I'm looking to start a discussion on frame design! I'm currently a mechanical engineering student who wants to design bikes for their career. Looking to have a space to bounce ideas and collaborate!
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking about picking up linkage to start using that.
Great idea for a forum thread Sir! I'll be around to see what goes on, but I don't have much to contribute as I like single pivots and I just use good old full sized paper drawings.
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing.
The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location.
The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs is narrowing.
My past builds.
2014 first fully, classic single pivot
2018 same design at the time as Nukeproof DH bike, now used on their Giga
2019 pull link. I pulled this design from Ancillotti, seems that Specialized likes this to and using it on the proto DH.
2022 another linkage driven single pivot, this little scissor link is a copy of one that Xprezo used on the AdHoc but I moved things around to get the LR I wanted.
Not shown....the countless number of designs worked out in Linkage to get numbers I liked but didn't build. I'll dig some of them up later.
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the...
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing.
The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location.
The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs is narrowing.
My past builds.
2014 first fully, classic single pivot
2018 same design at the time as Nukeproof DH bike, now used on their Giga
2019 pull link. I pulled this design from Ancillotti, seems that Specialized likes this to and using it on the proto DH.
2022 another linkage driven single pivot, this little scissor link is a copy of one that Xprezo used on the AdHoc but I moved things around to get the LR I wanted.
Not shown....the countless number of designs worked out in Linkage to get numbers I liked but didn't build. I'll dig some of them up later.
Those bikes look awesome, did you do the welding yourself or did you out source it?
Those bikes look awesome, did you do the welding yourself or did you out source it?
All fabrication done by myself in the garage. I have small benchtop mill, benchtop lathe, and an oxy-propane brazing set up. Jig is also garage made out of cold rolled steel a design copied from a number of Colorado builders that use a similar design.
The first single pivot frame was build with hand files, hacksaw and a vise. No jig and no machines, just a couple of pieces of cheap aluminum angle to float the rear axle in space relative to the front end. A full size paper drawing was done to figure it all out.
All fabrication done by myself in the garage. I have small benchtop mill, benchtop lathe, and an oxy-propane brazing set up. Jig is also garage made...
All fabrication done by myself in the garage. I have small benchtop mill, benchtop lathe, and an oxy-propane brazing set up. Jig is also garage made out of cold rolled steel a design copied from a number of Colorado builders that use a similar design.
The first single pivot frame was build with hand files, hacksaw and a vise. No jig and no machines, just a couple of pieces of cheap aluminum angle to float the rear axle in space relative to the front end. A full size paper drawing was done to figure it all out.
You get a like for full sized paper design. Oh, and some cool bikes!
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking...
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking about picking up linkage to start using that.
From pictures I have seen it looks like solidworks is the most common. Solidworks would definitely be my choice, but I am biased since I use it every day and have years invested in it. I have tried others, but none of them compare for me.
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking...
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking about picking up linkage to start using that.
I think Creo/ProE is used by lots of the big boys (and Asia) due it's powerful surfacing functionality. To make those carbon frames purdy. But it is absurdly expensive, last time I checked it was something like $15-20k a seat, with $3-$4k a year renewal cost. Solid Works is less expensive, but not by much.
A really good basic CAD/CAM package is Fusion 360. You can get it monthly for like $70, they even have a free 30 day trial, and have tons of on-line tutorials to help learn it.
I had never used Fusion before (but do have 15 years of ProE experience); I modeled parts and cut them on a pretty complicated dual spindle live tooling lathe within a week.
Linkage Design + Fusion 360 and you can have your own Frameworks!
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot this way. Kind of like it’s good to learn calculus before just using calculators to solve calc equations. It probably sounds more daunting than it is, but leverage ratio is just the derivative of y axle position so you can solve for axle position as a function of shock stroke and whatever other dimensions you might be playing with and then you’ve got everything. Once the equations are there it is way way faster to iterate than linkage. I like mathematica just because I got quite familiar with it when I was a student.
