I was wondering if there are particular situations when you're better off switching the front or rear gears to change speed? I normally change the front gear speed when I want a big speed change rapidly such as if I'm on flat pavement and a sudden steep hill appears, and change the rear gear for more subtle changes like a slight change in the path's inclination.
Am I using them right?
Thanks
It is very situational, but this is how I use my 3x9 (3 in the front , 9 in the back). 44,32,22 Tooth count and 11-34 cassette (11 on small cog, 34 on the big)
Middle chain ring for most terrain. Level ground to moderate climbs and descents. Just about every ride starts in the middle chain ring and use all 9 rear cogs with the middle ring. I use the big ring for street riding or for fire road descents. Last ride I had smooth fire road descent and hit 25 mph using my big ring and small cog giving max speed. I also used the big ring on 15-18 mph single track descent to minimize chain slap. No pedaling needed, but the bigger ring and corresponding bigger rear cog tightens up the chain some as compared to middle ring and small rear cog. I tend you use only the smallest 5-6 cogs in the back to reduce cross chaining. I never use the big ring and my 34 tooth large cog. There to severe of an angle between the front and rear gears putting side load in the chain. Plus a 44 /34 ratio is nearly duplicated by 32/ 26 or 32/23 combo. These are using the middle ring middle cogs. Same applies to using a 22/11 combo. That is very similar to 32/17 ratio. This the main reason why you can choose to not use certain combinations that might cause cross chaining.
Now.. Small ring... I use that for longer and tougher climbs. While I have the same exact gear ratio in my middle ring 32/34 = 22/23 the middle ring combo leaves me no place to drop a gear. The reason is the front derailuer works very poorly shifting under load. The rear does not work well under load either, but a slight pause and it will shift. The front will drag for 4-5 crank rotations and may never shift. So if I am on a long steep grinder of a climb I will use the small ring and smaller cog. So for example
32/34 = Middle ring / 9 cog = So nowhere to go for more gearing other than big ring
22/23 = small ring / 6 cog = I still have 3 more cogs in the rear to lower down to in case I need them at an easy turn.
Once I finish the climb and start the descent I will change from the small ring to the middle ring bring the ratios up quickly for the higher speed stuff.
The hardest parts are quick dips where the trail goes from descent to very steep up. If the path is smooth you can attempt to roll the up with momentum. Take the drop fast and hope you have enough speed to pull you most of the way up the hill in big gear (higher speed). You may need to stand and mash completed it. Or when it is really hard there might be turn at the bottom killing all your momentum. In these cases you need drop gears early and may over spin some parts have enough to make it over the top. I have also down shifted cogs in the back and pedaled a few turns while riding the brakes just to change gears to be ready for the climb out. If you need to put power down you rather not be having the derailuers trying to change gears as that increases the risk of breaking stuff. You want to already be in the right gear.
