Why do 6-speed manuals exist?

[javacontour]

Originally Posted By: vintageant
Why do road bikes have 15 speed? Discuss.


Because they are old. My road bike as 20 speeds. Some have 22 or 24

 

[Brad_C]

Originally Posted By: bunnspecial

I know a lot of folks who drive their O/D MGs similarly, except that on an MGB transmission 3rd O/D is roughly the same as 4th no o/d(1:1). For around the town driving, they find cruising in 3rd and kicking it in and out of O/D a lot more convenient than shifting between 3rd and 4th. I'm still kicking myself for not spending the money for an O/D when I changed mine(granted my non-OD was free)-the thought of 70mph at 2800rpms is very appealing

.


The old laycock O/D is not a fan of torque, so popping it in and out in 3rd isn't particularly advisable. If you are going to do it, geting off the loud pedal and using a bit of clutch makes them live a lot longer. Still, it's a lot better for it that kicking it in while in reverse.
We have a '65 TR4A with the laycock, and several of my older Volvo's had them also (4 speed + O/D). Neat little units, but not great with more torque than they were built for and they hate running backwards.

6 speeds is nice in the Diesel Landrover. Boost comes on at about 2k and it's out of puff at 4.5, so the more gears the better (especially when towing).

 

[ZeeOSix]

Why not go with the high tech 3-speed ... LoL. C7 Vettes have a 7-speed manual transmission. Skip to time 2:40 to get into the high tech 3-speed.

 

[y_p_w]

Originally Posted By: vintageant
Why do road bikes have 15 speed? Discuss.

Which ones do these days?

A serious road racing bike would only have two chainrings and thus an even number of speeds. Three chainrings usually only goes on touring bikes, where the smallest is of course the "granny".

State of the art these days is a 11-speed freehub. So that would typically mean 22 speeds, although there's usually a bit of overlap that depends on the particular combination of gears. A racing setup typically has a pretty small biggest gear.

'

When I was riding bikes, I would have looked at this and thought "what's the point?"

 

[supton]

Always wanted to say that my bike went to "11"... still haven't made the jump. 3x9 works for me. My boss was telling me that there is a 12 speed group now, for mountain bikes (perhaps for fat bikes?). Yikes.

Bicyclists and large trucks do have something in common: low horsepower and high weight. It's doubtful that one can achieve what, a quarter horsepower? to move 180lb plus for any long length of time. [So way more than 500lb per hp.] It's nice to have small gearing jumps, for small terrain changes. A like a CVT, actually.

 

[Cujet]

Originally Posted By: veryHeavy
In the Honda CRZ the low-end ratio and the top-end ratio are the same as the standard 5-speed in my Civic (and same engine by the way: 1.5 liter).

It's the same overall spread. So where's the benefit of 6-speed, other than making the driver do more shifting?



So you can shift from 1 to 3 to 6, completely skipping 2, 4 and 5. I do this from time to time in my Honda S2000.

 

[IndyIan]

Originally Posted By: supton
Always wanted to say that my bike went to "11"... still haven't made the jump. 3x9 works for me. My boss was telling me that there is a 12 speed group now, for mountain bikes (perhaps for fat bikes?). Yikes.

Bicyclists and large trucks do have something in common: low horsepower and high weight. It's doubtful that one can achieve what, a quarter horsepower? to move 180lb plus for any long length of time. [So way more than 500lb per hp.] It's nice to have small gearing jumps, for small terrain changes. A like a CVT, actually.

When I was light and fit, I liked the 3x7 on my mountain bike, as the low gear was low enough to go up anything I could keep the front tire on the ground, and when you shifted it was a significant change in ratio. With the 3x9 I always was skipping gears, especially coming into a steep hill.
Now that my power to weight ratio has lowered I use more of the gears.

 

[javacontour]

Originally Posted By: IndyIan
Originally Posted By: supton
Always wanted to say that my bike went to "11"... still haven't made the jump. 3x9 works for me. My boss was telling me that there is a 12 speed group now, for mountain bikes (perhaps for fat bikes?). Yikes.

