I purchased my first Retul back in 2009. Used it for fitting a few times, but fell short of my expectations. Decent program for salespeople trying to determining proper bike size, but seriously flawed for optimized fittings because it relies on normative data and fails to consider the entire person.
I’ve since designed an integrated 3D & sEMG program for BTS Bioengineering which is considered the most sophisticated bike fitting protocol in the world. One factor that makes it unique is an internal test for marker accuracy. Unfortunately this element unveiled marker placement errors inherent to even the most stringent application techniques which means these data are neither reliable or valid for bike fitting. Most difficult part of the entire project was designing internal tests and corrections for inherent marker errors.
Retul is still a big part of my business. Each client’s personal data and bike-dimensions (via the Zinn) is saved in my documentation and printed for his/her records. This information can be used for rental bikes, bike replacement, etc.
Once upon a time Retul Frame Finder included a large database of bikes that I could use to help client’s determine the best bike for his/her Zinn-data. I was even promised that this database would remain intact, despite being bought by Specialized, before buying my new system in 2012. That promise was good for about 6-months. Specialized is now the only manufacturer in the database, which makes it virtually worthless for comparative analysis.
So much for referrals.