There’s been a long trend of ever increasing number of speeds on bicycles. From single speeds, “tenspeeds”, over 18 speeds (bicycles with 3×6 chainring setups), to modern “1X” trends with only one front chainring and 10 to 12 rear chainrings (“sprockets”). This post will try to answer the question: how many speeds are really needed for cycling?
1. How many speeds is the best for a bicycle?
In order to answer, it is necessary to understand how derailleurs and gearing work, as well as the construction of the rear hub. Which are explained in the following chapters.
2. Speeds and gear ratios
Short explanation:
It is important to have gearing slow enough for steep climbs and fast enough for wind at one’s back, without large gaps in between (equivalent of a large gap would be shifting from 2nd to the 4th gear in a car).
Detailed explanation:
Bicycle gearing is explained in detail in this post: Bicycle gear ratios – speeds.
3. Derailleurs
Short explanation:
There are two groups of derailleurs
- Front
- Rear
There are three derailleur systems
- External cable activated derailleurs
- External electronically controlled derailleurs
- Intergnal gear hubs (only rear group)
This explanation will be limited to external, cable activated derailleurs. Internal gear (rear) hubs, as well as electronic derailleurs are a special case and will need a special topic. To just put a short explanation: internal gear hubs are good for riding in very cold conditions (colder than -15 degrees Celsius) and electronic derailleurs are similar to cable activated ones but a bit more expensive, use batteries and automatically trim the front derailleur cage – good for racing.
For front derailleur, number of (front) chainrings is important (is it 2 or 3).
For rear derailleur, also, the number of rear sprockets is important.
For both the front and rear derailleur, these two things are also important:
- The size of largest and smallest chainring (sprocket).
- Difference in tooth number between the largest and the smallest chainrings. This directly influences gear range – how fast is the fastest gear and how slow is the slowest one.
Detailed explanation:
Front derailleur functioning is explained in the post: Front derailleur.
This article explains how the rear derailleur works and how the number of rear sprockets influences sensitivity of the RD: Rear derailleur.
4. Front derailleur – number of chainrings
One, two, or three front chainrngs?
Front chainrings (and derailleur) make big changes of gear ratio (that is finely tuned with rear derailleur). Three chainrings up front give a very wide gear ratio, superior to having just two front chainrings.
For example: instead of having just two front chainrings, with usual tooth counts of 50-34, or 52-39, three chainrings will provide both wider and more tightly spaced gearing, like 30-39-50 (for road bicycles), or 22-32-44 (for MTB).
The main advantage of 2 chainring system is easier shifting, with less worry about cross chaining. This is important for competitive cycling, while for recreational cycling it simplifies shifting a bit, but one gets used to 3 chainring shifting quite quickly.
The advantage of one chainring system is lower weight and even simpler shifting. There is one shifter handle less and one derailleur less. However, either gear range, or gear spacing must suffer with this system. Usually both.
Here you can read more about the pros and cons of 1x drivetrains.
5. Rear derailleur and rear hub- number of “sprockets”
One, 6, 8, or more – 10, or 12 rear chainrings (“sprockets“)?
Functioning of rear derailleur and the number of rear sprockets are tightly connected. The basic problem is that with more gears, rear derailleur has a lot more chance for error: it needs to make smaller, more precise movements as the number of rear sprockets increases, since they are thinner, and more tightly packed.
Systems with 8 and less sprockets, there is a wide gap between sprockets. This enables RD to be less than perfectly tuned and aligned and still work well. Also the chain is thicker and stronger.
Also, shifter levers and cables often have some friction and some housing provides a wee bit of play. This affects systems with lower margin for error: the smaller spaces between rear sprockets, the narrower the chain – the less margin for error.
Going to more than 8 sprockets, to 9, 10, or more changes everything:
prices of parts are higher (chain, cassette), error tolerance is lower, because sprockets are more tightly packed, with smaller gaps. The advantage of narrow sprocket spacing is a bit quicker shifting at the back.
On the other hand, 6 and 7 speed systems are hard to find with a cassette rear freehub, just with a freewheel. Why having a freehub is an important advantage is explained in this post: Freewheel vs cassette. If minimal cost is priority, 6 speeds is probably the best choice though.
Still, if budget allows, quality rear hubs are made as cassette freehubs, which fit 8, 9 or 10 sprockets. Cassette freehubs for 6 or 7 speeds are getting harder to find.
6. Rear sprockets
For detailed explanation of the topic, look at this post: Speeds – rear sprockets.
