Chain slip causes bent derailleur The chain of my bicycle slipped of the top sprocket and cause the derailluer case and hanger to bend. Anyone experienced this?

Edit - More Info:

I crashed a couple days ago before the derailleur got bent and after the crash, I realized that when I try to shift to the big sprocket stationary ,it sometimes will slip off and goes to the back of the cassette. I thought it won't be much of a problem and told myself just to not try and shift to the largest sprocket. But during that time when I was cycling, I tried to shift to the second largest sprocket but accidentally shifted too much and I think that caused the chain to slip to the back of the cassette.I was pedaling really hard at that time and I think that bent the derailleur.

The derailleur was really badly bent since it was facing up, I had to push it back to its original place as the bike would not move. After I did that, I saw that the cage plate (if I'm not wrong) was bent towards the spokes, applying pressure on to them, and making that ting ting sound. So I used some force to try and bend it back so I could go home. Now that I'm looking at it, I saw that the cage plate was both twisted and bent and the rollers are not aligned. The chain is also not on the top roller and is laying on the the cage plate.

Edit:Changed the rear ,working fine now. Thanks for all the help!

I crashed a couple days ago before the derailleur got bent and after the crash, I realized that when I try to shift to the big sprocket stationary, it sometimes will slip off and goes to the back of the cassette:

It sounds like the derailleur was already damaged in this crash, causing the shifting to be off. Perhaps the hanger got bent, causing the cage to point inward, throwing the entire shifting alignment in the direction of the wheel hub, thereby allowing the chain to derail from the largest cog. This is a bad situation if, additionally, the derailleur makes contact with the spokes.

In this situation, the lower limit trim screw won't help, because its action plays out in the pivot mechanism above the cage.

If you're prone to damaging your derailleur, consider installing a derailleur guard.


Can I mix shifter (deore m4100 10 speed) with my Rear Derailleur (deore m6000)? Can I use deore m4100 10speed shifter with my RD deore m6000 10speed RD?

Yes, all Shimano mountain 10 is the same actuation rate for rear derailleurs as can be seen in the compatibility chart:

Note that 9, 11, and 12 are all different, so speed generation mismatches are the thing that doesn't work.


Will magnetic pedals interfere with ebike batteries or motors? I am wondering if magnetic pedals would induce current in mid-drive ebike motors or batteries.  I am assuming for theoretical purposes, they would, because all oscillating magnetic fields induce a current in everything conductive within their lightcone, but for all practical purposes, the effect would be so negligible as to be unmeasurable, but I don't really want to do the calculations myself.  Is there any research out there on this, or can anyone do any napkin calculations?

They won't interfere with the batteries (which aren't sensitive to magnets) or the motor (which contains stronger moving magnetic fields). Anyway even in the worst case both are a good few cm away and magnetic fields reduce quickly with distance.
Even wiring run along the downtube is reasonably well separated from the pedals, and it takes a lot to induce a measurable current in a straight wire with even a strong permanent magnet (I've tried - even a coil has trouble picking up much unless far closer than your setup would suggest). A problematic current would be even harder to induce.
There's a slim chance they might interfere with a magnetic cadence sensor in the cranks, which some electric bikes use to sense pedalling to know when to assist. You may be able to whether a particular model uses that sort of sensor.


Help identifying a vintage Diamondback full suspension MTB Can anyone help me with identifying a vintage Diamondback full suspension MTB? I know there are a ton of similar requests, but I need parts and I am stuck without the correct model/year of this Diamondback frame.

Regards and thanks for any help offered

Peter

Looks like a late 90s BSO.

I also notice the boots/stanchions from the forks have rotted and dropped off.  And that you're missing the front brakes completely.

Not only that, the front rim is completely missing a rotor and doesn't even appear to have a rotor mount.   I suspect the front wheel was replaced at some point.  As such, this bike is not safe to ride.

The suspension is a spring with a damper on the inside.  The damper will be purely cosmetic and any damping capability will have long since vanished.  I found that a 60 kilo teenage rider could over-compress the rear suspension making the whole bike extremely saggy to ride.

That frame shares a lot with this late 90s Raleigh RFX

UPSHOT  If you have a disk front wheel, rotor, and spare working front caliper/lever already, it looks like a straight forward tune up.  If you have to buy any more than cleaner and lube then think twice.  Unless its sentimental in which case its your decision.


What is the typical structure and location of a check valve in a floor pump? I decided to take apart a Bontrager reCharger floor pump recently on a whim, one of those whims during which you pay no attention at all to what you're doing. After putting it back together, the pump now admits air so that when connected to a full tyre the handle goes all the way up by itself.

Looking both here and at manufacturers making more serviceable models reveals the existence of one-way check valves within the pump itself to prevent air escaping from the tyre. Never thought about this and had always assumed it was either handled by the inner tube valve or some magic in the pump connector.

What do these check valves look like and where are they typically in a pump? If anyone knows the answer to this specifically for the Bontrager reCharger, or would be willing to spend two minutes taking theirs apart more carefully than I did to look, then that would also be very useful. I have a feeling something went boing and I'll find it under a skirting board in a few years time.

There are also some genius solutions out there which I might have to try.

Thanks

I managed to fix it! The only valve like thing I could find in the pump was a small bit of brass tubing, but it was hollow all the way through so figured there must a small ball that is displaced when air goes in to the tyre but falls back preventing air going the other way. My partner miraculously found it in the sink. It looks like this:

It goes in the base here:

On top of that goes the metal tube that runs up the side of the piston tube:

Thanks for the replies. I love it when I manage to fix the consequences of my own idiocy.


Cannot raise V-brake blocks high enough to align with wheel rim After adjusting my V-brake blocks to their highest setting on the lever, they still do not align with the wheel rim (they sit half on, half off).

Is there any thing I can do about this, or is it an incompatibility between the wheel size and fork?

You will find (usually an allen/hex key) bolt on the brake pad itself. Loosen that, align your brake pads then re-tigthen. You may also need to adjust again on the bars to get it to fit.

You will also find it easier when loose and aligning them, to pull the brakes right up to the rim and tighten the bolts.

Everything you need to know you will find here: http://sheldonbrown.com/rim-brakes.html


Seatpost of a folding bike is always dirty, filed down by frame? I fold and unfold my Dahon Speed D7 at least four times a day, and each time its seatpost is being pulled up or pushed down the frame tube.

Problem is that the seatpost becomes dirty really quickly even on a dry weather. I suspect the aluminium it's made of is softer than the frame alloy and every time I move it up or down the tube it's being filed down a bit, and so the dirt is actually very fine chips of the seatpost itself. However, it hasn't been changing for a couple of years (shouldn't it already be polished enough by this moment?)

It's hard to tell for sure from the dirt look itself though. Is it possible for the road dust to get that quickly through the opening of the frame below? Would oiling the seatpost help or it would only make it worse (dry dirt is much more preferable to deal with than when mixed with oil)?

Maybe it makes sense to replace the seatpost with a steel one (not sure if they exist as a specific diameter and length are required).

Must be a common problem for folding bike owners, how do you cope with that?

If you have an old inner tube available cut a section slightly longer than your seatpost. Slip it over the seat post and zip tie it in place. It will act as a somewhat water/dirt resistant boot, similar to what mountain bikes have on the front shocks. You may have to look for a fairly wide tube to fit over the post. Check with your local shop to see if they have any unrepairable ones left laying around.


What is a power meter and why do I need one? So I've been looking to become a triathlete soon and I'm hearing all this talk about power meters.

Now, upon googling I found vague information which is why I came here. Exhibit A. That article gives me some sort of idea but it's not good enough, questions that remain unanswered are:

Is this another toy to measure data when you train so you know how you've trained?
Does it help in any way during a training session?
More details… how does it all work? There are heart rate zones and I'm told to run/cycle in a certain zone while training … anything similar for power meters?
Lastly and most importantly, I am a beginner/intermediate (ran a few mediocre run and cycle races).
Will a sports watch (say Garmin Forerunner 920xt with the run HRM) be good enough?

Since you say you're looking to become a triathlete soon it's far too early to be thinking of advanced training aids like power meters.

The first few things to do (not necessarily in this order) are

join a tri club
enter a triathlon or two
join a tri training squad
observe your (comparative) strengths and weaknesses
get a well recommended triathlon book.
use a GPS app for recording and comparing your training and race efforts (eg Strava, mapmyride)
use a heart rate monitor to help find and track your training levels

It's easy to spend lots of money in the first blush of enthusiasm, only to find later that it was wasted.

Take it a little slower, and make sure you're getting good advice. When talking up a new sport it's easy to go about it the wrong way and cause early injuries, or develop poor habits or techniques that cause long term problems. This applies to all three triathlon legs.

In the case of the cycling leg, you need to get cycling advice from a seasoned triathlete. Triathlon cycling is quite different to normal road racing, especially as the distances increase. You'll be trying to avoid using the muscle groups that provide the drive for the run leg, using a much lower cadence than a roadie would, and using a different bike.

The time to consider a power meter is when you're at the stage where you have a training bike and a race bike, and both are worth more than your car.


How can I stop a belt brake (band brake) from squealing? One of our bikes is an electric bike.  It's an older iZip HG 1000, and although we got it through the American "manufacturer" (Currie Technologies), like most of the low-end ebikes it's made in China of heavy steel and uses cheap, cheap, cheap components.

The rear brake is called a belt brake or band brake.  When I was researching this a bit, I came across a discussion that said this type of brake is something like 20 cents cheaper than V-Brakes to manufacture in bulk, which is why it shows up on this type of bike.

Here's a couple pics: just the brake and then one mounted on a bike (not our bike):

Actually, now that I look closely at the pictures, I can see part of why it's cheap - no special frame fittings needed.  The donut-shaped "drum" mounts to the hub, the other piece just fits over that drum and is clamped to the seat stay.

My problem is that the thing squeals like a banshee.  There's no pad adjustment as there would be for cantilevers, the only adjustment is how tight the belt starts.  If I loosen it enough to stop the squealing, there's not enough pull to actually stop the bike.

Is there any adjustment I could do to get rid of the squealing?

