This past winter, I decided to build a new Marauder prototype to try out a few new to me concepts. Most important of these concepts was a short stem/long top tube with a slack front end. I was curious about what effect wheelbase played when it came to handling. During that same time span, I also had planned out a 3rd Marauder prototype in Titanium. Not much in terms of change in that bike but more of a refinement in how I was building with Titanium. Both of those frames were finished up early in the spring of 2018. I wound up building the steel Marauder, which had the longer/slacker concept applied to it first and it completely turned everything I was previously working on upside down. It exceeded all of my expectations and charted an entirely new course for “how” I designed bikes. That new course I now refer to as “44WRD”. (My own take on “forward geometry”.) So much was my thirst to push the 44WRD concept, I immediately went back to the drawing board this summer on both bikes. The above Marauder Ti and the steel bike below are the results of that new direction. My overarching goal of 44WRD is to design a well-balanced mountain bike where it climbs and descends equally well and can handle everything in between those two extremes. I won’t say I’ve cracked some magical code, but I feel as though this latest pair of bikes has achieved that goal and I’m curious just how far I can push the concept moving forward. But before we get ahead of ourselves, let’s roll up our sleeves and take a closer look at what makes this pair of bikes tick!
How we talk about Bikes
First things first! Let’s talk a bit about the “how” we talk about bikes. Head tube angle. Bottom bracket drop. Seat tube angle. Chainstay length. Front center. Reach. Stack. Etc. et al and then some. Take all of that and throw it as far as you can see. We need to start talking about mountain bikes in a totally new way. All those terms are familiar but boy can it get way too far into the weeds of the nebulous. All of these factors are important. All work in harmony. But we really need to collectively look at bikes, especially mountain bikes in a simple clean fashion. The very first piece of information we need to talk about is Rake. This is the angle of the head tube from 90° perpendicular to the ground. Some who tear around on motorcycles will understand this immediately. Rake has often been confused with Fork Offset. Fork offset, or merely offset is the distance the axle is from the steerer’s centerline (i.e. a Fox 34 Float offset is 51mm). Second is Trail. Imagine that centerline of the steerer projecting down through the fork and landing on the ground somewhere out in front of you. Now drop an imaginary line perpendicular from the front axle to where the front wheel contacts the ground. The distance between these two points on the ground is Trail. The larger this number, the more stability the bike will possess. (Here’s a nice diagram). The Third factor is Wheelbase. This is the distance between front and rear axle centerlines. Like all things, there is a tipping point of diminishing returns. So how much of each of these 3 factors should a hardtail mountain bike have? How do they play off of one another? That’s what I’m after with 44WRD. This is not to say that bottom bracket drop, seat tube angle, chainstay length and say reach are not all important pieces of the puzzle. But those numbers, I think, tend to confuse the conversation when we talk about mountain bikes, geometry, and handling. Reach and Stack are important numbers for determining FIT on a production bicycle frame. Bottom Bracket Height? This should be as low as possible without making the bike a pedal basher. Seat Tube Angle? This should replicate the saddle position of a straight seat tube of 73/74°. Chainstay Length? This should be as short as it can be without negatively affecting drivetrain performance, shifting, and longevity. There is a such as being #TOOTUKT. I am of the opinion that Rake, Trail, and Wheelbase are the most informative pieces of geometry for a consumer to understand handling and that BB Drop, Chainstay length, seat tube angle are factors that the design and engineering team must have in hand in order to deliver a bike that performs for the end consumer. Like the saying goes: You’re on a need to know basis and you don’t need to know. Bottom bracket height, Reach and Stack all tell the consumer about clearance and fit for any given production bike. Suspension, tire choice and tire pressure also play a large role in overall performance of a bicycle and are far more informative to the consumer than some of these additional numbers that get thrown around. So from here on forward, this is how I will be talking about bicycles. Push on the pedals, the bike stays hooked up to the trail.