Bicyclists and large trucks do have something in common: low horsepower and high weight. It's doubtful that one can achieve what, a quarter horsepower? to move 180lb plus for any long length of time. [So way more than 500lb per hp.] It's nice to have small gearing jumps, for small terrain changes. A like a CVT, actually.

When I was light and fit, I liked the 3x7 on my mountain bike, as the low gear was low enough to go up anything I could keep the front tire on the ground, and when you shifted it was a significant change in ratio. With the 3x9 I always was skipping gears, especially coming into a steep hill.
Now that my power to weight ratio has lowered I use more of the gears.


Now I'm coming from a road bike perspective, so maybe it's the same on a mountain bike...

They've built that into the groupset. I have 2x10 as my road bike is a few years old now. The downshift can go one or two gears depending on how far I move the lever. My upshift is only one gear with the paddle. The downshift uses the brake lever and can be one or two gears depending on how far I move the lever.

 

[supton]

Yeah, it is nice on my road bike that it will downshift 2 gears with a full sweep. I bet on an 11 speed it'd be even nicer if it'd sweep three cogs.

 

[bunnspecial]

Originally Posted By: Brad_C
Originally Posted By: bunnspecial

I know a lot of folks who drive their O/D MGs similarly, except that on an MGB transmission 3rd O/D is roughly the same as 4th no o/d(1:1). For around the town driving, they find cruising in 3rd and kicking it in and out of O/D a lot more convenient than shifting between 3rd and 4th. I'm still kicking myself for not spending the money for an O/D when I changed mine(granted my non-OD was free)-the thought of 70mph at 2800rpms is very appealing

.


The old laycock O/D is not a fan of torque, so popping it in and out in 3rd isn't particularly advisable. If you are going to do it, geting off the loud pedal and using a bit of clutch makes them live a lot longer. Still, it's a lot better for it that kicking it in while in reverse.
We have a '65 TR4A with the laycock, and several of my older Volvo's had them also (4 speed + O/D). Neat little units, but not great with more torque than they were built for and they hate running backwards.

6 speeds is nice in the Diesel Landrover. Boost comes on at about 2k and it's out of puff at 4.5, so the more gears the better (especially when towing).


There again, I don't have one, so I'm primarily speaking second hand.

With that said, the ones in MGs do at least have lock-outs. On earlier units("black label" prvve-74.5) they use a switch(same p/n as the reverse light switch) in the circuit that will only allow the O/D to engage when in the 3rd/4th gate. The later(blue label) units relocate the switch such that it can only work in 4th.

When I considered installing one, all I could manage to turn up(in the 1 week window I had) was a blue label unit. I talked to several folks about converting the box to 3rd/4th operation, and the expedient option was to just bypass the switch. That came with a BIG warning that I had to be smart and not engage it in reverse whatever I did(I did consider wiring up a relay to the reverse light switch). Finally, given how easy it is to swap the transmission I decided I'd rather just wait until a nice black label came up or pay someone to convert the blue label to 3rd/4th operation(along with giving it an overhaul).

 

[Vikas]

I have driven only few 6-speeds but they were geared too tall at the 6th speed. I will agree with OP that a good ratio 5-speed can be more fun to drive than bad ratio 6-speed. This is very similar to how 8-speed auto can lead to better driving experience than 9-speed auto even with very similar internals.

 

[IndyIan]

Originally Posted By: javacontour
Originally Posted By: IndyIan
Originally Posted By: supton
Always wanted to say that my bike went to "11"... still haven't made the jump. 3x9 works for me. My boss was telling me that there is a 12 speed group now, for mountain bikes (perhaps for fat bikes?). Yikes.

Bicyclists and large trucks do have something in common: low horsepower and high weight. It's doubtful that one can achieve what, a quarter horsepower? to move 180lb plus for any long length of time. [So way more than 500lb per hp.] It's nice to have small gearing jumps, for small terrain changes. A like a CVT, actually.

