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12

This is actually a matter of the force multiplication that each chainring provides, and the size/mass of each chainring. Force difference Let's propose, only for a moment that you had a chainring as big that the radius of it is almost the same as the crank length. If the rider stood to pedal while using that chainring (and using simple platform pedals). ...


11

It depends on how the fork is engineered for safety. While its plausible that the curved shape does add to some shock absorption, that is determined by the width and construction of the fork tubing. You could design a fork which was reliable and curved in aluminum or carbon or whatever, but the engineering wouldn't be the same as a steel fork. Whether the ...


9

Steel makes for a heavier rim; the modern-box section design works well for taking advantage of aluminum's lower density. Furthermore, since steel will rust, the rims are typically chrome-plated. The chrome plating makes rim brakes almost useless in the wet, which is exacerbated by the poor pads used on most of the classic bikes that shipped with steel ...


9

That is purely marketing. It's a common ploy with components, but I've never seen it on an entire frame until now. Aluminum and carbon can be used in conjunction effectively, but not in this case. The carbon wrap on that bike is basically veneer. While Schwinn was once upon a time a well respected brand, they suffered a major fall from grace after going ...


7

For the carbon fiber to be of any use structurally, it has have multiple layers. If it says it is wrapped around the aluminum, my bet it is for show only so it gives the appearance of being an expensive frame when it is clearly not. There is no way that a composite of the two will be very light without being very weak if it were compared to a full Carbon ...


7

I ride aluminum frames almost exclusively and have had no problem with them. The welds are what tend to break first on most bike you hear these horror stories about, but this can happen with any sort of weld (though some forms of welding are more effective than others), so if a bike seems to be too good of a deal to have an aluminum frame, make sure to ...


7

If it were a steel frame and fork there would be no question -- steel lasts nearly forever, even when moderately rusty, and can take all sorts of abuse. Aluminum is a bit less robust, but if it only has "a few thousand" miles on it (and not 30,000) and has not been abused (or hit by a car) then it should be good. The problem with aluminum is that it can ...


7

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' ...


6

Good question! There are a couple important reasons for the differing materials: Wear: Steel lasts longer than aluminum, plain and simple. So why not use steel on all the rings? The larger rings have ramps on the sides that facilitate shifting and cannot be flipped as the ring wears. The granny ring can, therefore it can last a lot longer. Flexion/Bending: ...


6

First, try to find a modern wheel that's the right size. They are still made and you can get very shiny ones that will match the bike very nicely. Or get a 120mm fixie hub and add 3mm of spacers each side. If you must use a modern wheel, try to shrink your hub. Many hubs have washers between the locknuts and cones, or other spacers. If you can remove even a ...


6

I had an exactly same problem: Ritchey WCS seatpost, Merida frame (both alu alloy) and a lightweight clamp, like in @Frisbee's answer. What I tried: Beefy clamp with various torque settings. Didn't help at all. PVC tape. Helped, but didn't last long. More torque on a lightweight clamp. I snapped it in half with only 6Nm. Hair spray. To my surprise, it ...


5

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


5

How much unusual stress are you talking about? The weight of the bike all on one leg of the fork? Or the weight of a really large person leaning back against the fork? If it's just the weight of the bike leaning "wrong" on the fork, I wouldn't worry about it. That fork leg is built to handle a lot more stress than that in normal riding. If it's worrying ...


5

Really deep dents or cracks are a cause for concern, but not little dimples and such. Also, the "work hardening" of aluminum is considerably less than industry types would make out....I've worked on numbers of aluminum frames that are at least 20 years old with no sign whatever of any structural problems. Kind of depends what you're doing. The average ...


