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61

No. The consequences of fork failure are likely to be severe and painful. This may only be a secondary fork crown but it's still structural. The fact that it's such a wide crack means something is already deformed and weakened. Any glue joint would be under huge stress and aluminium doesn't glue well. If this happened out on the trail it might be possible ...


55

Frames designed for women do have that part - its called a top tube. Historically women wore skirts, so a lower frame in the middle made it easier to mount and dismount, and was less likely to accidentally show an ankle. This picture shows a modern "woman's frame" with the top tube paralleling the downtube, and attaching to the seat tube lower down. ...


47

NO!! That's not a "crack" – it's broken in two! You need a new fork. Your current fork has completely failed. Any attempt to repair it will create a massive weak spot which will just break again. Anything going wrong around your front wheel has the possibility of throwing you over the handlebars into the path of a truck. Furthermore, a ...


39

This is downright dangerous and should never be done on a bicycle someone intends to ride. The top tube is integral to the strength of the bike. The frame can buckle or worse when you try to ride it. First, make sure you're looking at the right size of frame. If its too big, it's going to be hard to get on and off from. You can buy a stepthrough frame or a ...


36

Back in the day, women primarily wore dresses, and getting the dress over the top tube was difficult and awkward. So the women's bike was developed with a slanted or sloped top tube so women could step though with their dresses and ride without their dresses coming up. Although the top tube shouldn't be hitting you in that "embarrassing part" when you're ...


34

For a standard bike in normal use you should not, from the seat, be able to touch the ground (without leaning, or except, perhaps, on extreme tip-toe). A standard diamond frame (with horizontal top bar), for road use, should be sized so that you can stand flat-footed over the top bar with a "comfortable" margin (but no more) between the bar and the stuff ...


33

A resonant frequency encountered on a road surface would be for the whole bike system, i.e. frame, wheels, rider etc. The rider is effectively attached to the frame via elements with spring, damping and active control properties (arms and legs). Bumps encountered at a specific frequency might buck the rider off. Bicycle frames are pretty stiff so any ...


28

Way back when safety bike were becoming popular women wore skirts. Skirt lengths were to the ankle. The dropped top bar made getting on possible while maintaining resectability. Women were considered to fragile to risk hitting the top tube hence the slanted bar. The trend continued even long after women stopped riding in long skirts. Modern WSD (women ...


28

I think the simple reason is that the drivechain hadn't been invented. In 1818 the dandy-horse or draisine was invented. This was similar in shape to a modern bicycle, but without pedals. Riders would scoot along with their feet. If you want to go a bit faster, especially on any kind of incline, then you need a better way of putting power in. Without a ...


28

If an aluminium frame has to be bent back into alignment, it's trashed. Aluminium cannot be deformed without causing weakness in the material. If the bicycle repair shop literally hit the seat stays with a hammer near the dropouts to straighten the frame is probably weakened in those areas and is very likely unsafe. I personally would not ride that frame. ...


26

Yes it will damage the bike. Frames that have that top tube rely on that bar for structural integrity. Other bikes with step through frames are built to add rigidity elsewhere.


23

Other than the obvious fact that your better quality (and better handling) bikes tend to be lighter, there's no real correlation between weight and performance (other than a modest effect on acceleration and the obvious effect on hill climbing). But you can generally (with some exceptions) assume that a bike that is quite a bit (like 2x) heavier than others ...


23

Its a chain hanger. Purpose is to hold the chain when you take the wheel off. The idea is to support the chain and stop it falling through itself, making a tight loop and shortening the life of those links. They're not common on carbon bikes any more, but handy on any working bike. Don't forget to undo the chain after reinstalling the wheel and before ...


23

Comfort isn't really an issue for a 30-minute ride, as long as the bike fits. Also, for any given price point, an aluminium bike will have better components than a carbon bike, so will probably be more enjoyable to ride. For a commuter bike, I'd be much more worried about theft and damage, unless you have somewhere secure to park the bike at work. If you ...


21

From metallurgy for cyclists: a tube's diameter increases (D), the stiffness increases to the third power of that number (d is the inside diameter). Comparing a one-inch tube and a two-inch tube of equal wall thickness., the fatty is going to be eight times as stiff as the little weenie tube. And the weight will only double. Now does the ride of those ...