When I was light and fit, I liked the 3x7 on my mountain bike, as the low gear was low enough to go up anything I could keep the front tire on the ground, and when you shifted it was a significant change in ratio. With the 3x9 I always was skipping gears, especially coming into a steep hill.
Now that my power to weight ratio has lowered I use more of the gears.


Now I'm coming from a road bike perspective, so maybe it's the same on a mountain bike...

They've built that into the groupset. I have 2x10 as my road bike is a few years old now. The downshift can go one or two gears depending on how far I move the lever. My upshift is only one gear with the paddle. The downshift uses the brake lever and can be one or two gears depending on how far I move the lever.

I'm pretty sure you could do a triple downshift with one swipe on a 9 spd cassette with shimano rapid-fire, but its still time where you can't put any real power down and hitting bumps mid shift sometimes would cause a skip or worse. I found with the 7spd you could pedal into the hill better as you could get some cranks in between shifts. The ratios for the 1x10 mtb cassettes must have even slightly bigger ratio changes than the 7 spd.
Here our hills aren't too big and its rare to get a sustained climb on the same slope for very far, and even then often you can find the right gear on a different front chain ring.

 

[Olas]

Basic 'arrrive and drive' type go karts, and some koeniggseggs, only have one gear. They're both quite entertaining to drive. Maybe all these extra gears are a step backward?

 

[supton]

Originally Posted By: Olas
Basic 'arrrive and drive' type go karts, and some koeniggseggs, only have one gear. They're both quite entertaining to drive. Maybe all these extra gears are a step backward?


Well, multi-speed transmissions were always about dealing with engine limitations. ICE makes no torque at zero rotation, not a lot at idle speed; and has an rpm limit. Bicycle engines aren't far behind (lots of zero rpm torque but most riders still appreciate deep gearing on hills to prevent motor lugging, and eventual walking)

 

[bunnspecial]

Originally Posted By: supton
Originally Posted By: Olas
Basic 'arrrive and drive' type go karts, and some koeniggseggs, only have one gear. They're both quite entertaining to drive. Maybe all these extra gears are a step backward?


Well, multi-speed transmissions were always about dealing with engine limitations. ICE makes no torque at zero rotation, not a lot at idle speed; and has an rpm limit. Bicycle engines aren't far behind (lots of zero rpm torque but most riders still appreciate deep gearing on hills to prevent motor lugging, and eventual walking)


This is one area where electric motors can actually be complementary to ICE engines.

The peak torque of an electric motor is just before stall, while it falls off to a sustained value at constant RPMs. By contrast, as we all know the torque of an ICE increases with RPMs to a point, then of course falls off.

Steam engines also have the same property of generating maximum torque at near stall speeds, but of course they have their own issues.

My mom's Buick uses a pseudo-hybrid system(I forget what GM calls it) where rather than a discreet starter motor it has heavy duty motor/generator tied into the drive train. During slow down/braking that motor charges a Li-Ion battery back in the trunk, and under heavy acceleration the same motor draws from that battery to add to the available torque. In practice, it's actually a very nicely done system that makes the car pleasantly responsive from a stop.

 

[Nickdfresh]

Originally Posted By: javacontour
Originally Posted By: vintageant
Why do road bikes have 15 speed? Discuss.


Because they are old. My road bike as 20 speeds. Some have 22 or 24

My old GT mountain bike has 27 speeds, but I think they've actually cut them back to 9-18 for serious ATB'ers...

 

[sciphi]

To have a stump-puller 1st and crazy overdrive 6th like my Cruze Eco. 3000 RPM in 1st is 15 mph. 3000 RPM in 6th is ~100 mph. Definitely not a gimmick. 5th is about 300 RPM higher. 40 mph on flat ground is about the bottom limit where 6th can be used. The car pretty much won't accelerate in 6th, although it keeps speed up most hills just fine.

GM made 6th a bit of a gimmick in other trims of Cruze. Those didn't drop the RPM much from 5th, maybe 150 RPM.

 

[y_p_w]

Originally Posted By: IndyIan
Originally Posted By: javacontour
Originally Posted By: IndyIan
Originally Posted By: supton
Always wanted to say that my bike went to "11"... still haven't made the jump. 3x9 works for me. My boss was telling me that there is a 12 speed group now, for mountain bikes (perhaps for fat bikes?). Yikes.

