I have a Garmin 1030 plus. It's been a great computer. One thing that always bothered me is the huge lag for the percentage grade. Is this normal for all bike computers or this just an issues with my single device ? Feels like a good 20 to 30 second delay. I have not timed yet so I could be wrong on how long of a delay that is.

Bike computers that use barometric pressure sensors are always a bit of a guesstimation and vary with weather and regional barometric pressure.

My XOSS G+ has one and while it's semi-okay, I rarely look at it during a ride due to the lag time and inaccuracy.

After I sync my XOSS data to Strava I usually click on the option to correct the elevation according to Strava's database, which is derived from map data and user data from millions of users and rides, so it's generally more accurate. If I don't use that option the graphic depictions of my elevation will appear choppy and blocky. Using the Strava correction option smooths out the slopes to more closely resemble the actual terrain.

Same with the temperature reading on my bike computer. It's just a rough guess and often wildly inaccurate due to heat reflected off the pavement or baking in the sun. With Strava premium subscriptions it'll stamp the weather data from more reliable sources.

When I used my phone mounted on the handlebar or stem there were apps that more closely indicated the actual grade of the road, closer to real time. But it was essential to calibrate the whole mess for accurate readings. And I got tired of the bulky, heavy phone and mount on the bike, so now the phone is in my pocket.

Occasionally when I'm curious about a particularly steep grade I'll stop and physically measure it using the phone. Most of the time it's the same as the data provided by reliable mapping services.

My Garmin Edge 500 had lag for displaying the grade. My Edge 530 seems to even have a tad more lag. And my son's Garmin Edge 1030 plus has about the same lag displaying grade. I've never worried too much about it. It's one of those gee whiz numbers that really doesn't mean anything that that specific moment. You just need to shift to what ever gear you need and keep pedaling.

I don't know, but I imagine part of the issue is that they are doing a running average for a certain number of polls of the barometric sensor in their calculations and also the algorithms that cancel out the "noisy" data probably play a part in that too.

All Garmin Edges I've had - since the original Edge 305 - have been very slow to respond to grade changes.

Last sat I went to the Sports Basement / Wahoo gravel ride. They let you borrow a wahoo computer to test out. I had the garmin 1030+ and the newest wahoo computer side by side for my ride. It was night and day different how much faster the Wahoo changed to the grade.

I still prefer the bigger screen, touch screen and how I can custom configure the garmin 1030+ with profiles over the wahoo.

I guess Garmin can't fix it with a batch update :/