A SS-rider vs a Geared-rider

[Garz]

Note that Sheldon said for bikes of comparable quality.

I have two steel roadbikes built from bits and pieces, a Carlton and a Peugeot. I used the lighter Carlton as a SS and put gears on the Pug

Yeah, but reality is your steel bikes will weigh more than my geared bike and again il mention any cheaper end fixies or old coverted ones will too. So your point about lighter is not always true..

 

[GrasB]

Carbon geared v's steel fixie isn't that clear cut garz. While my steel fixie is heaver it's a few 100g more than my carbon road bike & due to it's much lighter drive train has better acceleration once I'm over 60ppm!

 

[jimboalee]

I just done the sums to assess how heavy my SWorks would be if I converted it to a fixie.

About 13 lb 12 oz....

 

[Garz]

My point is GrasB that most people wont be buying a 'carbon' SS and more likely use an old hack or a entry level new one which will all weigh tons more than your 'carbon' fixie.

 

[MacB]

My point is GrasB that most people wont be buying a 'carbon' SS and more likely use an old hack or a entry level new one which will all weigh tons more than your 'carbon' fixie.

That's true but level playing field applies, especially when looking from a utility purpose. If you're speccing a bike of this nature then low maintenance, low cost of replacement parts and ability to leave locked up with lower risk of theft are important. This is true of any utility bike you spec up. To save weight you can up the cost but you also up risk and the cost of new parts. Alternatively you can remove gears.

 

[Garz]

Yep totally understand Mac, just wasn't totally agreeing with the weight ideology as it depends on what your using and the reason.

 

[jimboalee]

Coming back to Arnuld’s bike.

Studying the photos, it looks like it is a 42T ring to 18T freewheel sprocket. Confirmation required.

That’s 61” with a 26 inch tyre.

I’m making some assumptions here but in my experience, that bike might have a drag coefficient of about 1.15 and a weight of 35ish pounds.

This computes to a power demand of 135 Watts ( 7 3/4 kCals/min ) at a speed of just about 14.5 mph. The kind of output to successfully finish an Audax 100 in 5 hours.

The gearing on this bike dictates 80 cadence at 14.5 mph, so Arnuld, you have a bike which has a ‘near perfect’ ratio.

When you get to a 5% hill, you will pull 270ish Watts and climb it at 8 mph at 50 cadence.
When you get to a 10% hill, you will need to pull the same 270ish watts but you will be riding at just under 5 mph at 28 cadence ( probably with your bum hovering off the seat).

Low and behold, when riding up a 10%, speed reduces to 1/3 and the power requirement doubles.

“Mumbo Jumbo in action”….

 

[MacB]

“Mumbo Jumbo in action”….

"Mumbo Jimbo" surely?

 

[jimboalee]

"Mumbo Jimbo" surely?

Yeh...

That's a dreadfully low cadence up a 10% moderate hill, but what else can one do?
I just hope there are few of these where Arnuld rides.

In fact, if each pedalstroke is on the second, it's 30 rpm, which would be an easier rythym to keep.

 

[GrasB]

My point is GrasB that most people wont be buying a 'carbon' SS and more likely use an old hack or a entry level new one which will all weigh tons more than your 'carbon' fixie.

Garz, please re-read that because I have a steel fixie, admittedly a 753R rather than the more typical 531 but it's still steel.