That style of drum brake relies on friction between steel and leather. If it is setup to stop reasonably well, they will always make some noise. Quite often, when new, they do indeed howl like Baoine Sidhe.

This will get better with use. From the photos, it appears your brakes are fairly new? Assuming that they are actual photos of your bike...

Rubbing talcum powder into the leather strap will help quiet the brake, but it may also have an adverse effect on your braking performance. Best to let it work out naturally, with time and use.

I hope that helps.


How should I approach hills? I've been biking to work 2-3 times/week this summer and I enjoy it for the most part.  My big problem is that my ride is mostly downhill on the way in to work and mostly uphill on the way home.  These aren't mountainous climbs or anything but for a newbie like me they're tough.

I have a 21 speed street bike and my hills are on streets in quiet residential areas.  What is the proper way to approach a hill in terms of gear selection and effort?  Someone told me you shouldn't have to stand on the pedals to go up hills, but that seems like it can't be right from what I've seen (briefly) of the pros on TV.  I'm completely in the dark on gear selection.  Obviously its easier to pedal in lower gears but then I feel like I'm just wasting my energy pedaling quickly and not getting anywhere.

Any help would be appreciated!

I try to put out a constant amount of effort no matter what slope I'm on:

A constant 'cadence' of 60 to 90 RPM (that's how fast you spin the pedals)
A constant force on the pedals

The useful energy you put in is proportional to a product of the force multiplied by the cadence: spinning faster at the same force results in more energy input.

To keep my cadence and force constant, I change gears: if it's spinning too easily/quickly and I'm going too slowly, then I change up into a higher/harder gear; on a hill if it's too hard to spin (at 60 to 90 RPM) then I change down into a lower gear.

I'm always seated (not standing on the pedals ... except when riding over bumps on the road).

With many (21+) gears you can find a gear (or a range of gears) to match the slope.

The pros on TV are sometimes sprinting etc. You don't necessarily want to ride like they do, when you're commuting (and a self-described newbie).

FWIW now that I'm more practised (5 times/week since March) I sometimes find myself taking a hill in a bigger gear than I used to: but still sitting, and spinning quickly.

  Obviously its easier to pedal in lower gears but then I feel like I'm just wasting my energy pedaling quickly and not getting anywhere.

When approaching a hill from the bottom, approach at a good speed: fast cadence, high power, and a big gear.

When you're onto the up-hill, increase your push slightly (to try to maintain your cadence even though you're now going up-hill). Depending on various things (short hill, enough reserve power) you might thus get all the way up the hill without changing gear (but this might be exhausting) and finish before you're even tired (you complete it quickly because you're going quickly).

If you can't power up-hill in the big gear then your speed (and therefore your cadence) begins to drop. It's not worth letting your cadence drop: if you allow your cadence to halve, for example, then to maintain your power output you would need to double your pedal force to compensate (which you're not strong enough to). So whenever the terrain drags your cadence down to some minimum (e.g. 70 RPM) then shift down to an easier gear to compensate. Don't change down too far: only one gear at a time and only as necessary.

The end result is that you're always pedalling at a good cadence and with a strong force: and that is as fast as you can go! Not "wasting your energy".

When you change gears (especially on a hill) it's convenient if you have nice gears which let you shift quickly while you're loading the pedals, or which require you to ease up on the pedals (to avoid grinding and jumping the drive chain) for only a small fraction of a second.

Postscript:

I since moved to a hilly area (a few years ago) so I've had more practice. Wearing bike shoes (so my feet can't slip from the pedals), I now stand on the pedals to climb hills. My endurance has improved, so now I can sustain that for about 100 breaths consecutively before getting tired and sitting down.

On a horizontal, you want a sustainable effort (you don't want to become exhausted after a couple of minutes).

On a hill you may use a higher, less-sustainable effort because:

If you reach the top of the hill before exhaustion then you won't need to sustain it
If the ride is a mix of faster (flat) and slower (up-hill) segments, it's the slower segments that take more time, and so are those into which it's worth putting any increased effort.

Standing on the pedals puts quite a bit more weight (force) on them, so you can be in a higher gear and go faster etc. I almost never use the bike's lowest gears any more: the hills up which I used to spin, I now climb standing.

In summary I think my earlier advice above is good, but with practice some people grow out of it.


Hydraulic disc brakes not sticking after replacing pads and bedding in So i first bleed my brakes and really botched it, getting brake oil everywhere. I cleaned up, got new pads and wiped the rotors down. I got new brake pads which i the proceeded to bed in. Eventually they stuck well and I declared them ready to go and put my bike away. About 2 weeks later I get it out again, and the brake doesnt stick well, and is squeaking. I sand the brake pad and bed it in again and then braking performance improved. Now i took my bike out and it seemed like the same thing happened.

Is it that the brakes arent fully bed in yet? Why would my braking improve then become worse after I put my brake away?

Place a wooden ruler or a piece of paper folded 8 times instead of disk rotor to check brakes.
Then take your rotor and pads and thow them away to get new one.

When oil gets between rotor and pads, your pads get oiled and they will place oil onto new rotor.

Rotor itself can still contain some oil on it after washing, you will not be able to remove it. So old rotor will place oil onto new pads.

That is why you need to replace both.

The other way is to overheat your pads and rotor in open flame for about 10..15 minutes. Open fire will burn oil, but it is dangerous - pads may blow up and rotor may get screwed, so this is "i have no money" way


What size would be appropriate for me? I'm 173 cm or 5 feet 8.11 inches tall. The frame sizes I'm getting are 16 inch or 17.5 inch I'm looking to buy the Hercules Roadeo A50 bicycle. (Hercules Roadeo A50)
I'm confused about which size I should get : medium (16 inches) or large (17.5 inches)
I looked up some conversion tables online and I found out that the suitable size for my height is about 16-17 inches. This makes it even more confusing.
I am a 173cm or 5 feet 8.11 inches

Don't be confused by bike size - the 16-17 inch measurement is a measurement of the bike frame - from the center of the bottom bracket to the top of the seat tube. If your choice is mountain bike, that size sounds close. At your height, according to the charts I saw, you're probably closer to 17-18 than 16-17.
There are a bunch of bike sizing tables on the Net. Personally, I've always preferred a slightly larger bike when given that kind of choice, but it's really a matter of personal comfort.


How to keep a component "pressed" so the chain remains hooked? I am really at a loss of words to describe my problem, so apologies in advance for the poor choice of words in the title.

Basically I have this component at the rear wheel (which I think is called rear derailleur):

and how far it is from the spokes of the wheel is controlled by the springs(?).
The trouble I have (as it seems) is that this component is too "loose" causing the chain to not be able to catch on to the component's "wheel" properly.

Compare:

Not pressed:

Pressed in:

And notice how in the former case, the chain doesn't lie flush with the "component"'s metal wheel. So that when I cycle the pedals, the chain always unhooks and causes a jam.

Is there any screw etc. that I can adjust to keep the component "pressed in", presumably something to do with the spring..

Yes, that is the rear derailleur. FYI there is a Terminology Index on this site that provides all component names.

It seems the problem you are having is that the derailleur is not lining up with each of the rear sprockets, so the chain is not running on them properly.

Most modern derailleur systems are indexed, that is the shifter lever has discrete clicks that correspond to each sprocket. What has probably happened on your bike is that the cable has stretched or loosened so that the derailleur does not sit directly over a sprocket at each position.

The derailleur or shifter cable usually has a barrel adjuster that can shorten of lengthen the cable to adjust the dearilleur position. In your case the cable likely needs to be detached from the derailleur and the effective length reset.

There are several online guides that detail how to adjust derailleurs. This one from Park Tool is probably one of the best ones - https://www.parktool.com/blog/repair-help/rear-derailleur-adjustment.


Fixing broken STI shifters - plastic gear cable surround As pictured, after knocking over the bike I've broken one of the plastic surrounds where the gear cable enters the front derailleur shifter. Shifting between the lower two chainrings still works, but when trying to shift to the outer ring, the cable tension is sufficient to pull the cable into the crack/gap and prevent the shift.

Is there any way to repair this, or have I written off an entire set of STI shifters? Do Shimano sell spare parts for their STI levers? (If not I'm thinking of going to bar-end shifters if STIs are so fragile!)

Most shops don't carry spare parts for STI shifters. Most problems are internal and even if you can get spare parts, the cost in labor to replace most things (except clamps, hoods, and name plates) coupled with the cost of the spares exceeds the cost of a whole new unit.

The piece you need is called an outer support unit. Shimano does have part numbers for individual pieces like that, but in general, you'll have to go direct to Shimano to get them. The biggest bike distributor in America doesn't have them. This makes them a little harder to attain.

And then there's the other problem: you have old Sora components. Generally, Shimano engineers new stuff and drops support for the old, at least when it comes to spares.

That being said, you might look around but I'd say you have an incredibly small chance of finding the replacement part.

Not too mention, as I implied earlier, it's not trivial to replace things on STIs. If you're willing to take it on, you'll generally be on your own, as few shops do such repairs.

If you're ambitious, I'd just try to find a broken shifter that you can scavenge the piece from.

Another thing you could do is hack it. Fabricate a sleeve to cover over the housing stop that goes as far as your barrel adjuster. It might just be enough. Make sure the inner diameter is as close as possible to the outer diameter of the stop. I'd suggest something that isn't going to be too annoying if it rattles, which it probably will. This is one case where carbon fiber might be useful! ;-)

If you use this for competitive purposes, professional (on Sora? Probably not), amateur, or just for fun, I'd suggest STIs. Otherwise, bar end shifters are a technology that has been around a long time.  They're simple and anyone can figure them out. Plus, the friction mode is very useful. I'd give it some serious thought if you don't mind moving your hands off the lever to shift.


How to fix problem with mountain bike chain falling off gears? The chain on my girlfriend's bike came off the front gear today, it looks like the back gear changing mechanism isn't handling back-pedaling properly, whenever she pedals backwards the chain slacks rather than feeding through.

The chain doesn't seem to be taut enough and has at one point gone round the front gear and caught in the front gear changing mechanism.

Any idea what might be wrong? I'm sorry if I've got my terminology completely wrong here.

It's a 21 speed mountain bike if that helps.

