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63

How is this damaged aluminium frame likely to fail? Sorry. It's not going to fail, it has failed. It's no longer ridable. The head tube is near vertical making the steering very unstable and the front wheel has been pushed back and will overlap with your toes. The frame tubes are not dented they are buckled and severely weakened. If you ride it the frame ...


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 ...


58

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 significant ...


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 ...


38

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 ...


35

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 ...


34

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 ...


30

Although I support keeping older bikes in circulation in general, this particular bike comes with some caveats. One of my riding buddies had a very similar bike. The Vitus 979 is a bonded aluminum frame with small-diameter tubes. It was notoriously flexible when new. It was rumored that Sean Kelly, who raced on one of these, had to replace his fork after ...


30

At 480lb/220kg: You need good custom handbuilt wheels from day one on any bike you get, regardless of genre or usage, and it has to be from someone who knows what they're doing. Rims exist that can do that, but not many of them, and this is also an application where you really want 48 spoke, which takes a builder that's willing to jump through some hoops. ...


29

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

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 ...


23

Sloping top tubes started with mountain bikes, and were brought over to road bikes by Giant, following a design from Mike Burrows. Partly because a perpendicular joint between the seat tube and top tube is more efficient at transmitting loads, and partly so the manufacturer can get away with making fewer frame sizes. There really aren't that many bikes with ...


22

It isn’t possible to resize a bike like this. You would be talking about removing each individual tube, cutting it down to size, and then rejoining them. We would be talking about all the tubes, not just one. You don’t know how much to remove. You don’t know how to rejoin the tubes. You would basically be destroying the bike to rebuild it even if you knew ...


20

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 ...


19

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 ...


19

Depends what is your goal, but personally, I'd go for the modern one. Maybe for this budget, you can find something second hand with Shimano 105, that would be also an option. The reasons are: weight is a secondary concern, unless you are in competition and are looking for 1/10th of seconds (and other parameters are similar). The weight that matters is the ...


18

If a manufacturer found they had a quality problem with a batch of products (e.g. bikes but equally cameras, phones...) the serial numbers would allow identification of the substandard units. If you've recorded the serial number of your bike and a bike thief is caught with bikes in their possession the serial number should help you get it back. This has ...


18

Certain parts of a bicycle are more easily upgradeable than others, while other types of upgrades require special tools, much more money investments or are limited to whatever standards are used in its design. For some parts, the opportunity of an upgrade coincides with the older part being worn out; in other cases, the replacement is not warranted by this ...


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.


17

Oh, that frame is done. It’s not worth saving a few hundred bucks now and spending thousands in the hospital later. Make sure to check over the rest of the bike, especially the fork. It might have cracked from the impact.


16

To identify a frame firstly see if a magnet sticks, if it does it's steel, if not it's carbon, aluminium alloy or titanium alloy. If not steel look down the seat tube if it's metallic inside it could be aliminium or titanium if black and plastic looking, carbon. Tap the frame with a screw driver, aluminium and titanium will have a definite metallic 'tink' ...


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 ...


15

Despite what others have said, a warranty is a bona fide contract between the company and you. It's used in the selling of the product thus is covered by decent consumer protection law (in the UK anyway). This article from Which suggests a good process to follow. Keep a record of the contact with the company, try to follow their warranty procedure. If you'...


15

I have 4 bikes, and the one I keep for just riding around a city is high-ten steel. Yes, they're heavy, and normally cheap, but they can be tough and practical. What's more important is that it works for you - that it's the right size and convenient.


15

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

The brake pivot broke off the frame in a very unusual way. A framebuilder may be able to contrive a pretty cheap way of fixing it by putting a new pivot stud in. This would still require removing the paint in the area, but it wouldn't necessarily be that bad. Minimum prices for framebuilders to even get into repair j jobs are typically in the $100-200 range ...


15

Do not do that. Although the question you referenced is about carbon fiber, the answer mostly applies. Aluminium alloys used in bicycle frames are quite fragile. Drilling may easily start cracks that will then spread under stress. Even if it does not happen, you weaken the frame unpredictably. Not only the warranty is gone, but you just don't know if it will ...


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