Why Derailleurs gears?

[Cabo]

true, but speaking of weight, and on a bit of a tangent, I've lost over a stone by doing my weekly distance on a non-electric bike and feel better than ever, and have no intention of going back; it may seem at odds with being on this forum, but I can seriously recommend it.

Similar to myself.
I reached nearly 20 stone and decided to try an electric bike for exercise.
Back in those days most of these bikes were rated for a max. weight of 16 stone, and the hopper did not specify. I managed to get down to just over 16 st.
A few years ago a bought a standard bike which i do all my distance work and have got down to 14st.
Still use electric bike for all shopping and messages, and still enjoy it - also to keep batteries in condition.

 

[Deleted member 4366]

I too now ride a road bike for exercise and pleasure. I just use my electric bike for shopping, visiting and other utilirarian reasons. The road bike weighs 8.5kg and is about equivalent in speed and effort to my electric bike on level 1 power. It was from riding my road bike that I realised the importance of low weight. To this end, for me, only derailleur gears are an option.

There's only one downside to derailleur gears as far as I can see, and that's the problem of getting caught in a high gear from an emergency or unexpected stop. If you have a hub-motor, that's not a problem because the motor will bail you out until you get up to a speed where you can sort out the gears. it's just crank-drive bikes that are problematic. The Nuvinci doesn't suffer any of that, but it has the weight problem. Hub gears are very tricky for pulling away up steep hills because you have to stop pedalling to change gear, which slows you down so you have to change down again. They also can be problematic with crank-drives, especially the ones that run on after you stop pedalling.

For me, the simplicity, versatility, low weight and reliability of a hub-motor and derailleur gears is always going to win. I think a lot of people are put off derailleur gears because they look complicated, when actually they're very simple. Also, they're often not adjusted by the shop properly before selling the bike.In fact just about every one I've checked was not not adjusted properly, and it's not as if they're difficult to adjust.

 

[vidtek]

d8veh-
The comments you make are well thought out and perfectly valid. I can only go on my own experiences with dérailleur gears which have been pretty awful. I suspect that none were correctly adjusted and were on cheapie bikes and therefore may have coloured my judgement.

All the hub geared bikes I have had had no problems changing down on hills, you can change down to the lowest one at a standstill, so I don't get what you mean there, but maybe I would have done things as second nature the way you automatically change down with dérailleurs when slowing which is so problematic for me.

Muscle memory is so ingrained we don't have to think about the things we do as a matter of course. Interesting how we have developed the different muscle memories to suit the different bikes. Good job we're not all the same eh?
Cheers, Tony.

 

[ibike]

How difficult would an electric bike with 21 gears as apposed to 6 gears be to someone who hasn't ridden a bike for 30 years. Would I be forever changing up and down gears.
The bike I'm thinking of is the Zipper mk4 folder.
Also could I fit almost any rear luggage rack to this bike, I'm of the impression most pannier racks are adjustable to any bike?

 

[Warwick]

The main drawback with multiple front-chainring derailleur set ups (IMHO) is that there is significant overlap between the gearing. Put simply, (& sorry if that sounds patronising, it isn't my intention) the lowest gear ratio on the largest front chainring is usually higher than the highest gear ratio on the middle or adjacent chainring. (But the chain alignment might not be as good...)

That's because the spread of ratios (gears) on the rear cassette is usually much larger than the spread of ratios (gears) on the front chainrings. To exploit the overall wider range of ratios a 21-/24-/27-/30-speed derailleur combination offers you need to be prepared to jump between front chainrings, as well as rear cassette ratios. Eventually that becomes fairly intuitive, but you need to persist.

To answer your question; inexperienced cyclists would probably initially benefit from a half-decent 6- or 7-speed derailleur set up with a wide-range rear cassette or freewheel as opposed to a more complicated double or triple front chainring one.

Generally speaking, hub gears offer a single front chainring set up, so might be better suited to the uninitiated. My 8-speed Alfine hub is, so far, a very positive change with instant gear changes and the option to change gear whilst stationary. Whether I would be so pleased with it on a purely human-powered machine is a moot point.

 

[Deleted member 4366]

How difficult would an electric bike with 21 gears as apposed to 6 gears be to someone who hasn't ridden a bike for 30 years. Would I be forever changing up and down gears.
The bike I'm thinking of is the Zipper mk4 folder.
Also could I fit almost any rear luggage rack to this bike, I'm of the impression most pannier racks are adjustable to any bike?

You won't have any problem with the gears or the panniers.

 

[anotherkiwi]

An ideal derailleur set up for an e-bike is an 8 speed. I have a 7 speed and you are either missing a high enough top gear or a low enough bottom gear with the cassettes on the market. In 8 speed you have 11-34 which is my personal nirvana. I have opted for a 12-32 7 speed which is almost there but not quite.

