Hi y'all I'm new to the the form! I tried to Look it up but can't find anything! Will Sram 3V Road Bike Bar End Shifter fit 10 speed on a 21 speed bike? Thanks

I'm not sure what, exactly, you are asking but index shifters have to match the number of rear cogs. A 21 speed bike has 7 rear cogs so no.

They say they are 10 speed shifters but I have a 21 speed bike just wanted to know if they will work or not! Thanks

What about theses Shimano Dura Ace SL-BS79 Road Bike Bar End Shifter Set 2x10 Speed TT Time Trial

Assuming those shifters have a friction function, set them on that and they'll work. You'll just have to sense when the chain moves to the next gear. There are a number of riders who prefer friction to indexed click shifting systems. My personal bikes are half and half.

10-speed shifters won't index with 7 rear cogs because the 7-speed cogs are spaced farther apart than 10-speed cogs are. Consequently, 7-speed required more cable pull to "click" into place.

This. All my bikes but one are friction, because that's what I learned on and it's not worth the trouble and expense of switching. The difficulty of shifting a non-indexed driveline has been WAY overestimated.

A 21 speed bike is likely a 3x7 setup (3 chain rings on the crankset and 7 cogs/sprockets on the cassette). The shifters you ask about as 2x10 are designed to work with gearsets of 2 front chainrings and 10 cogs/sprockets on the cassette. If you are trying to replace the shifters on the 21 speed bike it would be best to find a shifter set designed to match the number of chainrings and sprockets you have, likely 3x7.

Yea it's a 3x7 set up! It has a shimano revo twist shifters on it right now

I beleive the newer dura ace bar ends are indexed only...so they probably wouldn't work with a 7 speed rear end.

Maybe I'll just get theses they will work right Shimano EF-51 Shifter/Brake Lever Combo (3 x 7 Speed)

Those should work. They are for a straight bar, not for a drop bar.

Those are 10s indexed only rear and friction front. FWIW they will shift a triple in front - they came standard on my 2014 Novarra Radonee touring bike with a Shimano LX triple front. Will not work with the rear of your 3 x 7 drivetrain

Do you have a straight handlebar or a drop bar?

Also, your bike doesn't happen to have a weird 3 pieces drop handlebar?

Canadian Tire used to sell a road-bike that had a 3-pieces handlebar and used Revo shifters. That's why I ask.

An image of your handlebar would be a big help.

Cheers

Friction Sun tour Bar end shifters have been fine with my 7 speed drive train rears ..
Friction/power ratchet

straight bars the thumb shifter is the way to go ..


New 10 speed' is all 10 on the cassette .. Old '10 speed' was 5 on the back 2 on the front
'21 speed' is 7 in the back 3 in the front.. ( 7 in the space of standard 6 )

a new '10 speed' with a triple crank would be a "30 speed " [10 in the space, of 8]


V can be the French 'vitesses' same thing as "speeds"

You might want to upgrade the bike. Generally bikes like that have lower end components and aren't worth putting a bunch of money in. If it were an older 7 speed bike with Dura Ace, Ultegra/600, 105 in the road range or XT, Deore, LX in the mountain range I would say you might put money towards it and me I would run it on friction unless I could find some old shifter that were in good shape for not too much coin.

If you wanted Bar End shifters you can get the Ultegra 8 speed, Dura Ace 9, 10 or 11 speed (some are indexed left meaning you can only run 2X front and some are friction based meaning you can run 3x) or ZIPP Vuka R2C 10 speed (two different version one is for SRAM and one for Shimano) and Microshift has some in 8-11 for Shimano derailleurs (some can be run on friction) SRAM has 10 and 11 speed shifters and also some in R2C (return to center) but I don't think can be run on friction and are for SRAM Derailleurs. Campagnolo also has bar end shifters also in 10 and 11 speeds and are for Campy derailleurs. You can also find some friction ones such as the Silver Shifters from Rivendell Bikes.

You can also find some vintage or NOS stuff on the electronicBays or bikerecyclery.com.

All of that could but put on a modern drop bar road bike but you would need to pay your favorite local shop to install them and then you would probably want to sell the "Brifters" that came on it and also add some drop bar brake levers like the S500s from SRAM which look nice and feel nicer. TRP, Cane Creek, Tektro also do some decent ones but my faves are from SRAM (no matter how much Shimano blue courses through my veins I will always like SRAM brake levers are better)

What bike are you needing these for? The reason I ask it I'm wondering if you have one of those drop bar bikes what have the twist shifters. That's the only reason I could think of to be trying to go from twist to bar end shifters.

A friend had a Canadian Tire dropbar bike that used Revo Shifters. The bar was in three pieces. Left hand piece slid through a stiffener/reinforcing sleeve and over the right hand bar section until a hole in everything lined up. Then a bolt and nut was used to keep the assembly together. This 3 pieces steel bar was the same diameter as a normal steel dropbar. i was wondering if this is what the OP has because if it is the bar end shifters might NOT fit inside the handlebar.

Cheers

OP, the revoshifts for 7-speed (yes, you have to match the labeled number of speeds for shifters with the number of gears you have front & rear, no cross-matching) are just about as good as it gets for 7-speed bikes. There ARE triggers out there, they're pretty cheap, but you won't see much improvement. What you will realize is the difference between twist and trigger shifting.