100 mile rides and my longest ever was 175 miles (it was fairly unpleasant towards the end).

I'm quite squeezed for time, so getting really long rides in prior to this event is difficult.

My question is, what's the most effective training possible over several shorter sessions (perhaps up to about 2hrs long) between now and then? I can probably just about get 8hrs of training in per week.

I quite enjoy doing really hard threshold intervals, and I've heard sweetspot training is highly effective, but I'm just not sure if that's better than sticking in zone 2 for this event?

Note: I feel strong enough to complete 250 miles now, but I want to make it as pain free as it can be. I have a power meter so I can train effectively, and I also have a turbo trainer and the trainerroad app.

I did a ride of this length solo in March this year. I designed a route to suit me (not flat, not steep), and intended to be quick (I was aiming for under 21 hours). At 400km it was a tough day, but I never doubted I'd finish. I have seen people (tougher then me) go from a solid base of centuries/200km rides to this distance without anything in between, so it's possible.

A few things that helped me get round (an hour faster than my target).

all the riding I'd been doing. Prior to this I'd ridden at least one 200km (125mi) ride a month (often more) for over a year, of which several were 320+km (double centuries) in tougher conditions, though none for a few months before the 400km. When training for endurance, even commuting counts, especially if you've got stretches you can push hard.
fasted training. Until I injured myself recently I was going out once a week for 90 minutes before breakfast. For endurance rides this is really beneficial - you don't bonk as easily or as hard, and you learn what it feels like to be out of carbs. Once a week is ideal, twice as an absolute maximum. This seemed to help after only a handful of training rides.
a feeding schedule on the day. I set an alarm on my phone to remind me to eat, drink and stretch out of the saddle every half hour. I tried to remember to drink in between as well. This really helps when pushing a personal distance record.
aim to cruise round. Hard efforts only on climbs and if you're riding in a group take turns at the front especially into a headwind. You don't have to be right on each other's wheels to get some benefit.

A ride of this length is never going to be easy, and by going for it so suddenly you're doing it the hard way - so plan the actual ride carefully. Know where you can get a meal - you'll need real food - and where you can stock up on snacks and drinks. You might need to carry more water than you think. Know where the bike shops are in case you run out of tubes. Know how you can get home if things go more wrong than you can fix (it happens; it's happened to me twice this year).

Apart from fasted training, I suggest you try to pack all your training time into long sessions, rather then hard efforts. You need the saddle time. But don't push yourself for a few days before the event.


Will 0.5mm gap/play in a seatpost shim work without cracking the seatpost tube? I have a Day 6 ebike; it's a large frame--the Samson model. The seat post (the frame member) is 31.4325mm or 1.2375 inches (I.D.) at the clamp collar. The seatpost (the seat support post) is likewise on the O.D. I would like to switch to a more comfortable seat, and the seats I'm looking at require the old-school seat clamp that bolts to a 7/8 inch end post atop the seat post. With me so far? These seat posts come in 25.4mm (1 inch) and 27.2mm (1-1/16 inch) seat posts (with the 7/8 inch seat mount at top). If I switch seat posts, I will need a seatpost shim; either 25.4mm to 30.9mm or 27.2mm to 30.9mm. There is no seatpost shim for my existing Day6 size: 31.4325mm--it is an odd ball. Here is the question: using either of these shims will leave a gap of 0.5325mm (31.4325 - 30.9mm = 0.5325mm)between the shim and seat post tube inner wall. The next size up, 31.6mm, is too large to fit. So, if I use a 30.9mm shim in my 31.4325mm seatpost tube, will I be able to tighten the seatpost collar/clamp without cracking the tube frame (aluminum alloy)? Anybody have experience with this? The ebike weights 54 lbs and I weigh 195 lbs. Thank you!!

To answer the question of whether you can get away with the .5mm gap, absolutely not. It probably won't be able to clamp securely, and even trying it once could destroy the seattube opening. Bikes are essentially never tolerant of this type of mismatch.

I presume you are in this spot because you want to use a seat like a double-rail Brooks or similar that requires a pipe-style seatpost, as opposed to a more common cushy seat, most of which come with a usually-superfluous clamp that can be removed in the case of a post that has its own clamp. If that's the case, I think all you need is a 27.2-31.4 shim, which is oddbal but does exist.


2015 Fox RC2 160/36 (650b) fork - negative air pressure problem As far as I can tell after speaking with 2 different Fox Service technicians, nobody seems to know why their forks have this well-known problem with negative air pressure increasing and migrating, and not re-equalizing.

I don't understand the whole thing, but there's only one port that allows air to move from the positive to negative chambers. I've now had 2 of the 2015 RC2's and both began doing the same thing after about 3 months of riding: the stanchions started not fully retracting when I am standing next to bike, compressing fork as far as possible and immediately lifting front tire off the ground. I tried "burping" with a ziptie between dust wipe and stanchion, but nothing there. I will next try removing the top cap and rod and slick honey it as directed and see if that fixes the problem, as well as do an oil change.

One year ago, with my first 2015 RC2 (160/36 - 26") Fox had me send it in under warranty - they ended up sending me a brand new fork, but it was never clear what the problem was. I hope I don't have to send this one in. Even one of the techs I talked to said he had asked an engineer about this who also didn't know what causes this problem(!) Hard to believe as it's a well-known issue, and I'd like to know how to prevent it. Btw, I have not been riding at high altitudes. I have bottomed out a few times - but why should that, if it has something to do with this, be the cause?? thanks!