20

It only seems strange to you because you've had the benefit of never having to learn the lessons of the penny farthing and the technological achievements of the safety bicycle firsthand (aka 'standing on the shoulders of giants syndrome'). The penny farthing is only awkward and dangerous because you are comparing it against a technological leap forward. ...


20

Unfortunately I think that level of damage with a big dent and buckled top tube will make the bike dangerous to ride. There's a chance that when a big bump or pothole is hit the top tube will fold and dump the rider face first into the road. Additionally, the head tube probably is not aligned with the seat tube anymore, which means the wheels are ...


17

Yes, frames do fail even if they're not crashed or ridden excessively harshly. The only way to mitigate this problem is to inspect the frame regularly during your maintenance and cleaning. Look for cracks. When riding, pay attention to creaks and squeeks and always find the root cause (it could be a crack). Keep in mind that: A bad weld could hold fine for ...


17

Steel is still very common for relatively expensive "touring" bikes (bikes intended for long distances carrying panniers). The slight additional weight of a steel frame over aluminum (well less than 10 pounds in most cases) is inconsequential when you have 40-100 pounds of gear on the bike, the bike is more durable, and the flexibility of a steel bike is ...


17

The purpose of such a steering damper is to stop the front wheel from turning when using a (two-leg) kickstand or while pushing the bike. Not much use otherwise.


16

If you look at titanium frame bikes on the web you can see their warranties. Most have very long or life time warranties that cover everything but crashes and deliberate damage to the frame. So I would assume this frame was involved in a crash. There are three types or cracks in titanium frames (from best to worst): Weld crack seam crack (titanium comes in ...


16

Yes it's possible to hacksaw the clamp bosses off and then file the seat tube round and smooth so that a quick release clamp would slip over it. Before taking such drastic action - which will significant hurt the resale value of the bike if you care about that - perhaps try to find a QR lever and skewer that will work with the existing clamp bosses.


15

General rule of thumb, a stiffer frame will absorb less of the input energy and transfer more energy - hence more power from you legs means more power to the wheel. But.... The bikes have different designs, so the aerodynamics of the bikes and the rider on them will be different which will result in different speeds. And then... A stiff frame will ...


15

For MTB I have observed that many bikes marketed as woman specific are almost a scam, they are only the same frame with different colors and lower grade transmission parts (I remember one where the male model was 9 spd while the female was 8 spd, but the frame had pink patches... ) Before any feminist starts pointing out that I'm a male rider, let me state ...


15

I thought this was an interesting question, so first of all, +1. First off, the sloping tube (your second image) is known in cycling parlance as a compact frame. I found an article on the Giant web site about the advantages of a compact frame. When I say "advantages" - this is Giant's word not mine! The full article is here, but to summarise it: the ...


15

That frame is definitely not safe to ride anymore. While some steel frames can handle dents pretty well, that is some major damage in what seems to me an aluminium frame. The top tube seems both dented and bent, which likely has affected the steering of the bicycle and also introduces risk of the frame bending inwards under stress. I recommend you don't ...


14

You seem like you want three different bikes all smashed up into one, and the result is not going to be good. First, the time trial frame is not intended to be a track frame. If you're going to race at the track, use a frame and components that are designed for the track. For starters, the time trial frame will have a lower bottom bracket, dramatically ...


14

You might want to talk to a motorcycle shop that does paint. They are most likely setup to do smaller parts with lots of details. They would be more familiar with masking threaded holes and bearing surfaces.


14

To crudely simplify things, a triathlon/TT bike position is much the same as a road position, but basically "rotated forward", so your arms rest atop the very-low-set bars. A consequence of this is, the seat ends up further forward. (source) Using Chris Froome's TT position as an example, noting the hip position versus the bottom-bracket position: (source ...


14

What he hammered down is the star nut. It's a gription (yes I made that word up) device that serves as an anchor point in the steer tube to allow the top cap to properly compress the headset during a headset adjustment. Old or damaged star nuts are often driven all the way through the steer tube to remove them (that's why your steer tube is open at the ...


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