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Guide #1 Component Compatibility

Guide #1 Component Compatibility

ReCycleD Mountain Racing’s Guide to:

Mountain Bike Component Compatibility for Gravity Athletes.


  • Need to replace a few parts on your mountain bike for Spring?
  • Got a sick new frame, but not sure if the old parts will transfer?
  • Building your dream bike but not sure if all the parts on your list are compatible?

This guide is for you!

How to use this guide:

In this guide we have mapped out all the connection points between bike parts. The guide can be used as a checklist to make sure the part, parts, or build you are doing will integrate. We will cover the basics of mountain bike component compatibility and add value by offering up our opinions and preferences on what we look for in quality new and used parts. This info is presented with the goal of getting all your parts to play nice with each other on your next bike build. We are biased to parts with universal standards and are less that excited about manufacturer proprietary component sizes and standards. This guide will cover the major part standards for mountain bikes, but is far from all inclusive. If your part(s) uses sizes or standards not covered here, we suggest you email us at: info@recycledmountainracing.com or consult with the manufacturer’s customer service desk.

Let’s get started!

Fuselage / Primary Components:

Frame:

  • Headtube to Headset
Head tubes and headsets in regards to size are typically referred to by the size of the fork steer tube they accept. For example a frame’s head tube size or a headset size might be referred to as 1 ⅛”, this does not meet the frame head tube inner diameter or the headset outer diameter is 1 ⅛”. The correct interpretation of this info is the frame and headset accept a universal standard to run forks’ with a 1 ⅛” outer diameter steerer tube.  There has been 3, maybe 4 major fork steerer sizes; most mountain bikes over the last 25 years have been 1 ⅛”. The two other major sizes you see are 1.5” and a combination of the two called “Tapered”. Tapered is a 1.5” lower with a 1 ⅛” upper. The larger diameters increase the front end rigidity of the bike. There has also been a good number of frames made in the last 5 years that use internal headsets. These are often cited with a measurement such as 40mm or 44mm. When purchasing the headset it is also important to consider what fork you're going to run, see more under the fork to headset section.
Major Head Tube / Headset (fork steerer) Sizes:
  • 1 ⅛”
  • 1.5”
  • Tapered (1 ⅛” upper, 1.5” lower)
Less common:
  • 1”
  • 1 ¼”
  • Internal (40mm, 44mm)

  • Seattube to Seatpost
The frame and seatpost are commonly cited with a diameter in millimeters and length also in millimeters. When purchasing your seatpost it is important that they are an exact match. The most common size are 27.2mm, 30.9mm, and 31.6mm. No there are many less common sizes, especially on old steel hardtails. If you have something less common you have two options: 1) find an exact match, or 2) shim the seatpost to a common size. For example, your frame may require a 29mm but you could purchase a alloy sleeve called a seatpost shim to shim the frame 29mm down to a common size post say 27.2mm. Shims are easily found at most bike shops and usually run $7-$13. If you are running a full suspension bike many seat tubes are interrupted by swingarms and suspension. You have a few options in this situation: 1) find a post that fits 2) use a dropper post such as the RockShox Reverb or 3) use a telescoping seatpost. We love Dropper posts. There are a few issues to consider with dropper posts. If you are running a dropper seatpost some frames allow for internal cable routing. An example of this is the “Stealth” version of the Reverb post. You might also have options of left hand or right hand remotes for the dropper post’s activation switch. Dropper posts travel can also vary widely from as little as 30mm and as much as 150mm of movement. Suggest getting a dropper that suits your riding style.
Major sizes:
  • 27.2mm
  • 30.9mm
  • 31.6mm
Issues to consider:
  • Interrupted seat tubes
  • Dropper post issues
  • Seattube to Front Derailleur
In our opinion the front derailleur is currently becoming obsolete. We think that narrow-wide chainrings with wider range cassettes work so well there will be fewer and fewer bikes specced with front derailleurs going forward. If you are going to run a front derailleur, there are three major factors to consider when selecting a front derailleur for your frame:
Mount style:
Clamp on
Common sizes:
  • 28.6mm
  • 31.8mm or 32mm
  • 34.9mm or 35mm
Bottom Bracket mounted
See XTR E-Type - usually model specific
Ring mounts to bottom bracket
Direct or Post mounted
Bolts directly to frame - usually model specific
Top or bottom swing:
shifting cage is above or below clamp
Top or bottom pull:
refers to routing of pull cable relative to front derailleur
 