Thanks, moderators, for asking contributors to answer the actual question! So different from the millions of unmoderated, often tangential and perfunctory answers found on MTBR.

This problem occurs on both new and serviced forks. Fox's 40 mm downhill fork has pressure release micro-bleeders near the top of the legs, just below the dust wiper seals that get pushed in to activate. Since these are on both legs in the same location, and since sliding a zip tie past the wiper seals on both legs can usually release the pressure and return the stanchions to full extension, I find this statement,

  air negative spring becoming over pressurized due to air migrating
  past the seal separating the positive/negative sides of the FLOAT
  assembly,

confusing, at best. And again, it's not just Fox Floats having this issue, Rock Shox users do, as well. I'm doubting there's an answer to how to prevent this, but hope in near future that Fox puts those micro-bleeders on the 36 if they can't engineer the problem away.

Posts #104, 106 & 108 on the link below has a contributor who shows how to modify your fork with your own micro-bleeders:

http://forums.mtbr.com/shocks-suspension/air-pike-lowers-psa-929695-3.html


Will 28" - 29" rack suit my 27.5" bike? The particular rack is
Cube
Luggage Carrier Bosch

The particular bike is Cannondale Trail 6 with 27.5" wheel size.

Can the rack be attached to my bicycle in a right way?

Most racks are adjustable so that the rack can be fitted to a range of seat-stay lengths (more accurately, the distance between the eyelets the rack attaches to).

I think this rack designed for a 28-29" wheel may be made to fit as the forward support arms can tilt down but the rack may be positions a little high.

BTW, that rack is specifically for the Cube Bosch drive. The double-decker design is for holding a Bosch battery pack.


(racer) Standard vs compact crankset: Increased leverage for same gear ratios true? I'm a road and mtb regional racer about to have a go at my first road endurance nationals very soon.

I'd like some educated scientifically validated answer on a matter that has been on my mind ever since I got a new bargain race bike that unfortunately came with a compact crankset. I actually went from 39/53 + 12/28 10speed to 34/50 + 11/28 11speed.

On paper I'm a lot better off with the new setup, since I'm using the exact same spacing on the cassette with the benefit of the 11t cog i didn't have, which, even though doubled with a compact gearing upfront, ends up giving me a lot more headroom in bottom and even a tad bit more top speed.

My coach has always insisted that even on same gearing ratios, when compared, a larger crank ring with a smaller cassette cog end up giving you higher leverage and ultimately better power transfer or whatever mechanical benefit. Last Saturday, trying out hard climbs on fresh legs with about same gear ratios on the 50 vs my 34, actually felt less efficient on the 34 for some reason, mind you same cadence, intensity, gradient.

What's your take on all this? If the math says gear ratios are same, are the actual ring and cog sizes irrelevant? Is it actually beneficial to switch to my standard crank due to increased leverage?

Thanks a lot, lads!

While it's true that a larger chainring will have slightly less friction and thus slightly more efficiently, it's an extremely negligible amount, that you wouldn't be able to feel. More importantly, are your crankarm lengths different on the new crankset than the old? That makes a much bigger difference. For example, if you've went from 175's to 170's, that will be a noticeable difference that could more likely explain what you're feeling.


Steel road bike with frame that hides cables I'm trying to recall the name of a bike maker that I had found while researching steel bikes a few months ago.  Their bike had a frame that hid cables.  i.e., the frame had holes to run the cables inside.  If my memory serves, they are based in Portland or somewhere else in Oregon and their bikes came only in red.

I had really liked this bike, but now I can't recall their name.  Does this ring a bell to anybody?

I wonder if you were looking at the macho man disc, which has a steel frame and only comes in white/red:

http://allcitycycles.com/bikes/macho_man_disc


Whatever happened to solid bike tubes? As a child I had solid rubber inner tubes in my bike. They were a pain to get on but after I never had a flat again!

Now I've recently started biking again and have had two flats in two days, each resulting in a three-mile walk back home. I've been searching for solid rubber tubes for a few hours now, but have only found them at wal*mart, and they don't have the correct size? (700x38c)

Why have they disappeared? I thought they were a fantastic product . . .

You should not be getting multiple flat tires in such a short timespan. I commute on poorly-maintained roads in Atlanta, and have not had a flat tire in 4,000 miles.

In order of estimated likelihood, either:

your tires are not properly inflated
your tires are worn or punctured and need to be replaced
you have a sharp object embedded on the inside of your tire
you are exceedingly unlucky

If you've just started cycling again, I think it's exceedingly probable that you've simply neglected to inflate your tires to their recommended pressure. Standard road tires should be inflated to pressures of 100PSI and beyond. Mountain bike tires (which are awful for road use, but I digress...) require much less. It's easy to grossly underestimate how much to inflate a bike tire, and a standard hand pump will likely only get you to 30-60 PSI before you give up.

Take your bicycle to your nearest bike shop and have them examine the situation. Flat tires should not be a common occurrence.


Removing lubricant from the rear brake and rim? I accidentally got lube on my rear brake (v-brake) and my stopping power seems diminished. What is the best way to get it off the brake pads and the rims?

Clean them.  I'd avoid using any sort of solvent, as it would be bad for the pads and might simply make things worse.

