Saturday , 31 October 2020

 

THE GREAT CHAINRING DEBATE

Truth is, until recently, I wasn’t interested in gear ratios. Actually, nobody was. Except maybe for mechanics and some pro riders. They understood the physics and could talk with genuine excitement and insight about swapping chainrings and cassettes to suit changing weather conditions, gradients and different terrain. And, of course, our truly fruity friends from the singlespeed mountain biking fraternity. In fact, gear ratios is all singlespeeders talk about, which is why I don’t invite them to dinner parties any more…

By Nic Lamond

Catherine Williamson and Esther Suss (obscured) of Team Sasol climb the Swartberg Pass during the 2015 Cape Pioneer Trek. Williamson is using a 1x11 drivetrain. Photo: Zoon Cronje/Nikon

Catherine Williamson and Esther Suss (obscured) of Team Sasol climb the Swartberg Pass during the 2015 Cape Pioneer Trek. Williamson is using a 1×11 drivetrain.
Photo: Zoon Cronje/Nikon

 

For the rest of us, hidden somewhere between the triple front chainring, the chain, a 9-speed rear cassette and a derailleur, was the perfect gear. In theory. And even if we didn’t find the exact gear, we had a whopping 27 to mash through. Then 10-speed derailleurs arrived and instead of upping the gear count to 30, it became de rigueur to ditch the smallest chainring, and tackle our local climbs with just 20 gears.

In our enthusiasm to adopt anything we see underneath a pro rider on the UCI World Cup circuit, we soon followed the movement to 11-speed systems. It was a no-brainer: 11-speed offered a cleaner, simpler and lighter set-up. Another advantage worth mentioning was the fact that you were now always in the correct chainring by virtue of having no choice! It may sound odd, but it does allow you to focus more on the riding part of mountain biking. The front derailleur became the appendix of the modern mountain bike. Don’t need that useless organ weighing me down! Remove it, doc.

The new system was expensive (it required new chainrings, chains, cassettes and derailleurs, obviously!), but 11-speed was touted as the saviour for all. It’s pricing, until SRAM introduced the entry-level GPX 11-speed system very recently, really only made it an option for the pro or the well-heeled. Especially since the narrower chains were prone to snapping a few years back. Thankfully, they did sort that issue out.

With 11-speed we could now impress the mechanic at the local bike shop with our discussions of front chainring tooth sizes. We were now also going to ride so much more efficiently because of our (marginally) lighter bikes, that the loss of actual gears to get up steep inclines would easily be outweighed by our improved fitness and power.

Except that didn’t happen. We didn’t magically find more hours in the day to ride towards our ideal fitness or extra power to smash our local climbs with a 34T. Don’t get me wrong: single front chain rings have their place. Downhilling and cross-country lap racing make sense. So too Enduro racing; or touring in remote places when you want reliability. The simple reality is a single chainring up front is a compromise. Simplicity and weight saving over versatility. It’s important to remember that. So, apart from choosing to ride with fewer gears if we do away with a front derailleur, what are the essentials to understanding what option suits us best? 2×10, 1×10, 1×11 or even 2×11?

2×10

From the early days of mountain biking we had three chainrings up front, which slowly gave us access to more and more gears as we jumped from 6- to 7- to 8- to 9-speed cassettes and rear derailleurs. Even though 2×10 has only been available to the masses for the past few years, it’s unfairly considered ‘old’.

There are still plenty of good reasons to consider two front chainrings. Cost is the first one. It’s been around for long enough that it’s become pervasive with SRAM and (soon) Shimano versions to suit any pocket. Its history also makes 2×10 reliable, as improvements to the system have added to its durability over the years. Then there’s the most important factor – it makes your bike more versatile. With a wider gear range you don’t have to worry about being fit enough or strong enough to turn a certain gear. When you’ve blown with 10km left of a race to do and there’s still one mother of a climb to go, you don’t have to panic. You have 20 gears to get you home!

The downside is weight, as the extra chainring, front derailleur, cabling and shifter adds up to around 500g, depending on the brand and model. The complexity of adding mechanical devices to your bike is also a consideration. Simply put: there’s more things to go wrong out on a ride. Wear and tear from a constantly ‘stretching’ chain and shifting derailleur can shorten the life of your drivetrain. In seriously muddy conditions a front derailleur might clog up, but 2×10 will offer easier gearing to push through… It’s your call.