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot...
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot this way. Kind of like it’s good to learn calculus before just using calculators to solve calc equations. It probably sounds more daunting than it is, but leverage ratio is just the derivative of y axle position so you can solve for axle position as a function of shock stroke and whatever other dimensions you might be playing with and then you’ve got everything. Once the equations are there it is way way faster to iterate than linkage. I like mathematica just because I got quite familiar with it when I was a student.
I am super down to learn how to do it manually, I want to understand what I am doing when I design bikes and how to manipulate the linkages to get what I want out of the bike.
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot...
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot this way. Kind of like it’s good to learn calculus before just using calculators to solve calc equations. It probably sounds more daunting than it is, but leverage ratio is just the derivative of y axle position so you can solve for axle position as a function of shock stroke and whatever other dimensions you might be playing with and then you’ve got everything. Once the equations are there it is way way faster to iterate than linkage. I like mathematica just because I got quite familiar with it when I was a student.
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the base math skills needed to do it. Same with anti rise and anti squat.
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the...
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing.
The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location.
The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs is narrowing.
My past builds.
2014 first fully, classic single pivot
2018 same design at the time as Nukeproof DH bike, now used on their Giga
2019 pull link. I pulled this design from Ancillotti, seems that Specialized likes this to and using it on the proto DH.
2022 another linkage driven single pivot, this little scissor link is a copy of one that Xprezo used on the AdHoc but I moved things around to get the LR I wanted.
Not shown....the countless number of designs worked out in Linkage to get numbers I liked but didn't build. I'll dig some of them up later.
I agree with your observations. Here's my latest creation. split High pivot pinion gearbox downduro bike. 210mm travel for 75mm stroke. around 120% anti-squat, 90% anti-rise, 25% progression. Next design will have a motor in it as I feel this analog one outside of small design details, is about perfect for my use with the current available components.
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the...
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing.
The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location.
The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs is narrowing.
My past builds.
2014 first fully, classic single pivot
2018 same design at the time as Nukeproof DH bike, now used on their Giga
2019 pull link. I pulled this design from Ancillotti, seems that Specialized likes this to and using it on the proto DH.
2022 another linkage driven single pivot, this little scissor link is a copy of one that Xprezo used on the AdHoc but I moved things around to get the LR I wanted.
Not shown....the countless number of designs worked out in Linkage to get numbers I liked but didn't build. I'll dig some of them up later.
I agree with your observations. Here's my latest creation. split High pivot pinion gearbox downduro bike. 210mm travel for 75mm stroke. around 120% anti-squat, 90%...
I agree with your observations. Here's my latest creation. split High pivot pinion gearbox downduro bike. 210mm travel for 75mm stroke. around 120% anti-squat, 90% anti-rise, 25% progression. Next design will have a motor in it as I feel this analog one outside of small design details, is about perfect for my use with the current available components.
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot...
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot this way. Kind of like it’s good to learn calculus before just using calculators to solve calc equations. It probably sounds more daunting than it is, but leverage ratio is just the derivative of y axle position so you can solve for axle position as a function of shock stroke and whatever other dimensions you might be playing with and then you’ve got everything. Once the equations are there it is way way faster to iterate than linkage. I like mathematica just because I got quite familiar with it when I was a student.
How would you go about this when you have no fixed points on a clean sheet build?
The number of variables seems like it would take much longer thorough out an idea. With Linkage you can quickly moch something up and see what your general kinematics would look like and decide if it's worth more time.
How would you go about this when you have no fixed points on a clean sheet build?
The number of variables seems like it would take...
How would you go about this when you have no fixed points on a clean sheet build?
The number of variables seems like it would take much longer thorough out an idea. With Linkage you can quickly moch something up and see what your general kinematics would look like and decide if it's worth more time.
