Big Bike Thread

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You sure did mate! I've already spent £820 and my current projected total is now at £1145 :eek:

I'm enjoying it though and the excitement of getting it finished is growing.
 
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The Giro paid a very moving tribute to the big fella today. Awesome to watch. Sometimes this sort of thing shows the cycling community are absolutely up there with the best when it comes to respect. Nice touch when Farrar joined in.

Watching the Leopard Trek guys crossing the finish line arm in arm resulted in a lump in my throat.
 
The Ritchey WCS bars are a bit on the narrow side. More of an XC bar. But the cosmetic weave looks much much nicer than the Monkey Bars. I have both. :D

I have done DH (as feable as I am at it) with the Easton Monkey XC CNT carbon bars. Plenty strong. :D

The Monkey Bars have been replaced with the Havon/Havoc bars which are lighter and stronger. Plus IMO look the dogs danglies. ;)
 
a smart fella said:
Why carbon?

Well let me be of some assistance. I have an MSc in the subject and work with it and test it every day at the top level (Formula 1). Are you sitting comfortably?...
Here's a brief guide:

For a start do not buy carbon bars for downhill or any kind of harsh riding!

Carbon composites are materials made by using a resin (usually epoxy) reinforced with carbon fibres, these can be continuous, as in woven cloths or unidirectional ribbons for example, or discontinuous short fibres or even nano tubes!

Pros:
It is light and strong and can be made into almost any shape.
Its strength can be designed into it in the desired locations depending on fibre placement and number of plies (layers).
It can be very stiff, or very compliant (depending on how it is designed and made etc).
It has excellent fatigue life (verging on the infinite).
It can absorb huge amounts of energy when it fails (hence great for making helmets).
It can be tough (depending on the resin).
It has excellent damping and shock absorption properties.

Cons:
It is expensive.
Its purely elastic nature means that it does not locally yield at points of high stress, unlike metals which relieve stress concentrations by deforming plasticly around the point.
It is not indestructable.
When it breaks in tension it goes with a BANG and without warning.
When it breaks in compression it crumbles (with a not so big bang).
When it breaks it splinters (health hazard, in more ways than one).
It is weak in any direction other than the fibre direction.
It can be brittle (depending on the resin).

So you can see why they are not good for handle bars, where there are many stress concentrations with everything that is bolted to it. These can induce failure. Carbon composites are best joined by adhesive bonding, not with mechanical fasteners like nuts and bolts (see cons).

Now, Carbon Nano Tubes (CNTs) Not to be confused with Carbon Ultra Nano Tubes are minute (on the nano scale) tubes of carbon. Imagine a sheet of carbon atoms, one atom thick rolled into a tube. These are some of the stiffest and strongest (to weight ratio) fibres known to man. Hence if used correctly as a reinforcement can make some very strong stuff indeed. However CNT's are very expensive to make. Recent developments in technology have reduced the costs though and we can now see such technology in things like bicycle handle bars. However, still at a price of a couple of hundred pounds a gram of CNTs (or something ridiculous) I wonder how the likes of Easton make a bar entirely from CNT reinforced composite for the price of £70. I imagine they use a tiny amount of CNTs in their bars. Meaning the rest of the bar would likely be made up from woven carbon (as some of those photos suggest).

Anyway if you've read this far - well done, I hope this has been interesting.

In summary: Don't buy carbon bars, waste of money.

I might add that carbon can be used to make ideal frames (Lahar for example) and some components. It just takes good design. Metal inserts bonded into the carbon structure are a good way to provide locations to thread / bolt to etc. However there can be problems with bonding Alu to carbon (thermal expansion and stiffness differences, galvanic corrosion etc).
Click to expand...
 
That is a very generic overview of carbon. I really don't see the arguement for not using it in handlebars over any other component at all.

Smart fella was smart about carbon in 1998. Complete tosh!
 
I'll take someone who works in F1's word on carbon bars, above that of dirt.
I tend to put a lot of faith/stake in their reviews, but this is very specialist subject matter which they wont know much/anything about. They can comment on the feel of the bar sure... not the material it's made from.
 
weescott said:
That is a very generic overview of carbon. I really don't see the arguement for not using it in handlebars over any other component at all.

Smart fella was smart about carbon in 1998. Complete tosh!
Click to expand...

Generic overview yes... but I doubt youd keep reading an entire thesis on the matter in a forum post ;)


Also, from personal experience.. I have bent alu handlebars. Cabon bars in that situation would have snapped, and I sure dont want to be impaled by a carbon poker rod. If they in fact wouldnt have snapped, they could have caused a major tension/stress point and would have failed me at some other.. possibly more inappropriate time.

ps: his nickname aint "a smart fella" ..I just added it for dramatic purposes

Hello bent alu
DSC01579.jpg
 
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I used to race rc cars.

You would bend/break aluminum parts but you wouldn't with carbon fibre.

All the chassis were made from it, and these are a 1.5kg object that will do 40mph+

In the hands of a n00b, it will also do 40-0 instantly into a barrier and I never saw one break! The edges would start to shard/wear away where it had been cut, so the ends of the bars could potentially be a problem if you dropped it a lot and they weren't protected, but to break the bars would be difficult!





Personally I would probably use one and take my chances, but then I wouldn't notice the weight saving anyway!
 
Okay, taken it out for a ride earlier. Aside from obviously needing new pedals ASAP as I have to compensate with my feet to ride them without proper shoes at the moment, the bike rode very comfortably.

The only negatives are: the saddle is very uncomfortable to the point after 30 minutes I have a very sore backside, I'm not sure I like the grips (but they may grow on me) and finally, I can't shake the horrible feeling that I may have got a size too big. It's not an issue as I can stand over the frame easily, and am quite comfortable riding it, it's just I can't help but wonder if I was better suited for the next size down. Not the end of the world by any means, but it's giving me a small degree of buyer's remorse which isn't nice. Perhaps I just need to get used to riding again is all.

Anyway, on with the matter at hand:

I need a new saddle, one that is a little kinder on the buttocks and suited for long rides (as I'm likely to be entering the London-Southend ride soon).

Any suggestions?
 
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