EDIT
I've looked up the terminology now and it seems like there might be a problem with the rear derailer? It doesn't seem to be keeping the chain taut at the top and is just getting pulled almost to its limit towards the front of the bike.

Yeah, first clean the rear derailer well.  Simplest way to do this is to lean the bike against a wall (outside, where you can make a mess), slide some newspapers up behind the derailer and drape them down the the wheel (to keep from dripping all over the tire), then spray the derailer well with WD-40, using an old toothbrush to clean it up a bit.

Afterwards, wipe the derailer dry, then oil it up well with a heavy oil (preferably bike chain oil).

If the bike has more than maybe 2000 miles on it then likely the chain is worn out, and possibly the rear sprockets have developed a "hook".  A bike shop can check for this with a special gauge, and replace the chain if it's too badly worn.  (If "hook" has developed a new chain will help a bit, but the rear sprockets may need to be replaced.)

Regardless, likely the rear derailer is out of adjustment.  It's not very complicated to adjust, but it takes a touch of mechanical ability to understand which way to turn things.  But mainly it's a matter of adjusting the cable tightness, which is usually done by turning a knob on the cable near the shift lever or elsewhere along the cable route.

The other odd possibilities for this problem are that spring has broken in the derailer (or sometimes the spring has just "jumped" off the tang where it's supposed to be hooked), or some jackleg replaced the chain and didn't get the length right.


What to look for in quality mountain bike pedals? After a few rides in mucky trails, I am finding my Norco Bush Pilot pedals are getting rough and do not spin very well. Additionally, the plastic of the pedals are getting pretty beat up.

I realize the bike is not exactly high end, but what should I look for when judging quality pedals?

My intuition so far is to look for:
1) a good all-weather seal around the bearings
2) a platform ready for rugged use (steel?).

You want pedals that have sealed bearings and a metal spindle. I would think that a plastic platform would be less painful in the event your shin comes in contact with it but, metal would be more durable. You want the platform to be fairly open so the mud will pass through.


How often should I grease and repack my hubs and bottom bracket? I am commuting 7 miles a day (round trip) in all weather in New England (temperate, moderately wet climate, cold winters). Overall I am putting about 1000 miles per year on my commuter bike, a 2009 Giant Transend DX with lower-end Shimano components (Alivio and whatnot).

I lube my chain and check brakes and tire pressure weekly, but how often do I need to get the hubs and bottom-bracket taken apart and lubed?

Looking at the spec of your bike it says the BB is a cartridge unit. This probably isn't serviceable -- it's designed to be replaced when worn out, so just keep riding it until it grinds or gets excessively sloppy.

The hubs might be serviceable. If you ride a lot in nasty conditions, or you're aggressive with the degreaser you might want to service them. However, if they're well-sealed (like most modern hubs and in particular Shimano hubs) then they almost never need servicing. If you're worried, learn how to service them yourself and see what they look like. If they're still packed with grease and nice and clean inside they don't need servicing. Servicing them isn't hard but it's a bit fiddly -- you'll lose a bearing under the fridge, then you won't be able to remember if there should be 9 or 10 balls, and whether they're 3/32" or 1/8" or 5/32", and so on. Don't do it for fun.

I ride a lot. My Campagnolo Neutrons have probably seen 10,000+ km. In that time I've had a look at the bearings once or twice. Still greasy, still smooth. The rims will wear out before the hub bearings do.


SRAM i3 coaster brake only activating after multiple turns backwards My son's bike has a SRAM i3 internal gear + coaster brake hub. It has recently started sometimes only activating the coaster brake after backpedalling a good one or two full revolutions. When in this situation, it sounds somewhat clunky or grindy when the brake finally activates. However, sometimes, it kicks in straight away. I haven't found a solid pattern to when it works and doesn't, but it seems that the brake is more reliable in gear 1 than in gear 3, though I might be wrong about this. Can this adjusted/fixed, or do I need to replace the mechanism?

EDIT: After experimenting with the brakes and gearing with the bike in a stand (previously I had been trying while riding it) it seems that in gear 1, the brake always works fine. In gear 3, it requires almost a full rotation backwards before the gear engages. While in gear 2, it's somewhere between - about half a rotation.

SRAM recalled 7,700 of these hubs due to brake failure in 2019.
Evidently the brake pawls were not lubricated properly.

According to the company, some of the affected hubs may have been manufactured with grease that gets sticky over time, especially if the bike sits unused for a while or is stored in a hot area. When the grease becomes sticky, the brake pawls in the hub can fail to engage.

Further

The recall applies to all bikes with this cruiser brake model that do not have independent front brakes.

The logic appears to be that if you have a front brake your hub does not need to be recalled.
According to the SRAM manual for this hub there are no user serviceable parts.

Only a qualified bike dealer should perform any necessary work on the gear hub, shifter, and brakes.
SRAM i-Motion 3 User Manual

The manual says that "the brake jacket has to be lubricated with special grease. This work must be performed by a qualified bike dealer"
First I'd read the manual and make sure everything is adjusted correctly.
If that does not work then you can choose between:

Fixing it yourself
Finding someone else to fix it
Replacing the wheel

The easy way to get rear brakes might be to add a hand brake to this bike if it will take one.


Ideal distance between chainring and chain stay I am building a single speed bicycle, and I have most of the drivetrain parts:

Rear hub
18T rear cog (40-40.5mm ideal rear chainline -- wheel undished)
1/8" chain
crankset with 40T chainring

I used the formulae in the answers of How do I calculate the diameter of a chainring from the number of teeth? and calculated that a 32T or smaller front chainring is needed to maintain the chainline for an undished rear wheel (otherwise the chainring would rub the chain stay of my specific frame, and I will be forced to increase the chainline, adjust spacers on the rear hub, and dish the rear wheel).

But 32/18 is too low of a gear ratio, so I made a compromise and chose a 40T chainring which I intend to place as close as possible to the chain stay, in order to have a front chainline as close as possible to 40mm, for a rear wheel as undished as possible (because it will be stronger, from what I've read).

The last part that I need is a bottom bracket cartridge with the proper spindle length, that will dictate the front chainline and how close the chainring seats to the chain stay. For the proper spindle length I need to take into consideration (and maybe other factors as well):

JIS vs ISO square taper types -- I think I need to add 4.5mm to the chainline just to leave room for a non-ideal combination of the 2 standards that may result now, or with future replacements; But using this knowledge:  How can I tell the difference between a J.I.S. and ISO square taper bottom bracket? I think I can avoid mixing them wrong.
Flexing of the steel chain stay and frame while riding which may cause the chainring to hit;
After being used for some time, the crank hole might get larger, thus needing to be screwed in farther on the spindle, closer to the frame;
The chainring might slightly bend with time. I don't want the lightest hit to cause it to rub.

No crankset chainline info is specified. But I have an old spindle, I will install the crankset on it, make some measurements, then calculate the proper spindle length and symmetry relative to this one that I have.

How should I proceed with the measurements? What would be the optimal chainring - chain stay distance to aim for? I don't have enough experience to know how much each of the above mentioned factors weighs into the equation.

UPDATE: It turns out that in order to have the 40T chainring placed at 4-5mm away from the chain stay, the rear wheel needs a 4mm dish. How much will 4mm dish weaken the rear wheel?

4mm at the closest point is about the safe spot. 3mm is about the sane bare minimum you can go to if you want to push things. Less is asking for trouble. Note that frames, cranks, rings, and spindles do vary in how flexy they are and riders vary in habits and strength, so one can only approximate here. If you stacked the movement from a bunch of flexy things under a strong rider, 4mm probably wouldn't be enough. But it works well as a rule of thumb.

A simple way to actually do this kind of measuring is slipping an allen wrench in the gap, essentially using it as a feeler gauge, or just eyeballing it with one. 2, 2.5, 3, and 4mm wrenches are conveniently sized for the purpose.

It sounds like you're sacrificing an optimal chainline to make use of an 18t cog you already have. I kind of hate that idea; having perfect chainline is one of the big payoffs to all the work you're doing here, and makes fixed/singlespeed bikes work like they should. If this is fixed I would just go for a 14t cog instead. It's true that it will wear out faster, but I think it's worth it.

With steel, another approach is just to dimple the frame, if the clearance that could be gained by doing so would be enough. It's less of a big deal than it may seem like. Frames get squished in the chainstay area at the factory in ways that aren't terribly sophisticated. Usually techniques for doing this involve making a wood form to cradle the back of the stay while you push something rounded into the front, using a vise or clamp.


Can I drop-in a compact crank set with my current 105 groupset I live near a lot of hills and am fairly new to biking.  In my lowest gear I still can't keep up at an efficient pedal rate on the hills.  I found out they sell "compact cranksets" which in addition to having a different bolt pattern have fewer teeth (50/34 vs 53/39).

Can I simply replace my old crank set (Shimano 105 5600, 53/39) with a new 56xx or 57xx compact crank?  I'd expect to have to take a few links out of my chain too, but other than than can I keep my shifter and derailleur?

You are right to say that the compact crankset will give you smaller gears to help you get over hills.

You can do a straight swap of the crankset, everything else will be compatible, although will need readjustment.

If you currently have a 5600 crankset, then you are absolutely safe to swap for another 5600 (compact) crankset. Now, the compatibility between different Shimano ranges is governed by the number of sprockets on the cassette, and the good news for you is that both 5600 and 5700 are 10-speed. So, basically, 5600 or 5700 cranksets will fit you perfectly (as would any other Shimano 10-speed road crankset).

5800 is an 11-speed system, you could probably get away with using this crankset (since the differences are small), but it will not fit as perfectly as 5600/5700.

So, looking at Shimanio's site, the part you need is either the FC-5750, or the FC-5650. The "50" appears to denote compact.

Lastly, do you know what length your cranks are? It might be worth measuring this just so that you get the same length with the new crankset. (You'll see on the Shimano site that things are available in four different lengths, the differences between each are small but they will affect your fit.) Here's an example of what you're measuring:


Does toddler need a helmet inside a bicycle trailer? I am thinking about buying a trailer for my 1yo daughter. They are quite common in my region (southern Germany) but I haven't seen a single kid with a helmet inside. I know that there is no law that regulates it. Does trailer's manual ask to wear a helmet? Or are there any official (not necessary German) recommendations about wearing it?