The math really isn’t that bad. You just keep everything as a variable and you can change it to your heart’s content. It’s just linkage one position as a function of shock position then linkage two position as a function of linkage one position and so on. Plus at the end of the day there really are only so many different layouts. For example the math for a DW link bike and a Horst link bike happen to be exactly the same with the main thing that differentiates them being the length of the lower link. In the case of Horst link it’s the entire chain stay.
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the...
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the base math skills needed to do it. Same with anti rise and anti squat.
It’s actually really basic stuff just tedious. As the post above said, you just work back from the shock. Anti rise and anti squat are kind of funny ones. I’m not a fan of the whole lines traced through points from points thing. It feels kind of detached and more mysterious than it should be. Anti rise, for example, is driven by chain growth rate and horizontal axle movement. That’s how high pivots can get away with very little chain growth. The more rearward your axle path is the more the suspension tries to stand up when you pedal. Anti rise is driven by instant center of the member with the brake on it as well as horizontal axle path again. Horizontal axle path is in there because deceleration tried to drag the wheel to the most rearward point in its path. So I actually have my own way of looking at anti rise and anti squat and anti rise that I find much more tangible.
Popping in to add that Redburn Design (a British firm who have worked with Orange and Privateer) have a very helpful series of tutorial videos on frame design using OnShape, which in my experience is a little simpler and easier to work with than Fusion 360. I'm currently in the middle of trying to design a frame in Fusion for an industrial design project based on a linkage I came up with over the summer.
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking...
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking about picking up linkage to start using that.
I’ve used solidworks for designing bikes for a few years, it works really well and has everything you need to make steel/alloy bikes. The surfacing is a little tricky if your thinking carbon hence all the mentions of creo and onshape. You can also get a solidworks connected license for $12 a month.
If you’re wanting to use frame building to get a job in the bike industry- document the process a little bit.
Start with a problem, timeline, budget etc that you want to solve- Ie design an enduro bike with features x, y and z, done in 1 year costing $1000 or less. Something unique that is not available already always helps.
You want to not only show a company your capable of designing and building a frame but also planning ahead, some project management skill etc.
I did similar 15 years ago and it definitely helps get you noticed. Also make a weird bike. More fun.
Thanks… had a lot of fun and good learning doing them.
going to buy a welder again someday. Would like to make something trying to use an alfine hub wheel. Bb pivot full suspension with a gear hub seems like a cool bike for some reason. Run a tiny chainring / micro drive
Super clean looking and silent. with all the downsides of a super heavy hub and terrible pivot location
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the...
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the base math skills needed to do it. Same with anti rise and anti squat.
It’s actually really basic stuff just tedious. As the post above said, you just work back from the shock. Anti rise and anti squat are kind...
It’s actually really basic stuff just tedious. As the post above said, you just work back from the shock. Anti rise and anti squat are kind of funny ones. I’m not a fan of the whole lines traced through points from points thing. It feels kind of detached and more mysterious than it should be. Anti rise, for example, is driven by chain growth rate and horizontal axle movement. That’s how high pivots can get away with very little chain growth. The more rearward your axle path is the more the suspension tries to stand up when you pedal. Anti rise is driven by instant center of the member with the brake on it as well as horizontal axle path again. Horizontal axle path is in there because deceleration tried to drag the wheel to the most rearward point in its path. So I actually have my own way of looking at anti rise and anti squat and anti rise that I find much more tangible.
"Anti rise, for example, is driven by chain growth rate and horizontal axle movement. " Do you mean antisquat here?
Isn't Creo really bad when it comes to surfacing? As far as I understand it, carmakers use Creo for physical parts (suspension, driveline & similar) and Catia for the bodywork (and everything that attaches directly to it) because of the surfacing and sheetmetal capabilities. Likewise for shipbuilding and aeronautics.
As for Linkage, does it allow you to make a suspension design without having the shock tied into it? So to only throw around the pivot points and define a desired travel number and to see the antisquat and antirise values. And deal with driving the shock later.
