Linkage bike suspension simulation software

There are 1214 files in the bike library now.

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Frequently asked questions

On what operation systems does Linkage run, is there a Mac or Linux version?
Linkage runs on Windows from XP to the latest versions (Vista, Windows 7 etc.). There is no Mac version, though it's working fine with an emulator, we tried it on Parallels Desktop. Or, if you set up a Windows Virtual Machine on any OS, it will work. Though please try the Linkage demo first to be sure.
For Windows XP users: we've experienced that certain drawings sometimes does not display, especially dotted lines, like crosshairs. In this case, please disable the "smooth drawing (anti-alias)" option in the Settings window.
I have a laptop and a desktop computer. Should I buy two licenses?
For the Personal version one license is OK, if it's really only you using the software (you are granted 2 computer installations by default). For the Professional version please buy license extension(s) to use it on more workstations. Please contact info@bikechecker.com if you got your computer crashed and have a fresh operation system installed and you can't install Linkage on it.
In what languages is the software available in?
In alphabetical order: Czech, English, French, German, Hungarian, Italian, Spanish, Russian, Slovak, Romanian and Traditional Chinese. The help is only available in English and Italian.
If you find translation errors or you are interested in translation to other language(s), please contact info@bikechecker.com. We usually offer a full software license as payment, or let us know what you would like in return!
The Linkage staff thanks all the translators their great work.
Could you please model the bike ABC ? (substitute ABC with an actual bike model)
The best place for asking a question like this is the Forum. Maybe someone will listen and upload a file for the desired bike. Or you can create your own model, all you need is a good sideview picture, with possibly no perspective distortion - use telephoto on your camera and focus on the middle of the rear part, looking straight, not sideways and not from above. Then click on "New" and open the photo and click on the points the software asks for.
How can I make a file that's as accurate as possible?
You have two ways in Linkage to make a new model. Either you make a side-view picture of the bike and after pressing "New" you load it and click on the points the software asks for. When you're finished with points, you can draw the outlines (polygons) of the frame to make it look better. To make an accurate model, you should make a photo which is exactly sideways (perpendicular to frame), have no perspective/barrel distortion (telephoto is better). It's hard to achieve, but if you can measure your bike you can modify pivot coordinates/bike geometry later. The other way to create models is to start from templates, Linkage has now 21 built-in frame types to choose from, which covers about 99% percent of the bikes available. After creating a bike from a template you can modify every point, draw outlines, modify shock, fork, wheel parameters etc. You can also change frame type (ie. single pivot, 4-bar etc.) any time.
I have a special bike idea, can I draw it in Linkage?
Probably you can, but keep in mind that it only supports specific frame arrangements from single pivot frames to (real) six-bars. It does not calculate frames with two shocks or frames with flexible parts.
Can I model 650B or any size wheels?
Yes, just type the size into the wheel size fields. You can enter for example "27x1.5". If you rest the mouse over the input field, it will show the inner and outer actual diameters in the measure unit you selected.
Do you support "Trunion" mount shocks and pull-shocks?
Yes. Pull shock can be checked as an option. Trunion style shocks are basically short eye-to-eye shock with big travel relative to the eye-to-eye distance. So you can set it up as a short shock, just please ignore that the software won't display the part of the shock beyond the trunion mount.
What does the air shock parameters mean and how to set them up?
The parameters model a shock with a positive and a negative chamber, the positive being simple cylinder shaped and the negative chamber being a thick walled "pipe" shape with inner and outer diameters. The actual sizes for a real shock are hard to tell since these are not publicly available and their chamber shapes may be different - or utilizing a special elastomer negative spring for example. So you either measure your shock, or use an estimate, or use a predefined shock curve from a speradheet csv file. You can download an example data file here.
Can I fix shock the stroke?
Yes, from the update 1 of version 2012 there is the possibility to fix it after entering shock stroke value at the shock parameters. So the software will always refresh the maximum travel according to shock stroke. Just check "Fixed" below the shock stroke field. You can also check "Fixed" for shock length which will keep it constant when dragging the endpoints of the shock with the mouse.
What does anti-squat "a1" and "a2" mean?
There are two anti-squat values in Linkage, one involves chain drive (a1), the other does not (a2). Basically they show a percentage of the acceleration, deceleration affecting the suspension. The model for a1 is for example here: http://www.desertrides.com/reference/images/terms/anti-squat.gif
So, connect the IC (or main pivot) and the rear wheel traction point (CP) and measure the rate of two distances, which come from crossing a vertical line at the first wheel: - the IC-CP line - the center of gravity (CG) point's horizontal level line This method is said to be useful for examining braking behaviour. The other method seems to be in common knowledge, maybe came from the DW link create Dave Weagle originally but now bike forum people tell this to each other, so we implemented it. It uses another line instead of IC-CP, the CP-Ia line (named "Ia" in Linkage, but I think some people call it ICF). This point is the intersection of the chainline and the Rear axle-IC line.
While we think the methods are theoretically correct, it is possible that the real world results differ a bit. Currently there seems to be no agreed-by-everyone method for calculating anti-squat for mountain bikes.
Update: The cooperation with I-Track suspension added the possibility to calculate anti-squat for frames with an idler (chain guide).
Update: For the Professional version we added the option to calculate anti-squat with the vertical direction fixed to the main frame. The default calculation uses a vertical direction which is given by the wheel-ground contact points, so it rotates as the suspension compresses. The new vertical mode does not take this into account. Please use the case which you think suits you better.
Note that the anti-squat values displayed in the current values panel always show the drawn position's values, so they change with either rear/front suspension movement.