taz777

That is the question.

On my Townie cruiser, the manual states that I should not be pedalling whilst using the twist-shift to change gears. However, on a different type of bike that I have it says I must pedal whilst changing gears.

Why is this the case and how are people supposed to know unless they actively seek out this information? Also, what potential issues might arise if you don't follow the rules?

Machka 

A Townie Cruiser is an electric bicycle isn't it?

On a non-electric road bicycle, for example, you won't shift gears if you don't pedal ... or at least not completely. You don't have to seek that information out, you'll know it the minute you try to shift.

Or are you comparing two electric bicycles?

taz777

No, both regular non-electric bicycles - one is a cruiser, the other is a hybrid.

Machka 

So what happens when you don't pedal and try to shift?

jgwilliams

Is one a hub gear and one not? With hub gears (at least, the ones that I'm familiar with) you don't pedal when changing gear. With derailleur you have to.

mcours2006

Townie has an 8-speed IGH. Crosstrail has derailleur. That's why.

taz777

Right, so it's dependant on the gear system used then. Took a bit of getting used to!

cyccommute 

Even for a IGH, I find that a little odd. Are you supposed to coast every time you want to shift gears? That seems very inconvenient and kind of momentum killing. I can imagine slowly riding up a hill and really needing to downshift. Having to pause pedaling before shifting could lead you to slow too much to keep up speed and you have to stop.

I don't have a lot of experience with IGH but what limited amount I do have I don't recall having to coast to shift.

fietsbob

There is the difference... derailleur, shift while turning the pedals without much force (use your momentum)

IGH , pause, I use a quick backpedal (hub without coaster brake, of course) while flicking the lever/turning the grip shifter.

allowing the mechs to work, without power input, for that brief moment..






.....

Reynolds 

You're right, on my Nexus you can shift coasting or pedalling, even back pedalling. Just ease off on the pedals and it will shift fine.

taz777

@cyccommite: indeed, you have to very briefly stop pedalling on the cruiser when changing gears. However, the gear shift is so quick and precise that you can do it very easily. Going uphill takes a bit of practice.

I don’t know what would happen if I didn’t stop peddling during the gear shift though. Potential damage or extra wear and tear, I imagine.

fietsbob

Standard transmission, in a car or truck you use the clutch, when changing the gear , a pause is not that big a deal ..

BlazingPedals

I used a SRAM 3x7 for years, finally retiring it because I didn't need all the gears it produced. I could pedal lightly while shifting either the derailleur or the IGH. That's the way I think most users shifted: turning the pedals but no power being applied. A derailleur, of course, wont shift if you're not moving the chain.

JohnDThompson 

No, but you should ease off the pressure on the pedals to shift an IGH. You don't need to fully coast, otherwise an internally geared 3-speed fixed gear hub would be impossible to shift. These have a small amount of "lash" built into the mechanism to allow the shift to occur when pressure is taken off the pedals.

JohnDThompson 

One of the "tricks" you can do with a Sturmey-Archer AW 3-speed hub is to shift the trigger in advance of when you want the gear to shift. By keeping pressure on the pedals you can delay the shift until you ease up, then the shift happens instantly.

HTupolev

The thing about IGHs is that forward pedaling isn't a fundamental part of the shift operation, and drivetrain tension can still disrupt certain mechanisms from doing their thing, so the general safe bet is to micro-pause pedal force for the shift.

What exactly happens when you shift under tension within an IGH really depends... the exact mechanism of the shift can differ between gears within a given hub. Sometimes they won't start, or won't complete, a shift until the pedal force gets low enough.
(The middle-of-the-range shift on a Rohloff Speedhub is a very interesting example of this. The hub is essentially a 7-speed hub, used over two ranges via a 2-speed gear reducer of sorts. The shift in the middle of the range is thus an absolutely huge double-shift, both engaging or disengaging the reducer and sweeping all the way across the whole range of the 7-speed mechanism. For safety, Rohloff engineered the hub to always execute the upshift before the downshift, and it won't execute the downshift until you back off your pedaling force... so, if you try to pedal hard during that particular shift, you'll find yourself in the hub's highest ratio until you back off.)

Awesome.

But, not quite as awesome as having a derailleur drivetrain on a downtube-shifted bike ghost-shift to a higher gear right when you need it in a sprint. Everyone thinks you'll have to sit back down to upshift, and then BAM, you just controlled the rear mech telepathically. Or maybe it was frame flex, but who cares?

fietsbob

FWIW the new production has eliminated the old UK AW3 quirk that not quite engaging 3rd, could have your pedal disengaged.

sweeks

As noted by several ^^, a momentary (small fraction of a second) reduction in pedal pressure synchronized with the shift, while still pedaling, works fine. (My experience: S-A 3-speed, Shimano Nexus 7- and 8-speeds, and Alfine 11)
Steve

Gresp15C

I have a couple of old S-A AW's, and what I've found is that you quickly develop a sense of how to shift it. It becomes something that you don't even notice, like shifting a manual transmission car.

coney462

I owned a small fleet of delivery trucks for over 25 years and only used the clutch when starting from a dead stop

Juggy_Gales

Pedal like a banshee!

fietsbob

"whoop'' r So? Was at the helm of an ICBM Nuke Sub before I got my DL on land..

My Saab 96 had a freewheel bearing in it.. also , only clutched from dead stop . coasted down hills at an idle , still in 4th..

Bike forum... left my derailleur bikes friction shifting and stopped being pushed my the industry & marketing at 7 speeds.

now prefer IGH .... never ride the C&V race bike.. though its pretty.


yadda yadda..




...

cyccommute 

You essentially do the same thing with derailer bikes, especially old friction systems. Shimano, bless their evil little corporate hearts, have done a lot to reduce the need for the pedaling lag with all the ramps built into the system now but I remember many a hill climb that was interrupted because you couldn't downshift back in the bad old days.

taz777's post seems to suggest that the delay in IGH is more active and more noticeable than derailer systems.

fietsbob

we planned ahead.. get in the granny before you need it ..

cyccommute 

If you rode mountain bikes you tried to plan ahead. It didn't always work out.