What Software do people use when designing frames? I've used solid works and Autocad before, but I am no expert in them and I am thinking about picking up linkage to start using that.
Great idea for a forum thread Sir! I'll be around to see what goes on, but I don't have much to contribute as I like single pivots and I just use good old full sized paper drawings.
First rule of frame design, ignore marketing crap. Compare a whole bunch of different designs in Linkage and realize that everyone is slowly converging on the same thing.
The window of preferred anti-squat and leverage ratios is narrowing in on roughly 100% anti-squat at sag and a LR of 20-25% linear progression starting around 2.8 to 3.0. Anti-rise seems to still be down to designer tastes or a compromise of the chosen linkage platform / shock location.
The more time you spend in Linkage the more you realize everything has already been done...and thus why the window of optimized designs is narrowing.
My past builds.
2014 first fully, classic single pivot
2018 same design at the time as Nukeproof DH bike, now used on their Giga
2019 pull link. I pulled this design from Ancillotti, seems that Specialized likes this to and using it on the proto DH.
2022 another linkage driven single pivot, this little scissor link is a copy of one that Xprezo used on the AdHoc but I moved things around to get the LR I wanted.
Not shown....the countless number of designs worked out in Linkage to get numbers I liked but didn't build. I'll dig some of them up later.
Those bikes look awesome, did you do the welding yourself or did you out source it?
All fabrication done by myself in the garage. I have small benchtop mill, benchtop lathe, and an oxy-propane brazing set up. Jig is also garage made out of cold rolled steel a design copied from a number of Colorado builders that use a similar design.
The first single pivot frame was build with hand files, hacksaw and a vise. No jig and no machines, just a couple of pieces of cheap aluminum angle to float the rear axle in space relative to the front end. A full size paper drawing was done to figure it all out.
You get a like for full sized paper design. Oh, and some cool bikes!
For the record. Here are my homemade bikes.
https://dirtmountainbike.com/bike-reviews/homemade-bikes-big-bird
I know a few bike engineers that use Creo.
From pictures I have seen it looks like solidworks is the most common. Solidworks would definitely be my choice, but I am biased since I use it every day and have years invested in it. I have tried others, but none of them compare for me.
I think Creo/ProE is used by lots of the big boys (and Asia) due it's powerful surfacing functionality. To make those carbon frames purdy. But it is absurdly expensive, last time I checked it was something like $15-20k a seat, with $3-$4k a year renewal cost. Solid Works is less expensive, but not by much.
A really good basic CAD/CAM package is Fusion 360. You can get it monthly for like $70, they even have a free 30 day trial, and have tons of on-line tutorials to help learn it.
I had never used Fusion before (but do have 15 years of ProE experience); I modeled parts and cut them on a pretty complicated dual spindle live tooling lathe within a week.
Linkage Design + Fusion 360 and you can have your own Frameworks!
Fusion has free options for students and personal non commercial use.
On the contrary, if you’ve got the time and patience I would highly recommend doing the math instead of using linkage. You will learn a lot this way. Kind of like it’s good to learn calculus before just using calculators to solve calc equations. It probably sounds more daunting than it is, but leverage ratio is just the derivative of y axle position so you can solve for axle position as a function of shock stroke and whatever other dimensions you might be playing with and then you’ve got everything. Once the equations are there it is way way faster to iterate than linkage. I like mathematica just because I got quite familiar with it when I was a student.
I am super down to learn how to do it manually, I want to understand what I am doing when I design bikes and how to manipulate the linkages to get what I want out of the bike.
What are some good resources to learn the math needed to calculate those values? I'm currently taking Calculus 2 in college, so I should have the base math skills needed to do it. Same with anti rise and anti squat.
I agree with your observations. Here's my latest creation. split High pivot pinion gearbox downduro bike. 210mm travel for 75mm stroke. around 120% anti-squat, 90% anti-rise, 25% progression. Next design will have a motor in it as I feel this analog one outside of small design details, is about perfect for my use with the current available components.
