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36

Carbon tubes tend to be very strong at withstanding forces in the direction they are designed for, but weak at resisting other forces (such as clamping forces compressing the tube), hence why bolts for carbon bars, seat posts etc are usually only torqued to 4-5Nm.


33

While some will say "it's just supply and demand" and companies charge "whatever the market will bear", I'm not convinced that your comparison is fair to try and determine whether bikes are overpriced relative to motorcycles. Using a $4,000+ road bike and comparing it to a $3,000 motorcycle is comparing the upper end of one product to the lower end of ...


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 ...


14

@Gary Has a valid view on the answer, but its also a bit more complicated than that. He has compared a 250 motorbike to a 1000cc motor bike - completely different to comparing a $500 road bike to a $5000 road bike. A better comparison is a 250 GP Motorbike vs a 250 Sports bike vs a 250 Commuter..... Unlike motorcycling, Road Cycling is the new Golf. As a ...


14

UD, 3K and 12K specify the carbon weave pattern. 3K means there are 3,000 filaments per "tow", 12K means there are 12,000 and UD means unidirectional (no pattern): The construction of bike parts is always UD, only the top layer when naked can be specified to these different finish types. Also there is usually an option to choose between matte or glossy. ...


14

A crack, unfortunately, is a crack. That’s dangerous no matter what the material. You could contact Allied to see if you have any options in terms of warranty. However, if you didn’t secure the bike properly, I would guess that they’d offer a discounted frame at most. You could find a carbon repair shop, e.g. Calfee and Ruckus Composites are two well known ...


13

To answer your questions No, they are not safe to ride due to risk of the tube blowing out or the tire rolling off the rim. No, I do not think they are repairable (at home). If they were repaired I would not trust them again. I believe that this item is not fit for the purpose of a bicycle wheel. It should be returned to the place of purchase on those ...


13

Carbon fiber composites are made up of sheets of carbon fiber filaments. These are usually impregnated with resin. To make CF structures, manufacturers will cut up the sheets, then lay them up onto a mandrel or other structure. They will then bake them at high pressure and temperature to cure the resin. The image below is from a Youtube video showing how Mad ...


12

Aluminum has gotten a bit of a bad reputation from the early generation of frames which were overly stiff. This is less the case today as manufacturing technology fixed most of these earlier problems, and bicycle designers can create formed aluminum tubes that provide compliance (i.e., vibration absorption) in one direction (e.g., vertical compliance) and ...


12

There are an intersection of a number of reasons: Public Perception - Carbon as that "wow" factor. Colloquial it is associated with "space age" technologies. Therefore it must be better! The truth is that the performance of carbon depends heavily on manufacturing techniques used (e.g., materials and layup). See point 3 for an example. Weight - Carbon ...


12

That's just a light scratch. No issues. if you are worried that the carbon-fiber composite has been damaged by an impact or scratch, the abrasion is far too shallow for that. It has not even penetrated through the paint. It's not a crack because cracks do no start in the middle of frame tubes, they propagate from edges or holes.


12

I don't see a problem hanging a bike from a carbon fiber composite rim. The amplitude of the load would be much, much lower than when riding over even moderate bumps. OK, the load is radially outward rather than radially inward but the wheel is not weak in that direction. Maybe of the inside edge of the rim is particularly narrow in profile you could damage ...


12

I don't normally go around inspecting fork steerers, but I suspect that's highly abnormal and a significant cause for concern. I don't clearly see torn fibers. If you did, that should mean the steerer got gouged in transit. Raoul Luescher is a carbon fiber repairer and consultant with extensive aerospace and bicycle industry experience. He describes some ...


11

Short answer: No. Long Answer: I would not use carbon rims for commuting for several reasons: They make the bike look more shiny than you want, attracting all kinds of unwanted attention. I ride my commuter bike in any weather without too much maintenance. Should the carbon rim fail at some point, I at least won't notice a hairline crack until the wheel ...


11

In short yes you can, carbon brake pads will stop you but you shouldn't. Firstly the brake pads will not be as effective on the alu rims. Secondly the change between alu and carbon rims could be risky to your carbon wheels, a tiny fragment of alu from the training wheels could damage your carbon rims (source: Swiss stop website). So to answer your question ...


