Gear ratios, cadence, speed.

[simmi]

With the help of Mike Shermans gear calculator (thanks GrasB) it would seem that to get the optimum gear ratios I would be better changing my crank to a compact 34/50 and reverting bactk to my original 12-23 cassette.
The main issue I can see with this is the speed I do 90% of my riding at (15-20mph) would mean I was mainly using the higher 4 gears with the small chainring and the lowest 4 gears with the biggest.
So in effect would be doing a lot of crossing.
Is crossing a big no no with a dual system, not such a big deal is it is with a tripple I would guess?
What point does it become crossing is it bottom chainring to smallest cog? 2 cogs? or even 3 cogs?
So much to learn!

 

[Rob3rt]

Got to be honest here, I seem to get the impression that there is a lot of thinking going, rather than a lot of doing! Go ride, then ride some more, then ride just that bit further until the parts are worn out, then think about it, but only a little, don't think for too long, that will just delay getting the bike back on the road so you can begin the cycle once more!

 

[simmi]

Got to be honest here, I seem to get the impression that there is a lot of thinking going, rather than a lot of doing! Go ride, then ride some more, then ride just that bit further until the parts are worn out, then think about it, but only a little, don't think for too long, that will just delay getting the bike back on the road so you can begin the cycle once more!

It's alright for you youngsters us fortysomething newbies have to get all the advantages we can!

 

[derrick]

I have just gone down to 11-25 from 12- 23, should be right for my rides, don't tend to mess around to much with cassettes, am finding it harder to get the fixie gearing right.

 

[simmi]

I have just gone down to 11-25 from 12- 23, should be right for my rides, don't tend to mess around to much with cassettes, am finding it harder to get the fixie gearing right.

Fixie, you have my respect! but not for me, why would you, its like going out and playing golf with just one club!
infact I am starting to think I should have gone for 10 instead of 9 speed

 

[Rob3rt]

Fixie, you have my respect! but not for me, why would you, its like going out and playing golf with just one club!
infact I am starting to think I should have gone for 10 instead of 9 speed

The extreme's would be the same, you would just have a closer spacing, yes, this is good for keeping your cadence within an optimal range on the flat, but no tangible benefit's other than that.

 

[derrick]

Fixie, you have my respect! but not for me, why would you, its like going out and playing golf with just one club!
infact I am starting to think I should have gone for 10 instead of 9 speed

I really like it as a commutter and training winter bike, i get a good workout when i can't fit in a longish run on the road bike,
Every body should have one, and it's only a fiver to change your gear ratio.

 

[GrasB]

The main issue I can see with this is the speed I do 90% of my riding at (15-20mph) would mean I was mainly using the higher 4 gears with the small chainring and the lowest 4 gears with the biggest.

Also but would you really? Say your average cadence is 90rpm. On the flat at the higher end of that speed range you're going to be +5-10rpm on your average cadence, at the bottom end of that speed range you'll be -5-10rpm on your average cadence. That would put you on the 13 & 14t sprockets most of the time. I'm having to ask do you actually know your average cadence on the flat? Also you're starting to see the other side of wanting an 11t sprocket - it helps push the high end of the bottom chainring into a higher speed range.

 

[simmi]

I'm having to ask do you actually know your average cadence on the flat? Also you're starting to see the other side of wanting an 11t sprocket - it helps push the high end of the bottom chainring into a higher speed range.

This was my last ride, quite short and very flat, rode the first 10 miles without a gear change on the 17T.
averaging about 17.5mph, at this point changed direction 90 degrees and was getting a little tired so changed down one gear to 19T my average speed then dropped by about 2mph.
I think if I had had a 18T I would have felt better, The smallest cog I used the whole ride was a 15T for the last few miles, and did the whole trip without using the 52T chainring.

Also you're starting to see the other side of wanting an 11t sprocket.

With the compact crank I would need a 11T or 12T but with my current 39/52 I don't usually get near them.
This is my current set up and thanks to you I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

 

[Rob3rt]

This was my last ride, quite short and very flat, rode the first 10 miles without a gear change on the 17T.
averaging about 17.5mph, at this point changed direction 90 degrees and was getting a little tired so changed down one gear to 19T my average speed then dropped by about 2mph.
I think if I had had a 18T I would have felt better, The smallest cog I used the whole ride was a 15T for the last few miles, and did the whole trip without using the 52T chainring.


With the compact crank I would need a 11T or 12T but with my current 39/52 I don't usually get near them.
This is my current set up and thanks to you I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

I run a compact and rarely get near the 11T/12T except on negative gradients (I am not a powerhouse but I am not slow either - can average upwards of 20mph over 40-50 mile), just use the gears you use

 

[GrasB]

This was my last ride, quite short and very flat, rode the first 10 miles without a gear change on the 17T.
averaging about 17.5mph, at this point changed direction 90 degrees and was getting a little tired so changed down one gear to 19T my average speed then dropped by about 2mph.

Without being able to do speed/rpm plots from the data it looks like you hover around 90 rpm +/-5 rpm with most variation being to do with speed relative to gear.

This is my current set up and thanks to you I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

That looks like a compact 12-23 setup... I'm confused!

 

[simmi]

That looks like a compact 12-23 setup... I'm confused!

Sorry , this is my current set up I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

 

[black'n'yellow]

Sorry , this is my current set up and thanks to you I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

you'll get more options as your fitness improves - in the meantime, I really would just concentrate on riding.

 

[GrasB]

Sorry , this is my current set up I can now see it is totally rubbish for the most part, the "Speed over RPM Range" shows i need more options in the money zone.

It's not that bad in reality, nice steps from just under 54" to a little over 70". A 53t chainring would have given you a good spread between just under 70" & 85"

 

[cyberknight]

The extreme's would be the same, you would just have a closer spacing, yes, this is good for keeping your cadence within an optimal range on the flat, but no tangible benefit's other than that.

+1
Ride an 8 speed for commuting/winter runs and a 10 speed for the nicer weather, apart from closer gaps theres no real benefit , in fact teaches me to put power down at different cadences .