What’s new and what might we be riding in the not so distant future? We speculate on what the future holds…
Bike technology is in a constant state of flux. Every year we hear of new designs and new concepts that are going to ‘revolutionise’ the machines that we ride. Here we are going to focus on concepts that are already gaining popularity on the latest bikes, as well as taking an educated guess at what we are likely to see in the next couple of years.
Take it to Ten
Ten speed rear cassettes have been around for some time on the road, but it wasn’t until last year that we saw SRAM launch an off-road specific 10-speed cassette, with their XX group. With that initiation, it appears that the floodgates may be about to open. Now speculation and rumours abound that both Shimano and SRAM will have 10-speed cassettes within their 2011 line-ups. Early leaks suggest that Shimano’s SLX and XT groups may be 10 speed and we can only assume that XTR will follow suit. Again based on leaks and rumour, SRAM looks set to introduce an entirely new version of the X.0 group which promises to be a lower cost version of XX, with all of the same features; 10-speed and two chainrings. Early internet leaks hint at X.0 running a similar hollowed out one-piece cassette body, with an alloy inner cog to transmit the drive through to the hub.
While they could use the extra cog to obtain closer gear ratio spacing, both Shimano and SRAM appear to be offering their 10-speed cassettes with a big 36 tooth low cog—just like the existing XX system. A good thing in my mind, as the broader spread of ratios allows you to stay in one chainring for longer before having to shift up front. This leads to fewer chainring shifts (always a good thing) and also makes two chainring set-ups a more viable option for trail riding.
If this is all true, the move to 10-speed won’t be pain free. Those looking to upgrade an existing bike will need to buy new shifters, derailleur, cassette and chain—most of the drivechain really. As with XX, the width of the cassette will be the same as nine-speed but the cog spacing is closer with a narrower chain and narrower cogs. This is good in some respects as the rear wheel retains the same amount of ‘dish’ and doesn’t lose any strength. However, the narrower cogs, chain and closer gear spacing has the potential to compromise durability and make these new drivechains more vulnerable to shifting issues caused by cable friction and less than perfect trail conditions. You could also say that the same issues were raised when we went from eight to nine-speed, yet the market now seems happy with nine-speed drivechains—will the same happen when we move to 10? Only time will tell!
Double chainring cranksets have been steadily gaining popularity, and this is only likely to snowball with the broader availability of 36-tooth cassettes. The combination of 26/39 or 27/40 chainrings with a 36-tooth cassette doesn’t duplicate the low gearing of a triple chainring set-up, but it comes pretty close. It’s certainly enough to keep the XC racers happy and the gearing will get typical trail riders up most hills (steep and sustained mountain passes will still warrant a true granny gear unless you are really fit). The main benefits come from the reduced chain angle when using the ‘cross over gears’—the largest chainring combined with the biggest rear cog for example. Limiting the angle that the chain is forced to run on improves drivechain efficiency and reduces chain wear. Early unsubstantiated reports suggest that SRAM will have an X.0 level double crankset with the same chainring sizes as their XX model. This should be matched with a double specific X.0 front derailleur. FSA has recently expanded their range of double MTB cranks and you can expect to see more and more bikes coming out with 2×10 set-ups. While the rumour mill is rolling, it looks like the new Shimano XT and SLX groups should still use triple chainring cranks, but it is thought that they may be fitted with a slightly tighter ratio spread— something like a 24/32/42 for example. Theoretically, the closer ratios should speed shifting while keeping your pedalling cadence more consistent as you swap from one chainring to the next. With the 36-tooth cog on the back, a 24-tooth granny provides a true ultra low gear that will get you up any rideable hill. Shimano has always believed that double cranks are best left for XC racing, while triples equip the average recreational rider with the low ratios needed to conquer any hill. With this in mind, it is fair to expect a double option on XTR but Shimano’s more trail/all-round groups should retain a triple crankset as the only option.
While there are plenty of manufacturers offering new double specific cranks, no one seems to agree on a common bolt pattern for the chainrings. FSA has two different bolt patterns within their range and SRAM has another completely different format. With rumour circulating about the option of a double crank within Shimano’s XTR line-up, I wouldn’t mind betting that they’ll be creating yet another chainring mounting pattern. All of these differing sizes mean you’ll be limited for choice when it comes to replacing your chainrings.