Easy mounting brake calliper on a Lefty So I have this second hand Canondale lefty MTB which I love very much. Rode it around home in the woods, but now I visit more and more events and I need to transport my bike by car to the event. Unfortunately I have to remove the front wheel of the lefty and with that the brake caliper. And the biggest problem is putting the bike together again without the caliper screeching against the disc.

For clarity, I remove the two bolts and then the whole black part on the right in the picture below. I think that's the brake calliper.

What is the trick?

I've watched some video's on GCN, asked my friends (who don't have a lefty), read forum posts, but no failsafe solution. It takes me sometimes almost an hour and three times removing the wheel again before it finally fits perfectly. Surely there is an easier way....

Please help.

With most of them the trick is you only unfasten the adapter to get the wheel off, not the caliper itself. The adapter doesn't have any range of adjustment in how it mounts to the fork, so it can be removed and re-installed without disrupting the adjustment.

There may be a post mount only Lefty out there. If so, the difficulty you're having is basically unavoidable.

It's also important to get a pad spacer in there when the wheel is off.

Edit in reply to comment:

So, you have the XTR brakes, I believe BR-M975, that represent one of very few disc brakes ever made that connect directly to IS tabs without any kind of adapter. There aren't many brakes like this and dealing with this design involves some steps that won't be covered in generic instructions about adjusting disc brakes. This design can only be adjusted for alignment by adding and taking away micro shims between the caliper and the fork. It's a little cruel and unusual that you wound up with the combination of this brake on a Lefty, because it creates hoops to jump through that would be troublesome for anyone. The good news is that once you get the shim configuration figured out that results in good alignment, you can keep the shims there on the bolts while the wheel is off and it shouldn't require readjustment when you put the wheel back on.

Such shims can be ordered online or bought from any good shop. There are two types; one (Shimano) is open and has two prongs, the other is like a really thin (0.1mm) washer. You want the washer type because the other one will want to fall off whenever you go to remove the wheel. With the washer type, just screw the caliper mounting bolts back in to the fork a few turns once the wheel is off, down to the loctite.

The goal of the design is that with fresh pads, properly faced tabs, and everything to spec as per the IS standard, the caliper can be bolted to the frame and everything is perfectly aligned without any adjustment at all. This may or may not be achievable on any given fork or hub, depending on exact adherence to the IS spec in terms of lateral position of the IS tabs and the rotor mounting surface on the hub.


Folding basket - is there such a thing? I'd like to be able to go to a grocery (or some other) store on my commute from work. I've got a rear rack (b-tween).
I know, that I can permanently mount a basket on it, but I'd prefer not to since it makes noise, can be too wide and so on (and looks uncool for me, yes).

So, are there any folding baskets or some alternatives to use?

edit
The accepted answer is not about baskets, that's true, but it really about a thing I needed.

To clarify: I want something that I can fold and put inside my backpack (not a big one) and unfold when needed.

A subset of panniers that are designed for shopping bags are often called "grocery panniers," the distinguishing features being an open top and dimensions similar to the base of a paper grocery bag (not that you can get those very much anymore).

They are typically easily removable (just hooks), and in my experience do not bounce around alot, as was suggested in another answer. There is an elastic cord to the lower hooks that keeps them secure.

If you want to leave them on your bike, they do fold compactly against the rack and usually have velcro or snap closures to hold them folded. I usually just remove them when I'm not using them.

Here is an example:


Lubed Chain getting temporarily seized I recently cleaned and lubed my chain, havent had a chance to ride it yet, but if I leave the chain alone for a day or 2, it seems to seize up. It takes a lot of effort to backpedal it free. After that it seems fine. Does this mean the oil is not able to reach the inner workings? Or is it a reflection of bad lube? I use https://www.fasttech.com/product/1392817 (I am not asking if the lube is bad, but rather if simply bad lube might cause this. Havent had issue on other bikes with singer oil), or are there any other things that might be the issue?

My chain did something similar but less severe, I was cleaning it and adding dry lube from a posh brand, then keeping it and riding it indoors. The chain got gummed up and harder to turn.

What I needed to do was to clean it more thoroughly. I might have been breaking down some of the oil every wash but it must have been leaving a cumulative sticky residue, 1, adding friction and 2, preventing new lube reaching every inner surface. What I was doing was effective for a different lube but not the one I had switched to.

Try giving a more thorough wash (degreaser first) and use a sponge on the chain rollers to carefully work the dirt out of the links. Then rinse thoroughly. Dry the chain with a towel and allow it to dry fully before adding new lube to every link and turning the chain backwards to work it in. Wipe away excess lube.

I you think any dirt or residue remains when you’ve rinsed the chain, repeat the cleaning.

I don’t think ‘bad’ lube would be the main cause, because you should be able to clean away any bike lube with the right cleaner.


Shimano crankset with FSA bottom bracket? I have just taken off an FSA crankset from my Orbea Avant M30. The bottom bracket is a BB 86/92. I would like to replace with a Shimano crankset, an Ultegra or 105. Do I need to change the BB to a Shimano or can I use the existing one? It seems to be in good nick.
Thanks

If you have the FSA MegaExo crankset it should have a 19mm axle diameter. The Shimano Ultegra FC-R8000 has a 24mm axle. Measure your current crankset’s diameter but you’ll probably need a new bottom bracket for the 24mm axle.

If you’ve ridden a considerable distance (something like >7Mm) on your current bearings it doesn’t really hurt to replace this 10€ part in any case.


Does it make sense to complain to companies about bad driving? On my commute in this morning I found myself in another situation where I was in conflict with another road user. (Briefly, a truck and I arrived at a roundabout at a roughly similar time, but I was into the junction marginally sooner and, crucially, had priority. He didn't/couldn't stop in time and only my emergency stop prevented a collision.)

So, naturally, I shouted at him, pointing out his faults. I know this won't help the situation but adrenaline and the rush of almost being knocked off aren't great ways to start a productive discussion. We had, as they say, a full and frank exchange of views which ended with my whipping out my phone and taking a couple of quick photos of his number plate and the company name from his door.

Realistically the police have better things to do with their time for this likely non-offence, but I did find the company's website and have filled in a 'contact us' form. I fully expect to not hear another word about it, I presume my complaint will be filed in the lunatic/whinging file and nothing will come of it.

The question here is what should we do in these situations? We could just put up with it, going gently into that good night, putting up with a genuine belief in some other road users that cyclists are not equal peers (cf. discussions about ignoring red lights and cherry picking rules).

Or if it's not serious enough to report to the police, am I just being too thin-skinned?

Anecdotal evidence I have heard is that in a lot of cases complaints actually do have an effect, particularly if the company is a large one.  All complaints have to be followed up and while you may not hear back from the company, management does speak to the drivers involved.  Whether this has a positive effect or just creates resentment with the driver, I don't know.


New pump - Topeak |Pocket Shock I bought this new pump, but i think I made a mistake.

I need it for my road bikes, with presta valves. I don't understand how I connect the pump to the presta.

Is it even possible?  do I need an adapter?

http://www.topeak.com/products/Pumps/PocketShockDXG

It is for adjusting the suspension on a medium to high-end mountain bike (fork), hence the lack of 'Presta' option.

Since you will be returning it, to keep the shop happy and get what you really need, consider getting:

A track pump with gauge and aluminium body. Look for one with a well
engineered head that does Presta and Shrader valves. The easiest
ones to use have a lever that you fold out to get a snug fit.
For the road, carry an affordable, light mini-pump with as few
movable parts as possible. The deluxe mini-pumps with dual-action,
fancy gauges and other features have a tendency to rattle apart,
rendering them useless when you need it.

Keep it simple is what you want with a mini-pump, it only has to get you home and you hopefully will have a proper track pump with gauge at home.


How do I adjust Luxos IQ2 mount? I'm trying to mount Luxos IQ2 onto the fork crown. There isn't quite enough space between the back of the light and front brake cable and I was wondering if I could add a spacer between IQ2 metal bracket and the fork crown. Or would it weaken the stability of the mount?

There is not that much load on the light - just add spacers or bend the mount as @super proposed, you'll be fine.


Chain skipping despite new cassette and chain My chain keeps skipping loudly. Replacing the cassette and chain had no effect. I also zeroed the derailleur to the 5th gear of the cassette and it shifts smoothly. I have also replaced all ball-bearings and assorted fittings at suspension joints. The freehub seems to work properly. I feel it may be due to frame flex, since I ride a full suspension MTB (poison bikes) and it has noticeable frame flex when pedaling. Undesired gearshifting happens when I turn. I have replaced aluminum washers at the main suspension joint near the bottom bracket several times and this solves the problem for about three months. Has anyone experienced this and have another idea how this can be fixed permanently?

Details: 27 gear MTB, full suspension

UPDATE: Jan 9th: I replaced a washer in the Suspension tightening it up a bit and reducing Frame Flex but the problem persists albeit slightly improved. Based on Responses here I have been watching the chain and noticed that it sometimes bunches up when coasting (not pedalling) -- it seems that the cassette keeps moving despite the pedals being stationary.

I had a similar problem with my road bike.  I replaced the cassette and it still skipped.  I replaced the chain and it still skipped.  Finally, I changed the rings and it worked perfectly. The rings looked only slightly worn but I think one or two of the teeth were shortened slightly through excess use.  I saved the rings just for a side-by-side comparison with future rings.


Is this a real Concorde or just a replica? I'm confused with this, the lugs in this bike look identical with another Concorde but the tubing sticker clearly says "Reynolds". (Concorde only uses Colombus, right?)

I have a 1990s Concorde Americas that has Tange tubing. I bought it when it was just a couple of years old.


Can one replace double chainrings with a singlespeed chainring on the original crankset/spider? I have an 80's Peugeot steel-framed racer that I want to convert to singlespeed/fixed. It has a standard square-taper BB with a double chainring chainset. I can see the chainrings are removable from the spider and was thinking I could just remove them and replace with a singlespeed ring to save having to buy a whole new crankset.

