Max HR (vs LCTHR) on bike and training zones vs Running (Joe Friel)

Training
1

Hello, I am trying to do a quick and dirty HR zones for my biking. I have done the Joe Friel 30 min fiield test (lactate threshold HR test, LCTHR) to find my LCTHR for running and calculated my training zones for running accordingly (as percentages of my LCTHR - which is different from Max running HR I believe, LCTHR would be lower than max?).
I would like to do something similar for biking now. I know max HR won’t typically get solicited during a ramp test. Is there a protocol in TR to find out what my max HR for biking is?
Or, is there a way to determine your lactate threshold HR on the bike?
I have looked at some of my outdoor rides and found what is likely close to my max HR for an outdoor ride.
Are the below the generally agreed upon training HR zones for biking (I suppose you could calculate training zones as percentages of your LCTHR for biking but the percentages would be different - is there any data on how closely the 2 different methods compare for calculating your zones, based on max HR vs LCTHR?):
Zone 1 50-60% of max
Zone 2 60-70% of max
Zone 3 70-80% of max
Zone 4 80-90% of max
Zone 5 90-100% of max

Thank you for any assistance and information that can be shared.

2

A steady paced all out 5-6 minute effort with a kick at the end will probably get you really close.

Do a long steady state 30-50 minute test and take the average HR of the effort after the first ten minutes.

I’ve found that my LTHR tracks pretty closely to be around 90-91% of max HR, but it will vary within the season, with higher max HR in the off-season and lower max HR during peak season.