unravelling Gearing theory and formulae

[peanut]

RESULTS ARE IN


I thought we should give jimbolee an opportunity to demonstrate his gearing theory and put it to the test. If it works then we should at least give some creedence to the results even if we do not necessarily agree with the theory.
Hope you'll agree to give this a go jimbo

My winter road bike weighs 23lbs
it has a 9 speed cassette and double compact chainset fitted
I currently weigh 16st 10lbs
height 5.11"
wrist circ is 8.5"
pinch and inch waist is 28mm
I have a compact 50x34 chainset
My rides are approx 20miles and quite hilly 80 -100 mt climbs
what else do you need to know to work out my ideal gearing?

 

[yello]

Jimbo has critics? No, I won't hear it!

Faith, that's what it's about. Faith.

 

[Ant]

Just out of curiosity, what's the exact criticism of Jimbo's formulae?

 

[peanut]

hey guys please don't just add spurious posts to my thread its going to confuse things . I don't want this to end up being another free-for-all bunfight as it usually does
Do a search on 'gearing' and read up on all the previous posts about the subject you'll soon see the reason for this thread.
If Jimbo agrees to my request then perhaps he might offer to list his formula so that everyone can work out a suggested gearing for their bike

 

[Ant]

hey guys please don't just add spurious posts to my thread its going to confuse things . I don't want this to end up being another free-for-all bunfight as it usually does
Do a search on 'gearing' and read up on all the previous posts about the subject you'll soon see the reason for this thread.
If Jimbo agrees to my request then perhaps he might offer to list his formula so that everyone can work out a suggested gearing for their bike

I think I've already read all his gearing posts and as far as I can tell the criticisms come from a position of not understanding exactly what the formulae are for.

You seem to be starting with the assumption that these formulae will work out 'your ideal grearing' They won't and aren't intended to. They're a starting point upon which to build. How can any formula work out your 'ideal' gearing when your fitness level and strength are a complete unknown?

I just think that you're starting this thread based on a complete misunderstanding of what these formulae are for, and wanted to clarify that.

 

[peanut]

I think I've already read all his gearing posts and as far as I can tell the criticisms come from a position of not understanding exactly what the formulae are for.

You seem to be starting with the assumption that these formulae will work out 'your ideal grearing' They won't and aren't intended to. They're a starting point upon which to build. How can any formula work out your 'ideal' gearing when your fitness level and strength are a complete unknown?

I just think that you're starting this thread based on a complete misunderstanding of what these formulae are for, and wanted to clarify that.

thanks Ant you are now hyjacking my thread to start another argument just as I requested you not to .Theres always one isn't there. I've already blocked randochaps posts.

THIS THREAD IS NOT THE PLACE FOR ARGUMENT OK

 

[yello]

THIS THREAD IS NOT THE PLACE FOR ARGUMENT OK

Oh yes it is!

 

[peanut]

oh no its not!

guess it soon will be though

 

[Ant]

thanks Ant you are now hyjacking my thread to start another argument just as I requested you not to .Theres always one isn't there. I've already blocked randochaps posts.

THIS THREAD IS NOT THE PLACE FOR ARGUMENT OK

Fair enough. I'll sit back and watch this unfold then

 

[jimboalee]

Thanks Peanut.

Please find a list of questions on the other thread.


My observations as a forty plus year cyclist. NO criticism of anyone on this forum.

It amazes me how many people buy a bicycle and don't consider it's THEIR legs that have to power it.
It isn't like buying a moped where the only prerequisite is how to operate a fuel dispenser pump.

RandoChap has repeated stated and linked us to his Veloweb many times saying gearing is probably the hottest topic amongst cyclists.
He's right.
Absolutely newbie cyclists won't know about gearing. The bike has 18 gears, GREAT! It'll get up that steep hill then. Not necessarily.

A chap I work with has a Raleigh Equip. It weighs 28lb and has a 42 x 24 lowest. It was originally sold as a 'Racer'! Some hopes.... It needs a 30 tooth ring ( a triple ) with a 23 sprocket. 25 to be safe. 27 to be safer.
It's owner is not overweight and he deperately struggles, puffing and panting to climb up Corley Rocks which is about 11% and only 100m duration. At the summit, he should be able to accelerate away to cruising speed. No. Time to recover is necessary. The gear is way too high.

Peanut, when i get your details, I'll run them through my calcs and post a gearset I would fit if I were yourself.

My Dawes Giro is geared a treat. 15 gears from 32 to 106" in a steady progression.
The bike weighs 24lb so the 30 x 19 ratio is the '10%' gear. It gets me up a long 10% at 60 cadence doing 7.5 mph.
In reality, I climb up a short 10% on 42 x 17 at 38ish cadence. I'm a real grinder

 

[peanut]

Fair enough. I'll sit back and watch this unfold then

thanks. we'll no doubt have a lively debate after the results are in ok

 

[peanut]

jimbo I've added all the details you requested to the first post in this thread ok

to be completly fair I should add that I am currently very unfit and overweight so we could technically class me as a new cyclist for the purposes of this thread .

I'll send my current gearing to Mort as an independant ok .This gearing has been arrived at through extensive testing and suits me perfectly at the moment.

I have 6x full cassettes and numerous wheels and spare sprockets so I have experimented lots and can fit practically any gears i want to.

 

[jimboalee]

jimbo I've added all the details you requested to the first post in this thread ok

to be completly fair I should add that I am currently very unfit and overweight so we could technically class me as a new cyclist for the purposes of this thread .

I'll send my current gearing to Mort as an independant ok .This gearing has been arrived at through extensive testing and suits me perfectly at the moment.

I have 6x full cassettes and numerous wheels and spare sprockets so I have experimented lots and can fit practically any gears i want to.

Send me a PM with your wrist circumference and skinfold ( pinch an inch ) measurements. & any others on the other thread you haven't already answered.

 

[peanut]

Send me a PM with your wrist circumference and skinfold ( pinch an inch ) measurements. & any others on the other thread you haven't already answered.

jimbo I have already answered all the questions and put all the info you asked for on the first post in this thread
My winter road bike weighs 23lbs
it has a 9 speed cassette and double compact chainset fitted
I currently weigh 16st 10lbs
height 5.11"
wrist circ is 8.5"
pinch and inch waist is 28mm
I have a compact 50x34 chainset
My rides are approx 20miles and quite hilly 80 -100 mt climbs

 

[jimboalee]

jimbo I have already answered all the questions and put all the info you asked for on the first post in this thread
My winter road bike weighs 23lbs
it has a 9 speed cassette and double compact chainset fitted
I currently weigh 16st 10lbs
height 5.11"
wrist circ is 8.5"
pinch and inch waist is 28mm
I have a compact 50x34 chainset
My rides are approx 20miles and quite hilly 80 -100 mt climbs

OK