Will this work or will I have problems with chainline? I have yet to buy a new rear wheel with singlespeed hub so it's quite hard to check if chainline will work. I presume it is possible to bolt the chainring to either side of the spider giving me a choice of two positions. Beyond this I'm not sure how I would adjust chainline if it's out.

Any general help/tips regarding conversion appreciated. The bike has horizontal dropouts (not a track rear fork) so tensioning shouldn't be an issue.

Here's a (not very good) picture:

Indeed It should work.

The other answers address chainline correction options for the rear end, but I know at least two for the front side:

Usually two big rings in a triple, or the two rings of a double would be fixed by a single set of bolts. That means the chainring bolts are long enough to hold 2 chainrings. When going to hold only one, it may happen that the bolts are too long, so you may need spacers to fill up the gap. These spacers can be used to fine tune the chainline in the front side.

Also, if the bottom bracket is the old cup and bearing style, the cups can be adjusted to provide a few millimeters of adjustment. Shimano sealed BB's can be shifted side to side by adding Bottom Bracket spacers, which should be really cheap.

I will mention a third one, although the OP clearly states that wants a lean budget approach, chainline can also be altered by swapping the bottom bracket cartridge or axle. (Can be done low budget if using secondhand parts).


4L of water and 2 max protein bars. Is it sufficient for a four hour ride? I am from India and it's really tough getting gels. So I thought I'd put for protein bars which are pretty easy to get. But Alot of people say to have carbohydrates every hour of your ride. Can anyone tell if having 4L of water and 2 protein bars is sufficient. Else can you suggest some snacks that can easily be made or bought.

I'll concentrate first on the carbs side, because the water depends on so many factors.

Gels are around 30% non-sugar carbs with the rest water, according to the SIS ones I have here.  They're actually a fairly heavy way to carry a small amount of carbs if you can get water along the way, but they're easy to consume while riding hard, and are meant to give a quick (but not too quick) energy boost.

Protein bars have more sugar (which you may or may not want) and a fair bit of protein, which is a poor energy source during a ride, and they're overpriced if you're using them as a source of carbs.

There are also energy bars.  One I have here is 67% carbs (about 1/2 of that sugar) and 4.9g protein.  It's based on oats and fruit.  These are probably better than protein snacks for use while riding.

Alternatives you may find easier to obtain are bananas and dried fruit.  Even bread-like carbs can be good  (second breakfast after an early start for me might be a wrap with a banana and chocolate spread in it, for example). It partly depends whether you can stop to eat or want to eat on the go (in France, for example, a bakery stop for fresh croissants is good).]  If you want to make something, flapjack is great (mainly oats, sugar, and  butter, add dried fruit/chocolate chips/crystallised ginger if you like).  Sweets have a place towards the end of a ride or for a specific effort like a big hill.  They're essentially flavoured sugar so your energy levels go up fast -- and down fast.  Jelly babies are popular in the UK, but they may not be available/suitable (gelatine tends to come from pork/beef).

It is perfectly possible to ride for that long without food (3.5 hour example in my case, after lunch), but you won't be as fast and you have to be careful. Make sure you're well fed to start with, carry snacks just in case, and don't even think about it if there are medical contra-indications.  I just chose to keep going without calories on the exploring/training ride I've linked, as I wanted to try running on empty.  I still got through a fair bit of water and the temperature wasn't much above freezing (I had to wait until after lunch for the ice to melt on the roads).

Water: on a hot ride I rely on topping up rather than carrying everything I think I'll need.  A recent hot ride got me through 6 litres in 12 hours, plus 1 before I started and another 2 when I got back.  That didn't feel like enough.  Bottled water seems pretty easy to buy in India, unless of course you're out in the countryside for the entire ride. I'd plan to pass somewhere with water available every couple of hours, at least until you've got a good idea of how much you get through.

Links are to arbitrary examples, including my own rides.  Products are ones I have lying around, usually because I picked them up cheap.


what is the biggest chainring I can put on my mountain bike? I am going to do a 'gravel grind' ride with lots of elevation gain and want to be able to keep up with the cyclocross bike riders. From what I understand they have 46/36 chainrings.
My mountain bike came with 36/22 rings. 104/64 bcd crank. 10 speed cassette. I would like to run a 44/30 or 42/28. Does a 44 or 42 tooth 104bcd chainring exist that fits a 2x (and not 3x) crank?
My bike is a specialized crave. I would put on a 40t chainring or consider going to a triple crank.
Or could I put a road crankset on? My bottom bracket is 73mm gxp.

Do you have a crank that's easy to replace, like Shimano Hollowtech 2? It's actually easier to exchange those than chainrings. I usually ride a road-compact (50,34), but for long tours around the alps I exchange them for a MTB one (44,34,24). I have a non-indexed front-shifter, so I don't need to change settings. Triple crankset axis seem to be some 3mm longer than double road cranksets, don't know about double MTB - double road difference.

Anyway, beware that you might need to change the derailleur distance to bottom bracket - 44 chainrings are quite a big larger than 36 ones. With that comes readjusting the cable.

However, do you really need a bigger ring to keep up? I don't know your exact wheel size, but with 2m circumference at 36/11, 90 rpm you do about 35km/h


BMX stem slipping; how to stop? I recently bought a BMX bike that currently has all stock parts. Recently, with the school and weather, I haven't been able to ride it that much. Anyways, when I picked it up from the shop, the bars were positioned leaning forward, not parallel with the forks, so I adjusted them.

After playing around on the bike a bit, I noticed that the bars would slip forward if I put a good bit of pressure on them, so I completely removed the bars. In the stem there was a lube, I guess for the screws, which I mostly wiped off because I figured that wasn't helping the slippage. I also tightened the bolts pretty tight, and I had to use a hex wrench + a cheater bar to get them pretty snug... I could go further, but I don't want to snap off a bolt in the stem and have to buy another.

So, does anyone have any suggestions on how to lower / stop the bars from slipping forward? I'd prefer to not cut grooves in the stem (unless it's the bottom, the bottom part of the bracket is completely smooth) but if that's what it would take I'll do it. Does anyone have any other suggestions?

Note: I did tighten the bolts in the correct pattern

Try sanding the stem and bars because most BMX company's paint there bars and stems all the way so there is no grip. If you sand the inside of the stem and the grippy part of your handlebars it should be fine.


What crankset should I buy to suit an 8 Speed Campy freehub? I've just bought a pair of campagnolo/mavic wheels without a freewheel.
I'm finding it very hard to understand what will fit on the rear hub.

It's English thread, does this mean that any 8 speed freewheel will fit (as long as it is an English thread)?

Secondly, what rear derailleur will I have to use (if I buy a Shimano freewheel, can I use a 8 Speed campy derailleur, or does it have to match)?

Thirdly, will this influence what front cranks and chain wheel I get (If I buy a Shimano/Campy freewheel, will I have to get a matching crank/chainset combo)?

I'm trying to understand the whole crankset picture in one go!

Here's a link to the wheels:

http://www.ebay.co.uk/itm/170802467619?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_500wt_1413

Many thanks in advance

Freewheel threading is pretty universal. You can put any freewheel which is appropriate for your drivetrain on those wheels.

Regardless of whether you choose Campag or Shimano, stick with gear designed for one system, and as much as possible one gear number. (8 speed, 9speed, etc...)

For instance, if you use an 8 speed Campag freewheel, use 8 speed Campag shifters, chain, derailleurs, and either an 8 or 9 speed Campag crank set. You will need the appropriate bottom bracket to match your crankset.

It is possible to mix and match a bit, mostly the chain could be either Shimano or Campag without major issues. But best to stick with one system, especially if you don't understand the compatibility changes you're making.

By the way, those wheels are tubulars. That is, glue on tires. Were you aware of that?


Wheel spokes missing I have 5 spokes missing. Is it OK to ride on it, and how long will it last, or will my wheel just break on me? I will be going to work on it every day.

Yeah, by the time you have five spokes broken it may be that only one more and it'll collapse (depending on exactly how the broken spokes are arranged).  Plus with that many gone the others are under much more serious stress.

In the general case you may have a spoke go now and then and, if you replace it reasonably promptly, it doesn't imply any serious problem.  But when spokes are going right and left it usually means that the spokes are nearing end of life and they all need to be replaced.

On a good quality bike with stainless spokes, well cared for (and not abused by jumping, etc), the spokes should last at least 10,000 miles and possibly 30,000.  On a lower quality bike, however, with galvanized spokes, corrosion will often do in the spokes before they reach 5,000 miles.  And exposure to weather could cut that number in half.

Depending on the quality of the bike it may be cheaper to buy a new/used wheel than to have the existing wheel "relaced".  But you need to do one or the other -- that wheel could collapse on you tomorrow.


1991 (I think) Trek 850 MTB bottom bracket replacement. Maybe similar to 830? I have a Trek 850 MTB that needs the bottom bracket replaced. Is there a standard size to order? If I take off the bike will there be a number that will help me order a new one or do I measure somehow? Thank you.

Bicycle blue book says the 850 came with a BB-Lp26 bottom bracket, which was 68mm wide, 110mm spindle length, square taper. There are some new (old stock) on ebay, but I don't see why a newer BB-UN26 couldn't also be used (or any other standard ISO bottom bracket made for a 68mm wide shell, with a 110mm spindle).

I'd measure the BB shell and spindle width, just to make sure. Shell width is self-explanatory. You'll need to pull cranks to accurately measure the spindle width, and a caliper would be best. If you pull the BB, this info might be legible somewhere on the BB. I'd try pulling it before ordering a new one. Remember that the drive side has reverse thread, so clockwise to take it off. If it's from 1991, it may be seized pretty well. You may need to clamp a BB tool into a vise and use the entire bike frame as leverage to get it loose. I've had to do this in the past.