First undo the noodle so you can access the face of the pads, then wipe pads and rims thoroughly.  Scrub pads and rims with a dab of detergent on a rag, then hose down to remove the detergent.  Reattach noodle.  (I always forget that part.)

The brakes will likely still be a bit "slippery", but riding with the brakes partially engaged for a minute or two should bring things back to normal.


The right saddle for touring In a month time I will be doing a two week tour in southern France. I was wondering which is the best kind of saddle for touring? I have a Specialized Tricross that came with a modern narrow and not so cushioned saddle with a hole down the middle (any idea what this is for?).

I also have a Brooks saddle B66 (with springs). Now, I love this saddle but I've been told that it is preferable to use one without springs and that is not so wide for longer rides. Exactly why I don't know...

Any idea, comments, etc very welcomed! Thanks!!

The best kind of saddle for touring is one which you find comfortable.

The cut-out is intended to relieve pressure from your soft bits leaving most of your weight on your sit-bones.

A very wide saddle might start to rub excessively inside your thigh on a long ride, while one with springs may be too bouncy at higher cadences and waste some of your effort.

A saddle is a personal choice and there is certainly no one ideal, "best" touring saddle for all people.

Given that you "love" your Brooks, I'd suggest looking at another Brooks (maybe a narrower one), or if you're confident it will be comfortable over longer distances, use your B66.


How do I know what brake rotors to get for my bike? In the next month or so I plan on getting the 2019 Trek Crockett 5 as a cyclocross/road bike. I will also be getting some nicer road wheels for the bike so I can swap out the wheels whenever needed. Of course I plan on getting the same cassette for the rear wheel, but I was wondering about the brake rotors. On Trek's site it says the brakeset is "TRP Spyre mechanical disc" and in the close up of the brake rotors it says "160-35" on the rotor. I'm assuming this means they are 160mm rotors, but I don't know if I need to get the exact same discs that come with the bike or if I can just get any 160mm rotors.

Here's the link to the bike for more info: https://www.trekbikes.com/us/en_US/bikes/road-bikes/cyclocross-bikes/crockett/crockett-5-disc/p/23092/?colorCode=black

Thanks!

TR160-35 is the model number. They are 160mm Centerlock rotors. If your new wheels have Centerlock hubs, then you need either centerlock rotors or adaptors. If the wheels are 6-bolt, then you need 6-bolt rotors. Either way you'll want 160mm rotors and to keep it easy, I'd stick with Tektro rotors for this system.


What type of brake pads should I run on my Shimano RS80 C24 wheels? I recently purchased a new (used) bike that has Shimano RS80 C24 wheels. The wheels say "carbon" on the side, though a couple of different sites indicate they feature a carbon and alloy laminate clincher rim that take "standard brake pads".  I'm not quite sure what they mean by "standard brake pads".

Should I be using carbon brake pads or something different on these?

Standard brake pads would be ones for aluminium rims.  If your carbon rims have an aluminium/ shiny-metal brake track then this is what you want.

"Carbon Fibre specific" brake pads tend to be made of cork and cost a lot more than normal brake pads.  The braking surface has no trace of metal, and has a clearly visible carbon-fibre weave visible.  (after all you paid a lot for that rim - got to make it known!)

The group consensus seems to be that koolstop in Salmon or Black are an excellent brake pad choice.

Your last resort options are to ask the Previous Owner, find an owner's manual for your rims/bike, or to take the bike to a LBS for a visual confirmation.


Rockshox Reverb dropper seatpost squashing from new I have a new bike with factory-fitted Reverb Stealth dropper seatpost. Having never had one before, I would like to know what movement you would expect on a seatpost if any. If I lift the bike up by the saddle, the post extends a bit if it’s not already at the top of its extension. This may be normal but I wanted to check.

The movement I’m getting that is more concerning is the squash that I get on the seat. It drops up to 1 cm. I’m not sure whether it needs a bleed, air pressure check or what. Any thoughts?

If I lift the bike up by the saddle, the post extends a bit if it’s not already at the top of its extension.

Yes, it is normal. reverb works like that.

  It drops up to 1 cm

Also possible and fine.

Just do regular maintanance and it will last.


What is the difference between I.S., post, and flat mount disc brake mounting standards? What is the difference between "I.S." (international standard),  "P.M." (post mount), and flat mount disc brake mounting standards?

Does one have a clear advantage over the other and is there a general trend towards standardization of one over the other?

Image source: https://xkcd.com/927/

And why do most people here spell it 'disc' rather than 'disk'. Is this an Americanism vs. British English?