Geometry Changes
So what did I change? First was Rake: 23°. Note that I’m doing this incrementally. Mountain bikes are a game of small changes with big results. Every degree and every millimeter count and can radically change how the bike handles and performs. So I want to approach this methodically and understand how much is too much or how much is “just so”. Both bikes differ only in wheel size. The Steel Marauder was built around 27.5 x 2.8″ wheels while the Ti Marauder was built around 29 x 2.4″ wheels. Both are relatively the same overall diameter with about a .25″ difference in BB Drop. Increasing the Rake also increased my Trail number which came out to about 100mm / 3.94″. Remember, more trail equals more stability. So I’ve slackened the front end and stretched out that front center when I shortened the stem/lengthened the top tube. This has a dramatic effect on that third factor: Wheelbase. It’s 1220mm / ~48″. That’s quite long for a hardtail some may say. My biggest concern was: Does this increase in wheelbase slow down handling? Quite the contrary. Not only did I find that both bikes remained quick and nimble but it was incredible just how much stability both bikes gained. At speed downhill, these bikes really can be pushed. Through tech, they hold their line. Make a mistake? The longer wheelbase “wants” to stand up and seek a straight line with a little input from the rider. Through tech, at speed, the bike is not bouncing around due to the longer wheelbase. All this means more confidence and sure-footed feel out on the trail.
FIT
Keep in mind that I’m building these bikes for myself so Reach/Stack are custom. I use a different set of numbers when fitting a bike: Cockpit (center of handlebars to saddle tip), Saddle tip to center of saddle/seat post connection, and saddle height (center of bottom bracket to center top of saddle). Those 3 numbers triangulate a rider on the bike and help to establish that cockpit number which is crucial to know if I want to design around a very specific length stem. In this case, I wanted to run 35mm stems and my cockpit length is 21.75″. Top tube length is determined from these factors as is seat tube angle. I know I want a bottom bracket height of about 12-12.25″ (which I’ve long found to be that sweet spot of low without being a pedal basher). Like I said above, chainstay length should be short without affecting drivetrain performance and to achieve that, I’ve come to use radius seat tubes (made in-house). The consequence of using these types of seat tubes is it naturally kicks the rider forward by quite a large margin. I replicate a seat tube angle that places the saddle in the same position as if the seat tube were straight and somewhere around 73/74°. And I’ve long held I had the rear end of the bike pretty well figured out and hence why most of my tweaks and subsequent focus has been on the front of the bike.
Fit wise, I try and build the rider down and in the bike keeping the rider’s center of gravity low (this quickens handling) and centered between the wheels so the weight is fairly balanced. Handlebars and saddle are nearly level and I really think this sets the bike up to be well balanced. Using that radius seat tube literally moves the rider forward in space. So stretching out that front end really helped to further balance the weight between the wheels. When I’m charting a course for fit and geometry, these are parameters which help guide my decisions. Slackening the front end also drops the head tube in space. This enabled me to up my travel from 120mm to 130mm (I think even going to 24-25° of rake and I could run 140mm of travel which I previously thought was unheard of for a 29″ hardtail at my size, but we’ll save that for another bike or two!).
If the shoe fits… Performance follows
Rake set to 23°, Trail coming in at 100mm, wheelbase stretched to a cool 1220mm, and fit dialed, the bike really can be an extension of the rider. I’ve really been impressed with just how much performance gains have been achieved when the trail heads down. You really can push through turns hard. Leaning the bike and getting LOW are crucial. And that’s something I remind myself every time I go down: GET LOW! Climbing wise, I can sit comfortably and use traditional techniques as the trail steepens to keep the front wheel planted without the bike feeling unruly. Bend at the hips/waist, flatten the lower back, bend your elbows and lastly, sneak up to the nose of the saddle for really steep seated climbs. Approach the summit and get out of the saddle for that last bit of push without getting gassed. The front wheel stays planted and the rear wheel stays hooked up.
Big differences in the builds other than material and wheel sizes are, of course, one is initially built as a geared 1×11 and the other is a singlespeed. Both can be run as either setup and I’ll be building the Ti Marauder up with gears shortly to compare both bikes back to back on the same stretch of trail just for the heck of it. More on that comparison at a later date. 29″ wheels really want to go the distance where I feel 27.5 has this uncanny similarity to 26″ wheels where you can really manhandle them up and over objects. Both are nimble, roll fast and soak up that chatter but they do have subtle differences.