Will mountain bike front derailleur work with Shimano Tourney index shifter? I am having trouble getting my Shimano Deore DX front derailleur to work with a Shimano Tourney index shifter. I would like to know if anyone else has made this setup work and am interested if anyone has had success with a different front derailleur. Also, of course, I am interested in any ideas folks might have, besides getting a second bike -- I am mobile and don't have the room -- and I'm both cheap and not rich. Swapping out parts and tires for various uses has worked for me, at least until now.

Here is my setup:
1990 Specialized Stumpjumper (basic model), Shimano Deore DX derailleurs are original to the bike.
It has 3x7 gearing. 11-28 at rear, 26-36-46 in front. The only original gear is the biggest in front, a Shimano SG-X 46.

For my road bike setup, I have a Shimano Sora Flight Deck index shifter on the right -- for my rear derailleur -- and a Shimano Tourney on the left -- for the front derailleur.

I used to have Sora shifters for both derailleurs, but, alas, the front shifter was broken when a family member mailed my bars to me without enough protective packaging. I bought the Tourney on the fly to make a 60-mile group ride.

Factors to consider in any answers folks might provide:

I was able to make the Sora shifters work with this setup.
The front derailleur is stock and pretty beat up. It has some slop and the cage has taken some hits. I have strengthened the cage in the past, so it's likely not perfectly aligned. In the past, this didn't matter. After writing this up, I'm going to see if I can find a replacement online.
I have confirmed the shifter is for a 3x7 setup by checking its model number.
I know how to adjust derailleurs and even checked in with videos by Calvin Jones of Park Tools to make sure I wasn't missing something.
Basically, the Tourney shifter only has enough travel to give me the bottom and middle gear or the middle and top gear.
Oddly, I can get the front shifting to work on my stand, but not when I give it a road test. My wife helpfully suggested my weight is the factor here ... (190 pounds/86 kg, 6 foot/182cm).

Thank you in advance for any help you folks can provide.

In case anyone is interested, I got the following suggestion on www.bikeforums.net. The limit screws are not an issue, but I bet flex is. I'm going to check it out.

"Since the front shifter works on the tensioned part of the chain, it does take more force for front shifting. If you have the range on the stand, but isn't getting all gears on the road, then either something is flexing, or the limit screws needs to be backed out some to allow a little more overshoot."

Here is a link to that thread:
http://www.bikeforums.net/bicycle-mechanics/1118824-shimano-tourney-shifter-work-mountain-bike-derailleur.html#post19798217

Here is an update:

I ended up swapping out the front derailleur, which made it possible for me to shift to all three front rings. However, it was laggy and unpredictable. That got me to look closer at the bottom bracket. I have a bit of slop there, which is likely the final thing -- I hope -- needed to fix this. Alas, I am now thousands of miles from my bike and won't be reunited with it until mid-October, so trying that will have to wait.

Another up date: my front derailleur now shifts great. I repacked the bottom bracket and eliminated that bit of slop. However, I think the biggest factor was that remounting the front chain ring and crank arm actually moved the front gears closer to my frame. I can tell it ended up closer because my limit screw setting was off. Not by much, mind you, but I didn’t need much. This is an old bike; the pedals are a press fit onto the bottom bracket shaft, essentially a square wedge going into a square, tapered hole,

Anyway, now I’m having trouble with my rear derailleur, but that’s a problem already on the way to being solved.


How to stop dealing with flat tires? I have a very nice fixie bike, which I keep suffering from flat tires. I live in Bogota which is a city full of potholes in the road.

I have been examining options to implement in order to have less issues with this flat tires, I got to know this company which is so far the best option I am considering, but it's quite expensive to order a pair of tires just for me, to Bogota.

So I kept checking and I found this videos in youtube 1, 2 and 3 that shows how to do that with a special sealant. Have you tried that in a fixie? Does that work?

EDIT

In more detail:

I suffer a lot of "bite" punctures (so called here) which are two holes in the tube because of a hole or a sidewalk and the rim pressure.
I don't suffer that much of a single hole puncture.
I don't know exactly the amount of pressure, but always that I inflate the tires, are really "tight" you could say.
I ride almost everyday, home-work-home. Each trip around 13km.
I have flat almost once a week. Sometimes once each two weeks.
I inflate the tires at least once a week.
My tires are one year old.

You are correct that the type of puncture you're getting is caused by the rim "pinching" the inner tube.

The root cause here is one of the following:

pressure too low (most likely)
You're not avoiding potholes carefully enough
Weight is too high for the tires/terrain.

This has nothing to do with fixies except perhaps that people on fixies tend to awkwardly power through obstacles without unloading enough weight at the right instant in time.

There is junk you can inject into your tubes, but that stuff is terrible and increases rotating weight. You don't need it. Also, this has nothing to do with tire quality. Your rim is pinching the inner tube, not something from the outside the tire.

Suggest you increase pressure on tires and avoid potholes. If that fails to work, try fatter tires. It is OK to go beyond the pressure specified on sidewall.


How can non index shifters be limited to a specific range of gears? Searching on eBay, I find shimano SL-MY34s. Description says that they should only be used with 5/6/7 gears. What limits them to this range?

The main limiting factor is probably total cable pull. Moving between the largest and smallest gears requires pulling a certain amount of cable, which is determined by the design of the derailleur. It's possible that Shimano's 8-and-more-speed derailleurs require more cable pull than the lever can manage.

Also, more gears means a smaller movement of the lever to change gear. With five gears, the lever moves about 36° per gear but with, say, ten gears, there would have to be only 18° of lever movement per gear. At some point, the lever movement will become too small to perform accurately.


Is there a benefit of lacing trailer wheel spokes radially instead of crossed? Reading a review of a bike trailer one of the commentators noted that the wheels were laced radially:

It is a 16" wheel. Does this configuration have some advantage making it a good choice? I always had the impression that wheel spokes were crossed for greater robustness.

Cynically I suspect this could just be a way to make the wheels a little cheaper - but cheaper doesn't necessarily mean inferior, or does it in this case?

Crossed spoke lacing is primarily necessary to transmit torque from the hub to the rim, rather than for increased strength, although I suspect hub flanges have more strength when loaded by a crossed spoke. Given a trailer wheel will carry a lower load than a bicycle wheel this does not matter.


Keeping face warm in the winter I regularly use a hat under my helmet and a neck warmer.  This keeps me relatively warm in the winter but leaves a bit to be desired.  What are the best options to keep your face warm?

Some people in NYC particularly those riding electric devices wear full face motor cycle style helmets.  I’ve never tried that but it must keep you warm...

A trick that I found is used by NFL players to keep their face warm :
"A jar of Vaseline is an old trick from veteran players to block out the wind"
source: https://www.espn.com/nfl/story/_/id/14525394/seven-ways-nfl-players-stay-warm-frigid-conditions-nfl

BONUS: If you get too hot with the vaseline on you can use the excess to lubricate your drivetrain.

I think some skiing/snowboard goggles with a clear lense will also help in keeping your face warm.
Something like this:
https://mx-deals.nl/oakley-crossbril-o-frame-jet-black-clear-lens.html?gclid=CjwKCAiAluLvBRASEiwAAbX3GU82TCnNSiATDbKyg5txyfgQ22RLn0RFJsY-fwpcHCIu53Mn8MTdwxoCEVkQAvD_BwE

A balaclava looks like it would keep you warm,

you might draw unwanted attention though.

This might be a more subtle but similar alternative:

There are even versions of balaclavas which have heating elements inside:

https://www.thewarmingstore.com/heated-balaclava.html

A full face helmet will definitely also help in keeping you warm, but it's not the most practical solution. I've done a quick search regarding heated motorcycle helmets and could not find much so I assume it will not be needed even in cold conditions.
One comment I found on a forum thread regarding heated motorcycle helmets (to illustrate their effectiveness at keeping your head warm): "Are you serious? Why would you actually need that? A helmet acts like a thermos for your head because of the EPS liner. Keeps you warm in the winter and cool in the summer."
source: https://advrider.com/f/threads/heated-cooled-helmet.639790/

There are heated face shields for full face helmets but I believe their main purpose is to prevent frosting/condensation on the face shield itself, not so much to keep your head warm. They look like this:


What should I use, VeloPlugs, Rim Tape, or Rubber Rim Strips in new wheels? I'm building two new sets of mountain bike 26" wheels, and I'm wondering what to go with. Both are double walled rims, so in addition to the standard rim tape and strips, I can use a product like VeloPlugs.
Here's my current understanding:
VeloPlugs
VeloPlugs http://www.radfahren.de/typo3temp/pics/2378aa8792.jpg

Most expensive ($7 / wheel)
Reusable
Lightest (~5g)
Double Walled Rims only
Have to measure spoke holes in double wall (8mm vs 8.5-9.3mm)
May lose them when changing tubes, so carry extras on rides

Rim Strips

Mid-range price ($4 / wheel)
Reusable

Rim Tape

Cheapest (~$3 / wheel)
Won't slide around like Rim Strips
Weight (~20g)
Glue may prevent nipples from loosening in single walled rims
Won't slide around on rim
Most common / available

What are other points or guiding factors in selecting which to use?  I'm not concerned with price and availability, I'll wait/pay for the best option. I'm leaning toward VeloPlugs for dual walled rims and rim tape for single walled.
Furthermore, if anyone has used VeloPlugs before, how do you find the diameter of the spoke holes when the rim manufacturers doesn't publish it? Just wait until the rims are in hand and measure with a caliper?

There are advantages to all of them, but tape has always been my preference.

I've used velo plugs, but in my wheels the incidence of loss was too high. They lasted me less than a year, before I lost all the extras, and went back to tape.

I don't use rubber rim strips because the rubber degrades, and they move around too easily.

I prefer Schwalbe high pressure rim tape, because it gives a good seal, stays put, and sticks better than cloth tape like Velox, but still removes clean and easy when the time comes.

I hope that helps.


Is there a minimum weight limit for mountain bikes for USAC riders who are not UCI? Basically the title is the questions, but to repeat is there a bike weight limit for riders who belong to a national association such as USAC, but are not riding for UCI points or registered with UCI? Or is it the same as the UCI limit?