IS mounts (also frequently called IS tabs, disc tabs, etc) are unthreaded eyelets 51mm apart that bolts run through parallel with the hub axle. In almost all cases the brake caliper is then bolted to an adapter that has one set of threads for the IS mounts and another 74mm apart for the caliper. (There are a few caliper models that omit the adapter. Shimano, Hope, and Magura have all made brakes like this.)
IS has one clear upside: all the threads are in a relatively cheap and easy to replace adapter. The disadvantages are that it's more mechanically complex and expensive since there's always an adapter, and the design of the standard is such that the same adapter doesn't adapt the same caliper to the same rotor size front and rear. A adapter for 180mm in the front is an adapter for 160 used in the rear, for example.
With IS, outside of a weird custom fork, 160mm is the smallest size you can use in front, but all bikes with rear IS mounts can take a 140mm adapter.
Post mount places two threaded M6x1 holes 74mm apart on the frame or fork in the orientation that a caliper can be bolted to directly without any adapter, or with a post-mount adapter in between along with its supplied long bolts if a larger rotor is going to be used. The most common setup is for the minimum rotor size (the size you'd get the caliper positioned for if no adapter was used) to be 160 front/160 rear on most mountain bikes and 160 front/140 rear on most road and cross bikes, but all sorts of exceptions exist, i.e. downhill forks with 200mm minimum rotor sizes. Although it's seldom denoted this way by frame manufacturers, post mount is really a group of standards that you could call "140mm post mount", "160mm post mount", etc.
Post mount is mechanically simpler, cheaper, and arguably more elegant. It has the disadvantage of putting the threads in the frame/fork, which introduces some risk of difficult or impossible to repair damage resulting from carelessness or low-quality parts. It's acceptable to helicoil a stripped post mount in most circumstances, so the actual risk of ruining a bike forever with one overzealous tightening is small. I've done this repair a number of times, particularly on certain low-end suspension forks where the thread quality was poor to begin with.
Post mount does not have IS's issue where the geometry is different front and rear. A +20mm post mount adapter does the same thing on both.
Facing a rear post mount on the chainstay, where they often are now on road/cross bikes, usually requires an offset facing tool to reach in and do it without bonking into the seatstay. If all manufacturers and dealers were well equipped and did their jobs right, this wouldn't make a difference for consumers. As it is I feel like there's a relatively high proportion of bikes like this sent out into the world still in need of rear post facing, but I don't have any proof.
Post mount has increasingly become the norm, probably because it's simpler, cheaper, and inherently more structurally efficient.
IS and post mount adapters are mostly dimensionally interchangeable between brands. It's wise when mixing brands though to take a close look that the pad contact looks how it should; weirdness does occur in this regard sometimes even though on paper it shouldn't be able to.
Flat mount was designed for road bikes and has become the standard there due to its weight-saving and aero construction values. It has now spread to XC mountain bikes. It was designed by Shimano and has now been adopted by everyone else. As the name indicates, flat mount puts the caliper closer to perfectly flush with the frame or fork.
Whereas IS and post mount take the same brake calipers for the most part (the exception being adapterless IS-specific brakes), flat mount is a new caliper standard altogether. Adapters to put post-mount calipers on flat mount frames and forks exist, but in individual cases it's possible for hose/housing routing or frame clearance issues to make it ugly or unfeasible. Adapters to put flat-mount calipers on post or IS mount and forks frames exist, but face spatial constraints that may make using them impossible or impractical in a given application.
Flat mount calipers have the mounting threads in the caliper itself. Flat mount only is compatible with 140mm and 160mm rotors for either front or rear. (It's likely that somebody will break this rule someday, as in the front particularly there's nothing physically preventing it.) There are two completely types of flat mount adapters, for front and rear. A front fork adapter (called a 'mount plate' in Shimano parlance) is always used. It's switchable for 140 and 160 by flipping it around. The adapter is first installed onto the caliper in the desired orientation using flush-mount bolts. The fork has threaded mounting holes that the adapter then bolts to through the holes at either end of the adapter.

In back, flat-mount compatible frames use bolts going through a frame member, typically the chainstay, to thread directly into the caliper if a 140mm rotor is used, or an adapter for 160mm.

Flat mount in an of itself is a design that did a  good job of minimizing the number of adapters that may be needed, with the flippable front adapter that's always used and a choice of either no adapter or a +20mm adapter in back, for a very minimalist total of only two parts, but there are also 4 different flat mount to post mount adapter caliper permutations (140 and 160 for both front and rear).
Rear flat mount installations require the bolts to be exactly the length needed to protrude through the frame member, which vary in size, with a certain amount of length left over to engage the caliper or adapter threads. Some manufacturer feature a special tip on the end of their flat mount caliper bolts that fits a safety retention clip, creating a situation where bolts can't simply be trimmed to length if the caliper is to be installed as intended by the manufacturer.
At the moment flat mount adapters are interchangeable and universal between brands as far as I know. Hopefully it remains that way, but there's nothing stopping someone from releasing a brake caliper that's an exception.


freewheel stress and possible difficult removal with super underdrive gear? I tried to research this online but didn't see any examples of this exact concern, which is if I gear down a very cheap mountain bike that has a 7 speed freewheel, do I run the risk of creating so much torque magnification that something bad could happen?  Is it possible that something could break from the high torque?  What about if and when I need to remove the freewheel?  Might it be stuck from the high torque pedaling in the lowest gear?

Stock lowest gear is 24/28 and I will attempt either 20/28, 24/34, or 20/34 which is about 15.3 gear inches.  I ride mostly on the street at a slow pace (about 10 MPH average) but I also like to ride thru grass slowly and even in grass uphills so I put a good deal of force on the pedals in that situation.

Yes - chains can be broken and will also wear quicker when under stress from low gearing.

I have snapped a almost new KMC chain while on a 15% climb.   I would have been in 26/42 on a 26" MTB.  Fortunately I was going very slow.  The pedals spun, so I clamped on brakes while unclipping.  The slope meant I couldn't reach the ground straight below the seat, and so the whole bike and I fell over to the left (our footpath side) and tried to slide away down the hill.  Was quite embarrassing, but fortunately not painful or damaging.  One of the chain's side plates had come off the pin, so it was only a matter of time before it wrenched the other side out completely.  Never buying another KMC chain!