7. Conclusion
Considering prices of parts (sprockets and chains), robustness, ease of adjustment and maintenance, gear ratio range and gaps, as well as market availability, gearing with 3×8 setup is an optimal choice.
3×6 is good choice if minimal cost is the priority.
Advantage of systems with more rear sprockets are a few more transmission ratios in between – slightly smaller gaps between gears and slightly quicker shifting when everything is set up properly (new clean cables and housing). Speaking of gears, the “fast” part of the cassette is similar – differences come with slower gears, where large gaps can even be useful – climbing a hill, with one change gearing becomes much “easier”.
For comparison, 8 and 10 speed MTB cassettes of the same range 11-34 teeth:
11-13-15-17-…20..-23-26….-34 8 speed MTB
11-13-15-17-19-21-23-26-30-34 10 speed MTB
Greater gaps are at the last two thirds of the cassette, where they shouldn’t matter too much, except for competition, racing. Same goes for road cassettes:
…..13-14-15-….17-19-21-23-…26 8 speed road
12-13-14-15-16-17-19-21-23-25 10 speed road
Does it pay to have less reliable, more expensive system, in order to get an in between gear or two that are used when climbing? Each must answer for themselves, according to their criteria. For short distances on flat ground, one speed is often an optimal solution. For top racers, 2×11 setup is worth every cent and every gram.
8. Personal opinion of the author
I believe that more than 8 sprockets at the back, as well as wheels with less than 36 spokes are the biggest frauds in the cycling industry. At the expense of consumer, they are marketed as “improvements”, “upgrades”, but hardly bring anything measurably better.
This post explains the spoke count problem: Wheels and spokes.
Related post – Bicyle equipment (“groupset”) classes:
The existing comments posted under this article (questions and answers) have been moved to this BikeGremlin forum thread:
https://www.bikegremlin.net/threads/bicycle-how-many-speeds-article-comments.151/
there are special alloy spacers that are made to fit cassette freehubs,this allows you to use a custom 5,6,or7 speed cassette on a 8 speed freehub,these spacers come in many different thickness.
good conclusion!! I love your website and yt videos.
what is my main concern is that online and even to my lbs it’s hard to find 9 speeds and lower component, expecially regarding XT (or XTR): in this way if you want mid-high grade product [in my opinion (small experience!) shifter is #1 component to be precise] you have to stay on 10 speed at least [see for example LinkGlyde!]. In particular, looking at 9 speed (for me the more suitable for me) it’s very difficult to find Alivio: you can have an Altus. For 8 speed only Acera!!.
The most important question, giving all my hopes (in doing an upgrade of my 2×7 [22-32 x 11-28]) to your experience is: in terms of fluidity and above all reliability in time it’s better to have a brand new deore or xt 10 speed or have an 8 speed Acera? how would you compare the shifting?
Bonus question: do you think clutch derailleur could help to retain the chain (on bumpy real mountain tracks!! -not for going down the sidewalk of my city-) or it was “invented” to compensate the cross chainrings and so to overcome a problem create by the not-so-innovative big-hoax of 1x drivetrain?
thank you for your time and experience. I accept honesty: if you don’t have a reliable reply to my question based on your experience I will accept your educated guess and I’ll have in mind “in capital letters” when I’ll do the upgrade of my trasmission.
thanks again for your yt channel and forum: I appreciate it more than the other forum’s PUBBLICITY to Brands and “innovative tech” disguised as technical review.
Fabio,
Thank you for the kind words.
Here’s my reply – to be taken as “to the best of my knowledge,” and “based on my experience” (i.e. my, personal opinion):
Shifters
My choice are friction shifters. High-quality, used (“2nd hand”), Shimano, aluminium, or steel made.
That’s durable, robust and cheap. Also, they last for about 50 years… then you need to clean them a bit. 🙂
Deore 10 speed vs Acera 8 speed
Deore 10-speed will shift better and faster when it’s all properly tuned and aligned.
Acera 8-speed, on the other hand, is less sensitive to any imperfections, especially the RD hanger misalignment. Wack on a rock? No problem, straighten it with your hand to the best of your ability and get on. With 10+ speed stuff, even a minimal misalignment causes poor shifting.
Number of “speeds”
I prefer 7 and 8-speed stuff because chains and cassettes are cheaper (and still easily available in my country).
RD clutch
It is a fact that it does help retain the chain on very bumpy terrain.
Having said that, I did ride up and down our local mountain paths (and down 20 or so stairs on a regular basis, near our local pub 🙂 ) – very seldom did I have problems with chain drops. Not once did I think “oh, my chain drops quite often, I should find a way to keep it in place better.”
