4evrplan

I almost never shift the front, but I'm wondering about proper technique. I mean, do you shift the front and rear at the same time, having memorized which combo. gives the next higher/lower ratio? Or, is it normal to shift the front first and then just kind of feel around for the correct rear gear?

Here's a hypothetical: You're riding a 3x9 (not what I ride, but it's probably more typical) in the middle(front) - high(rear) combo and start a mild descent so you want to upshift. If you shift the front to high and leave the rear high, it'll be too much. So do you, knowing that with the setup of your specific bike that the next higher ratio is 3 - 4 for example, immediately shift both front and rear from 2 - 9 to 3 - 4, or do you, not having memorized the next ratio, shift to 3 - 9 and then just start downshifting the rear one at a time unil it feels right?

What's the best technique for smooth seemless shifts?

mzeffex 

It's just as bad here as road cycling now.

Shift when you need to. I generally shift both at once.

4evrplan

Oi. Is it so wrong to be curious about how other people do this? There's two ways to get better at something. One is lots and lots of trial and error, and since I don't get to ride much, I choose the other way, learning from those who are more experienced.

I generally do, but I sometimes don't shift any higher than 2 - 7 just because it's more trouble than it's worth to shift the front. But, if I know the proper technique to practice and eliminate bad habits, it might just become second nature enough that I will shift the front.

Do you know ahead of time which gear to shift the rear to, or do you just click a few and adjust from there?

buttdart

i run 1x9.....1 gear up front and 9 in the rear.

this is my preferred setup for a few reasons. 1) lighter 2) less maintenance 3) you only have to worry about 1 shifter

with a 1x9 setup i know exactly how each 9 work and where i need to use what gear. i'm guessing very few folks can honestly say they have 27 gears memorized - i could be wrong.

Tober1

Shifting both at once is a pretty good way to drop your chain. Better to keep some tension in it. I never shift both.
I only really drop to the small chain ring if I'm doing hills or I'm pretty cooked. Then again, my city is pretty flat

4evrplan

Yikes, that's good to know. I guess I've been lucky so far when I've tried it (but it drops the chain readily in other scenarios - like breathing on it).

rnorris

Agreed, avoid simultaneous shifts front and rear. When mountain biking, I'll choose which chainring to be in based on the general terrain I can see coming at me, and hop between gears on the cassette depending on what I'll encounter in the next few seconds. If you have a stretch of steep terrain coming, you want to downshift before you get to it.

BurnNotice

I shift the front first then get a rear gear that is right for the moment!

dminor 

I bet you do that with that 'rear gear railer' thingy, eh?



https://www.bikeforums.net/showthread.php?232682

Covalent Jello

I shift simultaneously (well, sometimes, not often) and it works out just fine.
Just don't do it when you're rattling the crap out of your bike, or when you have a lot of force on the pedals.

Aside from that,
All those numbers and combos = over thinking!

Just try to avoid bad ratios, that's the main priority. Keep it as evened out as possible in that sense.
Use your judgement, trust your innards, listen to your chain, and get a feel for it.
Then you'll know when you maxed out that small chainring, or if that big chainring is too much and you need to switch the front.
There is really no answer to which one to do first, because it could be either depending on what ratio you end up needing at the time.

That's the Jello way, and it works like gravytrains on ice. Covered in WD40. With Narwal blubber. And some jiggle.

dminor 

I'm with BurnNotice. Why worry about shifting both simultaneously . . . and run the risk of dropping a chain as Tober1 said?

Look at it from a gear ratio standpoint: if you are spun out in your 32/11 combo (assuming an 11-34 9-speed cassette), you are spinning a .34:1 ratio. If you hop up to your big rig (assuming a normal 44-32-22 front setup), you only need to click the rear back to your 15t cog (a couple clicks, or one big thumbfull on you SRAM X shifter) to get back to that same .34:1 ratio - - or just one click to the 13 to get one gear up from the 32/11 combo. A half-second shift after changing chainrings to get where you need to be and you're much kinder to your drivetrain.

rankin116

Wow, I have never put this much thought into shifting.