Generally helmets are recommended for carrier usage by manufacturers and governing bodies, although local cultural practices may vary depending on perceived risks.

Helmets are recommended because it is still possible to crash or even roll a trailer, just as it is possible to crash on a bicycle, even if you are riding slowly and in quiet areas. While children should be wearing seat belts within the carrier/trailer, the structures would not provide adequate protection against head injuries, making helmets the last line of defense against a head injury in the case of a crash.


Quick release wheels on kids bikes? Currently trying to find larger bikes for our kids aged 5 & 7. Oldest's next bike is going to be a struggle to fit in the back of the car (for various reasons they cycle to school in the morning and car it back in the evening, so this is important).

Seemingly there are no kids' bikes with quick release wheels. Problem is most ebay sellers are rubbish at describing their bikes in detail so it's hard to tell what's on offer.

Is this because quick-release wheels in kids bikes are non-existant? If they exist, what brands should we be looking out for?

(Ebay is where we go for children's bikes. There may be hard-core purists here who'll tell us to go to the nearest independent bike shop for the perfect bike and blow the cost, but there's so much value in second-hand kids bikes we can't justify buying new. Plus they so quickly grow on to the next one)

Don't think I've seen quick release on kids bikes, you could always use a wing-nut to make them quicker to remove.

Have you looked at the racks that just clip onto the back of the car (trunk/boot)  - a lot quicker and easier than getting bikes into the back of the car.


Bicycle clicking popping sound felt in the pedals usually when pedalling hard Bicycle is a year old fairly cheap road bike with ~1000 miles.
Transmission is 2x7 speed-derailleur design, so 14 gears total.
Clicking noise somewhere near the drivetrain-ish area when pedaling uphill or somewhat aggressively.
Started happening recently after I changed my rear inner tube.
Clicking/popping is periodic but much more than one crank rotation.
At worst, there is a loud pop felt in the pedals and the chain seems to skip.
Worst in gear 4-5.
Not very noticeable in gear 1 or 7.
Not noticeable when freewheeling or pedaling backwards.
Still pops/clicks when pedaling standing instead of on the seat.
I took the rear wheel off and put it back on to make sure the axle is seated properly.

I'm now out of ideas for what it could be. I'd really appreciate ideas.

That sounds like something wrong with the chain. You may just have a worn chain that is skipping over the rear sprocket. I'd do a check of the whole drive train to rule all potential issues out.

Check for play or roughness in the pedal bearings
Check for play or roughness in the bottom bracket bearings
Check chainring bolts are tight, chainrings don't have any play
Check cassette / freewheel / rear sprocket for any play
Check sprocket and ring teeth for damage or wear
Check rear wheel axle for play or roughness.
Check chain for stiff links
Check chain for wear and elongation with a chain wear gauge


Filing front dropout While carrying my road bike via plane one of my front dropouts has been bent slightly so I can't easily install or remove my front wheel. After I inspected the dropouts I found that one of them has closer tips compared to other, so the threaded axle of the front hub doesn't fit the entrance of the slot.
If I file my aluminum fork's dropout until it is the correct size, will that create another problems? If I remember correctly bending aluminum will create more damage than repairing.
Update
I've taken some pics to clarify my situation. In this picture you could see that axle of front hub has already started to abrade the dropout.

Not sure maybe it's my misalignment but looks like the 2 fingers (ears) of the dropout do not looks perfectly parallel.

If an aluminum fork dropout has been bent, it has already been compromised in strength. Bending it back will make matters worse. Filing it wider open will also make matters worse, even if it was not already bent: thinner metal can obviously carry less load.

I would say don't risk it and find a replacement fork instead. A fork failure when riding can cost you teeth or worse if you crash.

For the future, to prevent bending dropouts/forks/chainstays when transporting bicycle, it is recommended to insert "dummy" hubs when wheels are removed and to fasten them with your wheel axles. This way, any strike to the frame is more likely to be deflected and won't cause a permanent deformation. Of course, having a wheel axle in place would also help dropouts to survive as it will back them up.

A dummy hub can be just a piece of wood wide enough to fit between rear/front dropouts and with a hole big enough for the axle. Or it can be indeed an old hub without rim/spokes/etc.


How to tell if a carbon frame is damaged or if the paint just has stress cracks I am looking at a carbon framed road bikethat has me concerned.On the topside of the bottom bracket,drive side there is a very small hairline crack in the paint.The seller states that it has been there for two years with no change.He was told by the dealer that it is just in the paint and a fairly common occurence.Anyone else experienced this?It is a three year old cervelo.The crack is 3/4 inch long and you can't feel it with a fingernail.

Markus Storck, lead engineer and owner of German carbon frame powerhouse Storck Bicycles, told me at a conference about 3 months ago that the best ways to tell if a frame is cracked are movement and time.

Movement, because a crack will flex if it's through the paint into the carbon, and you put pressure on the center of the crack, and time, because a crack will grow with time if it's more than paint.

If you are even halfway concerned with a crack, don't buy the frame.

It's just not worth the risk, unless you can afford to be wrong about the frame's ride-ability.

I hope that helps.


Transporting a Carbon MTB I took a punt and purchased a Mountain bike second hand, unseen (off our local equivalent to eBay).  It turns out it is a much higher spec bike than expected - including a carbon frame.

Until now I have used Thule 591 roof racks to carry my bike, which clamps the down tube. Can I carry a carbon bike using these racks, if not, what is the recommended way to carry it?

I don't know the official recommendation, but the clamp could be problematic with a carbon DT.

Here's the thing, though: I don't think the clamp is strictly necessary. The purpose of the arm is to keep the bike from swaying laterally - you'll accomplish that as long as the arm is somehow attached to the frame. What I would do is put the DT in the clamp, but don't tighten the clamp: instead, use a rope or strap to tie the arm to the DT.

Another option: don't use the arm at all. Instead, use ratchet straps on either side to keep the bike upright. A lot of people do that when transporting motorbikes. This method seems more secure, but it might be difficult without a second set of hands.


Change old external ultegra brake cables to under the tape brakes Is it possible to change my old external ultegra brakes to integrated brakes ?

Yes you can change your STI brake levers/shifters for ones with cable routing under the bar tape. There is nothing special required.
However I see very little advantage in routing under the bar tape. It looks slightly better (subjectively) and improves aerodynamics slightly. Personally I upgraded from 105 5600 (good old “washing lines”) to 105 5700 due to a broken shifter. I have the impression that the 5700 with cable under the bar tape shifts slightly worse, which wouldn’t be surprising considering the sharp bent required.
I assume these are Ultegra 6600 STIs? They are 10 speed. Unfortunately the only compatible 10 speed shifters with routing under the bar tape are the 105 5700. Ultegra 6700, Ultegra 8000 and 105 5800 are all 11 speed. You’d have to upgrade your rear derailleur, cassette and chain as well.
Edit: Oh, Ultegra 6700 is 10 speed and has routing under the bar tape. Thanks to JoeK for pointing that out. So you could go for either 105 5700 or Ultegra 6700.
The 10 speed Tiagra shifters are incompatible with other 10 speed rear derailleurs.


I broke my rear axle, apparently it's an old style. Is it easily replaceable? My rear axle broke so I took my bike into a shop to see what they suggested. I had read a few posts that had said it should be fairly easy to replace the axle. The guys in the shop said that because my frame is fairly old (1980s) it would be hard to find one that was the right length and connected in the right way (apparently there are 4 different types?). I think they might have said that because the current wheel doesn't have a free hub it means you need a longer axle to fit over the cassette, which might also make things harder?

They said the easiest thing to do would be to buy a new wheel and suggested the Halo Retro (http://www.halowheels.com/products/part/RMHAR76S).

My two questions really are:

Would it really be so hard to find the right axle if I know what the length of the old one is?
If I should get a new wheel is the Halo Retro a good choice? A few reviews I've seen say it's pretty good and it sounds like it would suit the bike but I was just wondering if there were any cheaper options.

I have replaced probably three or four axles like yours in the last few months. It is fairly easy; the only special tools that you need are usually cone wrenches (very skinny wrenches to hold the cone-nuts in your hub). The axles are cheap (maybe 10 bucks or so online). You will also need a regular 17 or 16mm box wrench.

Is your axle a quick release (it is hollow inside) or solid? If it is solid, the length does not matter really, as long as it is longer than your old one. If it is quick release, then you have to get it within one mm or so so that the quick release skewer still holds properly. The thread pitch also matters, and is somewhat harder to determine on your own.

I would think that any decent bike shop would be able to tell you exactly what you need. You can order a cone wrench and new axle for probably ~$15 online and do the repairs yourself, and have the original wheel still on your bike.

I'll look around for instructions on how to change out an axle. BTW, this is pretty common for hubs that take freewheels.


New Tektro Novela Disc Brakes So two days ago I bought a brand new Carrera Sulcata MB. Ever since it came out of the shop the rear brake rubs constantly, but only on one side of the caliper. I've tried realigning by loosening, holding brake and then tightening, but to no avail. I also tried holding the rotor/calipers in a position where they don't rub, but as soon as I tighten the allen key bolt it goes back to rubbing. It doesn't rub when it's not tightened fully but I'm not sure that's very safe. Now they have started to squeak at a certain point of the rotation (very loud) - do I just have to let them bed in or is there anything I can do beforehand? It's quite frustrating.

Thanks!

The brakes are mechanical brakes. Normally (I don't know this brand) the brake lever moves one side of the pads only and pushes the disc against the other. When properly adjusted the disc moves very slightly into the non-moveable pad.

Normally the pad that move is the outboard pad, and the fixed one is the inside pad. To adjust you probably need to unwind the inside pad 1/4 or 1/2 turn, and maybe readjust the calipers.

Refer Here for some good instructions.


Riding my bike on empty pavement when the road is busy UK I often find myself in the situation that I'm riding my bike on the road, holding up several cars whom I can tell are getting impatient (there are oncoming cars so its hard to overtake safely). A lot of the time the pavement is completely empty. Would I be wrong to then switch to the pavement in order to (1) allow the cars to pass (2) reduce the risk of impatient drivers carelessly overtaking me? Where does the law stand on this? Moreover if it is allowed, does the pavement have to be completely empty?