Maybe I didn’t ride hard enough (I definitely didn’t do any really high jumps with my bike). But I do think that there’s a lot of “hi-tech marketing” involved and that you can ride with no problems even if your RD hasn’t got a clutch (with a note that your chain will bounce more, and scratch the chainstay more, which can be prevented with some stickers for protection if you mind scratches, or have a carbon fibre frame).
Clutch definitely makes more sense for the 1x drivetrains, but it does help with the 2x and 3x as well (though, again, in my experience chain drop has never been a real problem with those systems).
What to buy?
There is a problem with parts supply that started when Covid broke out, and is still not sorted out.
Also, manufacturers are trying hard to get us all to buy new parts – that’s how they make a living.
That is another reason why I love friction shifters – they’ll work with any cassette (or chainrings).
Everything else is more risky. I have no Idea whether decent-quality, reasonably-priced 10-speed, or 8-speed shifters will be available next month, or next year, in case one’s current shifter breaks, or similar.
With all that in mind – if friction shifters are not an acceptable solution (or are not available on your local 2nd hand market):
If my budget were high, I’d go with Deore (expecting higher maintenance/part replacement costs in the future, not just the initial higher price).
On a budget, I’d go with the 8-speed Acera. Acera is good quality equipment. Not a superlight “pro-class,” but still good.
Hope that answers your dilemmas. 🙂
Relja
Hello Relja,
thank you for your suggestions. It is a fantastic reply because I was thinking last night more on buying a 8 speed shifter to do a mid-upgrade: I’m continuing using my old rear wheel with 7 speed, but I have the opportunity to do an upgrade to buy a new wheel with a 8-11 speed freewheel body adding 32 teeth to my rear sprockets.
Good hint about the derailleur mount!!
regarding the friction shifters you mean non indexed, right? I know there are indexed ones even for 10, 11 or 12 speeds (microshift) but the price is similar to the other shifters. My question is: have you tried to use non-indexed friction shifters with 9 or more speeds? Can you feel and adjust the chainline in order to make it smooth or do you risk to damage the chain/derailleur?
I think I’ll be on 3×8 forever! (2×8 offroad) but I feel the attraction of modern tech even if I think it is only a “status quo” thing and practically the feeling of the transmission would be not so impressive.
Hi Fabio,
Yes, by friction I mean the non-indexed (or the ones that can be set to work in a non-indexed mode).
(A more detailed friction shifter explanation)
Chainline has nothing to do with friction shifter performance (in fact, they are among the most forgiving in terms of running an imperfect chainline).
For 9 or more speeds, it’s better running friction shifters with a RD that requires longer cable pull (i.e. models that have a shift ratio below 1.5 in this table). With “normal” RDs, it is difficult to tune a gear just right using a friction shifter, because the RD moves too much for a tiny movement of the lever, while all the cogs are tightly packed.
Whichever number of rear cogs is used, damage can occur only if one is really careless (shifting under load with a hard push/pull on the shifter etc.).
Shiny new things can feel good, and sometimes even work well, especially while they’re new. 🙂
Relja
Thank you a lot! precious suggestions.
So, just to be sure, to have a “better” performance should I buy a SRAM RD with 1.1 pull? (and of course not the fancy stuff of Shimano/SRAM 10/11 speed; for a $ reason).
A part from shifting under heavy load and break chain/RD and God knows what else… I was referring to a not aligned shifting in which you can’t hear the noise of the chain rubbing on nearest cog BUT not perfect so the chain will work slighty aligned for a LONG time so maybe (?) this little bad alignment could cause damage in the long run. I know it’s only a suggestion that I imagined, so what do you think in reality will occur?
Friction shifters will work with practically any RD. If a RD moves less per one mm of cable pull, it is easier to fine-tune the gears (this goes for indexed shifters as well).
For 9+ sprockets, combined with a friction shifter, I think it would be a good idea to use the cheapest decent-quality RD with 1.4 or lower movement ratio (the lower, the better) – including SRAM 1:1.
The potential problem you are describing is not something I have faced. As long as there’s no chain noise, it works just fine, even when using friction shifters.
ok thank you: for the moment when I’ll try the friction shifter I’ll use a normal Shimano RD with 1.7 pull…as I said I’m planning to use 8 speed so I’ll only keep in mind your suggestion of 1:1 pull of Sram X4 for example.
P.S. regarding sram rd, what do you think of the routin of the wire wih the “plastic curve”? It will improve the shifting as they say?
thanks again