Removing the freewheel can be hard, so remember to apply copperslip or anti-seize or even plain old marine grade grease to the threads before assembly.  The leverage of the rim means you can exert a lot of force when undoing the freewheel, provided the nut is held firmly in a bench vise (and said bench vise is fastened to a bench!)

Freewheels tend to seize their threads, but sufficient power can undo them.  Cassettes can "erode" their way onto a freehub body, and be unrecoverable completely.

Finally never underestimate the torque advantage of a handy piece of pipe.


Would learning to ride a unicycle boost biking skills? Unicycles are not particularly expensive, seem to be light and portable, also fun. This gets me wondering if spending a couple of months to learn riding such a thing would boost a mountain biker's coordination, balance, timing, reaction, fall handling, etc. Or would just riding the intended type of trails be more educational?

EDIT:
To clarify, I am sure that doing something is the best way to get good at it. However, I am also aware of the law of diminishing returns. That is, if one's idea is to be good at mtb, maybe after a lot of riding, they should consider other activities, hat are only somewhat beneficial in the same direction.

Here's my contribution: There is one bicycling skill that improved a lot after I learned unicycling: Riding the bicycle with no hands.
Before unicycling I could ride the bike with no hands in a straight line and do wide turns.
After unicycling I was a lot more confident to go over obstacles and do narrow turns.

Now when riding some long distance biking, I often leave the handlebar for a while to straighten by back and relax. Even in uneven or difficult tracks.

Apart form that, it contributes to your leg strength and general balance.


My rear wheel shifts in the dropouts, what could cause this? I weigh 175 lbs. and I can put some good torque into my compact double (I'm riding a steel frame). I'm having trouble with my wheel coming out of the dropouts, or becoming misaligned. It's a big problem. Are the wheels to blame? I already took out the dropout adjusters, and tightened the quick releases about as much as humanly possible. What can I do? Wheels are a big investment, I know this because the the wheels are brand new. The axle rests about half way through the drop out. Is this to blame? Maybe the axle isn't long enough? There is knurling on the quick release and on the outside of the hub.

Check the alignment of dropouts, and if QR mates with dropout with full surface on both sides. Maybe you could use marker or some kind of fresh ink, paint the dropout, install everything and then observe if paint transfer was uniform.

If you have spare wheel (or you can borrow one) ideally without QR try installing it and see if problem persists. If the problem persists, than the issue is on the frame side, or in the way you are tightening. Otherwise, it is on the QR side.

Lastly, I have to ask this, are you sure you are installing and tightening QR right way? (finger tighten, and then use lever on QR to get a good tight)


What defines a recumbent? Is there a clear technical definition for a recumbent? Is it the position of the knee in relation to the crank? The presence or absence of a back rest?

There seems to be a fine line between, for example, stretch cruisers and recumbents:

Short answer: whoever is describing it.

There are a bunch of dictionary definitions around that all centre on the "lying down" part, which doesn't help when there are recumbents with quite upright seating positions:

as well as (semi?) recumbents with quite small backrests and seats off upright bikes:

At the other extreme, of course, you have the virtually horizontal positions mostly used for racing:

I am inclined to the view that anything with a laid back seating position and a backrest is probably a recumbent.

Note that the racing world has side-stepped the whole definitional question in favour of using "human powered" to describe what they care about. You get the "International Human Powered Vehicle Association" which sadly doesn't have a space vehicle category yet. They do have categories for number of riders, multitrack and single track, and age/sex ones. But no "recumbent vs prone vs upright" rider position ones.


Differences between male and female road bikes? My girlfriend would like to take up road cycling and join me, but hasn't had a road bike before me. So, I'm gleefully eyeing up an excuse to go bike shopping :-)

I'm used to the idea that road bikes are also offered in 'women-specific' frames - not as in the old style with the lower crossbar, but a different geometry to an otherwise standard two triangle frame. When reading up, it seems this can be significantly a smaller frame - which wouldn't be an obvious benefit for her, because we're both 5'9 give or take and fairly similarly proportioned.

I know why women-specific saddles are a thing, but they're an easy swap at a friendly bike shop. Is there any other reason why a 'mens' frame wouldn't be perfectly good for her?

The term you may be looking for is "unisex" bike - although you're right that if a bike manufacturer is lazy, "unisex" will basically mean made for men.

One major element of bike fit is the position of the handlebars. Basically, you want to select the frame that will enable you to put your handlebars in a comfortable position where you can generate enough power. The image below from road.cc depicts frame stack (how tall the front end is) and reach (how long the bike is). Frame stack and reach influence where you can put the handlebars. Riders can further modify their handlebar position by putting spacers under the stem, and by selecting stem length. Secondarily, they can select handlebars that have a different amount of reach and drop as well.

Now, all humans have different ratios of leg length to torso length. Two of us linked previous answers about WSD bikes in the comments. Some of those answers showed that controlling for height, the average woman may have longer legs and a shorter torso than the average man. That's based on (I believe) some anthropometric data gathered by the US Army (see my answer in the Q&A I linked). If that assumption is true, a WSD bike is slightly more likely to fit your girlfriend than a unisex bike. Based on her personal preferences, there are other aspects of WSD design that may appeal to her more; e.g. a less aggressive position, different tubing to accommodate relatively lighter female riders, pastel colors. Some of these are substantive changes, and some are not - in fact, "shrink it and pink it" describes the a superficial approach to design for women that some bike companies have used; it very likely under-served competitive female athletes.