For the mounting type and style, there are 3 major types of mounts in our minds: clamp on, which is a ring mount that goes around your seattube and its what most of us have had for the last 20 years, bottom bracket mounted such as the XTR E-Types, and direct or post mount style that bolt directly to the frame. If you have a bottom bracket mount, direct mount, or post mount the best course of action is to either consult the frame manufacture or you can also “google” the the frame’s specs if you know the year, make, and model of the frame. You will need an exact match for these styles. Top or Bottom Swing refers to whether the derailleur shifting cage is above (top swing) the mounting ring or below (bottom swing) the mounting ring. Some frames can do either type of swing, in those case we prefer the “Top Swing” cage as it seems to get a little more lift on the chain. Bottom swing was the original style and has been around alot longer. Most front derailleur are advertised for certain number of rear speeds 8,9, or 10 speeds for example. We have found for best performance match to the advertisement but this is something that can be fudged in a pinch: example, run a 9 speed front on a 10 speed drivetrain, or a 10 speed front on a 9 speed drivetrain. Lastly you will want to consider whether you need a top or bottom pull- the pull just refers to how the cable routes on the frame into the front derailleur:
  • Top Pull: cable routes from shifter down the top tube, then down the seat tube to pull from above
  • Bottom Pull: the cable routes from the shifter down the down tube and up from the bottom bracket, to pull from below.
 
Warning: The front derailleur is the easiest part to get wrong. If you have questions please email info@recycledmountainracing.com
 
  • Frame to Chainguide
The chain guide is a component we believe we will be seeing less and less of in the future. Narrow-wide chainrings, rear derailleurs with a clutch, and wide range cassettes are contributing to chain guide’s obsolescence. We do still see racer’s using a top guide on wide-range narrow-wide drivetrains. Chain guides are still commonly used on gravity bikes. When selecting a chainguide there are a couple things you need to worry about to get the correct fit. You will need to get the right mount style, right plate or fit style, and if the chain guide includes a bashguard for the cranks, you will need to make sure the bolt circle pattern and size matches the cranks you are going to run.
Mount Style:
Bottom bracket mounted
mounts to a “lipped” bottom bracket cup
this is common on older chain guides
can suffer from chain guide rotating on the frame
ISCG -International Standard Chain Guide mounts
bolts directly to tabs on the frame
I few variants usually indicated by what years they were released. Usually the frame will have a model specific recommendation  
Examples:
  • ISCG
  • ISCG-05
Plate size and styles:
Chain Guides usually consist of a backplate and sometimes a bashguard
The back plates can be different shapes to accommodate different styles of rear suspension. The bash guard and plate sizes will usually state a range of chainring sizes
examples -
  • 30T-36T
  • 36T-42T
It is important to get a guide that fit your frame’s mounts, and suspension design
and also get one for the intended chainring size
Bashguard sizes:
You will need to make sure the bashguard fits your cranks.
Bashguards are fitted just like chainrings - see chainrings section


  • Rear Dropouts to Rear Hub
All-mountain and gravity mountain bikes are currently using several rear hub spacings and a few more have already been proposed. There generally two details you need to worry about to fit the rear hub to your frame; rear hub spacing, which is the length between dropouts, and secondly the axle size. the axle size is listed by diameter and refers to the parts that actually goes thru the frame and fork (the hub may have a larger internal axle.
Common Sizes:
  • 135mm QR
    • Quick Release
    • Most common rear wheel size over the last 20 years
  • 135mm x 12mm
    • found on downhill and freeride bikes that use standard 68/73mm bottom brackets
  • 142mm x 12mm
    • currently found on that latest bikes, often found on 27.5” wheels
  • 150mm x 12mm
    • most common size for downhill bikes, typically matched to a 83mm bottom bracket
  • 157mm x 12mm
    • less common but found on some popular models like the Santa Cruz V-10 late models
Generally the frame specs will tell you what size you need, or if you need to you can measure
The thru axle usually comes with the frame (not the hub or wheels)
 