Edit: Clarification - I'm more asking what more experienced bike riders do in this situation, rather than the exact legislation. If you've had any encounters with the police with such a situation, then that would be even more helpful.

It is illegal to ride a bicycle on pavement in UK by the law. It is covered by 1835 Highways Act and Highway Code Rule 64: "You MUST not cycle on a pavement". Penalty is £50.

But it makes common sense and cops generally put a blind eye as long as you are not doing anything dangerous. But at the end of the day it will depend on individual officer opinion.


Halfords just replaced my chainset and it is a 10 speed one, but my cassette is 8 speed. Am I ok? Last week my chainset was replaced (in warranty) and I just found out that the chainset is 10 speed (FSA Vero) but my rear cassette (+Claris gears and shifters) is 8 speed.

I want to know if I will be fine. The bike is Carerra TDF Limited Edition 2012 model.

In my experience this is a non-issue. The only difference between 8,9,10 speed chains is the exterior width not the interior. That matters a lot on the rear cassette, but not much if at all on the front. From this article the difference in the exterior width of 8spd chain vs 10 spd is 0.9mm. On the front that just doesn't make any signficant difference.

If you had a triple crankset and really short chainstays, you might run into some issues, but with a double and your bike, it should just work.

I'd say take the bike for a test ride and if you're happy with the way the front derailler shifts and it is capable of cross-chaining then I wouldn't worry about it. At this point insisting on an 8spd replacement will only get you a very low quality crankset.


Do I need to patch my tubed-tire if I have a puncture? I have about a 2 mm gash around the outside of my tire from a piece of brown glass. It gave me a slow leak and while I've patched the tube, do I need to do anything about the tire itself?

I think thats small enough that I probably wouldn't worry about it too much, but you can fill it in with a dab of super glue or sealants for rubber (like shoe goo) for peace of mind.

You could boot it (a nice boot is the Park Tool TB-2), but I think this is likely too much work.


When down-shifting my rear derailleur (Campagnolo 10spd) is skipping multiple gears. The problem feels like it is in the shifter as it just "lets go" when I press it. I'm told it could be the G spring. Is it something in the derailleur or the shifter? If its the shifter is replacing the G spring an easy task (doesn't look like it is in the exploded diagram!).

The correct answer to your query depends on the model and age of the system.

If it's an older system from the Record or Chorus ranges, when they were still 10s (pre 2009), then yes, the G-springs are a possibility.

If it's from pre 2007 and is from the lower Campagnolo ranges (Xenon, Mirage, Veloce or Centaur) then it could possibly be a G-spring issue - all of these ranges pre 2007 used a lever mechanism basically the same internally as a Record or Chorus 10s lever - Xenon moved away from that mechanism in 2004/5, Mirage etc in 2007 to a system called Escape.

The G-Spings (AKA the P springs - it depends what letter you think they resemble) are two springs which engage a ratchet. The ratchet is what sets the index interval and if one or both springs fail, or if the mount ring that holds them in place fails, you can get the problem that you describe although normally in these types of lever, if tou have a system that "falls through" all of the gears, the shift in the other direction won't "hold" a gear reliably either.

Levers of this type can be repaired as others have noted. If you don't want to tackle it yourself, we offer the service here at Velotech Cycling Ltd - please drop me an email at the address below, for more info.

Post 2007 and Pre 2009 Xenon through to Centaur all used "Escape". These levers have no G springs, but an escapement mechanism. If that is proving troublesome in the way you describe, the only relaible & long term fix is a complete lever body, Campagnolo part number EC-VL100.

Veloce and Centuar 2009 - 2011 used an UltraShift mechanism. These are serviceable but this kind of issue is very rare - I'd suggest a call in to a Campagnolo Pro-Shop (see the Campagnolo website for a listing) or drop us an email at Velotech - we are the main UK Service Centre - email us at velotechcycling"at"aim"dot"com.

Veloce and Centaur 2012-present - again, a system that works basically like Escape, called PowerShift - the only relaible fix is a new lever body complete, part number EC-CE300.


Belt drive, rear sprocket can move sideways I have (RieseMüller/Bosch/Nuvinci/center track) and the rear sprocket can move slightly sideways.

Is this on purpose or is there anything loose?

Ben from Gates Technical Support here, go ahead and drop us a line with any questions at carbondrive@gates.com. There could be a few things going on here but that sprocket should not have any side to side play. More than likely, a snap ring is missing or there may be some wear on either the sprocket or hub driver. Shoot us an email and we will get into the detail!


Urban Cycling Safety Innovations Portland, Oregon is one of several U.S. cities with a progressive bicycling culture. A couple of innovations the city has implemented are "bike boxes" and "sharrows".

Bike boxes are road markings that designate exactly where cyclists and motorists should place their vehicles when stopped at an intersection with a red light. The main idea is to prevent the notorious "right hook" as a cause of collisions. The jury is still out in terms of effectiveness, but bike boxes are receiving mostly positive reviews so far. (On wikipedia these are called Advanced Stop Lines and around here they're called "green boxes".)

Sharrows are shared lane road markings on roads/lanes shared by cyclists and motor vehicles. In Portland, they are found on city designated bike routes without bike lanes. The idea being that it's a visual cue to cyclists and motorists that the lane is to be shared.

Question: What are other infrastructure modifications a community can make to enhance bicycling safety?

Bike Loops (sensors for traffic lights)

One thing we have in the SF bay area are markings on the road where a bike can stand to trigger a green light.  In intersections where the lights are governed by sensors, bikes can't usually trigger those, and end up having to either run the light, push the pedestrian crossing button, or wait for a car to show up.  With these markings, cyclists can know where a more sensitive sensor is places that is more likely to trigger the light.


Is it Ok to lock or unlock my suspension fork while riding? When I need to switch the suspension fork, should I stop before switch?

Yes, you should generally stop and set the suspension to an uncompressed/unloaded position before you switch, especially if it's a cheaper lockout.

Similarly, you would not try to change the position of a deadbolt on a door while the door is partially open.

See Do I need to take my weight off the bike to lock out the suspension?


Can this crank arm be saved? Here's my drive-side crank arm, from the inside of the chainrings:

First off, those are not chain ring bolts, they are rivets, argh :)

It looks like the crank arm is fixed to the middle of the three chainrings, with the plastic spread out.

If I drill out these rivets to fit on new chainrings, can this crank arm be even re-used? Or is it fixed-on to the middle chainring for good?

My objective is to replace the chainraings, but maybe I'll end up replacing the full crankset.

I can't drill the rivets now and see, because I need the bike every day.

A replacement crank set will likely be your best bet. As once you drill out the rivets the structural integrity (what little it has) will be effected and eventually your new chainring bolts you install may wallow out and deform the holes cause a slight play, from there the slight play will gradually get worse until something snaps under force and you will be right back at this very place. Beyond that i don't know how you would remove and reuse the actual crank arm.

Bottom line riveted crank sets are made to be replaced when they wear out. Could you drill and use it? Probably.. well maybe.. but i wouldn't consider it a wise move. I think you would be better suited to look into a replacement and possible upgrade to one that has removable rings.

After all the time and effort put into converting the old one and hoping it holds you could just replace and forget about it. As others have said in the comments you should also check your chain and rear cassette or freewheel for wear as well. If your chain is worn it will not work as well with a new crank and will cause it to also wear prematurely.


Foster Brake + Through Axle My question is in regard to putting my beach cruiser on a bike trainer. I refuse to take no for an answer ;). 1st question: can I put a through axle in my coaster hub. If not, here is the 2nd question: I have 26 X 2.125 tires on my bike can I just change the back wheel to a road wheel with a through axle if I'm not concerned about the brakes?

I'm sure you can find exceptions, but most or at least many trainers can be made to work with nutted axles. The answers to your questions:
1. I think you mean quick release skewer and not through axle, and not practically because it would involve transplanting in a hollow axle, and hollow axles with the thread size for coaster brake hubs don't really exist.
2. Yes you could do this, but it's not very straightforward, because it would need to be spaced right for the frame, and it would need to be a singlespeed wheel to play nice with the chain that the bike probably already has, and singlespeed QR wheels are a rare breed. So you're talking about buying a standard-axle singlespeed road wheel, freewheel, tube, rim strip, tire, quick release, hollow axle, and some hub spacers, then chopping the axle down to fit a 110mmm spaced frame and installing it in there and getting the spacing right. That all is possible but probably not the simplest path.

Here's a video that shows installation of a nutted axle on a Cycleops.


front wheel takes more impact than rear? I was commuting to work this morning and was following a bus, suddenly I saw a huge crack, no time to steering around so just run over it. Then I felt my bike not steering properly. Pulled over and had a check I found the front tyre was complete flat. That must be from the impact because a puncture should take longer to flat a tyre. The inner tube may have exploded (haven't checked). Never MTB before so wondering is front of a bicycle takes more impact than rear? Is that why MTB has longer travel in the front?

Thanks everyone for the inputs. I have checked the front tube, there is 2-3 mm slit, so definitely from an explosion. That means the front tyre hit the crack, then deformed too much at the impact. Looking at vehicles in crashes (front ), they all have badly deformed front, rear is relatively intact. If front doesn't deform, then the force will go through all vehicle and cause even more damage to the driver. I think it's similar here.

It's more likely a combination of the front wheel hitting before you had time to react properly and unweight it, and you also probably pushed down on the handlebars to shift your body back ready to do that. Even just the first could have been enough to pinch flat your tyre.

There's a whole lot of more factors, from the size and pressure of your tyres, what suspension (if any) you have, how you sit on the bike, how fast you were going and so on.

Mountain bikes have different travel balances depending on their purpose, and riding style can make a huge difference to what makes sense or what's desirable in terms of suspension travel. One factor is that it's simply easier to build a bike with huge travel in the front suspension and much harder to get the same at the back. There have been a few MTBs with an intermediate drive, for example, that runs up to a cog on the suspension pivot, allowing them tom have a longer rear swingarm and hence more travel. But if you want more travel on a front fork you just lift the headset up and have longer sliders. It's not quite that easy, but it's easier than doing the same at the back.