My understanding is that UCI and USAC use the same minimum weight limit for bikes, but for USAC this only applies in certain circumstances. Taken from this document from USAC:

Bicycles must meet current UCI technical regulations at
events that select 17-18, U23 an
d elite riders for international
competition or national teams. A
ll bicycles used in Federation
National Championship (for age
17 and older riders) and NRC
races must comply with
the current UCI regulations
.

In other words, if the event you're racing in is not a qualifier for an international event or for a spot on the national team you can disregard the weight restrictions.
For completeness, should one of the above situations be applicable to you, my understanding is that the minimum weight for your mountain bike is the same as it is for your road bike, which is 6.8kg/14.99lbs. However, I must admit that I could not find a black and white answer to confirm this assertion. I think this is largely due to the fact that the nature of mountain bikes is self limiting in terms of this restriction. Unless you have something especially exotic in your stable you're not going to even approach the minimum weight that is explicitly defined for road, track, timetrial, and cyclocross bikes.


What type of shoes should a commuter/road biker use? I have a hybrid bike that I use for commuting (8k round trip to work). Currently, I wear low-backed converse shoes when biking.

I've been biking for about 5 months. After the first 2 months, I started getting Achilles tendon pain. I read about ankling and think that could be part of the problem. I'm also concerned it could be my shoes.

So, what type of shoes should a commuter/hybrid biker look into getting? I'm willing to spend about $100-$150.

I assume those shoes don't have cleats of any sort.

Do you currently ride without toe clips?  Adding toe clips might let you maintain a steadier foot position on the pedals.

But many regular commuters go in for cleated shoes of some sort, very often the "mountain bike"/touring style with SPD cleats/pedals because they're "walkable".

Whatever, you want a shoe with a relatively stiff sole.  Basically this means a biking shoe of some sort, perhaps the afore-mentioned "mountain bike"/touring style.


Its about the wheel size I have recently been scammed by a seller into giving me a 20inch wheel rather than a 26inch one. I didnt have time to check and have left that country where i bought it, forever. Now as i am 17 i cannot obviously fit into the 20inch wheels on my mtb bike. My question is can i replace its wheels with 26 inches one? Is it possible? I bought it for a hefty price and i cannot afford to discard it

It is likely the bike frame will not allow you to put 26 inch wheels on a 20 inch bike frame.  They simply will no fit.  Sorry.  At this point, try to sell it as is and get a 26 inch bike.


Knee Pain and Injury I ride a road bike, mainly on flat terrain.  About two years ago following a 100k ride I had major pain in the front of my knees, just above the patella. The pain did not subside, was present during the following rides,  and I have not been riding (due to a number of unrelated health issues) at all frequently or for any real distance since.

This is the third road bike I have owned - and I have been cycling seriously for about 10 years and have previously completed a couple of century rides.  I do not ride competitively.

I have had two professionals fit and adjust my bike for me - but this was prior to my injury. I now have little faith in their methodology:  After all, I wouldn't be injured if the fit was perfect, right?

My preferred course of action, to ensure I don't repeat the injury, is to make small adjustments to my bike to find a pain-free riding position:  I am currently feeling tweaks in my knees, in the same location, even though I am starting out slowly by only doing 20 to 30K rides.

Can someone provide me advice on how to move forward with this? Please let me know if you need more information from me. Thanks

The pain at the top of the kneecap is classical patellofemoral pain syndrome -- the most common knee problem.  The most direct treatment is simple strengthening exercises for the secondary muscles supporting the knee joint so that the kneecap remains properly positioned -- such exercises can provide relief in 48 hours or less in some cases.

But you should probably consult a sports medicine doc first.

(My personal experience has been that some sort of toe clip or clipless pedal arrangement helps this condition, vs plain pedals, though there are probably arrangements that can make it worse.)

(And probably the easiest way to make the condition worse is to lower your seat too low and pedal too slowly, in too high a gear.)


How do I maintain a Brooks leather saddle? I've got a Brooks leather saddle and i like it a lot, but i am entirely clueless on how to care for it. I know i am supposed to rub some sort of fat on it, but i have no idea what kind of fat, or how often, or how strong or how much, etc.

Can you give me pointers on how to keep it nice or if possible link to step-for-step instructions?

Brooks makes a product called Proofide for saddle care.  For normal use, once or twice a year is likely enough.

To use, start with a dry saddle and wipe off any grit or dirt with a dry rag.  Then take a very small dab of Proofide and spread it on the top surface of the saddle.  You want to spread this out into a very fine layer all over the top (finished) side, don't use too much.  Then let it dry -- probably takes 4-12 hours, depending on how much Proofide you used.  Finally, polish the saddle to get rid of any excess Proofide (looks like a white waxy residue).

There's a Brooks maintenance kit that includes a tin of Proofide, a polishing cloth and a tension adjustment wrench.

Also, try to keep your saddle as dry as possible.  Riding in the rain is ok, but make sure you store your bike somewhere that the leather can dry out naturally.


Identify this BMX logo please? Hi all, having trouble identifying this logo found on my Bmx frame- any ideas?

Many thanks

More info:  It was bought with all high end parts- and was said to be WTP Justice or other WTP frame—couldn’t find other markings but will check in crank space and other areas for any more.

Looks like a "We The People" bicycle logo
You can find the logo in several of their bike catalogs.
This is one of their 2010 catalog with the logo on the cover

When asking questions please be sure to include any information / clues you may have. Your comment "said to be WTP Justice" was the key to finding the logo.


Is there any difference between road and mtb discs? I'm trying to find which discs should be used with a 105 hydro groupset but I can´t find anything.

When I search for 105 dic brakes I'm always redirected to the calipers and not the disc it self, or just articles rim brakes vs disc brakes...

The only thing I've found which I think could be specially for road use and looks a little bit more aerodynamic than other disks are the RT800 which should correspond to ultegra.

Why aren't the discs included in the groupset? It is like buying rim brakes without brake pads.

The specific word you need is 'rotor'. If you search for 'Shimano 105 disc brakes' you tend to get the calipers rather than the rotor (which is confusingly actually the 'disc' part).

The latest 105 series rotor part name is SM-RT70. See the Shimano 105 series page.

There will be other rotors that are compatible with 105 calipers, in case you need a 6-bolt rather than a center lock version.

Calipers don't come with rotors because different sizes are required for different applications or preferences.


What are the advantages and disadvantages of different pedal formats for a recumbent? We're reasonably familiar with pedals on conventional bikes.

Flats are convenient for normal shoes
Clips and Clipless provide foot retention and option of pulling up

A recumbent has additional considerations

No way to "rest" the foot on a pedal because your foot pushes from behind nor down from on-top.
Heel strike - just the same as toe overlap for smaller DF bikes, heel strike is where your front wheel/s touch your foot while turning.
Getting started from stopped - pedals are a lot further from the ground so raising your foot in time for the second push stroke while maintaining low speed balance.
Danger of "leg suck" should your foot fall off the pedal and hit the road while rolling.

What other considerations are there for choosing a pedal for a recumbent bike or trike?

You can add "heel slings" as a choice too.  They hold under your foot's heel.

They fit flat pedals and do not provide any cliplike retention.  Instead they are a hammoch for the back of your foot (heel) to rest in.

http://www.bentrideronline.com/?p=5131

These wire ones look uncomfortable, but shoe choice comes into it.  Prolly not good for flipflops or sandales!

http://www.jsrldesignllc.com/  and    https://tadpolerider2.wordpress.com/2017/09/15/jsrl-design-vs-terratrikes-new-heel-slings/

Terratrike sell some that are more strap and less like a garrotte-wire.


Truing an 'out of round' wheel I am building my first wheelset.  The front wheel went without a hitch - nice and true both radially and laterally.

However, the rear wheel has a pronounced (5mm) bulge over about 1/4 of it. The rest of the wheel is pretty much true. As far as I can tell, I should be tightening the spokes around the bulge area, but they're already significantly tighter than the rest of the wheel, and the bulge isn't coming out.

What should I do at this point?  Is it worth loosening the spokes everywhere else so that the rest of the rim settles out? Wouldn't that bring the spoke tension to be even less even?

Thanks

Whenever I get stuck wheelbuilding, I loosen every spoke one turn, walk away and come back in a few hours or the next day.

The worst thing you can do is keep doing something that is not providing the results you expect. It is completely possible to overtighten spokes enough that they stretch significantly under the tension. You can even break them with a bow and arrow like result that can be slightly terrifying. ( Fortunately the spoke was pointed at the ceiling and not me when that happened. )

Part of wheelbuilding is getting a feel for how much tension the spokes will support. There is a point at which tightening them further just does no good and actually makes the wheel worse, not better. In the past when rims where just boxes made as light as possible and spokes were more burly, you'd get wonky things happening to the true to let you know when you'd gone too far. Now most rims have enough structual shape that they won't deform that way and the spokes are much lighter.

In my experience out of round truing almost always requires adjusting all 4 quarters of the wheel. ( i.e. the trough as well as the bulge. ) You can't fix
it by just working on one section.

If tightening stops working, it's time to take some tension out of the entire build. Start by loosening the spokes you've been working on a half turn at least and then start loosening other spokes to achieve the affect you want. If that still doesn't work, loosen all the spokes and start over.


Scott Addict R2 2008 crankset replacement I want to replace crankset on my Scott Addict R2 2008. Current crankset is Dura Ace 7800. If I looked correctly then currently I am using BB SM-BB71-41. New crankset will use BB386EVO.

Which BB do I need for this crankset? Probably BB for Pressfit BB386EVO?

Are there any other limitations (frame, ...)? Which BB is compatible with this frame and crankset?

It looks like your frame uses BB86, so you'll need a BB86 bottom bracket for BB386evo cranks: https://www.bike24.com/p2114179.html


List of tools to take apart a bike to minimise space for storage I have a bike that I would like to take apart to store for the winter. I live in a college dorm and don't have much space. What are the basic tools that I would need to take it apart?