Some other companies dispute the paradigm above. They feel that they can meet the needs of both female and male riders with unisex sizing, although they change the bike's contact points (different saddle, narrower handlebars) for female riders.

In both design paradigms, it's important to offer small sizes to accommodate women. When I first got into road cycling in 2001, I got a 48cm Specialized Allez. I believe this was the smallest size of that bike at the time, and it was a unisex design. I'm a 5' 5" with a relatively long torso. If I had a short torso, that bike may not have fit well. If I were shorter and I had a short torso, I would have needed a smaller bike, and I believe there were very few bikes smaller than that. This cut off a lot of women (and some men!) from easy access to good bikes.

To your question, bike fit depends on your girlfriend's leg and torso length. At 5'9", she's well within the range of heights served by unisex bikes. Actually, she might be at the upper end of the height ranges served by some companies using the traditional WSD paradigm. There's no intrinsic reason a unisex bike can't fit her, unless she has unusually long legs, an unusually long torso, or some other unusual attribute (just spitballing, but maybe unusually short or long arms). Even if it's true that the average women has longer legs than the average man of the same height, there will be many women who have long torsos and many men who have short torsos. It all depends on the individual.


What is the next step in teaching my child to ride? This is related to - but I think it's sufficiently different from - the question about how to teach a child to ride.  My 8-year-old daughter can ride her own bike, but she's a bit wobbly, especially when she's pushing hard on the pedals, so she's currently limited to fairly flat, uncrowded routes.

I'd like to know what's the best thing to focus on teaching her next.  e.g. should she practice riding uphill and back down? or should I try to get her comfortable pedaling standing up?

I think that, besides having fun - which is of utmost importance with kids otherwise they give up and choose to do something that is more fun and less distressful -, after they learn to keep balance and speed up, I'd say the next things must learn are to brake properly and to control their trajectory.

That said, one of the most exciting things to do, in my humble opinion, is to play tag (chasing game), or "follow the leader", in a park, taking turns on who is the leader.

When you are the leader (of course, not going too fast), she has to chase you and so she learns to do quick turns, brake, and change directions on demand (reactive).

When she is the leader, she develops her ability to read her surroundings and form trajectory-planning strategies in her mind (proactive).

Motor control resides in the cerebellum, and it must be automated by exhausitve repetition until it becomes automatic. There's no better way do do it than by playing and having fun, specially if it involves bicycle riding skills. It literally "grows in you". (I think that's why people say that no one ever forgets how to ride a bike).

Hope this helps


Is it possible to mount a disk brake hub to a rim-brake rim? Suppose I have a disk-compatible hub and frame, but want build a wheel based around a very specific touring rim, which is labelled as being for rim brakes.

My understanding is that you cannot attach a rim brake to a disk-compatible rim, since the sidewalls are not designed to withstand the stresses. However, it is not obvious to me whether there would be any problem attaching a disk brake to a wheel with a non-disk rim (assuming that it's been built around a disk-compatible hub, and is attached to a disk-compatible frame).

Is there some problem with this configuration? The obvious drawback would be carrying around the extra weight of a reinforced rim, but that doesn't seem to prevent the wheel from actually functioning.

There's no problem mounting a disc-compatible hub to rim-brake compatible rim. Just make sure they've got the same number of spokes and you're good to go.

You're absolutely right about the opposite though, disc brake rims generally do not have a braking surface on them, the rim profile is round there, so it wouldn't work. And if you did try to brake on it, it a) wouldn't work well and b) would probably cause excessive rim wear.

What you could do, if you want to be flexible and switch back and forth is to get a dual-duty rim that supports both, such as the WTB Dual Duty FR rims (probably a bit beefy, but you get the idea).


Is it worth converting a steel frame Trek Roadie to a Cyclocross? I have a Trek Elance 330 from the 80s and love it!  However, I find myself needing something that can handle fire roads (gravel jeep paths) and am wondering if it is worth the effort.   Also, if it would result in an effective ride.  I am fine with the higher center of gravity, won't be doing any rock hopping, and won't be buying a new bike.  Has anyone converted their steel frame?  What experience can you share?  Thanks!  :)

I've done a conversion on an old steel Schwinn, and these look similar. I'm not sure how in-depth you want to go, but at the most basic level you only have to worry about two issues:

Tire clearance
Brake clearance

Tire Clearance
The most popular size of cyclocross tire is 700x32. You may find that a knobby cyclocross tire will fit between your fork, but not clear the bottom bracket or chainstays in the rear triangle or vice versa. If you have a tire clearance issue with the rear triangle I would abandon hope right then. If the rear is fine but the front is tight, you can consider a new fork.

Brake clearance
The brakes on that bike may not have arms that are wide enough or long enough to properly place the pads on the rim without touching the tire. IF that's the case you can check a touring source like Rivendell for brakes with longer, curvy arms.

Note: If the bike came with 27 inch rims, you may have a hard time finding tires and your clearance issues may be even tighter. If that's the case you can look at switching to 700 wheels, but you may find on an older bike that it expects a narrower hub. With a steel frame  you can consider carefully bending the forks.

Is it worth it?
Well - to me it's worth it if you will ride it. Start with the tires - that's the cheapest first step. Move on to brakes and fork only if you have to.


Shimano short cage rear derailleur capacity Can an Ultegra or 105 short cage RD handle a 30T  ?