I weight about 40 lbs (18 kg) more than the weight limit for the trike I can afford I want to get an adult tricycle because I have balance problems, but I think that a triking/biking would be a good way to help get my weight under control. I weight about 40 pounds more than the advertised weight limit for the trike I can afford. How bad is the risk? I wouldn't be biking too fast. Just a couple miles a day.

Answer: Maybe - speed isn't the problem.

While most "limits" have generous tolerances, your manufacturer's warranty could be unusable if there was a structural problem.

Your brakes would have to dispel more momentum while stopping, so that will increase wear and runout distances.

Riding is a great way to get exercise, and I've successfully ridden road bikes while being at the upper boundary of weight.

Suggestion: can you try a spin bike at a gym?  Could give you the cycling motion without needing to be on a bike at all.  They are heavy, solid and stable so you're not going to fall off.


What groupsets are compatible with my bike? Question

Speaking generally, what things do you need to check about your bike (e.g. rear hub width and type, braze-on vs clamp on front derailleur attachment points, etc) in order to determine what groupsets are compatible with it?

Background/ specific example

I have a 2010 Specialized Tricross. It came  stock with a 3x9 Shimano groupset with Tiagra shifters & front derailleur, and Deore rear derailleur. It's got about 10,000km on it now, all original parts (yes, I should have replaced the chain and casette long ago but that's a discussion I've already had elsewhere).

I am interested in upgrading the whole groupset, and am leaning towards Shimano 105, 10 or 11 spd. It feels like anything more than that is overkill for this bike. However, I'm not clear if I can just buy one of those groupsets and expect everything to play nice with my frame or are there a bunch of measurements I need to check against first. The only thing I can think of is crank length which I would match to the existing ones.

I'm hoping any answers are generic enough to apply to others in the same situation, but feel free to use my Tricross situation for examples :)

Thanks.

There are a lot of things to check when doing a swap of your groupset.  Some things off the top of my head:

Hub/Freewheel compatibility:  Since you are increasing the cassette size, you may have to get a different hub and/or freewheel.  If the freewheel needs to be changed out, the new one may end up being a wider dimension, which will require a new hub that will keep the overall dimension of the hub/freewheel the same.  On mountain bikes, you may also have to contend with different axle designs as well.  i.e. through-axle vs. quick-release and different dimensions between chain stays.
Alignment of the chain-rings with the cassette: If you are changing the number of chain-rings or changing the spacing significantly, you will need to check that the spacing between the frame and rings is adjusted with shims on the bottom bracket or a new bottom bracket design entirely.  If you have braze-on derailleur hangers, this is critical.  If they are clamp derailleur hangers, there is some adjustment available.
Bottom bracket:  Most groups sets include the bottom bracket.  You will need to check that the frame diameter and fitment style (press-in vs. thread-in) will match the new bottom bracket
Shifters:  Since brake levers and shifters are typically integrated on a road bike, you will need to replace them to accommodate the new indexing on the rear cassette and/or front chain-rings.  Make sure that the new brake levers are compatible with your existing brake calipers.  Should be pretty standard on road bikes, but mountain bikes and hybrids require some more investigation when using integrated shifters.

Overall, you have a much better chance of getting a compatible upgrade if you stick with the same brand and similar technology (cable operated brakes vs. hydraulic for example)

Note:  As OP suggested, this answer was as generic as I could make it to fit other bike types/styles.


Why do so many people put the inside pedal down when cornering? When learning to ride, my dad taught me to always have the inside pedal up when cornering. He reinforced the lesson by telling me about a race he'd been in where someone clipped a pedal when cornering and took down 20-30 people in the pack behind him as he went down.

To me it's quite intuitive to keep that inside pedal up - it keeps it away from the ground when leaning into a corner and I'll often even hang my knee on the inside as I'm leaning to lower the center of gravity even further. Additionally, I think that I'm actually pushing on the outside pedal as I go around, which also feels very natural to do.

The vast majority of people I see riding these days (recreationally or light competitive, not professionally), including (much to my chagrin) my own children, insist on putting the inside pedal down when turning. I suppose that there is a belief that "my foot is closer to the ground, so if I start to crash I can save myself more quickly", but it just seems so totally counter intuitive and unnatural to me. It feels very unbalanced to have that inside leg down, like I'm going to fall over on it.

Why does this feel like the "right" way of going around a corner to so many people?

People put the inside pedal down because it's the natural thing to do. You want the bike to lean to the left, so you press down on the left side; you want the bike to lean right, so you press on the right.

Putting the outside pedal down is a learnt behaviour, so it's only done by people who have been taught it. Also, most people don't cycle fast and aren't on road bikes, so they're not leaning the bike much and they have reasonably high bottom brackets. Pedal strikes simply aren't an issue for most cyclists.


Road bike that is gentle on body, but can go in some dirt I found out that a racing type road bike is hard to shift as hurts the arthritis in my fingers. And even the frame is harder on the hips. I need something more gentle, but fast enough to keep up with road riders.

I now ride a Trek Utopia on and off road and I do ride it hard. Can't keep up with road rider, but can fly on the dirt!

If what you want is a true road bike, but without the pain, consider getting a Specialized Roubaix or a Scott CR1.

These are both excellent road bikes with a slightly more upright riding position, and a carbon fiber frame that is engineered with comfort and distance in mind, while maintaining the speed and agility of a road machine.

This is the nicest (and most expensive) of the Specialized Roubaix line up. I'm pointing out this one in particular, in spite of the cost, because it uses electronic shifting. The battery powered shifters and derailleurs are only currently available on Shimano's highest end group. But that will be changing next year, when they release the Ultegra Di2 kit, and they will remove the pain from shifting for you. A light touch with one finger produces the fastest, smoothest, and crispest shifts I've ever seen, and I think will eliminate the pain of shifting for you.

The Di2 kits also have the unique ability to have 2 sets of shifters operate the same derailleurs. Which means you can put a set of buttons on the flat part of the bar, as well as having the more traditional STI brake lever shaped set, with no loss regardless of the position you are riding in.

The bike is amazingly light, and agile. But the best part is the smooth ride, and the comfort. It is a Centurion's bike.

The Scott CR1 SL is a similar design, my preference, actually. But they don't currently offer it with Di2 Electronic shifting. Again, it's on the horizon for next year.

These bikes are in no way intended for dirt, but no bike which is intended for dirt, even a cyclocross bike, is geared to stay in the pack with a true road machiine. You're better off keeping your current hybrid machine for when you go offroad, and buying a true road bike for the days on pavement with your buddies.


How do I stop punctures for good? Last night I came out of work to a flat tire. This is the second time I've got a puncture with less than 100km done on a brand new set of schwalbe smart sam tires. needless to say I was quite annoyed. The first puncture happened after about 40km and the second was after 95km, last night. It was the same wheel both times. After the first puncture, I checked and double checked for any foreign objects in the tire and rim and I found nothing. I pumped the tire and kept it at about 55psi because I read this is good for avoiding punctures. All this to no avail.

I'm just wonder what can I do to stop punctures for good? I'm a heavy guy (about 110kg) so maybe this just isn't possible? I've tried slime before and that was useless. I currently ride on Smart Sam 26" x 2.25

There are a few things to do. I'd start by reading this link from Sheldon Brown.

First determine how the flats are occurring.

Inspect the tube. Is the rim tape on the rim properly? (if not, you'll see a puncture on the wheel side)
Is the tube being pinch flatted? (a snakebite flat, two very closely placed punctures - usually a sign of too low pressure)
When you re-install the tube, are you pinching it between the tire bead and the rim? (You can make a rolling motion over the rim with the tire after its seated to prevent this from happening).
If you can't find the puncture easily, pull the tube out of the tire, give it some air and then try to find the hissing. If you can't find the hissing, try passing the tube around your lips or dunk the inflated inner tube into water.

Check the inside and outside of the tire for any embedded debris, carefully. If you find some, remove it.
If the tube doesn't have any punctures, is the valve good? Sometimes a faulty valve causes pressure loss. You can either re-core the valve in some cases, or more easily just buy a new tube.

Many manufacturers make kevlar belted tires which have stronger puncture resistance (such as the Schwalbe Marathon Plus), but if your punctures are happening due to rim tape or something, then its not going to help.

If you are running such big tires at 55 psi though, I don't think it's low tire pressure -- I've had about 300 pounds of stuff (bicycle, rider, cargo) on a bike with 26x1.9" tires at around those pressures without any problems on some pretty shabby roads.

If the first flat was indeed a puncture due to debris, my guess is that you didn't actually get all the debris out.


Brifter loose even with bolt tight How to clamp a brifter to the bar more securely if the clamp is already very tight?

More detail: After a small crash (no scratches on me, just a few on the bike), one Shimano Ultegra brifter was wobbling relative to the handlebar. I tightened the clamp bolt that attaches the brifter to the bar as much as I could, but the brifter was still wobbling. I undid the clamp, removing the brifter from the bar and saw that the clamp is a bit rusty, but looks intact. Retightened the clamp bolt as much as I could (the hex key broke), but the brifter is still wobbling on the bar. Before the crash, neither brifter wobbled.

There is no bar tape or anything stuck under the clamp or brifter edge, I checked before retightening.

The Shimano dealer manual does not give additional info besides tightening the clamp bolt (http://si.shimano.com/pdfs/dm/DM-ST0002-05-ENG.pdf).

First thing to do is loosen the bolt all the way and grease the threads. If possible, snake a lube dripper in and get a drop of lube under the bolt shoulder too. That may completely fix it, but while you have the lever separate from the clamp, look everywhere you can see for cracks in the lever body that might be preventing the clamp from snugging everything up properly. Pull back the hood as needed to inspect. If none of that leads to an answer, next thing to do would be get better eyes on the section of bar it's trying to clamp, and also the clamp itself.

Given this started with a crash I'd be pretty worried that the lever body is broken somewhere.


How to find punctures in inner tubes? When I have a flat tire, I find punctures in inner tubes using three techniques, all starting with the inner tube outside the bike:

Hearing where the sound of air escaping originates.
Feeling the escaping air with my hand.
Putting it inside a container of water and seeing the bubbles. I end up using about 10 liters of water, and I have to rotate the inner tube to pass all of it through the water.