That thing looks fun, nice work!
How would you go about this when you have no fixed points on a clean sheet build?
The number of variables seems like it would take much longer thorough out an idea. With Linkage you can quickly moch something up and see what your general kinematics would look like and decide if it's worth more time.
The math really isn’t that bad. You just keep everything as a variable and you can change it to your heart’s content. It’s just linkage one position as a function of shock position then linkage two position as a function of linkage one position and so on. Plus at the end of the day there really are only so many different layouts. For example the math for a DW link bike and a Horst link bike happen to be exactly the same with the main thing that differentiates them being the length of the lower link. In the case of Horst link it’s the entire chain stay.
It’s actually really basic stuff just tedious. As the post above said, you just work back from the shock. Anti rise and anti squat are kind of funny ones. I’m not a fan of the whole lines traced through points from points thing. It feels kind of detached and more mysterious than it should be. Anti rise, for example, is driven by chain growth rate and horizontal axle movement. That’s how high pivots can get away with very little chain growth. The more rearward your axle path is the more the suspension tries to stand up when you pedal. Anti rise is driven by instant center of the member with the brake on it as well as horizontal axle path again. Horizontal axle path is in there because deceleration tried to drag the wheel to the most rearward point in its path. So I actually have my own way of looking at anti rise and anti squat and anti rise that I find much more tangible.
Are you one of those guys who long-hands 200 lines of G-Code?
Screw that. The only g code I manually write regularly is g53 y0 because it’s quicker to get the table to the door that way than it is to handle jog.
Popping in to add that Redburn Design (a British firm who have worked with Orange and Privateer) have a very helpful series of tutorial videos on frame design using OnShape, which in my experience is a little simpler and easier to work with than Fusion 360. I'm currently in the middle of trying to design a frame in Fusion for an industrial design project based on a linkage I came up with over the summer.
I’ve used solidworks for designing bikes for a few years, it works really well and has everything you need to make steel/alloy bikes. The surfacing is a little tricky if your thinking carbon hence all the mentions of creo and onshape. You can also get a solidworks connected license for $12 a month.
If you’re wanting to use frame building to get a job in the bike industry- document the process a little bit.
Start with a problem, timeline, budget etc that you want to solve- Ie design an enduro bike with features x, y and z, done in 1 year costing $1000 or less. Something unique that is not available already always helps.
You want to not only show a company your capable of designing and building a frame but also planning ahead, some project management skill etc.
I did similar 15 years ago and it definitely helps get you noticed. Also make a weird bike. More fun.
^loved your frankenbuilds. lots of fun ideas going on.
Thanks… had a lot of fun and good learning doing them.
going to buy a welder again someday. Would like to make something trying to use an alfine hub wheel. Bb pivot full suspension with a gear hub seems like a cool bike for some reason. Run a tiny chainring / micro drive
Super clean looking and silent. with all the downsides of a super heavy hub and terrible pivot location
^how about a jackshaft iteration? i ran my tmx singlespeed for a bit; concentric + slider dropouts = dead silent drivetrain. pretty neat.
Too busy looking. I’m sure it would work better but I’d be going for fashion over function.
"Anti rise, for example, is driven by chain growth rate and horizontal axle movement. " Do you mean antisquat here?
Yeah that's a typo that is anti squat.
Isn't Creo really bad when it comes to surfacing? As far as I understand it, carmakers use Creo for physical parts (suspension, driveline & similar) and Catia for the bodywork (and everything that attaches directly to it) because of the surfacing and sheetmetal capabilities. Likewise for shipbuilding and aeronautics.
As for Linkage, does it allow you to make a suspension design without having the shock tied into it? So to only throw around the pivot points and define a desired travel number and to see the antisquat and antirise values. And deal with driving the shock later.
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