  • Frame to Rear Derailleur

Fortunately fitting rear derailleur to frames is fairly easy. Generally speaking there has really only been one size bolt that threads into the hanger. There has been exceptions over the years. The one common exception today is Shimano’s shadow+ standard that allows the derailleur to mounted to the rear hub’s thru axle, but the shadow+ models also come with a bit to allow mounting to a standard rear hanger. There are a couple things you want to consider when choosing your rear derailleur. Rear derailleurs usually come in several lengths, what length you need will depend on the cassette you run. Generally longer cages will run wide gear ranges and shorter cages will run closer ranges. Many rear derailleur are available with a clutch mechanism. We are a big fan of clutched derailleurs as it helps to quiet and stabilize the drivetrain while still allowing easy rear wheel removal.  The derailleur will also need to match the chain and cassette in number speeds (8,9,10,or 11), but some fudging can be accomplished here in a pinch.
  • Frame to Rear Brake Caliper

The big thing to understand about mounting brake calipers to either the frame or fork is that these days the adapters are the key. The term brake calipers refers to disc brake calipers as all performance bikes run disc brakes. We are going to omit discussion on V-brakes or older cantilever brakes. When disc brakes first hit the market in mass there was two competing standards 51mm IS (international standard) which consists of two holes running side to side thru the frame, and shortly there after 74mm post mount, which consists of two small towers running front to back with threaded bolt holes. To understand why adapters are key in helps to understand the benefits of each standard. 51mm IS mounts are generally speaking easier to install in frames without needing the precision of installing two parallel threaded posts. We feel post mounts are superior because it makes it very easy for the calipers to self center on the rotor while under pressure from a good brake squeeze. The adapter bridges the two standards. This frees us from having to shim 51mm calipers left and right and still have the easy install of 51mm mounts on metal frames. The second benefit of the adapters is allows for different rotor sizes. In summary, almost all brake calipers on the market are 74mm post mount, more and more frames and forks are coming post mount, but most frames and forks are 51mm IS, so your adapters is most likely going to convert 51mm side to side holes to 74mm front to back threaded holes. You will also need to get the adapter to fit the whatever size rotor you're going to run.

Common size rear adapters:
  • 51mm IS to 74mm post 160mm rotor
  • 51mm IS to 74mm post 180mm rotor
  • 51mm IS to 74mm post 203mm rotor
  • The adapter bolts to the frame and then your brake bolts to your adapter
 
  • Frame to Bottom Bracket / Cranks
Most performance crankset these days are two-piece and include the bottom bracket. There are many press fit style bottom brackets on the market but most of the bikes we come across still use a bottom bracket that threads into the frame. Press fit bottom brackets are lighter, but frames are much more difficult to manufacture precisely so they have been slow to catch on. If you need cranks or a bottom bracket for press fit frame you will need an exact match to the manufacturer’s specification, google is your friend here. The crankset usually has two key measurements: the arm length, ranging from 165mm-180mm, and the chain ring bolt circle or BCD. The arm length you choose is personal preference for your leg length and your clearance needs. For example I am 6’1” and have a 32” inseam. I ride 170mm arm most of the time 165mm on my downhill bike for extra clearance, and a 175mm on my single speed for extra leverage. The BCD just need to match the chainring you are going to run, but most cranksets come with chainrings. You see more info under the crankset to chainring section. The bottom bracket has two key measurements, one you have worry about the other you generally don’t. The first is the width, most frames are either 68mm or 73mm width, but they make it easy on you in that most bottom brackets these days will do either 68mm or 73mm with included spacers. Downhill bikes use a little wider rear hub so to keep the chain line straight need a little wider crankset, as such most freeride and downhill bikes use a 83mm bottom bracket. The other bottom bracket detail is the spindle diameter. If you purchase your cranks and bottom bracket separately you will want to make sure your spindle diameter matches.  
Common bottom bracket sizes:
  • 68/73mm
  • 83mm

Fork:

  • Fork to Headset

Once you have figured out what size your headset you frame requires, it is time to make sure you get a headset that matches your fork. There are three major sizes that have been used over the last 20 years. The most common size is  1 ⅛”. The two other major sizes you see are 1.5” and a combination of the two called “Tapered”. Tapered is a 1.5” lower with a 1 ⅛” upper. The larger diameters increase the front end rigidity of the bike. Most mtb forks will have one of these three sizes. Many downhill and freeride bikes use a 1.5” headset even though most forks are manufacturers are producing either 1 ⅛” straight or tapered forks because the larger headtube allow more surface area for welding up a stronger front end. This also allows the greatest range of headset and forks. It is very common to see a dh bike with a 1.5” headset running a 1 ⅛” or tapered fork with the correct headset. Conversion headsets allow you to adapt a larger headset size to a smaller for fork steerer size. This also allow you to run a headset to adjust the head angle of the bike. or lengthen or shorten the length of the bike by offsetting the fork forward or backwards. We are a big fan of the 1.5” headset size for frames. The tapered fork steerer seems to be the direction forks will head in the future and we do think it strikes a nice balance between strength, rigidity,  and and weight savings for long travel single crown forks.

Fork Steerer Sizes:
  • 1 ⅛”
  • 1.5” (not compatible with Cannondale Headshok)
  • Tapered (1 ⅛” upper, 1.5” lower)
Less common:
  • 1”
  • 1 ¼”
  • Internal (40mm, 44mm)
  • Proprietary (example: 1.5” Cannondale headshok)
Benefits of 1.5” headset/frame:
  • Larger bearings / stiffer
  • Run 1.5”, 1 ⅛”, or tapered forks with the right headset
  • Run angle or length adjusting headsets with the right fork
 
  • Fork Travel to Frame Style and Purpose / Head Angle Issues

Finding the right fork is about finding the right match for your bike’s purpose. It is important to find a fork that has the appropriate amount of travel and height for the bike your building. In the mid nineties most performance mountain bikes were hardtails, They had a 71 degree head angle and were mostly for 60-80mm travel forks such as the RockShox Judy. Today most XC machines are probably running 80-100mm of travel and 69-70 degree head angle. This is mostly due to valving that has increases the efficiency of the suspension and the dominance of full suspension bikes that allow for faster speeds. We love enduro and downhill. In these disciplines of the sport we see new enduro bikes coming with head angles that use to be only seen on downhill bikes. The 2014 Santa Cruz Nomad has a nead angle of 65 degrees and is meant for a 160mm travel fork. Downhill bikes which started out with 80-100mm forks like the Rockshox Judy DH or the first dual crown from Rockshox the DHO which later became the Rockshox Boxxer. We are now seeing downhill bikes with head angles as slack as 63 degrees and travel has for the most part settled on 8” or 203mm for downhill forks. Most manufacturers will publish a recommended fork travel for your bike, when in doubt you can see what travel fork the manufactured spec'd on the complete bike. Many frames can accommodate a small range of different travel forks usually plus or minus 1” or 25.4mm. In these case just be aware that longer travel equates to a taller fork, slacker head angle, and a bike that favors higher speeds. Our rule of thumb is all else being equal for every 1” of travel you add your probable going to slack out your head angle by about 1 degree. Slacker angles tend to feel better at speed, but tend to make the bike feel like it is “swimming” at lower speeds usually when climbing. A steeper angle may feel sharper at lower speeds or while climbing, but feel “sketchy” at higher speeds. Fork manufacturers have employed many creative ways to address this issues including adjustable travel forks and smart valving to make the suspension smarter or more effient.