The Devil is in the Details
I’ve been finding myself using that dropper 100% of the ride. I’ll take a wild guess that it’s slammed about 98% of the time. Even on flats. I tent to ride “in the stirrups” and find I’m a bit more ready to move/tackle tech this way vs being seated. I also bumped from using a 125mm dropper to a 150mm dropper and as I’ve stated before, was quite surprised by just how useful that extra 25mm of drop can be out on the trail. For the steel rig it’s an internally routed 9point8 which I refined to enter/exit the down tube and wrap around the bottom bracket (T47):
The Ti Marauder uses an 83mm bb shell width while the steel Marauder uses a 73mm x T47 bb shell. This later set up allows me to use a “normal” tread Race Face Cinch crank with the ring flipped to achieve proper chain line while the 83mm bb shell uses Race Faces slightly shorter 143mm spindle which is about 10mm longer than the stock spindle. This makes room for the increased volume of those Ti .875″ chainstays.
Both bikes sport a 157mm TA rear:
Why? Because this allows me to make room for larger volume tires on a wider internal width rim while maintaining good chain line. And a custom Industry 9 Singlespeed hub gets the job done (170mm stock hub shell using a custom set of axle end caps to shift the hub into position with their SS cassette driver body). And yes, heel clearance is excellent as the crank’s tread isn’t extremely narrow both in the case of the Turbine or NEXT R’s case. Looking down through the frame while seated, my heel has over an inch of clearance between heel and dropout/rear derailleur.
Cockpit wise both bikes are sporting a Paul Boxcar 35mm stem. I’ve really been impressed with these Boxcar stems. Light, really well machined and easy to set up. I also really like how quick the handling is of a 35mm stem when you build around that specific length. It really throws that front wheel well out in front of the rider. Climbing, I was concerned about the lack of knee room. Again, off-trail concern never really amounted to real trail troubles. The longer front center plays well when climbing either seated or for out of the saddle hard efforts. And again, I’ve been even running my saddle fully dropped on long extended out of the saddle efforts. If I have to shift weight backward to pedal up and over an object, it’s out of the way automatically and frees up a lot of room to move.
One additional signature design element are my “straight edge” chainstays. What I do is add an ovalized section to the center of the chainstay to increase lateral stiffness and power transfer. So on a .75″ round steel tube, it tapers out to a .875″ tube at a crucial spot in the stay. Up above is the Titanium version. A .875″ O.D. tube tapers out to a 1″ O.D. ovalized tube. So I’ve been able to have the weight of a .875″ chainstay with the stiffness of a 1″ O.D. tube at the critical spot in the stay. Jump on the pedals and power is transferred immediately to the rear wheel. The bike goes forward. Fast. Both bikes also use .625″ O.D. seat stays which I think delivers a nice subtle resiliency (especially in the Ti Marauder). Top and Seat tubes of both bikes are 1.375″ O.D.’s. I used a 1.5″ O.D. down tube for the steel Marauder but changed the Ti Marauder’s down tube to a 1.625″ O.D. Tube. The jury is still out on overall stiffness but I will say the frame is notably lighter than it’s previous iteration with a 1.75″ O.D. down tube.
In summary, I could not be happier. There was a mad dash in August to rebuild both of these bikes to get new ideas off of the drawing board and back out on the trail to test. Stretching the front center of both bikes, lowering the front end and slackening Rake really had a positive effect on just how hard I found I can push the bike downhill and through tech. The stability gains were notable. But lengthening the wheelbase and slackening the front end did not slow the bike down handling wise. Keeping the bottom bracket relatively low, maintaining a short chainstay length and making sure to keep the rider’s weight centered and built IN the bike helped to keep the bike quick, nimble and maintained it’s ability to climb. I have the rest of the summer and well into the fall until the snow comes to keep testing this pair of bikes before I sit down for the long winter and re-evaluate what needs to be tweaked. So far like I said, I am incredibly impressed and have been completely floored by this new direction. I’ve always been excited to head out for a ride but it seems the rides have gotten more fun and more aggressive as of late. If you’re headed to the New England Builders’ Ball or the Philly Bike Expo, both of these bikes will be there. If you do come, please swing by the 44 Bikes booth and introduce yourself! I’d be really stoked to walk you through both bikes and share what sets them apart. But till then, there’s still a lot of riding to be done so till next time, keep pedaling!
