G2 RE 2018+
The pad compound is the material that actually contacts the rotor during braking and choosing the correct compound can have a significant impact on how your brakes will perform under different conditions on the trail. Pad compounds can generally be divided into two types. Organic compounds, which are made by mixing various organic (non-metallic) materials, and Sintered (metallic) compounds which contain metal particles. SRAM allows you to choose from four variations of compounds, each providing certain advantages while also coming with some compromises.
It should also be noted that when changing pads, and the new pads are of a different compound than the previously installed pads, new rotors should be installed and a rotor 'bed-in' process should be performed.
SHOP all SRAM brake pads HERE
]]>How do you know it’s the ideal length to achieve the best possible shifting? A properly sized chain is one of the most important factors for shifting performance and drivetrain longevity.
]]>If you’re replacing a worn chain, and you know the previous chain was properly sized you can simply cut the new chain to the same size. However, if you’re working on a new build or maybe you have replaced your cassettes with one that has a wider range, you’ll need to size the chain properly. Changing the size of the front chainring (up or down) will also require resizing the chain.
It also very important to remember that on bikes with rear suspension the distance between the front chairing and the cassette changes as the suspension moves through its travel. As such, this needs to be taken into account when sizing the chain.
Here is how to properly size you chain for a Shimano drivetrain, taking all the guess work out of it.
Start by wrapping the chain around the largest sprocket on the cassette and the largest chainring in the front, making sure you BYPASS the derailleur. Pull the chain as tight as possible making sure it meshes properly with the teeth on the cassette and front chainring. It should look like this:
At this point you will need to find the zero point at the rear of the largest sprocket as shown below. The correct chain length is determined by adding a certain number of links to this zero point. This number will differ slightly depending on if the zero point falls on an inter or outer plate of the chain and if you will be using a Quick-Link or a connecting pin to join the chain back together.
NOTE: On full suspension bikes, the correct length of the chain needs to be determined with the suspension fully extended.
If using a Quick-Link to join the chain:
If using a connecting pin to join the chain:
If using a Quick-Link to join the chain:
If using a connecting pin to join the chain:
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Before we get into the details it’s useful to discuss the current disc brake mounting standards, "I.S." (international standard), "P.M." (post mount), and flat mount. Flat mount is used primarily on road bikes, with some manufacturers starting to experiment with this standard on cross country race mountain bikes, but here we’ll focus on "I.S." (international standard) and "P.M." (post mount), the two most common standards in the MTB world.
The "I.S." (international standard), also sometimes referred to as IS tabs, are unthreaded eyelets (tabs) in the frame or fork. In almost all cases they require an adapter which is first bolted to the IS tabs. The brake caliper then bolts onto the adapter. The design and geometry of this standard also requires the use of different adapters to adapt the same calliper to the same rotor size front and rear. For example, the adapter for a 160mm rotor in the front differs from the one that would need to be used for a 160mm rotor in the rear.
The "P.M." (post mount) standard consists of two threaded M6x1 holes on the frame or fork, oriented such that a caliper can be bolted directly to the frame or fork without the need for an adapter. Most mountain bike frames and forks are setup for a rotor size of 160mm front and 160mm rear, where the caliper would be mounted directly to the frame or fork without the use of any adapters. That being said, all sorts of exceptions exist, with some downhill forks for example being setup for a minimum rotor size of 200mm. There are also both frames and forks setup for 140mm rotors. Post mount doesn’t suffer from the geometry issue of IS tabs, as such the same adapters are used front and rear to adapt to the same rotor size.
Now that we’ve covered some the differences in intricacies of IS tabs vs. post mount, let’s try to demystify which adapter to use in which case.