 

[Trevormonty]

An ideal derailleur set up for an e-bike is an 8 speed. I have a 7 speed and you are either missing a high enough top gear or a low enough bottom gear with the cassettes on the market. In 8 speed you have 11-34 which is my personal nirvana. I have opted for a 12-32 7 speed which is almost there but not quite.

There is nothing wrong with cheaper derailleur in regards to reliability but for fast smooth shifting you can't bet high end derailleurs.

 

[Deleted member 4366]

An ideal derailleur set up for an e-bike is an 8 speed. I have a 7 speed and you are either missing a high enough top gear or a low enough bottom gear with the cassettes on the market. In 8 speed you have 11-34 which is my personal nirvana. I have opted for a 12-32 7 speed which is almost there but not quite.

You can 11 - 34 in 7 speed.

http://www.tredz.co.uk/.ETC-7-Speed-Cassette_37494.htm?sku=90494&utm_source=google&utm_medium=cpc&utm_campaign=google_shopping&gclid=Cj0KEQjwpNm-BRCJ3rDNmOuKi9IBEiQAlzDJH2duitXX93dp_70oVENkaHJDf4tfoSb1sJEdKxAhB4oaAlOo8P8HAQ

Some cassettes have completely separate sprockets, so yo can make whatever ratios you want.

 

[anotherkiwi]

Thanks so much for that d8veh! How come that doesn't come up in a search for "11-34 7 speed cassette" beats me. Been searching with that term since last year... I see it is like my 14-34 mega range with a big jump to last cog, shame.

I looked at build your own cassettes then ran out to buy a lotto ticket, my numbers haven't been drawn yet

 

[Deleted member 4366]

14-34 is normally a freewheel set, not a cassette.
If it's a freewheel. 11 - 32 is about the best range I've seen from DNP.

 

[ibike]

thanks to all who chipped in on my question, some interesting comments which is swayed me to go for 6 speed.
The bikes I have in mind now are Elise Electric Explorer folder for me and AS bikes Electro Plus folder for my wife.
Any comments on these bikes would be appreciated.

 

[anotherkiwi]

14-34 is normally a freewheel set, not a cassette.
If it's a freewheel. 11 - 32 is about the best range I've seen from DNP.

I have a cassette in a normal wheel now with the GSM but I also have a Mxus with freewheel.

Today I found the limit of the GSM, +15% road and 46:28 gearing, I stopped in time for the motor... I'll have to go back and see if I can climb it with 46:32 when I get my new cassette.

 

[Deleted member 4366]

It's logical that a 14% lower gear will climber a 14% steeper hill, but 14% slower.

Another solution is a bit of solder on the shunt in the controller, which would increase the climbing without reducing the speed, and without the cost and inconvenience of fitting new gears.

 

[top drive]

12:36 availible if you go up to 9speed.

Which is where ive went for my Cargo bike. Will just up the front ring to compensate for the lack of 11 tooth.

I have a long chainrun though so not too concerned about chain line - i need 2.5 chains If you have a regular stay bike you may have issues with chainline if using a mid mount.

I went with a 9speed 12:36 and am hoping to mount that on a sturmey archer 3 speed cassete disk hub..... Ben at kinetics informs me they use the dualdrive - which is very closely related to the SA on the Rickshaws - which can see 400kg loads and loads of torque so should be fine for my use.

Monster gearing

FWIW ive got a rohloff - and while i love it in certain envorments - i almost always prefer to ride whtouth it - even to the point of riding a singlespeed. I had an alfine for 3 years of commutign 30miles a day before it **** the bed - i didnt get on well with it.

 

[oldtom]

For me, the most important characteristic of an electric bike is the weight. Low weight means better handling, longer range, easier to pedal uphill and easier to pedal without power. Each to their own.

Exactly! It has taken a long time but some manufacturers seem to be finding ways to reduce bike weight. Not so many people ride around these days on 30Kg machines that are too heavy for most vehicle bike rack applications so progress is being made, albeit slow.

Tom

 

[anotherkiwi]

12:36 availible if you go up to 9speed.

11:34 exists in 8 speed. Currently I am running 7 speed 11:28 and I have a 7 speed 12:32 on order at the LBS, I can live with losing 3-4 km/h downhill on this bike, it isn't a speed monster. If that doesn't work out in the mountains of Navarra I'll look at a 42 tooth chainwheel to replace the 46 and learn to live with a goat rather than a steeplechase horse...

http://www.bikecalc.com/gear_inches

This is a good calculator and spot on with what I am seeing on the road.

 

[dgncsk]

i hate adjusting screws. so my vote is on nexus or similar ones.

 

[Deleted member 4366]

i hate adjusting screws. so my vote is on nexus or similar ones.

They have adjusting screws too!

 

[Nealh]

Derailleurs are best adjusted on a bike stand, they aren't difficult to get right.
Back wheel a bit easier to remove on my derailleur mid drive bike then my alfine 8 bike, rear hub motor with derailleur takes a bit longer.