Fruits of Labor
This past winter, I decided to build a new Marauder prototype to try out a few new to me concepts. Most important of these concepts was a short stem/long top tube with a slack front end. I was curious about what effect wheelbase played when it came to handling. During that same time span, I also had planned out a 3rd Marauder prototype in Titanium. Not much in terms of change in that bike but more of a refinement in how I was building with Titanium. Both of those frames were finished up early in the spring of 2018. I wound up building the steel Marauder, which had the longer/slacker concept applied to it first and it completely turned everything I was previously working on upside down. It exceeded all of my expectations and charted an entirely new course for “how” I designed bikes. That new course I now refer to as “44WRD”. (My own take on “forward geometry”.) So much was my thirst to push the 44WRD concept, I immediately went back to the drawing board this summer on both bikes. The above Marauder Ti and the steel bike below are the results of that new direction. My overarching goal of 44WRD is to design a well-balanced mountain bike where it climbs and descends equally well and can handle everything in between those two extremes. I won’t say I’ve cracked some magical code, but I feel as though this latest pair of bikes has achieved that goal and I’m curious just how far I can push the concept moving forward. But before we get ahead of ourselves, let’s roll up our sleeves and take a closer look at what makes this pair of bikes tick!
How we talk about Bikes
First things first! Let’s talk a bit about the “how” we talk about bikes. Head tube angle. Bottom bracket drop. Seat tube angle. Chainstay length. Front center. Reach. Stack. Etc. et al and then some. Take all of that and throw it as far as you can see. We need to start talking about mountain bikes in a totally new way. All those terms are familiar but boy can it get way too far into the weeds of the nebulous. All of these factors are important. All work in harmony. But we really need to collectively look at bikes, especially mountain bikes in a simple clean fashion. The very first piece of information we need to talk about is Rake. This is the angle of the head tube from 90° perpendicular to the ground. Some who tear around on motorcycles will understand this immediately. Rake has often been confused with Fork Offset. Fork offset, or merely offset is the distance the axle is from the steerer’s centerline (i.e. a Fox 34 Float offset is 51mm). Second is Trail. Imagine that centerline of the steerer projecting down through the fork and landing on the ground somewhere out in front of you. Now drop an imaginary line perpendicular from the front axle to where the front wheel contacts the ground. The distance between these two points on the ground is Trail. The larger this number, the more stability the bike will possess. (Here’s a nice diagram). The Third factor is Wheelbase. This is the distance between front and rear axle centerlines. Like all things, there is a tipping point of diminishing returns. So how much of each of these 3 factors should a hardtail mountain bike have? How do they play off of one another? That’s what I’m after with 44WRD. This is not to say that bottom bracket drop, seat tube angle, chainstay length and say reach are not all important pieces of the puzzle. But those numbers, I think, tend to confuse the conversation when we talk about mountain bikes, geometry, and handling. Reach and Stack are important numbers for determining FIT on a production bicycle frame. Bottom Bracket Height? This should be as low as possible without making the bike a pedal basher. Seat Tube Angle? This should replicate the saddle position of a straight seat tube of 73/74°. Chainstay Length? This should be as short as it can be without negatively affecting drivetrain performance, shifting, and longevity. There is a such as being #TOOTUKT. I am of the opinion that Rake, Trail, and Wheelbase are the most informative pieces of geometry for a consumer to understand handling and that BB Drop, Chainstay length, seat tube angle are factors that the design and engineering team must have in hand in order to deliver a bike that performs for the end consumer. Like the saying goes: You’re on a need to know basis and you don’t need to know. Bottom bracket height, Reach and Stack all tell the consumer about clearance and fit for any given production bike. Suspension, tire choice and tire pressure also play a large role in overall performance of a bicycle and are far more informative to the consumer than some of these additional numbers that get thrown around. So from here on forward, this is how I will be talking about bicycles. Push on the pedals, the bike stays hooked up to the trail.