If it gets hard to pedal, shift. If it's too easy, shift. Is there more to it than that?

4evrplan

Yeah, makes a lot of sense d. Makes me wonder why bikes don't typically have any more spread between chainrings, since you're only gaining two useful high ratios, and probably not many low ratios either versus a 1x9 setup.

JonathanGennick 

This is a good question, imho. I run 22/36/bash, so I do run into this scenario and its opposite frequently.

On a descent, I tend not to worry too much, because I can always coast for a bit while I sort things out. But if I were concerned, I would downshift in the rear just before upshifting in the front.

Of more concern is when I approach a hill in the 36-tooth ring. Downshifting into the 22-tooth ring leaves me spinning against no resistance. If I'm still on flat ground, I'll generally upshift twice in back and then drop into the 22-tooth ring. If I'm already on the incline upwards, I'll probably upshift once in back, and then drop into the smaller ring. I hate it when I forget and spin out.

I do not have all the ratios memorized, but generally, on flat ground, an adjustment of two cogs in the back will more or less compensate for a switch between 22 and 36 up front--it gets me into the right ballpark.

cobba

There's no need to memorise 27 gears.
Just because a bike has 27 gears it doesn't mean they should all be used or all of them are useful. To use all 27 combinations you'll be cross chaining and this is bad for your drivetrain.

Cross Chaining = Noise, chain stretch & wear, derailleur rub & wear, chainring & cluster wear, more chance of the chain coming off.

Cross-chaining.gif

On a 27 geared bike there'll probably be a few gear combinations that are exactly the same and there'll be even more that are so similar in ratios that you won't notice the difference between them. There's probably only a real need to use about 15 of the 27 gear combos, depending on the cluster and type of riding you might use even less or maybe a couple more.

The following Correct Chaining image shows a reserved use of the 27 gears by only using 9 of them, I think it'd be a bit more realistic if it was a 5-5-5 combination of 15 gears with the smallest 5 sprockets used with the largest chainring, the middle 5 sprockets used with the middle chainring and the largest 5 sprockets were with the smallest chainring.

Correct-chaining.gif

The image below is from a Shimano page and shows which gears shouldn't be used with the different chainrings for the 8 gear cluster. Basically a 24 gear bike only has 18 usable gears and a 16 gear bike has 13 usable gears.

Shimano 8 Gear Drivetrain.jpeg

Gear calculator: https://sheldonbrown.com/gears/index.html

ed 

We wear condoms.

Daspydyr 

My front derailer tells me when I need a new front cog. I get a little chain rub. I downshift the back two and then move the front to a higher ring. When I'm climbing I rarely if ever move the front ring. I can't afford to loose momentum. Once I'm moving, I'm happy.

ed 

VERY conservative

Think about a 1x9 setup. You hit all 9 with the middle ring. I always set my drivetrain up so I can hit all nine from the middle. Nothing wrong with that.

vw addict

Threads like this make me love my fixie more and more....

colombo357

Shift the front upwards or downwards in the vertical and left/right direction if you need a chainring switch from downways to upways or vise versa, but only before or after you perform the cog swap from the right shift lever for the rear parallelogram to move the chain leftways or rightways as well as vertically along the cassette.

victim

You ride trails on a fixed gear? How tough do you find that to be???

Covalent Jello

It's really not as complicated as this thread would make it seem...!!

dminor 

Posts like this make me wonder why gears are so confusing that some people regress to tricycle-drive.

kitteh

^Agreed.

junkyard

I have memorized all gear ratios available in my drive train. Additionally, I have taken the time to break down all trails that I ride on into some critical components. First is grade (steepness of climb), second is technical rating (I use a 1-5 scale, one being lowest, five being highest) and finally number and degree of turns. With this information, I have mathematically calculated the best gear ratio for me in every situation. I based this calculation on a combination of my own personal output wattage and maximum heart rate, along with the gear ratios available and my personal trail rating system. I also take temperature and humidity into consideration since this affects my output capabilities. From there, shifting becomes a simple task.