Using the Grove Cycle Design ACCU jig, I believe this one was fabricated by Engine Cycles. I’ve measured everything every which way and the bb drop is 20mm too short on the front. Everything else measures correctly with levels, XY square tool, tape measure, and was correctly set up following jig instructions.
Anyone have experience with this jig or have this problem before? What is the calibration guide mark for the front axle slider?
Not quite sure what you mean, but I am using an original Grove so maybe I can help? 20mm sounds like the thickness of the headtube cup?
The headtube cup we’re using is marked 12mm, which is my headset spacing in bike cad. And the XY measurements from bb to bottom of ht are also accurate. You’ve never encountered anything like this?
Do you have a manual for the jig with detailed set up drawings of the front axle? My manual doesn’t include details about how to set up that whole horiz front center beam.
ACCU SET FIXTURE-SET UP (1) (1).PDF (1.3 MB)
This is what I got from Rody Walters. But we are missing some of the setup tools, so I am now using a 3d printed spacer on the BB axle that holds a steel ruler, and I add the diagonal distance from BB to front axle in my drawings.
It sometimes happens I come up to low or high on the front, but that’s always because I forget to set up the HTA, drop or fork length or offset correctly.
Reading back your question: You set up the drop with the blue tool, and then you put the blue pin of the front part on that level. (After setting the hta, fork length and offset) The drop should dictate the height of the headtube, not the other way around. If I come up short I always find this when I put the downtube on the headtube, not somewhere else.