gears - no-one ever told me this before!!!

[Donna]

I ride only using the 'hardest' 3 gears, i.e. pedalling slower rather than faster.... from what im understanding I need to learn to ride to pedal at the same rate, using the gears to go faster, slower, easier said than done... this is un-natural for me. I will try if the end result means its easier on my knees, which, by the way give me no trouble as I ride now.

 

[Arch]

The point about whether you have 21 gears or whatever, is not how many you choose to use, but how many are duplicated. Some of the gears at the extreme ends of the range of the middle ring will be duplicated at the low or high end of the ranges of the other chain rings....

(sorry, that was a reply to the post above the last)

 

[Donna]

yes I understand that they will be duplicated, thanks all think I understand now

 

[jimboalee]

Donna, if you have 7 at the back and 3 at the front then you are right, you have 21 gears all of which are useable. Some people prefer not to use them all but it is your bike and it has 21 gears so use whatever you like.

To say you have got 3 ranges not 21 gears is wrong and is just over-complicating things. I have yet to come across anyone with a 21, 24 or 27 speed bike that describes it as a 3 ratio bike.

Good luck with your riding, after a few more miles in the saddle you will know what suits you best.

Twaddle.

You have ONE range of gears.

The gearing on a bicycle with multiple chainrings and a cluster of sprockets has been engineered to give a smooth series of ratios from low to high.
As the ratio increases, so does the gap between the ratios. At the bottom end, the gap may be 3 -4", rising to 5 – 6" in the midrange and then progressively increasing to a 8 – 9" gap at the top end.

Along the way, the chain must be moved to a bigger chainring AND a bigger sprocket simultaneously to achieve the next ratio.

Apart from how to steer and use the brakes, this is the important thing to learn about your bikes; when to transition the ring and how many sprockets to climb/fall to get the next ratio.

 

[Debian]

Donna, if you have 7 at the back and 3 at the front then you are right, you have 21 gears all of which are useable. Some people prefer not to use them all but it is your bike and it has 21 gears so use whatever you like.

To say you have got 3 ranges not 21 gears is wrong and is just over-complicating things. I have yet to come across anyone with a 21, 24 or 27 speed bike that describes it as a 3 ratio bike.

Good luck with your riding, after a few more miles in the saddle you will know what suits you best.

No you don't, not as I understand it anyway.

Firstly, the big chainring/big rear cog and the small chainring/small rear cog combos shouldn't be used as the chain will be crossed too much - it'll be noisy and wear rapidly in these positions. So that reduces the set to 19.

Then there are almost certainly duplicated ratios within the three ranges.

A nominally 21-speed bike probably has 15 or so unique and usable ratios.

 

[Debian]

I ride only using the 'hardest' 3 gears, i.e. pedalling slower rather than faster.... from what im understanding I need to learn to ride to pedal at the same rate, using the gears to go faster, slower, easier said than done... this is un-natural for me. I will try if the end result means its easier on my knees, which, by the way give me no trouble as I ride now.

If you're happy at that then fine. However, I used to do similar until I discovered the advantages of a higher cadence. It initially felt weird to be "spinning" more but I soon got used to it and now it feels like the most natural thing in the world. About 80 - 90 rpm feels about right to me now.

I now find that I can ride much further with less effort than ever I could when I was "grinding".

I am intrigued though that you say you only achieve 10mph. That just sounds not quite right to me? You must be "grinding" ever so slowly to achieve that?

 

[jimboalee]

No you don't, not as I understand it anyway.

Firstly, the big chainring/big rear cog and the small chainring/small rear cog combos shouldn't be used as the chain will be crossed too much - it'll be noisy and wear rapidly in these positions. So that reduces the set to 19.

Then there are almost certainly duplicated ratios within the three ranges.

A nominally 21-speed bike probably has 15 or so unique and usable ratios.

You understand correctly.

A big part of the fun when buying or acquiring a new bike is to assess it's gearing, draw a chart and decide if it needs changing to suit your style and cadence.


A cyclist may have a collection of cassettes and rings to fit depending on the terrain to be ridden.
Well, when we only had two rings and five sprockets to play with, this was common.

 

[Debian]

You understand correctly.

A big part of the fun when buying or acquiring a new bike is to assess it's gearing, draw a chart and decide if it needs changing to suit your style and cadence.


A cyclist may have a collection of cassettes and rings to fit depending on the terrain to be ridden.
Well, when we only had two rings and five sprockets to play with, this was common.

If I actually understood gearing in the first place I might be tempted to do that . The whole mechanical advantage thing passed me by at school and uni.

 

[Donna]

10mph is the average what my cycle computer says.

I havent exercised for 20 years!!! Just started cycling and love it! On the flat I ride approx. 16mph plus. Although I havent actually counted (as i didnt know about cadence) I know I don't pedal no where near 80-90 rpm.

I am picking my bike up from the LBS on saturday morning and will have a trip out and see what its like to ride on lower gears, we will see!

 

[Arch]

You can check your cadence, preferably with a watch that has a second hand so that it's easy to see when a minute is up. Just count how many times one foot goes round in a minute, counting from when the second hand hits 12, and looking for it to come round again.

Obviously, beware of staring at the watch too much while you count, and not paying attention to the road ahead...

 

[buggi]

Donna, don't get so hung up on which chain ring at the front you use. use which one you feel most comfortable in. The only thing is that when you use the bigger chain ring on the front (outer) try not to run the chain at the back on the most inner ring. This is called running the chain to the extremes, as the angle of the cross over of the chain will cause extra strain and wear and tear. if you find you are needing this last gear, it's time to switch to the middle ring.

As said, it's not actually 21 gears. It doesn't quite work like that. The best way i can explain it is... it's more like 21 cogs, as there are some cogs at the back when you are in the big ring at the front where the effort required matches some of the cogs at the back when you are in the middle ring, and some in the middle ring that match the small ring. not sure if i've explained that clearly, but i hope you get what i mean.

 

[jimboalee]

The Carerra 1 has similar gearing to my Land Rover Tahora. That is a 42 largest ring with 11, 13, 15, 18? Sprockets.

In 42 x 15 ( 69" ), 16 mph on the flat will be about 78 rpm cadence. No need to change that.

In 42 x 13 ( 79" and a biggish step ), 16 mph is 68 rpm. A nice casual cadence for level ground.

In top, ( 94" ), 16 mph is 57 rpm and you will start to feel this after a few miles.


If it is an 18 sprocket next to the 15 sprocket, 16 mph will be 94 rpm cadence. This may be a little fast for a beginner to sustain for miles and miles.


One way round changing the gearing would be to fit a road cassette. A 13 to 26 cassette should give you 13, 14, 15, 16 sprockets.

Top gear will now be 42 x 13 ( 79" and 68 rpm at 16 mph ).

You will have 5" steps between the top 4 gears.

You will lose the very low bottom gears. Your 22 ring to the 26 sprocket will be 21". That's still LOW for a Town/trail bike

My LR Tahora has a 7 cassette. Next project is a 12 – 23 cassette.

 

[GrasB]

So as I suggested earlier the top chainring on this bike is close to what most people would consider a middle/bottom chainring on a road triple/double