I think taking apart the wheels, pedals, and handlebar will be enough.

Ex: Screwdriver, wrench

The bike is a Trek 7.2FX

You want to remove the wheels, seat post (you may be able to get away with setting this all the way at the bottom or doing nothing depending on how you're storing it), handlebars and pedals. If you can go to your local bike shop and get a (cardboard) box for shipping bikes, the bike should pack in nicely for storage. This video shows you the steps in a nice way visually. You're not shipping it, so you don't need as much bubble wrap and straps and foam, but bubble wrap is nice.

The tools you'll need are likely a set of metric hex keys (mostly 5 mm, possibly 4-8 mm) and a thin adjustable wrench (maybe a pedal wrench too).

To remove the wheels, you likely have quick release wheels, so just pop the lever and unwind it. Undo the brake's quick release and the wheel will come out. Be careful not to let the derailleur get impacted as that can make it come out of adjustment (e.g. don't drop the bike when you have the wheels removed).

The seat post will be either a hex key or quick release. If its a hex key, try the appropriate size hex key (4-8 mm). If its a quick release, pop the lever and unwind it. If you're not using a bike box, I'd stuff the seatpost with a bit of newspaper or something in case critters make a home there. The seatpost is also likely to be greased, so wipe it clean.

The handlebars should be removed and put to the side of the bike. I wouldn't disconnect any cables.

(from http://brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2010/08/moots-rsl-road-bike-review-stem02.jpg)

Simply remove the bolts on the front of the stem (the four bolts on the front of the red piece, in this picture), put the handlebars to the side of the bike and re- attach the red piece (so you don't lose it). You may want to tape them to the bike to prevent them from moving.

For the pedals,  you'll either want a thin adjustable wrench which can adjust to about 15 mm or a pedal wrench of the appropriate size (a combo 15 mm + 9/16" will be fine). Note the left hand side pedal (when you're riding the bike) is counter threaded -- that is, it tightens counter clockwise, rather than clockwise. The right hand side pedal tightens clockwise. Remove the pedals. Wipe the pedal threads and crankset eye clean.

This should all fit nicely into a bike box which would be ideal for storage. Gloves may be nice for preventing your hand from getting messy. To re assemble the bike, do this in reverse, making sure to grease your bolts + pedals + seatpost appropriately.


Do I really need to replace my helmet every 2-3 years if it hasn't been in a crash? OK, I know from the top answer here: When or how often should I replace my bike helmet?, that I should buy a new helmet every 2-3 years, even if it hasn't been in a crash and shows no signs of damage.

But can someone explain to me why this is so? I'm not trying to be a cheapskate, but just want to know why the helmet would degrade just with regular wearing? Do motorcyclists replace their helmets every 2-3 years too?

And don't tell me that this is what the helmet manufacturers recommend. Of course they will say it should be replaced even if there is no visible damage. Reminds me of the adage: "Never ask a barber if you need a haircut".

Appreciate any input/insights you can give.

The Bicycle Safety Institute disagrees with the 2-3 year rule. They have a good page on replacing helmets.

I usually replace one when the foam rubber gets old and crumbly, when the adjustments quit working, or when I damage it. UV can deteriorate the plastic if you leave it outside a lot. And, if you ever "use" a helmet, i.e., crash and save your skull with it, you should replace it because the styrofoam and outside plastic can weaken.


How do I gear up a bike for winter riding? I live in NYC and would like to ride to work during the winter as well. What should one do to a mountain bike?  a road bike?  If you can also show products that you actually use that would be great.

In the winter you will have to contend with:

Ice and snow on the road
Wet
Freezing bike parts
Cold winds
Overheating

1. Ice and snow on the road

This past winter I used the Schwalbe "Marathon Winter" tires for a 3-mile commute along a rural highway and town streets in central Vermont. Our winters are quite a bit more severe than NYC, but if you have ice on the streets that might be unavoidable, studded tires are a must.

(photo from Flickr)

At $74 a piece from Peter White Cycles, they aren't cheap, but they are decent in light/thin snow and fabulous on ice. Each tire has 240 tungsten-carbide studs, whose sharp (cylindrical) tips haven't dulled at all for me. While knobby plain-rubber tires will grip alright in snow-on-dry-pavement, as soon as a thin layer of ice forms on top of the pavement (either due to a melt-freeze cycle or packing by auto-tires) the rubber tires will very quickly loose any ability to grip and will send you down hard. With these tires I've had no problem riding a hundred yards on a large patch of black-ice on a fast downhill.

2. Wet

As freiheit mentions, your other big concern is being wet since even if it isn't raining, puddle-splash and lighter mist from passing vehicles will moisten you up. As well, your own tires will throw off a lot of water from wet roads (fenders are very helpful for this).

You have quite a few options to stay dry. Since my commute is only 3 miles, I wear gore-tex rain pants and jacket over my normal work cloths. I also keep a pair of shoes at work and bike in hiking boots during the wet months of October/November and then switch to snow boots January-March.

3. Freezing bike parts

When the air temperature is below freezing and your bike gets covered in moisture you can expect ice to build up. I keep my bike in my warm office at work (on some mats to catch the drips) and in an unheated shed at home. I haven't had repeated problems with freeze-ups, but did have to melt some ice off of the derailleur with a hair drier at home once. If you can get the bike warm at least once a day and keep it stored under a roof you shouldn't have too much build-up. Just remember to test your brakes frequently in case a layer of ice forms on your rims.

4. Cold winds

Due to the speeds of riding, you will almost always have at least 10mph of very cold wind to contend with. Your rain gear will help with that, but you also need to protect:

Your hands
Your head/ears
Your face

There are many options for gloves and mittens available, just make sure that you choose something wind-proof and waterproof. For the coldest parts of the winter I use a pair of gore-tex mittens marketed for skiing/snowboarding. I don't find the mittens to get in the way of shifting or braking on my commuter bike, but others prefer gloves for more dexterity.

There are many helmet-liners and covers available to keep your head warm under a bicycle helmet, but I just use a ski helmet (the Giro 9) since it has built-in ear protectors, changeable amounts of ventilation, and nicely fits goggles.

For most of the coldest months I ride with ski goggles. These keep the wind off of my eyes (which otherwise water a lot in the cold wind) and keep most of my face warm. They are also great for protecting the face when it is snowing or sleeting. On a few bitter cold days I've also added neck warmers to cover the lower part of my face, but usually the combination of goggles and the neck of my coat are enough.

5. Overheating

Counter-intuitively, my biggest challenge with winter commuting is staying cool. My commute profile is a broad 'w' with downhills at the start each way, a few small hills in the middle, and an uphill at the end. For the first large downhill I try to be a little on the cold side so that I can be comfortable for the rest of the ride. Often though, I bundle up a bit too much and overheat later. The best technique I've found (when riding in work clothes rather than changing) is to layer breathable sweaters or fleece so that I am just short of comfortable out of the wind, then add the wind-proof pants and jacket with the pit-zips and other ventilation open. The wind-proof material will keep most of the wind from cutting through while the ventilation openings will allow enough air circulation to stay cool.


Which rear mech to replace sram X-9 10 speed 2x10 I have a Whyte 905 2011 with a 12-36 Sram cassette and an X-9 medium cage rear derailleur. It's not been attenuating well for some time despite efforts to adjust. The bike shop couldn't fix it. So i'm thinking i need to replace. The X9 appears to be discontinued (and forums suggest people had problems with them) but i could get an ebay replacement. Sram  now appear to be going with the GX-Type 2.1. Is that the mech i should use? Thanks!

You need to purchase a SRAM 10 speed rear derailleur to ensure compatibility with your shifters. SRAM previously made a wide range of derailleurs for X5, X7, X9, X0 and XX but have limited their range to GX and X0 following the market shift to 11 speed drive trains.

GX has replaced the old X7 and X9 price points.

Your options are limited as SRAM and Shimano rear derailleurs/shifters are not compatible.


Solutions for a slightly loose crown race For a bike I'm building, I had my headset crown race press fitted to my fork crown by my LBS, along with my top and bottom cups into the headtube. The crown race was loose such that I could rotate it with my fingers, but there was no discernable lateral play. I was actually able to remove it with my hands, but it's not loose enough to put back on just by hand.

The headset is very good condition English-threaded Shimano 600 HP-6400. The fork is Italian threaded. My understanding is that the fork would expect a 26.5 mm diameter crown race, while the English headset has a 26.4 mm diameter race.

I measured the OD of the fork crown and it is exactly 26.4 mm (digital caliper). The crown race has an ID of 26.42 mm. What are my options? I really would like to use this headset.

(I hope it's clear to all that this is not an ISO vs JIS issue, and neither part is 27.0 mm.)

Thanks!

I was checking out Sheldon's website again and came across the following line in the article Servicing Bicycle Headsets:

  If the crown race is loose, sometimes you can fix it by using a hammer and centerpunch to create a series of "craters" in the side of the surface that locates the crown race. The raised edges of the craters may be just enough to remove the slop.

Although I was skeptical, this actually did the trick! I made punches 1/4" apart around the fork crown. Once I fitted the crown race again, there was no play at all.


Can anyone tell me what make or brand this frame is? I can't figure out who made this or what brand maker it is. It has the serial number and on top of it it has a different number.

G0Q230-2
Wbdo26l0431p

Sorry  serial numbers are only helpful if you already know the manufacturer AND they used some kind of system, AND kept records AND EITHER those records are available for searching, OR someone has figured+published the encoding system.

As it stands, I see a BMX frame with rear brake mounts for either U brakes or possibly V brakes if its more recent.  This shows it had rear brakes when built.

The trackends show its a single speed, so no gears.

The large bottom bracket housing shows it was probably a 1-piece crank, not a 3 piece crank like a nicer bike.

Upshot - it could be any brand, but the odds are its a low-grade big-box-store kids bike.   I do hope you have more of the bits than just the frame, else building it up will be expensive.


Does a Sturmey Archer 2 speed kick shift hub let you backpedal? Does a Sturmey Archer 2 speed kick shift hub let you backpedal?