Bicyclists and large trucks do have something in common: low horsepower and high weight. It's doubtful that one can achieve what, a quarter horsepower? to move 180lb plus for any long length of time. [So way more than 500lb per hp.] It's nice to have small gearing jumps, for small terrain changes. A like a CVT, actually.

When I was light and fit, I liked the 3x7 on my mountain bike, as the low gear was low enough to go up anything I could keep the front tire on the ground, and when you shifted it was a significant change in ratio. With the 3x9 I always was skipping gears, especially coming into a steep hill.
Now that my power to weight ratio has lowered I use more of the gears.


Now I'm coming from a road bike perspective, so maybe it's the same on a mountain bike...

They've built that into the groupset. I have 2x10 as my road bike is a few years old now. The downshift can go one or two gears depending on how far I move the lever. My upshift is only one gear with the paddle. The downshift uses the brake lever and can be one or two gears depending on how far I move the lever.

I'm pretty sure you could do a triple downshift with one swipe on a 9 spd cassette with shimano rapid-fire, but its still time where you can't put any real power down and hitting bumps mid shift sometimes would cause a skip or worse. I found with the 7spd you could pedal into the hill better as you could get some cranks in between shifts. The ratios for the 1x10 mtb cassettes must have even slightly bigger ratio changes than the 7 spd.
Here our hills aren't too big and its rare to get a sustained climb on the same slope for very far, and even then often you can find the right gear on a different front chain ring.

I haven't bought a road bike in over 25 years. I thought my bike was cool because it had index shifting. Still - it's easy to downshift a couple of gears with that setup, like going from 5th to 3rd. It still has a freewheel. It originally came with a Campy setup, but I didn't like the shifting an installed a bunch of mismatched Shimano equipment, like a 7-speed Dura-Ace freewheel and Ultegra downtube shifters and rear derailleur.

My best mountain bike is mostly as it came from the factory, but it's a mishmash of different parts that Specialized wanted to put on it.n They used Grip Shift shifters, which I still think are underrated. I remember when they had a setup on the guy who finished 4th in the Olympics road race.

 

[y_p_w]

Originally Posted By: bunnspecial
Originally Posted By: supton
Originally Posted By: Olas
Basic 'arrrive and drive' type go karts, and some koeniggseggs, only have one gear. They're both quite entertaining to drive. Maybe all these extra gears are a step backward?


Well, multi-speed transmissions were always about dealing with engine limitations. ICE makes no torque at zero rotation, not a lot at idle speed; and has an rpm limit. Bicycle engines aren't far behind (lots of zero rpm torque but most riders still appreciate deep gearing on hills to prevent motor lugging, and eventual walking)


This is one area where electric motors can actually be complementary to ICE engines.

The peak torque of an electric motor is just before stall, while it falls off to a sustained value at constant RPMs. By contrast, as we all know the torque of an ICE increases with RPMs to a point, then of course falls off.

Steam engines also have the same property of generating maximum torque at near stall speeds, but of course they have their own issues.

My mom's Buick uses a pseudo-hybrid system(I forget what GM calls it) where rather than a discreet starter motor it has heavy duty motor/generator tied into the drive train. During slow down/braking that motor charges a Li-Ion battery back in the trunk, and under heavy acceleration the same motor draws from that battery to add to the available torque. In practice, it's actually a very nicely done system that makes the car pleasantly responsive from a stop.

Locomotives basically operate in a world where they don't need transmissions. Steam power doesn't need a transmission because it won't stall. Diesel-electrics are basically a diesel generator that powers both the electric traction motors and head-end power. I've heard of a few diesel locomotives that actually had a transmission, but they're not terribly reliable and are mostly used for low-speed applications.

 

[Tomioka]

The ZF S6-650 is probably the first and last 6 speed manual transmission to be offered in a heavy duty truck. I had one in a 04 Ford F250 and there is definitely no fun factor with that trans in that truck. The clutch was soft fortunately.