As I said in a comment, there are 25+ years of 105 and Ultegra (well, ultegra was called something else back then, but the line has been around for quite a while), so you need to find the right 105/Ultegra you're talking about.

You can find the Product Info at this link.

In 11 speed: The Ultegra RD-6800-SS and 105 RD-5800 SS both have a 28t max. Thus, Shimano doesn't recommend you run a 30t with a short cage. The RD-6800-GS and RD-5800-GS both have a max of 32t.

In 10 speed: The 105 RD-5701-SS has a 30t max.

Note that Shimano has mucked up cable pulls between 10 and 11 speed road, so you can't just put a 10 speed RD in a 11 speed system.

Note that also there may be several RD's under the same group under the same year or # of speeds (e.g. in the Sora case), so you need to look up the particular RD you want to use.


Schwalbe Marathon Plus recurring puncture - options? Does anyone have any experience of using puncture resistant tyres when they have been cut so badly as the object pierces the tyre right through?

Being Mr. Unlucky, 2-3 months ago I managed to get a puncture on my Schwalbe Marathon Plus'.

I changed the tub initially. When the second, third puncture happened, I started looking closer. The object (what I am guessing was a piece of glass, from memory) cleanly cut straight through the "SmartGuard layer".

My guess was the object was still embedded in the tyre as it took 1-2 days after fixing punctures 2, 3, 4 for next puncture to flatten the tire completely.

I examined the site, and tried to clean it out with a pair of tweezers, narrow knife, etc.

What are my options to continue using this tyre? I have (rightly or wrongly) applied some patch adhesive to the outside of the tyre on the puncture site, to see what happens.

Or should I stop using it?

If I understand correctly, you continued to get punctures until you found the embedded object which you dug out with a knife and tweezers.

I have been in a similar situation many times and I suggest you try again. Punctures 1-4 where likely caused by the same object, which you hopefully removed this last time.  Does the tire have a small weakness at that hole, yes. But, the casing on these types of tires is incredibly tough. That is why they roll like bricks.  The tough casings however let you continue riding with small weaknesses without issue.

Just inspect it after inflating, and for a while afterwards, to see if the hole gets larger or the tube starts to breach (you usually need a larger hole for that to happen).  I personally haven't had any problems with these small holes enlarging or new debris entering the hole.  That said, there is a non-zero probability than an object could pass through the whole and cause more problems.  If you know the tire contact patch size and you measure the area of the hole you could even compute that probability for bravado.

My only other advice is getting more practiced at finding and removing debris. I usually keep the tire oriented so the tire label is over the valve stem.  That way when dealing with a flat I can track the tube flat back to the tire location quickly.  Then I running my bare hands around the inside found tire until I find the sharp that penetrated the tube.  Once you find it flexing the tire casing can often be enough to help loosen an embedded object so you can pull it out with your fingers, avoiding other tools such as pliers, tweezers, and knives.

Finally, stop riding over the sea of broken glass and all will be well!


Formula to calculate Single Speed Chain Length from Chainring Size, Cog Size, and Chainstay Length I've seen formulas to calculate chain length for multi-speed bikes, but I need something for single speed.

Example:
42T Chainring
17T Cog
406mm (16") Chainstay Length

The answer in this case should come to ~94L.

http://www.parktool.com/blog/repair-help/chain-length-sizing

Scroll to the bottom, equation is there, you want the "Rigorous Equation".

Better solution: start with heltonbiker's question on the math stack and ask how to convert to chain length.

Happy Riding.


MTN bike tyre sidewall wear question I’ve noticed some wear in my mtn bike tyre sidewalls.  Is this serious or can I get many more km from them?

From the knobs, that looks like a Continental X-King, but not the 'Protection' version as no checker pattern on the sidewall.

What you show in the pictures is quite normal to see on X-Kings (and some other tyres), and its quite safe to ride.  All that has happened is some of the very thin outer coating has worn off, but the structure of the tyre will be intact.

See review from Pro rider for an even more extreme example.


Is it possible to set this fork steerer / stem higher? Is it possible to set the stem / steerer higher in Cannondale R300? It feels like I need higher stack and I wouldn't like to tilt the drop bars from their current position.
Bonus question: are stem and steerer one single part here?

This is a traditional quill stem, meaning it's shaped like a "7", with the vertical part fixed inside the steerer tube by a wedge bolt.
There should be an allen bolt at the top--it looks like it might be covered by a rubber plug here. Loosen that and give it a light tap with a mallet to dislodge the wedge. You should then be able to raise the stem. If you can't raise it as high as you want, you could replace it with a new stem that's taller.


What advantages are there in mounting a butterfly bar with a drop instead of a rise? I own a tourer with a butterfly bar mounted with the near flats rising.  This puts the far flats rising towards the outside of my wrists.  I have, however, seen butterfly bars mounted so that compared to the stem the near flats drop.  This would put my far flats falling towards the outside of my wrists (a position I suspect I may like better.  But I'm having difficulty finding comparative evaluations of mounting butterfly bars in these manners.

Mounted rising: http://memberfiles.freewebs.com/74/22/55522274/photos/velocelestes-R20/R20top.JPG

Mounted dropping: http://sheldonbrown.com/deakins/images/flatandtrek.jpg

One thing you can be absolutely sure is: despite handlebars are designed to work some pre-defined way, there is nothing wrong about using them in a very different or even opposite way if that's what suits you best. The only two pre-conditions to do it is that you actually know what you want, and you actually know the practical, subjective pros and cons of each position.