A backpedal / coaster brake changes riding technique so much it drives me nuts; I am wondering if you can backpedal at least enough to reposition your pedals for starting (or while doing a track stand using your front brakes).

The original Sturmey-Archer 2 speed kick-back hubs are coaster brake hubs and do not allow much movement backwards before the braking happens.  Track standing on a coaster brake would be tricky because the pedal position would always rotate in the direction of travel and you would eventually end up at the dreaded 12 o'clock position.

The new versions have two models;

◎ Type S2 2-speed freewheel hub ,without brake
◎ Type S2C, B2C 2-speed hubs ,with coaster brake.


how do I adjust the wheel? I've just fixed my flat tire on the front wheel and now I found out that if I try to push the wheel to the sides it kind of moves a little. it feels like it's not secured to the hub. How do I fix that?

I tried to remove the wheel from the fork and to tighten a little the bolts from the sides of the hub - but it made the wheel to spin awfully!

Your basic bicycle hub is simple yet complex:

At each end there are bearings, either loose balls or a set of balls in a "cage".  They fit into the "cup" recess in the end of the hub body, then the "cone" is screwed onto the axle shaft to hold everything together.  A "lock nut" tightens against the cone to keep things from working apart.  (Note that this lock nut is different from the nut used to secure the axle to the frame.)

Adjusting an axle involves screwing one of the cones in or out as needed to achieve smooth motion with neither looseness nor a sort of drag and rough feeling (when the axle is spun by hand).  Then the lock nut must be tightened against the cone.

In order to do this adjustment one needs a "cone wrench", an inexpensive, non-adjustable open-end wrench that is very thin.  These are available online or from any bike shop that sells tools.  (Alas, there are several sizes, and you need to find the right size for your axle.)  The cone wrench must be used to hold the cone while the lock nut is tightened against it.

This adjustment is apt to take 3-4 tries to get it right the first time -- the cone must be very slightly loose before the lock nut is tightened, as doing so pushes the cone in slightly.


Bottom bracket creaking I replaced my bottom bracket with a Shimano 113mm cartridge.

Now 3 months later its making a creaking noise; the sound goes when free wheeling though.

Do l need a new cartridge?

Creaking from the BB area can be hard to localize, but there are basically 5 sources:

The cups holding the cartridge in place are a hair loose, and the cartridge is moving around a bit.  Not a real big deal but should be fixed.
The BB cartridge bearings are going bad somehow.  Unlikely.
A pedal is making noise.  Sometimes this is indicative of a bad bearing, sometimes it's just what the pedal does.
The pedal is loose where it's screwed into the crank arm.  Needs to be fixed fairly soon, or the crank arm can be damaged.
The crank arm is loose on the crank axle.  This is a serious problem and needs to be fixed right away (if not sooner) to prevent damage to the crank arm and the axle.


If a derailleur cable snaps on a long ride, how can I keep going? A couple weeks ago I rode around Crater Lake, a 35 mile ride with over 4500 feet of cumulative elevation gain – the sort of ride you really want functional gears for.

The night before my rear derailleur cable snapped while I was biking home from work. I was able to make it to the bike shop with minutes to spare before they closed, and bought a replacement cable. Everything worked fine on the ride, but it got me to wondering what I could do if my cable had snapped a bit later and broken mid-ride.

I'm not sure if this is universal, but on my bike and many I've seen, if the rear derailleur cable snaps, the rear gear will slip down to the smallest-diameter gear (i.e. the highest gear). This would make it almost impossible to climb significant hills and get home.

Is there any simple fix one can do in the field with just basic tools that would enable you to get home on a broken derailleur, specifically when there are significant climbs that can only be done in a lower gear? Is there some way to force the derailleur to a certain position that you would find most useful, and keep it from slipping down from there?

"Nothing is so broken you cannot make it worse" - breaking a perfectly good chain in the field, miles from nowhere, with a light weight emergency tool, would be my very last resort.

This will only work if the broken end is not too frayed. Remove the cable completely from the outers and the shifter. Thread the cable though the barrel adjuster on the dérailleur so that shifter end of the cable is butted against the adjuster. Clamp the cable onto the dérailleur (as you normally do, just with a  very long tail) with the dérailleur in a compromise position (usually middle of cluster, but towards the big cogs if you have hills to climb, and little cogs if you have lots of flat ground.) Adjust dérailleur with the barrel till its sitting on the chosen cog.  Cable tie/tape the remainder of the cable safely out the way (this is really important.....) - its unlikely you have have anything capable of cutting the cable so do not try.

If you cannot thread the cable, you my get away using something else - a cable tie, a piece of string or binding wire may be able to be used - whatever comes to hand.

This will leave you with a 2 or 3 speed bike using the front dérailleur - much better than single speeding it and a lot easier than breaking the chain.

Chain breaking to make a single speed is still an option if these attempts fail.

Edit : Feeling ingenious - if you are lucky and the cable and outers can be reconfigured......
If you have a separate shifter, and the cable is broken close to the dérailleur, you could remove the shifter from the handle bars, and clamp/tape/cable tie it onto the seat post. Rearrange the cable outers, connect the cable back up to the dérailleur, giving you a full range of gears - although shifting won't be as easy.


Can I fit road tyres on a cyclo cross bike? I've been considering purchasing a Boardman Pro CX Cyclocross Road Bike Large 2010. (Broken link replaced with Google search)

The spec says the wheels are 700C and that it comes with 700 x 35C tyres. I'm wondering, should it be also possible to fit some thinner road tyres with sizes 700x20c, 700x23c or 700x25c?

Yes, you can! It looks like that bike comes with Mavic CXP23 rims, which can fit down to 19mm tires I think. You would defiantly have no problem with 700x23 tires. I'm surprised it comes with 35, that seems a bit wide for those rims, but you should be OK.


Do bikes with carbon frame get detected by induction loops? Induction loops in my experience usually manage to detect bicycles with steel and aluminium frames. Do carbon frames also get detected? I'm wondering if a possible inability to trigger induction loops would be a reason against carbon frames.

EDIT: Thanks for the comments and answeres that came in already. Can in addition someone speak from experience?

The loops actually detect the metal in your wheel rims more than the bike frame:

So it's less about a carbon frame and about having carbon or plastic wheels.

One trick if the loop doesn't detect your bike is to tilt your bike so that the crank and pedals (which are mostly made of metal) are nearer to the loop and the ground.

Some areas will paint the road with the location of where the loop is most sensitive to bicycles.

They also sell magnets to help motorbikes trip automotive loop sensors but I'm not sure of how well they work -- on motorbikes or bicycles.

Addendum: I have a big honking ebike so I don't have problems tripping the bike specific sensors here in California. In Connecticut where I rode a road bike and the sensors weren't configured for bikes, only cars, I did have more trouble both with my motorbike and my bicycle and I seriously considered getting a magnet.


Changing freewheel singlespeed cog I bought a Soma flip flop singlespeed and the free side cog is a piece of junk. I've ordered a White Industries freewheel cog to replace it and my question is, how is this done and what tools are required? Well, actually two questions. Thanks, JB

You need a freewheel remover tool which fits the cog you have. Park Tool makes a lot of these, and has some excellent directions for replacing the freewheel here (and in the unlikely event you can't get a remover tool which works, there is a destructive way of removing freewheels, which is a last resort - we will assume you have the tool). Sheldon Brown also has some directions here.

Roughly speaking what you'll do is you'll look at the freewheel you have, buy the appropriate freewheel remover tool and a large crescent wrench or similar. Then, you'll put the freewheel remover tool into the notches on the freewheel and snug up your quick release skewer / axle nut to hold it in place. Then, using a crescent wrench or vise, turn counterclockwise for 1 turn of the freewheel remover tool, and then remove the QR skewer / axle nut. Then, use the crescent wrench / vise to remove the freewheel the rest of the way (still counterclockwise).

Installing the new freewheel is straightforward - apply anti-seize, thread it onto to the mounting threads (take care not to cross thread) all the way, and you're done. It will feel weird at first, but as you ride more, the freewheel will tighten down on the hub. You can also use a chain whip (clockwise) to tighten it down all the way if you want, before you ride (this will prevent the weird feeling).


Fortified Bicycle appears to gone out of business -- where to get one of their replacement bike light batteries? One of the two rechargeable batteries that go with my Fortified Bicycle's lights appears to have started to die permanently. (The other remains in good condition.) I have looked through eBay and found nothing there. Can I get usable replacements from another manufacturer via an online battery story or bike store?
I do not know much about bikes but I can tell you that these batteries recharge using ports. Printed on the battery: 18350 950 mAh 3.7 Li-Ion. These connect via port to a computer or charger for recharging.

If your light is not sealed, and you can see a battery that looks like this

(the colour/color does not matter) then you can pop out all the old batteries and fit new ones.   Replace all the batteries in one light together, don't mix and match.  The old ones should be recycled properly.
If the current batteries are soldered in, then its still possible to swap them, just takes more effort.
Aside, "18350" is a dimension, being 18mm across, 35mm long, and 0 means a round/cylindrical casing.   18mm diameter is slightly thicker than a common AA battery which is a 16mm diameter.
Matching the voltage and chemistry is important - you can't put a 1.5V battery in place of a 3.7V battery, because it probably won't work and it definitely won't charge safely.  Matching the size helps stop things from rattling about and becoming loose.

Additionally there is another size of battery called a 16340, which is 2mm smaller in diameter.  This is also known as a CR123A, which might be an acceptable fit if you add some tape around the outside as packing.  Note this battery can come as a disposable or as a rechargeable lithium-based chemistry.  Don't recharge a disposable.


Do all stems have the same stack height for the steerer tube clamp? Does the height of the steerer tube clamp differ between stems, or is there one standard height used on all modern mountain bike stems? In my particular case I want to replace the stem on a mountain bike with a shorter one, but can I pick any other threadless stem and have it fight right on without needing any more/less spacers etc.?