1×10

This is an alternative to the expensive task of replacing your whole drivetrain for 1×11, while achieving the desired simplicity and close to the same gearing range. With the advent of 1×11 the ever-inventive smaller brands in the bike industry clamoured to produce aftermarket chainrings and cassettes. You just swap your two front chainrings for these single rings, whip off your front derailleur and remove the shifter and cabling and you’re good to go. A mechanic can do it in under and hour. I’d budget a good 2-3 hours if it’s not your day job.

Just like 1×11 technology, these narrow-wide front chainrings feature teeth that alternate in thickness to avoid the chain bouncing off while riding. They are available in a wide range of tooth sizes (28T to 36T) and can be fitted to your existing crankset.

A few brands also introduced a large “dinner plate” sprocket to add to your cassette. This was to mimic the “easiest” gear, usually a 40T or 42T, on offer with the 1×11 systems. You now had a bailout gear for when your legs were struggling. It was a hit, although it did mean you had to remove one of the middle gears, usually the 17T, of your 10-speed cassette to make space for the dinner plate. This meant shifting wasn’t as smooth, as you jumped from 15T to a 19T when you shifted up.

Anecdotally, I ran a 34T Race Face narrow-wide front chainring, with a 10-speed Shimano XT drivetrain and a 11-36T rear cassette during the first three stages of the 2014 Absa Cape Epic. My timing was perfect and I’m glad I did. The early stages that year were muddy and the drivetrain was simple and faultless, the single ring up front shedding mud beautifully. It required a little bit of extra power on the climbs but my legs were relatively fresh early on. After Stage 3, with fading legs and a couple of mammoth climbs left in the race, I put my 2×10 system back on. I didn’t look back… 

1×11

Initially Shimano’s 11-speed offering only went as high as 40T on the rear cassette, while SRAM has always offered 42T. But Shimano rectified that in 2016, so the only real question left when you run a 1×11 drivetrain is: how big is your ring? Specialized Factory Racing pro Jaroslav Kulhavy made us all feel ridiculously inferior when he posted pictures of his 38T setup for the Czech Republic round of the UCI World Cup in 2015. But be wary of following suit. Kulhavy pushes more watts brushing his teeth than most of us do while riding – the aggressive set-up suits his power, skills and riding style. Besides, the Nove Mesto World Cup track is known to be “flattish”. Less teeth up front gives you more options when the trail gets steep or you blow. A 30T or 32T will be adequate for most of your trail and marathon riding duties in South Africa.

A cleaner cockpit is one of the benefits of going 'one-by'.

A cleaner cockpit is one of the benefits of going ‘one-by’.

 

You should do some asking around to see if it’s necessary to fit a chainguide, a fairly light, easy-to-fit device that attaches to your front derailleur mount to give you complete security in the knowledge that your chain won’t derail, as it sometimes can with a single blade. 

2×11

Shimano offers 2×11 shifting on its Di2 (electronic) system and XTR, both of which are pretty high-end in terms of price and beyond the reach of the average South African mountain biker. Di2 is just an incredible gearing system and is probably the ultimate in shifting currently. Its intuition is so on point that users of it would struggle to return to a mechanical/manual system.

Shimano recently launched XT 11-speed, which offers single, double and treadmtb-chainring-debatetriple chainring options as well as a wider gear range on the cassette than what XTR offers (11T-42T vs 11T-40T). It’s also a lot more affordable and you can bet your bottom Yen that the Shimano engineers are fine-tuning the SLX 11-speed groupset right now, bringing 11-speed shifting potential to virtually every mountain bike soon. (Consequently, in recent months this is exactly what Shimano did)

SRAM of course has been the leader in the less-is-more gear revolution and its launch of GX recently (more recently SRAM have also introduced NX) also brought 11-speed to the working class. SRAM’s 2×11 system offers the widest shifting range compared to Shimano’s 2×10 and 2×11 options, but Shimano lovers will quickly tell you that a wider range isn’t necessarily as efficient. (Sticking to their single chainring guns, SRAM launched it’s 1×12 Eagle. Look out for an upcoming in depth review from our first hand introduction to SRAM’s Eagle in the Swiss Alps)

All our TREAD editors agree that 2×11 is where the industry is headed. Mountain biking is still evolving, both as a sport/activity and, technologically. SRAM’s decision just six years ago to challenge the traditional triple chainring thinking in mountain biking has stimulated one hell of a battle with Shimano in the quest to find the perfect gearing. It’s a battle that’s sure to continue, albeit with less drama and the biggest winner really, is us, the mountain bikers.

Inside the TREAD Ed’s head

Sean Badenhorst gives us the stage-racing angle.