Fork selection guide:
Choose travel appropriate for frame and riding style
Think about how the fork will affect head angle
Think about how your head angle and travel will affect handling:
  • High speed handling
  • Low speed handling
  • Fork to Front Hub
Performance mountain bikes generally use three main front hub sizes that are two dimensions:
  • 100mm x QR or 100mm x 9-10mm
  • 100mm x 15mm thru axle
  • 110mm x 20mm thru axle
The first dimension (100mm or 110mm) refers to spacing between the forks dropouts. The second
dimension refers to what type of axle the hub requires. 100mm x QR, 100mm x 9mm, or just “Quick release” all refers to the same size and this size has been the most common over the last 20 years. Enduro and downhill bikes that are ridden faster and threw more extreme terrain are going to have a bolt on axle, either 15mm or 20mm. Downhill bikes are almost going to exclusively use 20mm thru axles. The bolt on axle generally comes with the fork. You will just need to make sure the fork you will be running matches with the hub you plan to run. Things are getting easier these days as many front hubs are coming with interchangeable end caps that allow the conversion from 15mm to 20mm and back again.
  • Fork to Front Brake Caliper
Matching a front brake to your fork is going to be very similar to matching the rear brake to frame (see Frame to Rear Brake Caliper section). The key here again is getting the correct adapter. Almost all disc brakes today use 74mm post mount standard. Your fork depending on how old it is is most likely either 51mm IS (international standard mounts) or 74mm post mount. If both your frame and fork are post mount you will either just bolt on the caliper and go or in some cases if you're planning on running a larger rotor a 74mm to 74mm adapter is used, just to space out the caliper for the larger rotor. If your fork has 51mm IS mounts (has two holes, unthreaded that run side to side threw the fork legs), then you will need a 51mm to 74mm post adapter. A few different sizes are usually available for to match the rotor size.
Fork disc brake mounts:
  • 51mm IS
  • 74mm post mount (usually for a specific rotor size)
Brake calipers mount size
  • 74mm (almost all disc brakes)
Common adapters:
  • 51mm IS to 74mm for 160mm rotors
  • 51mm IS to 74mm for 180mm rotors
  • 51mm IS to 74mm for 20mm axle and 203mm rotor
  • 74mm 160mm fork to 74mm180mm rotor 
  • Fork to Stem
Fitting a stem to your fork in general is pretty easy. Almost all stems on the market are fitted for 1 ⅛” threadless fork steerer tubes. There are a few stems available if you run a 1.5” fork. There are two other dimension that should be considered when selecting a stem. The first is handlebar diameter (see more under Handlebar to Stem section). The second is length. The distance from the center of the fork steerer tube to the center of the handlebar will affect the feel and handling of the bike. Enduro bike in general have shorter stem length than XC bikes and downhill bikes in general have the shortest stems. Your classic XC hardtail might have a stem anywhere from 60mm out to as long as 150mm. Today’s enduro bikes usually have stem between say 50mm and 120mm. The shorter stem is better suited for higher speeds. Downhill bikes will run anywhere from 35mm-75mm.
Stem Dimensions:
  • Fork Steerer Size
  • Handlebar Clamp Size
  • Length

Wheelset:

  • Wheelset to Tires (Width Issues / Tubeless Issues / Tire frame clearance)
We will use this section to cover several issues related to tires and wheels. The first basic issue to cover when matching your wheels to tires is getting the right width tires for the width of rims you have. XC bikes usually has 23mm outer width rims and were matched to 1.9-2.1” tires. When downhill bikes first became popular rims increased to 28-32mm and tires increased to 2.35-3.0”. We are going to omit discussions on the wheel size debate here. We like all three sizes and feel there is a place for 29”, 27.5” and 26” wheels. We are also going to omit discussions on fat bikes wheels setups. We love fat bikes but feel they deserve a separate conversation. These days in terms of rims and tires enduro and downhill are somewhat similar. Most gravity athletes are running 2.2”-2.5” tires on 28-32mm rims. A 2.5” front tire and 2.3-2.4” rear is a very common setup we see. We are a little old school on our own downhill bikes and like a 2.7” front and 2.5” rear tire on 32mm rims. The next issue to consider is if you're going to run tubes or tubeless. Each setup has advantages and disadvantages. The basic argument is tubes are simple and no mess while tubeless setups allow lower pressure allowing for a better tire footprint and all the benefits that provides. Most guys we see these days are running tubeless. Tubeless has come a long way since it was first introduce. There is a few ways a tubeless setup can be accomplished. Options include a wheel system (proprietary tire and rim system) such as UST rims and tires, a mixed system (tubeless rims and tires from different manufacturers), a pure conversion of non-tubeless rims and non-tubeless tires (converted to a tubeless setup with rims strips, valves, and sealant) or lastly a mixed conversion (rim or tires is tubeless the other is not). There doesn’t seem to be a magic bullet here. The most successful setups seem to find rim and tire combos that just seem to work well together. We see a lot of Stan’s Flow Ex and Spank wheelsets which are tubeless ready rims run with both tubeless and non-tubeless tires. Popular tires choices are WTB TCS tires, Continental UST tires, and Specialized Butcher non-tubeless tires. Popular sealant choices are Stan’s NoTubes and Orange. Proprietary wheel systems work well but limit tire choices. The last major issue to consider when connecting your tires to rims is to verify that the rim and tire setup you choose is going to have clearance in your frame and fork. A question we get allot is: “can I run a 27.5” tire/wheel in my 26” fork?”  followed by “I can see it fits”. We think it’s better to follow manufacturer's guidance and stick only with recommended sizes. We understand some tire and rim combos can run wide or larger than the number printed on the sidewall so we feel just having clearance isn’t enough, you need ample clearance in the frame and fork to account for two things: any flex in the frame and wheels, and any trail dirt, mud, or rocks that may pass through the clearance area. Following these guidelines will help avoid issues.
Are last point of discussion on the topic of wheel and tires is there is a lot of new technologies and product attempting to improve the wheelset. A lot of the new stuff look promising. We see several manufacturer going to beadless rims which makes you wonder why mtb rims ever had beads to begin with. We see a least three major manufacture including Syntace promoting ultra wide rims. A 35-40mm rim seems to increase air volume and footprint everything else being equal. Carbon fiber rims have become the standard for the racing set, but we feel they are too expensive to offer most performance riders a lot of value.  We find several other technologies interesting including Spank’s Bead Bite rim that is suppose to better secure the tire on the rim and Schwalbe’s ProCore system which has a high pressure tube within a lower pressure tube trying to combine the strengths of tubed and tubeless
Summary:
  • Choose tire widths and rim widths that are appropriate for each other.
  • Choose a tubed or tubeless system
  • look for good matches
  • Verify frame and fork clearance
  • Keep an eye to new tech here
 