Is the method 3 smart? Could water get inside and damage the valve? All three methods seem to work very fast. Is this just a matter of taste or does some miss some punctures?

Do whatever works, really.

The problem with the container of water approach is that it requires a container of water. It won't damage the tube. Also, if you need to patch the tube, you have to wait for the wet tube to dry. So, I'd generally recommend doing this last (usually leaks are not subtle enough to need the immersion), but no harm going there first.

The usual technique I use is to try to blow up the tube a bit and put the tube near my upper lip if I can't find the leak by ear or feel it around the tube with my hands; the upper lip area is pretty sensitive, so its pretty easy to detect it. Try to be systematic about it, like start with the valve and go clockwise. If you jump around all willy nilly, you'll take longer to find it.

Sometimes you get leaks that are too slow for that, and generally in those cases, you end up replacing the tube anyway.

You can also trace the leak by checking near the valve (a common culprit; if its the valve itself in a Schrader valve, you can spit on it and check for bubbles) as well as running your hand along the tire to see if anything is there. If you make sure to align the label of the tire (e.g. where it says "Continental" or whatever) over the valve, its easy to work back to where the leak is if you find something (since the label and valve are in the same position, the position of what you found relative to the label tells you where the leak is on the tube).

See this page as well. It also covers what leaks mean stuff (if you have a thorn in the tire, chances are that's your cause, for example. Snakebites are often insufficient tire pressure. If you have a leak on the rim side of the tube, chances are theres something off with your rim tape, etc.).


Not feeling good after a ride After a ride, usually about 15-30 minutes after a ride, I sometimes don't feel very good. I'll feel sleepy, lazy, lethargic or mentally foggy. It's not a physical tired. And often it doesn't take a great deal of riding to feel this way. For example, today I did about 15 miles and felt this way shortly afterwards.

I'm in pretty descent physical condition (I think), and I can ride 20-30 miles, at a steady 15-17 mph, without too much effort. But I'm really confused why I feel this way. I could/maybe should, see a doctor, but I thought I would check here first to see if anyone else experiences this.

First off, can you explain a bit more about how you "don't feel very good"?  Do you feel at all queasy?  Do you feel especially weak?

Also, how often do you exercise so intensely, and how long have you been doing it?

And how long does this period of feeling unwell typically last?

Anyway, there are several possibilities (though most apply to rides longer than 15 miles):

-- Dehydration.  Especially in warmer weather you need to drink plenty of water or other fluids.  We've had arguments here as to how much, but it's not a bad idea to down a 21-oz bottle of water every two hours or so, as very rough guide -- more in hotter weather.

-- Low sodium.  Again, in warmer weather it's quite possible for someone who exercises intensely to sweat off so much salt that the sodium levels in their body are not sufficient.  (This effect can be doubled if the individual consumes an extremely low-sodium diet.)  This results in fatigue and lethargy, and in extreme cases can be life-threatening, especially if mistaken for dehydration (which has similar symptoms) resulting in "water intoxication".

-- Low blood sugar.  When you exercise you first consume the sugar in the blood stream, then the liver and muscles start converting stored glycogen to sugar.  Several other mechanisms kick in as well.  Especially in someone who has not trained extensively, this mechanism may not be able to supply the body with enough sugar and low blood sugar can result.  In addition, some people suffer from what's known as "reactive hypoglycemia", where blood sugar drops paradoxically after a meal, after exercise, or at certain times of the day.

-- Ketosis.  If blood sugar gets too low for too long the body begins to burn fat and protein directly.  This results in the production of ketones which are released into the blood stream.  This again results in an unwell feeling, including nausea, extreme fatigue, lethargy, and "brain fog".  (Ketosis in particular will knock you on your butt for 2-3 days if it gets bad.  Most other conditions listed here you can recover from in a few hours at most, if properly treated.)

-- Blood pressure fluctuations.  Some people experience fairly extreme changes in blood pressure after exercising.  This is usually short-lived, but can produce a wide variety of symptoms, from pounding headache to fatigue and fainting.

-- Neurotransmitter fluctuations.  It's well known that exercise (especially intense exercise) causes the release of a number of neurochemicals.  This is cause of the so-called "runner's high".  And, of course, when one is "high", one will eventually "come down", and the result is a sort of "withdrawal" from the endorphins produced while exercising.

My guess is that you're experiencing a combination of slightly low blood sugar and the neurotransmitter "withdrawal", maybe combined with a touch of dehydration.  Eating some sweet or starchy snack every 30-60 minutes while riding will help to level the blood sugar (and if it's a bit salty, all the better). Drink a cup or two of water with the snack.

And when you finish the intense part of the ride, take a leisurely spin around the block or whatever for 5-10 minutes to "cool down" -- not your temperature so much as your endorphins.

(You can, of course, experiment with different combinations of the above to try to narrow down what's the primary cause of your particular symptoms.)

But (though the doctor's checkup is never a bad idea) I wouldn't worry about it too much.  After all, you've just participated in the second-best activity a man can experience, so a little let-down afterwards is to be expected.


Tight Seatpost Installation I'm having a bit of a problem installing my seatpost.

I have a 31.6mm carbon-wrapped aluminum seatpost which fit perfectly fine in my previous aluminum frame.  Unfortunately, that frame cracked, but I found the exact make, model, and size frame on eBay to replace it.  The only problem is that the seatpost doesn't fit into the seat tube very well.  It is a very tight fit, and I can only get it down 1 1/4" before it gets really difficult, even with a bit of grease.

The top of the seat tube doesn't appear to be crimped, so I'm not sure what the problem is.  I'm a bit gun-shy since I've already broke a frame this year.  So, I'm not sure whether to force it down, use a rubber mallet, or buy a new seatpost.

How do I determine if it's possible to fit this seatpost in this frame safely? Is it possible there's something else interfering with the installation, or will I need to buy a new seatpost?

Never use a hammer.

In order to check the inside of the frame, visual inspection most times FAIL, because the problem is caused by tiny bumps or misalignments that are not easily seen with naked eye and even felt with fingertips.

I would recommend that you take another seatpost (an old one you can take/borrow on a local bike shop) and try to insert more aggressively. You should polish the seatpost first someway (steel wool, for example).

You force it inside a bit, then take it out. Probably, there would be some marks on the seatpost surface, suggesting if there is some irregularity inside the frame. Most common are bending around the vertical cut around the clamping nut, or deformation caused by welding the tubes around that region too deep (to the point of almost melting the inside of the tube.

The seatpost tube of the frame might be not-straight, which would be a manufacturing defect.

In the end, you could polish/sand/grind inside the frame to make the seatpost go down easier, but since seatposts that don't go down so easy come out very hard afterwards, and your post has a carbon surface, taking the frame to the bike shop to check if it needs replacement or special service (with machining tools to improve surface quality and alignment) could be necessary.


Can a (20*1.35) tire fit on my rim that has a (20*2.125) tire on it now? Can a (20*1.35) tire fit on my rim that has a (20*2.125) tire on it now? Is there a general rule to know what tires are compatible with the rim?

For information a friend has the exact same bike with (20*1.50) tires on it if it can help...

Thank you in advance

Width compatibility is a matter of rim width, but according to the oft-cited table there's unlikely to be a rim that's particularly good for both 1.35" (35mm) and 2.125" (54 mm).  This is a big change, so unless your rim is on the narrow side for the tyre that's on there at the moment you might have trouble.  So in your case you really need to measure the inner rim width before going shopping.


Air compressor to fill up to 60 PSI I am looking for an air compressor and wish to get one which is not under or over powered.

I am looking at one in a catalogue which has the following attributes:

40 Litres/min free air delivery
1hp motor
Direct drive design (what ever that means)
8 Litre tank capacity

I wish to fill tyres at home for my hybrid bikes and mountain bikes up to 60PSI. I will be using a product call "Prestaflator", which is the air trigger with guage and presta valve connector.

I am not asking about floor pumps.

Don't bother with an air compressor. Get a proper bike pump.  They are cheaper, and will fill a tire to 60 psi with minimal effort.  A good bike pump will also require less maintenance. Also it'll only take a couple pumps to top up your tires. Much less time than to drag out a big air compressor.  Have you had problems with standard floor/track pumps? What is your reasoning for getting an air compressor over using a bike pump?


What are the positions on drop bars called? I've heard the different places to put your hands on drop bars given different names, like "hoods" which I think is the flat part on top or maybe the brake levers, or "drops", referring to the lowest part of the bars.  Can anyone tell me what the actual names of places to put your hands are?

"Middle of the bar", "On the tops", "Middle", "Top", "Tops", "Center"

Hands on the part of the bar closest to the stem. The middle has some width and you can slide your hands around there.

"On the corners", "Corners"

Hands at the outside end of the section where the bar turns. You can grip the corner different ways. There's a sort of position in between corner and hood ("ramp"?), too.

"On the hoods", "Hoods"

Hands on the brake hoods. The brake hood is that rubbery thing that the brake lever comes out of and on a modern road bike likely also contains the shifter. There's different ways to put your hands on the hoods, I'm showing two I use.

"On the drops", "In the drops", "Drops"

In the lower curved part of the bar. With the drops you can be leaned way down with your hands far forward/up in the hoods, you can be about where I'm showing in the picture, or you can be on the lowest part of the bar (where you can't reach the brake lever).

Note for all of these:

There are various different hand positions in each of those main positions, but not necessarily names for them. Some of the differences can be subtle and don't really look much different, but change the pressure points on your hands.

Most road-bike riders primarily use the hoods, and that's generally what's currently encouraged. It's the most comfortable position that you can brake and shift from and gives you good leverage. The drops are your fastest position and also give you good leverage. Middle is most comfortable for your hands, but gives you the least control.


Bike Size to Human Size Conversion Chart I am just shopping for used bikes right now online.  I want to try and save myself a trip to visit the bikes by determining which bikes will fit me.

Does anyone have an approximate height-bike size conversion chart or inseam-bike size conversion chart?

I know that this will not 100% accurate as Sheldon Brown observes.  I was just hoping to get an approximation.

IMO single most important factor of cycling joy is FIT!