If I were in your situation, I would choose the best position given my current stem. If that didn't work, I would perhaps swap the stem for another one that puts the handlebar in a better position.

Notice, also, that each image you posted places the brake levers in different zones, and that is a "design parameter" which you should consider. Most probably you'll benefit from having the levers in the position you stay most the time, so that they are within reach in case of an emergency stop being needed.

Hope this helps!


What year and make BMX do I have? Front back spring shocks 1970s. I'm sure is this a kawasaki BMX

EDIT from duplicate question.

After a lot of digging, I found that it is a 1975 Montgomery Ward Silver Fox

It's 1975 Montgomery Wards Silver Fox.

This is a pretty nice bike thanks for helping me


How fast does new technology "trickle down" to lower models? Is there a "rule of thumb" for how fast new technology "trickles down" from higher-end to lower-end bike models? Can you for example say that a mid-end bicycle frame or suspension fork is as good as the previous high-end, or does it usually take more than one generation for the technology to spread?

They say that this year's Tiagra is generally last year's 105, which is true to an extent. You'll see things like 10 speed cassettes move down the product line at a rate of one series per year or so.

It's not entirely true though. Features creep down, but quality stays about the same. The different series will maintain their relative build qualities year after year. I.e. a higher priced series will have better materials used throughout.

Having said that, I don't believe that build quality is really a deciding factor in most groups. I've put 20000km into a Sora group that is still running just fine. You just need to keep up the proper maintenance.


Can I change my bike's frame? A failed stealing attempt left my Bianchi Via Nirone 7 road bike with an ugly damage to the frame. The bike is still in place, and it hurts me every time I go to the bike shed. They removed the front wheel and twisted it 90 degrees, with the back wheel all the way up. The Kriptonite 2 D lock bent, but did not give in. Same for the frame. There is a big dent on the top tube of the frame.

I am considering buying a frame and having it replaced.

Any suggestions on which tools I could use to remove the jammed Kriptonite Series 2 lock?
When looking for frames, what are the technical specs that I have to pay attention to if I want to be able to re-use the fork, the seat tube and the pedals?
How unsafe is it to use the bike with a dented frame?

Thanks!

An angle grinder with metal cutting disk (or abrasive disk) will remove a U-lock in about 30 seconds. It is shocking how easy it is to cut through the shank. The one consolation is that it does make a lot of noise and a lot of sparks (and requires either a power cord or an expensive battery grinder), otherwise more thieves would be using them. If you do not have access to an angle grinder (and don't want to stop by your local bike shop, auto mechanic, or police station, all of whom will undoubtedly have one), then a hacksaw with a new blade  (or two) will eventually cut through, although it may take up to half an hour of vigorous sawing.
You should be able to bring over most of your previous components. However, be aware that bottom bracket sizes/types have changed considerably, the caliper distance (reach) and mounting style of brakes have changed, and there are peculiarities to seat tube and front forks based on country and year. Thus, unless you are replacing an early 1990s Italian road frame with an early 1990s Italian road frame (for example), you may find limited component capability. Pedals for almost all  recent bikes (except some cheap BSOs and children's bikes) are standardized thread so those will come over fine.
Yes, dented frames are dangerous -- especially aluminium and carbon fiber as their failure modes can be quite dramatic. Steel frames tend to fail more slowly (and can be re-welded).

tl;dr: Things that you can bring over (in general): Handlebars, brifters, seat, pedals, crankset, seat, front and rear derailleurs (with caveats).

Things you might not be able to bring over (unless your bike is the same era/style): bottom bracket, steerer/stem, seat stem, brakes, forks.


Is it normal for my derailleur cables to cross over on the down tube? I've just picked myself up a Specialized Allez Sport 2014 road bike from Evans Cycles (UK).

I test rode the bike and I'm happy with the bike, but when I got home, and flipped the bike over to make a note of the serial number (for insurance) and I noticed that the derailleur cables cross over on the underside of the down tube.

The groupset on the bike is Shimano Sora, installed by the workshop at the Evans store, before I test rode it. Full specs can be found here: http://www.evanscycles.com/products/specialized/allez-sport-c2-2014-road-bike-ec052507

The is the first road bike I've owned with a Shimano groupset < 105 and I wanted to know if this is the normal way to route derailleur cables with Sora shifters?

I have owned a 105 groupset equipped bike in the past with externally routed cables and the cables weren't crossed over on that. My current race bike has internally routed cables, so I can't even check against that.

The potential issue I'm concerned about with the cables crossed over is that through rubbing against each other, they will wear more than they would normally. I'm also worried that the cables will be more likely to rub against the downtube, but I could just be being paranoid...

UPDATE: It looks like I'm not the only person to ask this question: http://forums.roadbikereview.com/components-wrenching/crossing-derailleur-cables-downtube-243700.html

It would seem (from the above discussion, at least) that this is not uncommon for Specialised bikes to cross over.

Still doesn't sit right with me though...

This is one of those questions that can start arguments between bike mechanics--to cross or not to cross the derailer cables. Crossing appears to be becoming more common on new bikes, if the cables aren't internal, but it's also going to depend upon the bike. Smoother shifting is reported by some from crossed cables. I would talk to the mechanic at your LBS about it. There could be manufacturer recommendations or anecdotal experience driving the decision.