SOC12: A Second Look at Shimano’s New DH Groupos
Last week, Shimano announced its revamped DH line. During Sea Otter we were able to get our grubby hands all over the shinny new goods and pick up a few more tidbits on the updated Saint and all-new Zee component groups.
Check past the break to see what we learned…
The new Shimano Saint Cranks, which are 140g lighter than the previous generation, are single-ring only and will be available in 34, 36, and 38 tooth rings.
What Shimano casually didn’t point out, but hid in plain sight, was their new prototype guide. The guide will work with all of Shimano’s existing trail cranks and fit a 34-38 tooth ring. Two unique features stand out about this chain guide. First, notice that the bash guard is only protecting one quarter of the chainring. Why? Because most riders favor one foot forward when flowing over jumps and bumps, so why add all the weight to protect the whole ring when you only need a segment covered? Riders that are ambi-shredderous can install another one on the opposing side of the ring.
The Shimano guide uses a spring loaded lower guide. This allows the lower roller to tuck up during impacts and reduces friction through the entire range of gears.
With the recent introduction of Dyna-Sys, Shimano introduced a chain specifically designed for mountain bikes. Previously, all of their chains were designed for road groups, but had proven strong enough for off road usage. The new design eliminates cut outs to reduce the likelihood of twisting and is shaped to shed mud and maximize shifting on MTB gearing.
The current derailleur hanger was introduced in 1952 by Campagnolo. Prior to the replaceable derailleur hanger a badly bent or broken dropout meant a frame had to be scrapped.
Much has changed in the intervening time and the shift towards something more capable was long overdue. For those of you who fear change, the new direct mount is an optional standard at this point, and all of Shimano’s new (read: 2013 forward) derailleurs will be backward compatible. Read this article for more on the new DM rear standard.
It is easy to see the difference between a standard hanger and the new direct mount when they are super imposed upon each other. The new direct mount pulls back the derailleur’s mounting point 20mm further from the frame by replacing the intermediary link. It also allows frame makers an additional dimension for creativity because they can design the dropout’s base any width or shape they want, taking full advantage of the wider, thicker 142 and 150 axles now common.
The most notable difference between the two mounting standards is the width of the direct mount option. This is one place where an increase in stiffness will be both noticeable and welcome. A rigid hanger means crisper shifts under load or through chunder. Also, the hanger will be less inclined to bend during the kinds of impacts which would normally cause a slightly bent hanger and cause imprecise shifts.
The new Saint line up will be 10 speed. While freeriders will appreciate the extra gear, many DH racers prefer to run less gears for increased reliability. In fact, it is not uncommon to spot modified 6 speed cassettes on many DH rigs. The new Saint derailleur has extra long set screws so users can limit off up to three gears per side.
Depending on your cassette, the “close ratio compatible” mode converter allows riders to optimize the derailleur for either a close or wide ratio cassette.
The Zee derailleur also allows riders to swap between different sized cassettes by swapping out the B-Links. The derailleur will come standard with the DH oriented knuckle for use with 11-28 cassettes.
Both Saint and Zee get the Shimano Shadow Plus clutch system which cuts down on noisy chain slaps and ghost shifting. The design has been refined since it was first introduced and the cam is now grooved so grease is not pushed outward and out of the clutch mechanism.
The new Zee levers aren’t quite as pretty as the pricier Saint components because they lack some of the additional machining that keeps weight low. They also lack an external reach adjustment knob.
The Zee brakes don’t utilize the extra long brake banjo used on the new Saint caliper pictured above. The extra long banjo helps dissipate heat from building up in the caliper during those long descents. My rough measurement from the center of the bolt to edge of the Saint banjo was 37 mm long, while the Zee came in at just 22 mm.
One upgrade to the braking system across both the Saint and Zee groupos was a revamping of the hydraulic hoses. The new hoses have a narrower inner diameter and utilize a steel banjo versus a brass one. The narrower hoses, reduced heat conduction, and the higher oil pressures increases breaking power. The new steel hardware will be more durable than running comparably sized brass banjos.