No, the clamp that mounts to the steerer is not a standard height. There will be slight differences in the stack height of the clamp itself between different makes and models of stems that can typically be accommodated for with addition or subtraction of a small number of spacers, or the difference may be so slight that you don't have to change your spacers at all.
Spacers are cheap so don't sweat it. The only situation where you could run into trouble is if you have no spacers and a steerer that is already nearly too short and you move to a stem with a taller steerer clamp (stack height). Doesn't sound like that's an issue in your case, though.


Hybrid Fat/Snow Bike I've seen some bikes with a pugsley or similar fork and 3"+ tires on a hard tail mtb frame.

-Has anyone done this them selves?
-Do you really notice any flotation with only one fat tire and one regular? (2.3" is the max my rear triangle will accept)

You're describing a Fat-Front setup.

Cornering on soft surfaces should be improved, as well as shock absorption if you run low pressure, but drive would only improve in the case where the fat front tyre can compact snow enough for the regular rear tyre to dig in less than it would on a standard MTB.


What is the axle thickness of the Kent Road Tech 700c bike? I need to know in order to find proper fitting anti theft nuts to keep the wheels from being stolen.

I can't find "roadtech" on www.kent.bike so there's no real way to look it up in the catalog.  I could only find some pictures on mass-market websites, and from the look of it, you've already got regular solid axles with hex nuts.

If I had to guess, I'd say 9mm on the front and 10mm on the rear, but that's totally a guess.

Your best bet is to measure.  Take one front nut and one rear nut to a hardware store and see what size bolt fits.  9mm and 10mm are the most likely, but 12mm and 3/8" are also possible.

The other thing you could do is just lock the wheels to the bike and park in a public place.  Those locking nuts are really expensive.


Chain guard for a belt-drive bike? So this morning I'm riding to work on my shiny new tourer, when my trouser leg gets caught in the Gates belt drive. Not good!

I'd rather not go the leg-strap route if I can avoid it, which leads me to ask whether a chain guard or chainring guard exists that would fit over a belt, given that the belt is wider than a chain. The crank is a Shimano Tiagra, if that matters.

There are chainguards that work with derailleur bikes. Your belt might be wider than a chain, but it isn't wider than a triple :-)
Something like http://www.sjscycles.co.uk/hebie-chainguard-for-triple-ring-systems-with-a-48t-outer-ring-prod19993/
(If you've got a 52t chainring, it might be trickier to find something that will fit.)


Gears jumping/slipping from the rear cogset on a new bike Its been 1 month since I have bought my new MTB (Kross globate 1.1) with 18 gears (shimano)..
Now the problem is chain has slipped twice while riding. First time my speed was around 25kph and second time it was low around 15kph.

And another point to notice is that my gears are not working properly... chain does not move to other sprocket when I change my gear from rear 6 to rear 5 or vice versa, they start changing afterwards...

What could be the problem?

Parts need a break in time to stretch, flex, and do what they do before they kind of settle in. When I worked at a bikeshop, we told our customers to come in after a month or 2 so that we could go through and get everything tuned up to where it should be after the break in period.

Not only is your situation normal, most bike shops WANT you to bring it back to them, so they can get it running the way it should so you are happy with your purchase. Take it back to the shop and have them tune it up, it should be included in the purchase price.


The crank arm slips when pressing hard on pedals with Shimano Nexus I have replaced my wheels with a Shimano Nexus 8-speed internal gear hub set but I may have had the problem before the change. When I push down relatively hard on the crank arm for example starting off quickly or riding uphill fast, the crank arm slips with a jolt. Quite often the chain comes off soon after. I can't really see anything as I'm always obviously riding at the time, and the noise can't be located, but it is very irritating and happens in all gears.

Would anyone be able to tell me what this could be?

I'd start with a new chain as a simple maintenance matter - this should have been done when the new rear cog went on anyway.

Then compare how your new chain lies around the front chainring compared to the old one.  It should mesh fairly well over the whole length of contact, not having phased waves of contact and spaces.

Finally, are you positive its the front chainring skipping?  Your feet are on the cranks so it can still be the back, and you feel it through the pedals which makes it seem to be the front.   Get a friend to ride along side, or try riding on a treadmill or rollers... or even use a gopro and a mount to see what's going on.


I've had a bike in storage for over 10 years. What maintenance does it need? I've had a bike in indoor storage (my garage) for over 10 years. I'd like to get it back into good condition to use for my commute to/from work each day.

What things should I check/replace before I trust it to safely and reliably work on the road?

If the bike was in decent shape when put away, and has not been exposed to the weather, there's probably very little that needs to be done.

The tires would be the biggie -- likely they're checked and may need replacement (though not for certain).  Inflate them to listed pressure and check the sidewalls for cracks or bulges.

Assuming rim brakes, the brake pads may very well be hard and in need of replacing.  But you can't tell for sure until you try.

Otherwise, wipe off the dust, inspect for rust, and put a bit of oil on the chain.  Check that the wheels spin freely, with no play in the bearings, and that the steering tube likewise moves freely with no play.

Give it a test ride.  Make sure the brakes work OK and that the wheels don't rub as they turn.  Try a few corners to make sure there are no odd handling issues.

The shifters likely will be balky at first -- run them through their paces a few times.

Basically, if the tires are sound and the steering is good and the brakes are good and there's no massive rust anywhere, there are likely no major safety issues.  Dependability then becomes your concern, since you will be commuting, and there it's mainly the condition of the tires and how well the shifters work.

[I did miss mentioning cable housings.  The cables should be given a shot of spray lube down the housing tubes.  This is often all that's needed to turn a balky bike into a smoothly shifting/braking one.]


Where does the name "B-Tension" come from? Why is the "B-Tension" adjustment screw so called? Does it stand for anything, have there been A and C adjustments, or is there another reason for its name?

The B-screw is for "Body screw", since it affects the body angle of the derailleur.

B-Tension is Shimano's term for B-screw -- as Sheldon points out, on Campagnolo, the screw behaves the opposite of Shimano.

See Sheldon Brown and Park Tool for more details. Also, see the answer here for more details on what it does.


What is the difference between hub-cone type rear hubs? Assume a rear hub that consist of an axle, hub, cones, loose bearings, lock-nut, with hub space = 135mm, with bolt-on disc brake

Example hubs

Hub 1: Shimano XT  FH-M756 Cost Eur40

Hub 2: Cost Eur23

It seems both hubs are based on the same principle (same tools required to assemble them). But there is a price difference. And the one is branded (Shimano).

Questions

Between 2 manufacturers of such hubs, would there be a significant difference in the quality between the individual parts (axles, hub, cone, bearings, lock-nuts)?
Would the manufacturer of the more expensive hub, produce a stronger axle, more spherical bearings or more smoothly polished cones and hubs than the cheaper manufacturer?
Or are these parts all machined to the same standard quality and the Eur17 difference is for owning the Shimano brand?

I find it hard to believe that for such a standard hub there is much difference in quality.

There can indeed be significant differences in the manufacturing tolerances, quality of materials, quality-control processes, etc between manufacturers, or between the lines of a given manufacturer. No one would pretend that Tiagra parts are on par with Dura Ace parts (in fact people have found that Tiagra-grade chains are out of spec when new).

For all we know, the off-brand hub may be on par with Shimano's, but the point is that we don't know. There's a cyclical (heh) relationship between a brand's reputation and the quality of its products. We use the brand name as a shortcut instead of researching a product's materials, reject rates, etc (much of that information being proprietary anyhow); the reputation is built on quality, and if the quality declines, in theory the reputation does too.

There are ISO standards for hubs (and other bike parts) that limit how far out of spec even a shoddy manufacturer could go.

The real question is not whether there is a difference, but whether you're willing to gamble that the difference is unimportant, or that the value of the time you spend researching the cheaper option to reassure yourself is less than the price difference—assuming you accept that the more expensive option is "better."


Do I need to be aware of my diet? I have recently started biking consistently: commute 2x 5km@12min from/to school + 1x 12km@22min in the evening before dinner almost everyday.

Now I started reading and viewing deeper into the "cycling diet"-thing and realized that I generally eat a lot of sugar(cookies, chocolate bars) and fat(butter) across the day and especially for dinner after a quick power-round.

My question now: Do I have to be more aware of what I am eating or is it just fine for me to eat whatever I want, like I do at the moment?

PS: I don't have any weight problems by any means (55kg@1.73m@18years)

General answer to: 'Do I have to be more aware of what I am eating or is it just fine for me to eat whatever I want...?' I'm pretty sure a doctor or nutritionist would tell you that you should eat a balanced diet, not one that is high in calories sugar and fat. I'm also sure a lot of people in this community will tell you that diet gets more important an you get older and a more sedentary lifestyle is forced on you (sitting at a desk 8+ hours a day).

If you are only doing two 5km rides a day you don't need a special diet - just a reasonably healthy one will be fine.


Best bike for neck in straight position? What is best bike for person with neck problems ?
To be more specific, problems in inclining and looking up - I feel good when I am in straight vertical position. (for example, for long reading I use: http://www.bookholder.com/ )

Or is bike not recommended at all ? (ok, I know second question is for doc)

I've found answer about posture :
I often get a sore neck when riding. How can I adjust the setup of my bike to help prevent this happening?

