A question about Shimano shifter
10-11-21, 06:43 AM
#1
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A question about Shimano shifter
Hello all, just got back into cycling after a 20+ hiatus. purchased a bike yesterday of of craigslist. it has a shimano shifter that has a finger lever on top and I'm assuming a thumb lever on the bottom? can someone explain to me how this set up works. Thanks
10-13-21, 04:42 AM
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This is your left shifter in the picture. It controls your front derailleur.
The thumb shifter moves the derailleur to a bigger chainring, ie, shifts you into a higher range of gears. The finger/trigger shifter, which you should be able to reach with your index/pointer finger while riding, will shift into a smaller chainring, ie, lower range of gears.
The right side shifter changes the gears in the back, and will be similar but opposite; the thumb shifter goes to a bigger cog at the rear, which is a lower gear, and the finger/trigger shifter will shift to a smaller cog/higher gear.
The thumb shifter moves the derailleur to a bigger chainring, ie, shifts you into a higher range of gears. The finger/trigger shifter, which you should be able to reach with your index/pointer finger while riding, will shift into a smaller chainring, ie, lower range of gears.
The right side shifter changes the gears in the back, and will be similar but opposite; the thumb shifter goes to a bigger cog at the rear, which is a lower gear, and the finger/trigger shifter will shift to a smaller cog/higher gear.
10-13-21, 07:13 AM
#3
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Hello, have to let this sink in. it's a little confusing. years ago when I had a bike, only had one lever to shift, never thought about it. now, with youtube there is so much info. out there. I'm happy that there are forums like this. Thanks for responding.
10-13-21, 08:29 AM
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A simplistic description is basically a ratchet wheel and a pawl in the shifter.
As you press the thumb lever forward you turn the wheel and the shifter cable is pulled and winds around the wheel. A pawl stops it at a point where it is indexed to be lined up with the cassette cog or chainring.
When you pull back on the index finger shift lever you release the pawl and the derailleur spring turns the ratchet wheel and unwinds the cable. The pawl stops at the next ratchet which aligns the chain with the cog or chainring.
For trigger shifters each click is a shift. Exception are some road flat bar shifters that have a trim function for the chainrings.
I imagine better descriptions will he given, but it is basically pulling and releasing the shift cable.
John
As you press the thumb lever forward you turn the wheel and the shifter cable is pulled and winds around the wheel. A pawl stops it at a point where it is indexed to be lined up with the cassette cog or chainring.
When you pull back on the index finger shift lever you release the pawl and the derailleur spring turns the ratchet wheel and unwinds the cable. The pawl stops at the next ratchet which aligns the chain with the cog or chainring.
For trigger shifters each click is a shift. Exception are some road flat bar shifters that have a trim function for the chainrings.
I imagine better descriptions will he given, but it is basically pulling and releasing the shift cable.
John
Last edited by 70sSanO; 10-13-21 at 08:35 AM.
10-13-21, 04:12 PM
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it might take some time to get used to, but you’ll get it. You’ll have noticed the shifter has numbers in the window to tell you which gear you’re in (1 is your lowest gear). You probably have 3 gears at the front and 8 at the back. After a while, you’ll work out what sort of terrain you need which group of gears for.