  • Rear Hub to Cassette
Matching a cassette to your rear hub is fairly easy. Almost all performance mountain bike rear hubs and cassettes over the last 20 years have used the Shimano freehub body standard. The one exception we see is the Sram XD freehub driver body used on there 1x11 drivetrains. If you are planning to run a Sram 1x11 drivetrain you will want make sure your wheelset either has or can convert to a XD driver body- This is fast becoming an optional part for most high performance hub sets.
Standards:
  • Shimano
  • XD driver (Sram)
  • Hubs to Brake Rotors
Matching your hubs to brake rotors is very straightforward. There really just two standards: Shimano’s Centerlock standard or universal 6-bolt standard. We like universal standards because of the ease of compatibility and a widely adopted standard means many part choices. You can make an argument that the center lock system is lighter and better connection, additionally adapters are available if you really want to run a 6-bolt rotor on a centerlock hub. The other piece of good news here is that if you have a center-lock wheels and 6-bolt wheelset they will often be interchangeable with the same brakes (rotors work on the same calipers). You may wish to recenter the caliper when you swap wheels.  
Standards:
  • 6-bolt universal
  • Shimano’s Centerlock

Tires:

  • see: Wheelset - Wheelset to Tires / Width Issues / Tubeless Issues

Drivetrain

Crankset:

  • see: Frame: Frame to Bottom Bracket / Cranks
  • Crankset to Chainring(s)
Matching chainrings to your crankarms is fairly straight forward and getting easier. We highly recommend chainrings with narrow-wide tooth profiles. We think almost all performance drivetrains are headed towards 1x style setups. To match a chainrings to cranks there is two details you need to get right. The first is the number of teeth. How many teeth or what gearing you run is a function of personal preference and riding style. For the last 20 years the triple crankset has been the most common setup with 44-32-22t gearing that was matched to a 11-32 or 11-34 cassette. Downhill bikes originally had very tall gearing from 40-50T front matched to a road or mountain cassette. Todays enduro bikes run gearing 36-30T single front and 11-36 or 11-42 wide range cassettes. The number of teeth can be customized to your riding style. For example I run a 34t x 16t on my 26” single speed. A 34T x 11-36T on my enduro bike, and a 36T x 12-26T on my downhill bike. The second second set of details in matching a chainrings to your cranks is the dimensions. The chainring sizes is stated in bolt circle diameter or BCD. The most common BCD is 104mm in 4-bolt or 4 arm pattern. Before 104mm,  94mm compact 5-bolt was popular, and before that the standard size was 110mm BCD 5-bolt. There have also been a handful or proprietary standards for XTR cranks and various double chainrings setups. If you have one of these setups consult manufacturer specs or email us at: info@recycledmountainracing.com. You will also want to make sure the chainring is compatible with the number of speeds in your drivetrain or chain, example: 8,9,10, or 11 speed. The BCD discussed here is for outer and middle position chainrings there are also smaller matching BCD for the inner rings, you will just want to make sure the BCD matches up with your cranks. If you plan to run a single ring with no bashguard you will need shorter chainring bolts for the narrower profile. We like the narrow-wide chainring with a bashguard. This setup you can usually use the same chainring bolts from a triple crankset (the same bolts holding the outer and middle ring, the bash just takes the place of the outer ring).    
Most common size:
  • 104mm BCD 4-bolt
Recommended:
  • Narrow-wide chainring w/ wide range cassette
  • Bash Guard protects teeth from rocks and keeps clothing out of drivetrain
  • Crankset to Chainguide / Bashguard
If your going to be running a bash guard or a your chain guide includes a bash guard, fitting the bash guard to your crankset is handle the same way as fitting chainrings to your crankset (see: Crankset to Chainring(s) section directly above). To match the bash guard to the crank get a bash guard that matches your cranks BCD and that covers the chainring tooth count for the ring you're running. A bash guards coverage is usually stated as a  range of tooth profiles.
Examples:
  • 30-34T
  • 36-42T
  • Crankset to Pedals
All performance cranks and pedals use 9/16” threaded standard. Some downhill cranks will has steel inserts in alloy arms to make for a stronger connection but still use 9/16” threading.
      • Industry standard: 9/16”

Front Derailleur:

  • see: Frame - Seattube to Front Derailleur
  • Front Derailleur to Chain
In terms of matching chain to front derailleur generally you just need to make sure the speeds match. Example: 9 speed chain to 9-speed front derailleur. Chains and front derailleurs form different brands generally work well together. In a pitch chains and front derailleurs can be mismatched. Example: 9 speed chain with a 10 speed front derailleur. In a mismatched set up you are more likely to rubbing and noise issues but it can work, we recommend matching the number of speeds, but you can mismatch at your own risk..  
  • Front Derailleur to Crankset
When matching a front derailleur and crankset you will want to consider the shape of the derailleur cage and the number of speeds. Front derailleur for triple cranksets generally will shape to the out ring usually a 44t, newer 2x9 and 2x10 setups may be more compact. You can usually check the front derailleur and see what stock crank it was manufactured with to get an idea of the number of teeth on the outer ring it can handle.    
  • Front Derailleur to Shifters
Generally you can match the front shifter to any front derailleur. You will want to make sure your front shifter can handle the number of front chainrings you plan to run. In the past few years 2x9 and 2x10 drivetrains have added 2-speed front shifters, so if you plan to run a triple chainring crankset, just be sure your front shiftee has 3 speeds. Both Sram and Shimano front shifters use the same leverage ratio on the front shifter. If you're going from a triple crankset down to a double crankset you can use the same shifter and just have a dead speed in the outer position by adjusting in your limit screw for the outer chainring on the front derailleur.  
 

Rear Derailleur:

  • see: Frame - Frame to Rear Derailleur
  • Rear Derailleur to Chain
Rear derailleur and chain matching will come down to the number of speeds. Example: 9-speed chain to 9-speed rear derailleur. This can be fudged or mismatched sometimes with mixed results, but in general for a hassle free and noise free drivetrain we suggest keeping these two parts matched in the number of speeds. This is another area where you mismatching brands works just fine.
  • Rear Derailleur to Cassette
Matching a rear derailleur to a cassette can be a little tricky, but its not too bad. In the past generally any mountain rear derailleur could run any cassette and cassettes usually came in 11-32 or 11-34. For building a gravity bike there are few details you will want to pay attention too. The cage length will affect how wide a range and how crisp the shifting is. Shorter cages will favor closer range cassette. For example many downhillers over the last decade or so have run road derailleurs because they had shorter cages, stiffer return springs, and handle close ratio cassettes (11-26, 12-28) better. The other trend is wide range cassettes with 11-36 or 10-42 spreads. To run a wide range cassette you will want to verify from the manufacture spec that the derailleur can handle the larger range.  In general matching the number of speeds is also a good policy. Example: 10-speed rear derailleur to a 10-speed cassette.  
  • Rear Derailleur to Shifters
Matching rear derailleur to shifters is going to be about brand and leverage ratios. In general you’re going to choose either a Shimano system or Sram 1:1 actuation system. In this situation you will not be able to mismatch because the two systems use different leverage in the pull mechanism. As long as your system matches and the number of speeds matches your good to shred. In the past when Sram introduced 1:1 actuation we felt this was the superior system, but since that time Shimano has improved and we feel both dominate brands offer excellent shifting systems. We also like clutched derailleurs and 1x systems  that use narrow wide chains. The future of these parts seems to be moving towards electronic shifting, we would be excited to see a gravity oriented electronic group.