Geometry Changes
So what did I change? First was Rake: 23°. Note that I’m doing this incrementally. Mountain bikes are a game of small changes with big results. Every degree and every millimeter count and can radically change how the bike handles and performs. So I want to approach this methodically and understand how much is too much or how much is “just so”. Both bikes differ only in wheel size. The Steel Marauder was built around 27.5 x 2.8″ wheels while the Ti Marauder was built around 29 x 2.4″ wheels. Both are relatively the same overall diameter with about a .25″ difference in BB Drop. Increasing the Rake also increased my Trail number which came out to about 100mm / 3.94″. Remember, more trail equals more stability. So I’ve slackened the front end and stretched out that front center when I shortened the stem/lengthened the top tube. This has a dramatic effect on that third factor: Wheelbase. It’s 1220mm / ~48″. That’s quite long for a hardtail some may say. My biggest concern was: Does this increase in wheelbase slow down handling? Quite the contrary. Not only did I find that both bikes remained quick and nimble but it was incredible just how much stability both bikes gained. At speed downhill, these bikes really can be pushed. Through tech, they hold their line. Make a mistake? The longer wheelbase “wants” to stand up and seek a straight line with a little input from the rider. Through tech, at speed, the bike is not bouncing around due to the longer wheelbase. All this means more confidence and sure-footed feel out on the trail.
FIT
Keep in mind that I’m building these bikes for myself so Reach/Stack are custom. I use a different set of numbers when fitting a bike: Cockpit (center of handlebars to saddle tip), Saddle tip to center of saddle/seat post connection, and saddle height (center of bottom bracket to center top of saddle). Those 3 numbers triangulate a rider on the bike and help to establish that cockpit number which is crucial to know if I want to design around a very specific length stem. In this case, I wanted to run 35mm stems and my cockpit length is 21.75″. Top tube length is determined from these factors as is seat tube angle. I know I want a bottom bracket height of about 12-12.25″ (which I’ve long found to be that sweet spot of low without being a pedal basher). Like I said above, chainstay length should be short without affecting drivetrain performance and to achieve that, I’ve come to use radius seat tubes (made in-house). The consequence of using these types of seat tubes is it naturally kicks the rider forward by quite a large margin. I replicate a seat tube angle that places the saddle in the same position as if the seat tube were straight and somewhere around 73/74°. And I’ve long held I had the rear end of the bike pretty well figured out and hence why most of my tweaks and subsequent focus has been on the front of the bike.
Fit wise, I try and build the rider down and in the bike keeping the rider’s center of gravity low (this quickens handling) and centered between the wheels so the weight is fairly balanced. Handlebars and saddle are nearly level and I really think this sets the bike up to be well balanced. Using that radius seat tube literally moves the rider forward in space. So stretching out that front end really helped to further balance the weight between the wheels. When I’m charting a course for fit and geometry, these are parameters which help guide my decisions. Slackening the front end also drops the head tube in space. This enabled me to up my travel from 120mm to 130mm (I think even going to 24-25° of rake and I could run 140mm of travel which I previously thought was unheard of for a 29″ hardtail at my size, but we’ll save that for another bike or two!).
If the shoe fits… Performance follows
Rake set to 23°, Trail coming in at 100mm, wheelbase stretched to a cool 1220mm, and fit dialed, the bike really can be an extension of the rider. I’ve really been impressed with just how much performance gains have been achieved when the trail heads down. You really can push through turns hard. Leaning the bike and getting LOW are crucial. And that’s something I remind myself every time I go down: GET LOW! Climbing wise, I can sit comfortably and use traditional techniques as the trail steepens to keep the front wheel planted without the bike feeling unruly. Bend at the hips/waist, flatten the lower back, bend your elbows and lastly, sneak up to the nose of the saddle for really steep seated climbs. Approach the summit and get out of the saddle for that last bit of push without getting gassed. The front wheel stays planted and the rear wheel stays hooked up.
Big differences in the builds other than material and wheel sizes are, of course, one is initially built as a geared 1×11 and the other is a singlespeed. Both can be run as either setup and I’ll be building the Ti Marauder up with gears shortly to compare both bikes back to back on the same stretch of trail just for the heck of it. More on that comparison at a later date. 29″ wheels really want to go the distance where I feel 27.5 has this uncanny similarity to 26″ wheels where you can really manhandle them up and over objects. Both are nimble, roll fast and soak up that chatter but they do have subtle differences.