This is a great tool and worth the effort:
http://www.competitivecyclist.com/za/CCY?PAGE=FIT_CALCULATOR_INTRO

I have used it myself and referred countless folks to it, all with great success! Good luck!


Effective use of a coaster brake? I recently got a basic beater bike for pootling around the neighbourhood. All it has for brakes is a rear Sturmey-Archer AWC coaster brake. Having used almost every other kind of hand-operated brake in over 30 years of cycling, the coaster brake seems very strange:

stopping at a junction doesn't seem to allow any kind of gradual stop; you have to keep both feet on the pedals until the bike stops, then kind of flop off the pedal to put your foot down.
starting up again at junctions requires you to remember to leave your lead pedal at the 2pm position, because you can't back-pedal to get it to where you need it.

I should point out that I'm using this on quiet, mostly flat areas, and am not mixing it in heavy, fast traffic. I have other bikes for such use. I'm also referring to small-e effective, not Forester-style big-E Effective Cycling.

So how does one ride with a coaster and stay safe and sane?

Stopping is relatively easy - the rearmost foot is pressing back/down on the pedal to operate the brake, the other goes on the ground. If you're used to two feet on the ground when stopped you'll need to practice stopping with one foot first. You probably need to swap anyway, so the foot on the pedals is ready to push down when you move off. It's vaguely annoying but you'll get used to it.

To shuffle the pedals around while stationary you need to be pushing gently as if you're trying to pedal forwards, while rolling the bike backwards. Again, it's annoying. When I ride a bike like this I quickly get a little system organised so that I stop, rotate the pedals forward to disengage the brake and get ready to move off, then roll back a little until the foot that's on the pedal ready to start is in the right position.

I do think you should fit a front brake of some sort just for safety. Braking with the rear wheel is less effective, especially in an emergency stop situation. Even a cheap caliper brake is better than nothing (and often that's all those bikes are set up for).


Storing clip for Pro Design Aero Bottle So I keep my bike in the garage, in Florida where there are plenty of critters.  This would include lizards and frogs including the expected insects.  Heck the other day there was a bird trapped in my garage!

As such I really don't like to keep water bottles anywhere but inside the house where the critter population is far more controlled.  I have one of these water bottles:

There is a strap that holds it in place that without the water bottle in place, the strap would easily fall out.

Any hints on how to store the bottle and the strap so the strap does not become lost?

Without being 100% sure as the picture isn't very informative, it looks like you need to make a fake bottle.  I'd use a long strip of corrguated card cut to approximately the length of the bottle and rolled to the right diameter (you don't have to do this all with one piece).  You could start with a core from something like a roll of paper towel, and wrap the card round that.


Another flatbar to dropbar conversion noob I am thinking of changing my Boardman HYB to a drop bar setup. Trying to avoid having to change the entire group set if I being honest as I am on a tight budget.
Currently, its Shimano Acera 2x9 and has hydraulic disk brakes.
I can't find any drop levers that support 2x9 and hydraulic disks. Unless I am just not looking in the right place?
What are my best options for keeping this low budget without loosing the hydraulic disks?
Hoping to be in a position to buy a new gravel bike in the next year or 2, so I don't want to be chucking loads of money at this conversion now.
Thanks

I think you are out of luck there.
There are expensive cable to hydraulic converters available.
You could get (equally expensive) 10 speed hydraulic brifters and use a 10 speed to 9 speed cable pull converter. This should work with your existing drivetain (you’d have an "empty" 10th gear).
But all of that would be a hack. Is the frame even short enough to be comfortable with drop bars instead of flat bars?


Freewheel sprocket locking up I was just out riding my bike. Its nothing fancy, just a €300 single-speed with with a flip-flop hub. I usually ride the freewheel side. Today it made some weird noises and decided to lock up / be a fixed gear and threw me off the bike.

So now the freewheel sprocket is behaving like a fixed gear. Is the sprocket completely broken or is there any way to fix it?

Freewheels do require lubrication sometimes.

I suspect that if you drip some oil (I've used air tool oil, which is pretty light, but anything will be OK) in there with the bike tilted so the is freewheel up the pawls with become unstuck and it will work fine.

In my experience it won't take much oil or time, it should free right up if lubrication actually is the issue.


Seat rail clamp spins in the seat post When I last got on my Specialized Stumpjumper the seat wanted to spin freely. The seat post was firmly clamped in the frame. With further inspection the seat is spinning where the seat clamp goes into the seat post. Is that a connection that is just glued together? If so, what do I use to re-glue?  It believe its a carbon fiber post.

The image below is not from my bike, but does show that junction where it spins.  Any help would be appreciated.

Any time that different materials are joined together, there is a small potential for failure. I emphasize that if the manufacturer knows what they’re doing, the probability is small. However, if I understand the OP correctly, they may be one of the unlucky few.

The arrow in the photo on the original question seems to point to an aluminum structure that contains the clamping mechanism. Most likely, this structure was bonded (I.e. attached with industrial strength glue) to the rest of the carbon seatpost. Other methods of construction exist for carbon posts that don’t rely on that large an aluminum structure being bonded to a carbon tube. However, carbon to metal bonds or metal to different metal bonds are pretty commonplace. For example, many current generation cranksets have a steel or aluminum spindle bonded to aluminum or carbon crankarms. Carbon frames sometimes have aluminum bottom bracket inserts bonded to them. The list could probably go on, and I’m not a bike engineer (or any sort of engineer), so I’ve probably left a few off.

Nevertheless, if I understood the question correctly, the OP probably has a seatpost where an aluminum insert has un-bonded from a carbon tube. This was probably glued together. However, it’s almost surely not with glue you can just buy from Home Depot, Lowes, or another home repair store. This would be a warranty issue. If the OP isn’t the original owner, they should just buy another seatpost. To emphasize, the aluminum part was originally bonded with industrial-strength glue. Not consumer-strength glue. Remember that the person sitting on top almost always has at least 100lbs (45kg) of weight, plus this is a mountain bike that is being operated on rough terrain. The glue needs to be very, very strong. This is almost surely beyond the average consumer’s capability to repair. If any bicycle engineers want to correct me, please do so.


My brakes get mushy under heavy pressure I have some Avid Juicy 5 on my Specialized SJ FSR '08 and the front brake gets mushy and looses brake power on long downhill trails.

Do I have to purge the brake lines to get performance back on track?

As @Batman has suggested brake fluid is hygroscopic. Over time moisture from the air is absorbed by the fluid. When the brakes get hot enough the  absorbed water will boil. This results in air bubbles forming in the fluid. While brake fluid is not compressible the air bubbles are. This results in a mushy or spongy feeling to the brakes. Once cooled the bubbles may be reabsorbed allowing the brakes to feel normal.
+


Is this suspension fork user-serviceable? This is my fork and I want to open the suspension legs, inspect them, then reassemble, but I don't see how to get in there.  Any suggestions on what tools and procedure to use?

Is this user-serviceable at all?

The bike is a Genesis GS29.

Related questions:

What method of damping are they using .. is this springs only?

Do I have damping for both compression and rebound?

Would I have to take care to prevent springs from flying off while disassembling?

Would I need a special tool to compress springs during reassembly?

Pictures:

To expand on Batman's comment, its a BSO because its from walmart and built down to a price from low grade components.

So, the forks will not be user-serviceable.  They won't be serviceable at all even by a shop, and the only way to adjust them is to change them completely.

How do we know its a BSO?  Because the specs say things like

"Tyres, 29 inch" without mention of width/height
"Front/Rear Derailler - Shimano"   <-- there's a massive range.
"Available at walmart.com"   That's a pretty damning indictment right there.

Its a fine bike for tootling about, but don't sink any money into upgrading it, other than the normal replacement-wear parts like chain, cassette, and brake pads.   If you're interested in riding more and better, save your money toward a better bike.

Answer because its too long for a comment.


Can't do outdoor training for 150km and only on trainer. Can anyone give tips and training plan? I just found out that I cannot train outdoors for the next two months for the 150 km I was planning to attempt in the first week of September. Now I am planning to buy the In'ride 100 trainer from btwin as that's what my budget allows me to buy. Will I still be able to prepare for the 150km on the trainer. What are the advantages and disadvantages?  Can anyone give me a training plan and tips. Thanks.

Should be possible, but you are going to need a lot of dedication to sitting for hours on the trainer. You'll also need to put a trainer specific or cheap disposable tire on you bike as trainers wear rear tires fast.

The training you need to do depends on what your level of fitness is, the max distance you can currently ride and the nature of the 180km event (flat or lots of hills) and how you want to ride it (target average speed, how long you plan to take overall, number of stops etc.)

It will be easy to search for and build a training plan with 30-60 minute sessions 3-4 times a week that will increase your overall fitness and strength substantially. This should be your initial priority.

The difficulty will replicating the duration and nature of the long ride. I would not try to replicate the distance of the ride on the trainer, but instead the duration and intensity. Estimate the time duration you will take for the event and plan sessions on the trainer working up to about 75% of that, at your planned intensity.


How to improve climbing speed new cyclist here. I've recently started riding and have worked my way up to a 50K in 2 hours 24 minutes, averaging 21 km/h. I noticed that I really wasn't able to carry my speed through climbs and would like to know how to improve. On flat ground I can go 23-24 km/h but am usually going at a slow jog type pace on any type of hill. Thanks for the help.

Practice.

I moved to hilly area a few years ago: I now climb hills by standing on the pedals in a medium gear. I used to climb hills sitting down and "spinning" n the lowest gear, and sometimes stopping half way up to catch my breath.

I used to stand on the pedals for a few strokes before getting exhausted.

Now I can do it (stand on the pedals) for about 100 breaths (long enough to climb a steep little hill).

I deliberately practice on hilly routes. I've never practised only going up and down a hill repeatedly because I fancy that would be boring, but I also avoid sticking to the flattest routes because I'm lazy.

It takes me 20 minutes of riding to warm up, fortunately I start at the top of a hill so the up-hill is after I've warmed up. My most regular ride down to the river, and half an hour along the (flat river), and then home via half an hour of hilly route (ups and downs, slightly more up than down).

It took me quite a bit of practice, if you're younger than me I guess you'd need less.