Here I ask which types of bike (there are so many of them and their variants, including: mountain bike, european city bike, touring bicycle ,recumbent bicycle ) are suitable (and which are the best) for:

flat area
hilly area

(I am going to buy two bikes, each for different city)

A lot of recumbents, including the Cruzbike Sofrider pictured below, allow you to ride in the same kind of seated position you do in an office chair, and the ones that have high bars (instead of having the handle bars under the seat) allow you to mount rear view mirrors so that you needn't turn your neck to look backwards.
Recumbents are lower to the ground than upright bikes, which makes them a fast efficient alternative to "comfort bikes", though it also makes them harder to use than a road bike for fast city riding in dense traffic since you can't stand up to see over cars.

which are the best for:

flat area
hilly area

Recumbents are great for riding in flat areas, though not as good for hilly areas -- they're not quite as stable at low speeds since you can't as easily reposition your hips, and you can't stand up to torque when you run out of gears.

mountain bike, european city bike, touring bicycle ,recumbent bicycle

Mountain bikes can be ridden with back and neck straight but they're designed for people who ride with a slight forward tilt, and they're not efficient on roads.
Many European city bikes are similar to US Comfort bikes, and others like Dutch cargo bikes are designed with carrying capacity in mind.  They're good for riding wearing everyday clothes at a pace that isn't going to get you all sweaty, but are no good for recreational riding with people on faster bikes.
Touring bikes cannot as they have similar geometry to road/cross bikes.
As explained above, recumbents come in vastly different geometries, but many do allow the kind of riding posture you describe.


Reducing noise on a bike trainer I have a JetBlack M1 Pro Mag Trainer. I use my road bike on it, with slick tires. However it is still pretty noisy.

What are the ways to reduce noise from a magnetic trainer?

I found that by using trainer specific tires the noise gets lower (see these for example).

Another thing that usually helps is to put a carpet under the trainer.

Anyway, the major culprit for noise is the trainer itself, so I fear you should buy another model of trainer if, even by using carpet and proper tyres, it's still too much noisy.


Safety check for a used bike I'm a poor student and I bought a used bike. I don't have experience with bikes and I want to make sure that the bike is safe for me because actually I found the bike in a garbage container and the owner offered to sell it for 15 euros. Now I really need to be sure that it's safe!

I saw some videos on youtube to understand what gears are and so on and I found that the gears are working and the chain is switching correctly between the chainrings and the cogs. I also checked the breaks handles and I saw that the bike stops correctly when I press them. The rear breaks need a little adjustment to better stop the back tire.

The only thing I did so far is cleaning the bike. Actually I'm so happy about it that I go outside every few minutes just to look at it. I never had a bike when I was a kid but I know how to ride them :). But anyway back to subject!

Here are what I'm planning to do:

0- One of the breaks handles are not so tight, so it is safe to leave it?

1- Remove the rust from the chainrings, cogs, screwdrivers and other parts. (actually i have no idea how to do that and no idea how to do that in a cheap way, so I posted a question Restoring the original color of metal and chainrings)

2- Change entirely all the cables in the bike because I found them rusty.

3- The tires are completely damaged and I need to fully buy new ones. This is the most expensive thing ever to me since I realized I need to spend 25 euros on that.

So that is basically what I thought of for safety check but I wonder if there are other stuff I need to check or buy/change.

Here are some pics for my bike:

More pictures here: Painting a bike with minimum cost

By far the most reliable way is a visit to the Local Bike shop, find a smaller one with lots of kids bikes and entry level bikes (They know about tight bidgets). It should take less than 5 minutes for them to give you a quick assessment of what needs to be done to make it safe, and most will happily do the assessment for free (especially given they will get a sales of at least 2 tires and tubes)

Tires and tubes - replace.

Wheels - remove from bike and check bearings, adjust if required. If noisy not really a safety issue, but if too loose it is. Check rims for wear from brake pads and big dents. Check spokes for tightness. Check where spokes go into rim for cracks. Ensure the QR levers are tight (They should leave a dent in your palm when you press down to do them up). Check wheels to ensure they are true (Wobble from side to side or up and down) - only a safety problem if the brakes cannot be adjusted tight enough.

Brakes - Adjust so they are tight. Check pads for wear. Lube cables and replace if budget allows. Frayed rear brake is not a safety issue unless the tension side is frayed.

Seat - check seat post is tight and seat bolted on to seat post.

Steering / Handlebars - are all attachements tight (stem, handbars, brake levers and shifters). Do the handles bars turn freely and without play in the head.

Bottom bracket/Pedels - do they spin freely and smoothly without play. Listen for creeks and grinding noises. Look for cracks and damage to the cranks.

Frame - look for visible cracks - its steel so sudden failure is not likely. Go for a ride and jump up and down a few times, listen... Pick the bike up and drop it onto its wheels from about 300mm. Listen to the bike for rattles, squeaks etc. Some are normal, but it can give away a lot.

Rear derailuer and shifters - not really a safety issue unless the chain jumps off and jams. , but do read up how to tune it. Make sure the chain stays on the cogs.


Does anyone sell a direct-drive recumbent with no handlebars? This document well describes the benefits of a direct-drive recumbent. Is there any carbon-frame recumbent, commercially available, that implements all its recommendations.

And what are the pros and cons of having no handlebars like this ?

To the best of my knowledge there are no suitable direct-drive hubs available commercially, which means that there are no bikes sold that use them. Schlumpf make a unicycle direct drive hub that offers 1:1 and 1:1.55 gears, but for a recumbent bike those ratios would be ridiculously low. Also, it's obviously fixed gear so without a freewheel it would be even less useful on a bike.

You may be able to convert a standard hub gear to direct drive, using a larger axle and feeding the drive through the centre. Hubs are designed to have drive from one side, and pedalling torque is quote large so this would probably involve a major redesign of the hub (I suspect this is why so few people have built them). Another problem is that hub gears are designed to have 2:1 or more gearing up from the chain drive before the hub. So once you got it working, you'd have lower gears than you expect. Using short cranks is a partial solution to that at best, but it's the only thing I can think of that might help. Greenspeed suggest that 100mm cranks are quite usable with only a slight loss of power (but higher rpm = lower gearing needed)

Your second question, about having no handlebars, is much easier to do. Most front wheel drive, moving bottom bracket bikes can be ridden hands-off, and it's relatively easy to learn to ride without the handlebars at all. The problem is that most countries require bikes to have handlebars (it's an offence to ride without holding them).

One problem I see with the design you link to is that it's partially rear wheel steered. That will affect stability (making the design somewhat harder, but if you're buying one they've already solved that problem). But it will also affect turning. To turn away from something, the rear wheel must move towards it. All rear wheel steer vehicles suffer from this problem. One partial solution is to use a tadpole tricycle configuration, so that the rear wheel is between the front wheels and thus can move sideways as far as one front wheel when turning away from a kerb or other barrier. For a bicycle, the solution is to stop and lift the bike away from the barrier. The problem is that if you run up next to a barrier at speed it may be difficult to stop without hitting the barrier. That's annoying if it's a kerb and you end up sliding along the footpath, but can be dangerous if it's a wall or hedge.

With unusual bikes that someone is selling, I find it's helpful to ask how much someone other than the inventor has ridden one. If they've sold a few and someone has ridden a couple of thousand kilometres on one, then great, it's probably usable. But if it's a great project by one person and you're going to be the first real customer... be very careful.


Can I use SRAM DUB Red Crankset in a Trek Madone SLR 7 that requires GXP? I have an Allied Alfa Disc with SRAM Dub and Red AXS Crankset (with Quarq pm).... and I want to switch all my components onto this 2020 Trek Madone SLR 7 Frameset. My LBS says I have to buy a new SRAM crankset with a GXP spindle.
Is that the best option? Can I do something else like use different bearings or this kit?

Modern cranksets either have 24mm-ish width spindles, or 30mm-ish spindles. DUB (28.99mm spindle) falls into the latter category. GXP spindles (24mm, tapered to 22mm on one side) fall into the former. Almost all press fit bottom bracket shells can take cranks with 30mm or similar spindles. Trek’s BB90 bottom bracket standard appears to be an exception. That is described in this Cyclingtips article and it appears confirmed in this BB compatibility matrix by Ceramicspeed. The article was written before SRAM introduced the DUB standard with its 28.99mm spindle, but the Ceramicspeed document seems to indicate that BB90 shells aren’t compatible with DUB spindles. Consider that the BB90 shell has the smallest internal diameter of all the press fit shells. It has a 37mm internal diameter, while the next smallest shell has a 41mm ID. There is not be enough space to fit the DUB spindle and adequately sized bearings in a BB90 shell.
The BB90 bearing kit you linked to will fit GXP spindles only. You can’t cram a DUB spindle in there. It does appear that your only option is to get a power meter crankset with a 24mm or similar width spindle. You could also switch to a different power meter type, e.g. pedals, which are definitely worth considering if you’re already using Look pedals. The BB86 bearing kit you referenced in comments will physically not fit in your BB shell; BB86 shells have an internal diameter of 41mm, but your Madone's BB90 shell has an ID of 37mm.
As a side note, I suspect this is part of the reason that Trek is moving toward the T47 threaded bottom bracket standard. They did so on several 2020 bikes, including the Domane and Emonda - however, they did not update the Madone (the aero road bike) in 2020. For the record, T47 uses the same internal diameter and width as PF30 (46mm and 68 or 73mm depending on road or mountain bike). However, the interface is threaded, and the bearings sit just outside the frame, whereas most PF30 bearings are just inside the frame. Placing the bearings and their cups externally enables them to be bigger, and the wider spacing should mean lower loads on the bearings. Both should mean longer bearing life. I am not convinced that 30mm spindles are noticeably better than 24mm spindles, but the market did demand 30mm, and it was always a problem that Trek's BB90 couldn't accommodate those spindles. In theory, someone might be able to design a DUB BB90 BB, but there is not much space to play with. If it is physically possible, there's not likely to be much demand for that application because Trek is moving away from BB90, and that standard was proprietary to Trek.


How to protect bike frame mounted on the carrying rack? The ropes I fix the bike with on the rack and the rack itself (although covered with a plastic layer (an old inner tube) make marks on the frame. I would like to avoid using extra pads, sponges or foams that always gather dust and dirt or fall off the correct place. Is there any special trusty method?

Pool noodles, cut lengthwise and held in place with gaffer tape (or hockey tape if you're so-inclined)

Bonus marks for colour-coordinating with your bike and car.   Do the whole length of the rack upstand, not just the contact point.

Like this but on the upstand too, not just the tines.

You could put the protection on the bike, like this, but its more likely to fall off.  Velcro cable ties can help here.