The Devil is in the Details
I’ve been finding myself using that dropper 100% of the ride. I’ll take a wild guess that it’s slammed about 98% of the time. Even on flats. I tent to ride “in the stirrups” and find I’m a bit more ready to move/tackle tech this way vs being seated. I also bumped from using a 125mm dropper to a 150mm dropper and as I’ve stated before, was quite surprised by just how useful that extra 25mm of drop can be out on the trail. For the steel rig it’s an internally routed 9point8 which I refined to enter/exit the down tube and wrap around the bottom bracket (T47):
The Ti Marauder uses an 83mm bb shell width while the steel Marauder uses a 73mm x T47 bb shell. This later set up allows me to use a “normal” tread Race Face Cinch crank with the ring flipped to achieve proper chain line while the 83mm bb shell uses Race Faces slightly shorter 143mm spindle which is about 10mm longer than the stock spindle. This makes room for the increased volume of those Ti .875″ chainstays.
Both bikes sport a 157mm TA rear:
Why? Because this allows me to make room for larger volume tires on a wider internal width rim while maintaining good chain line. And a custom Industry 9 Singlespeed hub gets the job done (170mm stock hub shell using a custom set of axle end caps to shift the hub into position with their SS cassette driver body). And yes, heel clearance is excellent as the crank’s tread isn’t extremely narrow both in the case of the Turbine or NEXT R’s case. Looking down through the frame while seated, my heel has over an inch of clearance between heel and dropout/rear derailleur.
Cockpit wise both bikes are sporting a Paul Boxcar 35mm stem. I’ve really been impressed with these Boxcar stems. Light, really well machined and easy to set up. I also really like how quick the handling is of a 35mm stem when you build around that specific length. It really throws that front wheel well out in front of the rider. Climbing, I was concerned about the lack of knee room. Again, off-trail concern never really amounted to real trail troubles. The longer front center plays well when climbing either seated or for out of the saddle hard efforts. And again, I’ve been even running my saddle fully dropped on long extended out of the saddle efforts. If I have to shift weight backward to pedal up and over an object, it’s out of the way automatically and frees up a lot of room to move.
One additional signature design element are my “straight edge” chainstays. What I do is add an ovalized section to the center of the chainstay to increase lateral stiffness and power transfer. So on a .75″ round steel tube, it tapers out to a .875″ tube at a crucial spot in the stay. Up above is the Titanium version. A .875″ O.D. tube tapers out to a 1″ O.D. ovalized tube. So I’ve been able to have the weight of a .875″ chainstay with the stiffness of a 1″ O.D. tube at the critical spot in the stay. Jump on the pedals and power is transferred immediately to the rear wheel. The bike goes forward. Fast. Both bikes also use .625″ O.D. seat stays which I think delivers a nice subtle resiliency (especially in the Ti Marauder). Top and Seat tubes of both bikes are 1.375″ O.D.’s. I used a 1.5″ O.D. down tube for the steel Marauder but changed the Ti Marauder’s down tube to a 1.625″ O.D. Tube. The jury is still out on overall stiffness but I will say the frame is notably lighter than it’s previous iteration with a 1.75″ O.D. down tube.
In summary, I could not be happier. There was a mad dash in August to rebuild both of these bikes to get new ideas off of the drawing board and back out on the trail to test. Stretching the front center of both bikes, lowering the front end and slackening Rake really had a positive effect on just how hard I found I can push the bike downhill and through tech. The stability gains were notable. But lengthening the wheelbase and slackening the front end did not slow the bike down handling wise. Keeping the bottom bracket relatively low, maintaining a short chainstay length and making sure to keep the rider’s weight centered and built IN the bike helped to keep the bike quick, nimble and maintained it’s ability to climb. I have the rest of the summer and well into the fall until the snow comes to keep testing this pair of bikes before I sit down for the long winter and re-evaluate what needs to be tweaked. So far like I said, I am incredibly impressed and have been completely floored by this new direction. I’ve always been excited to head out for a ride but it seems the rides have gotten more fun and more aggressive as of late. If you’re headed to the New England Builders’ Ball or the Philly Bike Expo, both of these bikes will be there. If you do come, please swing by the 44 Bikes booth and introduce yourself! I’d be really stoked to walk you through both bikes and share what sets them apart. But till then, there’s still a lot of riding to be done so till next time, keep pedaling!