Oatdogg

Dear all,

Been hearing that since the weight between good aluminium and carbon frame is not much different anymore, the major carbon frame's benefit is to reduce the road vibration.

Instead of spending so much money on the carbon frame, can I just stick to my aluminum and reduce my tires' air pressure???

Ps. I love riding alone for the distance of 152 Km in a hot hot hot south east asia climate and yes... too fatigue

Thank you very much

Triguy

I find that carbon and ride similarly enough to be within the margin of a few PSI.

However, i will say that the primary difference between carbon and aluminum for is the ability to shape a frame mroe aerodynamically.

back4more

I rode both and thought I could go with more agressive geometry and still have a compliant ride with CF. With CF a manufacuter can put the material and strength where needed more readily.

back4more

But to your tire pressure question a lot depends on the size of tire, your weight, and surfaces. There is an optiminal pressure that is the best balance of ride, rolling resistance, and handling. Once that is discovered for a tire I wouldn't mess with it.

gazelle5333

In theory yes, but you'll be exerting more energy due to the aforementioned factor of rolling resistance...lower psi = more resistance = faster your bike coasts to a stop. I had an aluminum and upgraded to carbon after it was destroyed (hit by car). The ride is night and day between the two. It sounds as if you have a working bike, so why not just upgrade the frame itself and transfer components. Much cheaper IMO or look to ebay for a good frame at a cheaper price

Oatdogg

Thank you guys a lot.

I use 700x23 C tires and normally put 120 PSI on both tires. Last week I reduced the air to 100 PSI and feel more comfortable but it was just a short and relax ride. Don't know about the aforementioned factor of rolling resistance yet.

1. How much PSI do you guys normally use?
2. What Triguy and Back4more meant was that the comfort between two materials almost the same only difference were geometry, am I right?
3. Gazelle5333, thank you very much. may I ask... what does IMO mean? ha ha ha :-)

My goal now with my TT bike was not yet participating in any competition but to be able to go for 200 Km. with an average of 35 Km./Hr. (if I could) alone and still enjoy the rest of the day

Thank you all again

clink83

Not true at all. High PSI(<120psi) is slower due to not absorbing road variations.

gazelle5333

Oatdog - IMO = In my opinion

Clink - please explain that one...with less tire on the road, there should be less friction. I'm also talking pure physics here, not practicality. You could ride a 150 psi tire (if it would hold) but the ride would be crap and the handling would be sketchy.

The original question asked about carbon vs alum. in absorbing road vibration. All other factors aside, yes carbon absorbs more vibration and is a smoother ride. PSI is a whole other topic, but generally, higher psi means faster ride...would you race at 90 psi on a warm dry, day? most likely not, which was my main point