“After struggling somewhat on the steep climbs of the Tankwa Trek three-day stage race a month before the 2015 Absa Cape Epic, I decided I needed easier gears. I was riding Shimano’s brand new 1×11 XTR, which came standard on the Momsen VIPA Team. It had a 32T (32-tooth) front chain ring and the easiest gear was a 40T cog on the rear cassette. I decided that since I couldn’t get a 42T rear sprocket (Shimano hadn’t made one yet), I’d fit a 30T front chain ring to make my life easier.

After a week of searching (online bike shops abroad included) revealed there were no 30-tooth chainrings anywhere, I started to panic.

Chatting to semi-pro racer Nico Pfitzenmaier, who was riding the same bike as me and with the same gearing set-up, didn’t help my confidence. After Tankwa he also felt the 32T was too big a gear. So it wasn’t just me! I then heard that Swedish star, Emile Lindgren, also on the same bike, had requested to have a Shimano 2×10 XT crankset for the Epic. I was now panicking a lot!

Victor Momsen, owner of the Momsen brand, said I could swap the rear triangle of the Team model for the one on the VIPA XT, and then run a 2×10 like Lindgren.

Phew, problem solved! But then work pressure overwhelmed me and I never went through with it.

As the race approached I just accepted that I’d be walking up some of the steeper climbs at the Epic. And I stopped panicking.

Tread Editor Sean Badenhorst smiles while climbing Groenlandberg with a 1x11 setup during stage one of the 2015 Absa Cape Epic. Photo: Gary Perkin/Cape Epic/SPORTZPICS

Tread Editor Sean Badenhorst smiles while climbing Groenlandberg with a 1×11 setup during stage one of the 2015 Absa Cape Epic.
Photo: Gary Perkin/Cape Epic/SPORTZPICS

 

As the Epic race wore on I realised I didn’t have to walk once. Of course I wasn’t racing at my limit like the guys in the top 50 (we finished 104th), but I managed just fine. To be fair, I was in the form of my life. I weighed 64.5kg with single-figure body fat. Perhaps more importantly, I’d done some very specific power-based training in my preparation for the Epic, which also improved my pedaling efficiency and my power-to-weight ratio. And I’m an experienced, skilled rider, so able to tackle rough and technical climbs with a reasonable level of confidence.

This experience leads me to believe that the majority of South African riders competing in marathons and stage races, are still best off using a 2×10 or 2×11 set-up. The double chainring just gives you some peace of mind. Few things can be more ego-and-confidence-crushing than being forced to walk up a climb because you aren’t strong enough to ride it.

For the guys with no budget limit, there’s the perfect happy-medium with Di2’s 2x set-up…”

Thinking of converting to a single chainring up front? If your answer is YES to any of these, then strongly consider it!
Are you a very fit, conditioned male marathon/stage-racer?
Are you a very competitive, race-conditioned female?
Do you live in Gauteng, or anywhere else that’s not too hilly?
Are you largely a trail rider that’s in no rush to get up climbs?
Are you a keen Enduro racer?
Does simplicity appeal to you?

The main contenders

In these graphics, supplied by SRAM, you can see the range of gearing options available with 1×11 and 2×11 (and 2×10) from Shimano and SRAM. Obviously SRAM uses these graphics illustrate to its superior range of gearing over its chief rival, but as explained in our article, Shimano has focussed more on efficiency of shifting and pedalling and not range width.

sram-gearing-advantage-2

sram-gearing-advantage

All our bike testers have ridden both Shimano and SRAM 1×11 and 2×10. Some have ridden Shimano Di2. We really can’t say that one is obviously superior to the other. We’ve had a few chain drops (usually on very rough descents) with both, which is why we recommend a chainguide, but we can’t say that you shouldn’t get this one or should avoid that one. And that really is a good place for this industry to be right now – offering better, more appropriate gearing in a variety of options across the two main component brands…

What about the smaller brands?

While Shimano and SRAM are foundation brands for groupsets on most bikes, there are a number of small component brands that have become specialists in this field. In a follow up article, we’ll feature more detail on this option.

 

TREAD Magazine is sold throughout South Africa and can be found in: Spar, CNA, Exclusive Books, Discerning bike shops and on Zinio

*Originally published in TREAD  Issue 38, 2015 – All rights reserved

Tread38

THE GREAT CHAINRING DEBATE Reviewed by on . Truth is, until recently, I wasn’t interested in gear ratios. Actually, nobody was. Except maybe for mechanics and some pro riders. They understood the physics Truth is, until recently, I wasn’t interested in gear ratios. Actually, nobody was. Except maybe for mechanics and some pro riders. They understood the physics Rating: 0

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