5

Aluminium frames do not corrode, no need to worry. My 2006 mountain bike frame has lots of scratches and defects, but it is still stiff enough. Aluminium frames have shorter life expetency than steel frames had, because aluminium has a tendency to tire, but it can be used without worries for 10 years. If you are really worried, put a sticker over it :)


5

Others have answered the second part "what are the differences..." Here's an answer for the first part "why not many at the dump" In in my city 2015 light grade clean steel is worth $0.02/kg. Aluminium extrusion is worth $1.83/kg. Brass like nipples is $3-$4/kg and stainless steel is about $0.90/kg. Recycling metal pays money, but I'm not going to ...


5

Do you know the history of the bicycle (crashed, etc)? While bicycle geometry\components\preferences have changed over the last 12 years, the life span of well cared for aluminum frame and carbon fork are much longer. Clean the frame and fork and give it a thorough examination. Look for: Major dents in the frame that may compromise the integrity (minor ...


5

I am posting this as an answer but it is more of a long comment. The information I have is from the place I trust to do carbon repairs. According to Hot Tubes aluminum and the carbon resin react. The aluminum must be sealed to get a good bond. The materials are not your hardware grade epoxy. If we were talking about a fishing rod or something that would not ...


5

Abraham Olano won the 1998 Vuelta on an alloy frame. That might be the last Grand Tour win on alloy - as the Vuelta is the last Grand Tour of the year.


5

A crack developing there, is most likely too much seat post out of the frame, or in actual fact, not enough seat post being in the frame. The biggest problem with a crack in this location, is that it then causes most force to be placed on the join between the top tube and seat tube. You also have to think about what would happen if the frame were to suffer ...


5

There are a lot of more potentially useful avenues to investigate first, because you feel that chamois pad quality is not the culprit next most obvious choice is the saddle: Stock saddles are often not very high quality. They are also typically too soft (aka not supportive) which will cause problems on longer longer rides. Adding to this, if you still ...


4

Yep, "raw" aluminum develops a layer of corrosion fairly rapidly. Thankfully, unlike with iron/steel, the corrosion is "tight" and eventually develops to a thickness where additional corrosion is prevented (in normal circumstances). The corrosion can be prevented by either coating the aluminum with a lacquer-like coating or "anodizing" it. Anodizing is a ...


4

Steel has been the standard for cheap bikes for a very long time. Weight is a prime factor, as noted above. In addition, steel rusts.... If you go to someplace where lots of bikes are parked outside for any length of time, like the university where I work, you can pick out the cheap bikes instantly by the nasty rust that starts forming with great speed. ...


4

sillyyak is right. The weight of wheels makes a big difference. I've had (in the distant past) scary moments when not able to stop as fast as I'd like when braking on steel when it is wet. I notice a huge improvement in stopping in the rain on aluminum. On bike forums ( http://www.bikeforums.net/archive/index.php/t-449632.html ) everyone says aluminum is ...


4

Well, Al will be lighter, and I think I read somewhere that steel rims get really slick when wet (this is assuming that you are using rim brakes).


4

No, in this case it means that the steerer tube is alloy, but the fork blades are carbon fiber. About the only products where you may see a layer of carbon over an aluminum core are stems, which is usually to make a cheap stem to match a good quality carbon handlebar.


4

I can't see your specific rims from here, but plenty of bikes back in the 70s and 80s had rims that width capable of handling 90-110 PSI. And I definitely wouldn't run a 1-1/8" tire at 65 PSI. I'd imagine that the rims, if designed for tires that narrow, should be able to handle 80 PSI or so.


4

2 things: While many older forks used replaceable steerer tubes, the steerer tube is still specifically shaped for that fork. Tubing will not do it. You need an oem replacement steerer tube. Nobody makes forks like that anymore, hence the lack of google results. Also, that steerer tube in the photo looks to be steel, and should not be replaced with ...


4

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 ...


4

The problem I had was getting the ammonia to the corrosion. I hung the bike upside down by both tires so the seat post was vertical. You can either remove the bottom bracket or as I did the bottle cage screw and fill the seat post with straight ammonia. If possible plug the hole so the ammonia doesn't evaporate. I let it hang for 2 days. I then laid the bike ...



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