11

On the surface it doesn't look good, but I wonder if there is a reinforcement wrap for the brake posts, with an unfinished edge). There are some informal ways to try and confirm whether the structural carbon has been damaged. 'Carbon usually has a very crisp sound to it [when tapped] and when it’s damaged the tone changes completely,' says John Hansell of ...


11

What is visible in the photo is a paint scratch. Letting the bike simply fall over will not structurally damage carbon fiber composite. People seem to think CFC is fragile but it’s really quite robust. The fact that you had a collision is much more worrying. How hard? At what angle? Hard, head-on collisions can certainly damage the frame or fork. The ...


10

@DWGKNZ was right, turned out that there was a 3mm hex at the bottom. Picture of the removed plug, upside down: Thanks for quick and useful advice.


10

I give you the following, that you can read here: Talking to Jason Marsh the mechanic of Greg Minaar 2012 DH World Cup Champion about ENVE DH rims (which are carbon), he said that, ”Once you have built them, you don’t need to do anything, the spokes remain tight and they don’t need truing and we use a lot less through the year as they are ...


10

Why produce a heavy but durable carbon frame if one can have a heavy and durable steel frame that is cheaper? Apparently there are no (mass) buyers for such technology. The bicycle industry is mainly driven by the competitive cycling needs, whether it is good or bad for a regular consumer. The choice of frame material is driven by the material properties ...


10

I'm sorry to say that looks like a crack rather than a scratch. Bike looks quite new (I notice the dual pivot calipers), but I believe Trek's lifetime warranty covers CF frames and forks beyond 5 years anyway.


10

CFC frames are not as fragile as many people seem to think they are. If you got a heavy jolt but didn't feel like you were going to be thrown off the frame is probably fine. I'd be more immediately concerned about the wheels than the frame, and that may be the source of the rattle. You can examine the frame closely looking for cracks. If it's dirty clean it ...


9

Carbon is seen as expensive and light while Aluminum is heavier and cheaper. Both are, to all practical purposes, more than robust enough for the job. At the price point you are looking at (for a hard tail), Carbon is a no brainier and superior in every way. If you are worried about failure mode, both are as likely to fail catastrophically as each other, ...


9

I have never had or heard of a problem. Over at www.velominati.com, one of the rules is Rule #80 // Always be Casually Deliberate. Waiting for others pre-ride or at the start line pre-race, you must be tranquilo, resting on your top tube thusly. This may be extended to any time one is aboard the bike, but not riding it, such as at stop lights. While some ...


9

The safest way to carry luggage on a carbon frame is to use a trailer, like the BOB trailers. Carbon frames are very strong, but each area of the frame is designed and tested for the loads it expects from a given direction. Adding luggage to a frame not designed for it, i.e. Without braze-one or threaded mounts, is generally a bad idea.


9

They're for full fenders. Many disc road and fitness/urban/hybrid bikes now have them here in order to completely avoid strut interference with the brake. To install the fenders neatly I've been mounting the fender, then mounting the struts sticking off into space in the general direction they'll run in from the mount, then bending one with a non-marring ...


9

Any Shimano compatible 10-speed wheel, other than a very few with special deep-splined aluminum freehubs such as WH-7800, can take any 9 speed Shimano cassette without additional spacers. Shimano 11 speed road freehub bodies are longer and require a common 1.8mm conversion spacer to put a 10/9/8 speed cassette on. Many wheels come with this spacer, or a ...


9

Doesn’t look like a crack, looks more like a surface void that formed during the resin injection molding. These types of imperfections are not uncommon, especially on the inside of the frame where you can’t see them. Less common to see them on the outside as they are usually caught in quality control inspections. While they are not ideal, as areas with ...


9

I can't see the marks on the fork to which you are referring. They may not show up well in photos. The rim brake track appears to have some road-rash damage. I would remove the tyre/tube, and gently stone or file the rim to remove high spots without removing any more metal than absolutely necessary. Then true the wheel before reinstalling. This may wear ...


9

That is bad news. It's too clean looking and parallel to the headtube top face to be at all likely to be a random scratch. It looks like a defect with the headtube. Even if it were a scratch, it would be a deep one in one of the more highly stressed areas of the bike. It looks like something that should be resolved either via warranty or carbon repair.


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