Chains:

  • see: Frame to Rear Derailleur - Front Derailleur to Chain
  • see: Frame to Rear Derailleur - Rear Derailleur to Chain
  • Chain to Cassette

When matching your chain and cassette it’s ok to mismatch brands, but you will most likely not want to mismatch speeds. Example: 9-speed chain to 9-speed cassette.  

Chainguide:

  • see: Frame - Frame to Chainguide
  • see: Crankset - Crankset to Chainguide / Bashguard

Chainrings:

  • see: Crankset - Crankset to Chainrings

Cassette:

  • see: Chains - Chain to Cassette
  • see: Wheelset - Rear Hub to Cassette
  • see: Frame to Rear Derailleur - Rear Derailleur to Cassette

Cockpit / Controls

Brakes:

  • see: Fork: Fork to Front Brake Caliper
  • see: Frame: Frame to Rear Brake Caliper
  • see: Wheelset: Hubs to Brake Rotors
  • Brakes to handlebar

All performance brakes are compatible with all performance bars. The diameter of the bar where grips, shifters, remotes, and brakes mount has not changed over the years. There has been changes to the clamp center of bars and there are a wide variety of grip solutions but the diameter of the bar on the hand interface has not changed.

Shifters:

  • see: Front Derailleur - Front Derailleur to Shifters
  • see: Rear Derailleur - Rear Derailleur to Shifters
  • Shifter to Handlebar

All performance shifters are compatible with all performance bars. The diameter of the bar where grips, shifters, remotes, and brakes mount has not changed over the years. There has been changes to the clamp center of bars and there are a wide variety of grip solutions but the diameter of the bar on the hand interface has not changed.

Handlebar:

  • Handlebar to Stem

When the mountain bike first hit mainstream popularity the diameter of the handlebar  where they were clamped by the stem was 1” or 25.4mm, since then the diameter has experienced two step ups. The most common size we see now is 31.8mm this provides for a stiffer stronger bar. There are is also several manufacturer that have begun marketing 35mm bars. The step up again is to bring to market a stronger bar and potentially safer bar. When matching your stem and handlbar it is important that the sizes match. Adpaters are sometimes available to address mismatches, but in generally we recommend matching the size. Example: 31.8mm bar to 31.8mm clamp stem.

Common sizes:
25.4mm
31.8mm
35mm
  • Handlebar to Grips

All performance grips are compatible with all performance bars. The diameter of the bar where grips, shifters, remotes, and brakes mount has not changed over the years. There has been changes to the clamp center of bars and there are a wide variety of grip solutions but the diameter of the bar on the hand interface has not changed.

  • see: Shifters - Shifter to Handlebar
  • see: Brakes - Brakes to handlebar

Stem:

  • see: Fork - Fork to Stem
  • see: Handlebar - Handlebar to Stem

Grips:

  • see: Handlebar- Handlebar to Grips

Seatpost:

  • see: Frame - Seattube to Seatpost
  • Seatpost to Saddle

Matching saddle to seatpost is fairly straightforward as almost all saddles and posts use a two rail standard. Saddles vary greatly in cost and features but generally if it has two rails it will fit a two-rail clamp seatpost. When picking out a saddle it best to find one that matches up with your body, or more specifically the sit bones of your pelvis. SQLabs is the saddle line we most excited about right now and a free fit kit is avilable threw the USA distributor Radsportusa.com

Common rail materials:
        • Cromoly
        • NiCro
        • Titanium
        • Carbon

  

Saddle:

  • see: Seatpost - Seatpost to Saddle

Headset:

  • see: Frame - Frame to Headset
  • see: Fork - Fork to Headset

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