160mm rotor use: SM-MA-F160P/S
180mm rotor use: SM-MA-F180P/S
203mm rotor use: SM-MA-F203P/S
160mm rotor use: SM-MA-R160P/S
180mm rotor use: SM-MA-R180P/S
203mm rotor use: SM-MA-R203P/S
160mm rotor use: SM-MA-F180P/P2
160mm rotor use: NO ADAPTER
180mm rotor use: SM-MA-F180P/P2
203mm rotor use: SM-MA-F203P/P
180mm rotor use: NO ADAPTER
203mm rotor use: SM-MA-F203P/PM
Please note that you shouldn’t just put bigger rotors on your bike without first checking the frame and fork manufacturer specifications. Bigger rotors do have several advantages such as faster heat dissipation, they also generate more leverage, and therefore have more stopping power. However, frames and forks almost always specify a maximum rotor size, which has to do with the amount of forces they can safely deal with due to the increased leverage bigger rotors provide. Exceeding the maximum specified size can damage the frame and/or fork, so again, check with the manufacturers specifications before upgrading your rotors to a larger size.
]]>When Shimano and SRAM introduced their 12-speed drivetrains they introduced new freehub standards. Shimano introduced MICRO SPLINE, SRAM their XD freehub driver. Shimano’s previous HG Standard has been the cornerstone of road and mountain bike drivetrains for decades, both Shimano’s as well as SRAM’s before they introduced their respective new drivers. The HG freehub remained largely unchanged over many years and supported cassettes with 8 to 11 cogs. This was possible by squeezing increasingly more cogs into the same space by moving them close together and making the chains narrower.
Shimano MICRO SPLINE & HG Standard freehub bodies, side-by-side
But why couldn’t Shimano and SRAM just continue to squeeze more cogs onto the HG freehub? Technically they could, but in a quest for bigger gear ranges they needed to fit a smaller 10T cog onto the new cassettes which would allow for those larger ranges of 510% (Shimano) and 520% (SRAM). However, this new 10T cog is too small to fit onto the Standard HG freehub body. In order to accommodate the new 10T cog, the new MICRO SPLINE and XD freehub bodies are actually shorter than an HG freehub body. In Shimano's case this allows the smallest 10T cog to be attached not to the freehub body itself, but the 12T cog which is the last cog that mounts to the freehub body. The 10T cog then mounts inside the 12T cog and is held in place with a series of splines that match up with a series of grooves in the 12T cog.
MICRO SPLINE cassette 10T & 12T cogs
Two smallest cogs, MICRO SPLINE vs. HG Standard
Now let’s try to bring this all back to the topic of actually upgrading your older 9/10/11-speed drivetrain to 1x12. With the new MICRO SPLINE and XD free hubs an upgrade can become a lot more complicated because you’d need an entire new wheel with a MICRO SPLINE or XD hub, or a new MICRO SPLINE or XD hub with which you can rebuild the rear wheel. Both of these options can be quite expensive. In rare cases you may be able to upgrade your hub with a MICRO SPLINE or XD freehub body, but this is especially unlikely if you have an older drivetrain with an older rear hub.
Not all is lost though, as there are some very interesting options that do allow you to upgrade to a 12-speed drivetrain without having to replace the rear wheel or hub. SunRace makes a series of 12-speed 11-51T and 11-50T cassettes that fit onto the HG Standard freehub bodies and are specifically designed to be compatible with all Shimano and SRAM (respectively) 12-speed derailleurs and chains. The main difference is that the smallest cog on the SunRace cassettes is 11T vs. 10T on the Shimano and SRAM cassettes. We’ve put together a multitude of upgrade kits which include these HG SunRace 12-speed cassettes for Shimano and SRAM drivetrains ranging from Shimano Deore 12s M6100 and XT M8100 to SRAM GX. They make for a very cost effective and frictionless way to upgrade your bike to a 1x12 drivetrain.
You can check out our selection of these HG Compatible upgrade kits HERE.
Even if you have a much older 9-speed or even 8-speed cassette on your bike, as long as the smallest cog on it is 11T, one of our HG Compatible groupsets with the SunRace 12-speed cassettes will fit and be a great upgrade option.
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