Friends can anybody tell me what is the gear shifting techniques or formula in Shimano 21 gears?
What exactly are you asking for, are you asking about the gear ratio to be used on various terrains or is it something else in specific?
Hi Vinni, I want to know how to use or shift the gears in different terrains. Example:- when the front gear is in no1, then what should be the rear gears postion?
Im no expert in this, and im sure the experts here will be able to give u a lots of gyaan on this topic, however i can share the method that i follow.
1] for normal flat roads - its always 3 -7 , 3-6, 3-5 :- 3 being the biggest in front and 7 the smallest crank behind.
2] For small uphills - its 2-4, 2-3, 2-2, 2-1 even though I always start with 3-1 but this can damage ur knees if u push too hard.
3] for steep unhills, ghats where its most difficult to climb its always 1-3, 1-2, 1-1 .
Combinations like 2-7, 2-6 2-5 can also be used after cycling for long hours on 3-7, 3-6, 3-5 this always helps in getting that much needed relaxation for legs and keeps u going.
For me there is no hard and fast rule though but i do follow the above principle.
Hope this helps
Thanks Vinni. ....
Hi Pradeep, Im no expert either but basically you can apply the same fundamentals of gears we find in Motorbikes/Cars for cycles as well. Hence the lower the gear, the more power you get,but less speed, as you increase the ratio,the proportion of power decreases and speed increases. In short with experience you will find which ratio works best while maintaining an ideal cadence and using as litttle energy as possible on any terrain.
This is how I use mine on urban roads (i have a 3:8 ratio): I hardly use the front gears(Always on 3) unless Im climbing steep hills. From a stop I always start from 3-3, I find this is the best way to gain momentum quickly.As soon as the bike gets enough momnetum(within couple o seconds)I shift to 3-4, As soon as you find that your pedalling gets too easy(means your pedalling gets too fast but not getting enough desired speed) on any gear,increase your gear ratio accordingly.Whenever you anticipate slowing down or stopping always shift down a couple of gears. For eg.if you are riding on 3-8 and you are approaching a traffic signal or are going to slow down for any reason shift down a couple of gears, if you are going to stop completely shift down to 3-3, be careful as to not shift down all at once but gradually.If you are still stuck at 3-8 or similar on a traffic junction, getting your bike into momentum will take more effort.So always a good idea to shift down atleast a couple of gears whenever you anticipate slowing down. If you are riding 'within traffic' keep the ratio around 3-5 or 3-6 which is enough for you to shuttle around cars with reasonable bursts of acceleration. Remember with experience changing gears will come natural to you and you will FIND the ideal ratio which you can then use for long rides without tiring yourself.
1) 'Sheldon Brown' type it in the address and enter. all about gear gyan is there. Use internet to good effect. All the best.
In a general 21 speed bicycle, there are 14 usable gears:
1-1, 1-2, 1-3, 1-4
2-1, 2-2, 2-3, 2-4
3-2, 3-3, 3-4, 3-5, 3-6, 3-7.
If you are using a Shimano Megarange, the difference between the 1st and 2nd gear at the rear will be high. Use 1st gear only on very steep inclines.
Shifting (from slackest to tightest) goes like this:
1-1, 2-1, 1-2, 1-3, 2-2, 1-4, 2-3, 3-2, 2-4, 3-3, 3-4, 3-5, 3-6, 3-7.
This is the way (up or down) you should be shifting.
Avoid using odd combinations (3-1, 2-5, 2-6, 2-7, and 1-5 and greater). This makes the chain strike the front derailleur while pedalling.