[Closed] Carbon wheels & circuit racing

All depends really - having an aero rim may help provide structural strength allowing them to be lighter - like 'Lightweight' wheels as used by many of the top TdF/etc contenders.

You're right though, there are a lot of models that seem to be aero very much for the sake of it and are quite heavy.

On carbon wheels:
http://www.bikerumor.com/2010/05/17/hincapie-finishes-atoc-stage-1-with-smashed-carbon-easton-front-wheel/

Just get some Reynolds RZR's then you don't need to worry about the weight penalty. If they're a bit over-budget then yeah most cheap carbon aero wheels aren't great in most crits.

Your generalisation is right oldgit, but it depends on the circuit. I'd use deeps at hillingdon/dunsfold etc but not at palace or most city centre crits. The old westminster crit is an exception to that, that was always bonkers quick with wide corners

"having an aero rim may help provide structural strength allowing them to be lighter "

http://www.bustedcarbon.com/

you cant beat carbon fibre for "structural strength"

That website's a joke!

Never seen a light aero rim neither!

Macavity - Member
"having an aero rim may help provide structural strength allowing them to be lighter "

http://www.bustedcarbon.com/

you cant beat carbon fibre [s]for "structural strength" [/s] for misinformed rubbish

Fixed that for you 😉

Aero, very light wheels
http://www.wiggle.co.uk/p/cycle/7/Lightweight_Obermayer_III_Tubular_Road_Bike_Wheelset_2010/5360048520/

[img] [/img]

Somone on there complaining about warranty on a Trek 9800 that broke, yet the frame is over 10 years old?

http://www.rivbike.com/article/bicycle_making/frame_materials

clubber

One of the guys in a local club wrote off a rear Lightweight with a gilet when he missed his jersey pocket and dropped it straight into the wheel...... 😯

paulrockliffe - Member
Somone on there complaining about warranty on a Trek 9800 that broke, yet the frame is over 10 years old?

Lifetime Warentee on TREK carbon bikes IIRC

oldgit seeing as you are looking at lots of road wheels (judging by your posts) have you looked at the wheelsmith site?

they use gigantex rims (as well as IRD) who make carbon rims for most of the big names. hubs from royce tune PMP etc.

Macavity - Member
> http://www.rivbike.com/article/bicycle_making/frame_materials
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Some good stuff in that link but it's clearly very biased to steel (since that's what they sell!) and some of it is true but of limited relevance.

eg "Materials that fail fast are said to fail "catastrophically." Of all materials used in bikes, none fails more catastrophically than carbon fiber, and none fails more slowly than steel."

Essentially true but in reality, when components break, they then tend to break suddenly as they get stressed well beyond the limit of 'controlled/slow failure'. All the steel frames I've broken (and there have been a few...) and seen break have gone suddenly though clearly there had been a crack that had led to it happening.

further "In this regard, metals are far superior to rubber, plastic, and carbon fiber. The resins used to hold the layers of carbon fiber together degrade with exposure to ultraviolet."

Again, correct but this just hasn't proven to be a real world problem.

furthermore-er "The least defect-tolerant material used in bikes is carbon fiber. (And most carbon fiber comes from China, as a matter of fact.) The most defect-tolerant is steel. "

True (ish - I don't really think you'd distinguish to any significant degree between alu/steel/Ti) however based on the bikes that are out there now, it's clear that the quality control is good enough to ensure that these defects aren't common.

MrSmith you got me. I need wheels for the road bike, the crosser and some training wheels, but cash is tight thanks to needing a new TV, washing machine, tumble dryer, garage door and kettle? all in one month.

regardless of whether they are well suited to crits, i wouldn't use them. don't want to risk £1k on wheels in any bunch, they are are tt only for me.

J E Gordon wrote in his book New Science of Strong Materials: or why your feet dont fall through the floor.

"Like boron, this fibre has suffered from a great deal of irresponsible Government publicity.
Although frequently described by the newspapers and on television as a wonderfibre of exceptional strength, carbon fibres are not in fact, particularly strong; if anything they are a little weaker than glass fibres. They are however, for their weight, something like eight times as stiff as either glass or the normal engineering metals. As might be expected the resin-fibre composites made from carbon fibres are very stiff but not especially strong in tension. They are also, at present, rather inconveniently weak in compression. While it might be possible, in theory, to put up the compressive strength of carbon fibre composites by using a metal matrix, this does not usually work in practice because of the chemical reactions which occur between the carbon and the metal.

However, for many purposes where weight saving is important but where the strength requirements are not too critical – such as artificial limbs, golf clubshafts or the stiffening of car bodies – carbon fibre composites have been very successful.
When we turn to more exacting applications, like aircraft parts, the trouble is generally lack of toughness. When the composite is made in the conventional way the work of fracture whichis actually achieved is not far short of the calculated theoretical limit – but unfortunately this is, in practice, not sufficiently high."