Thanks Jake328 for your post. If your max is 164 then the 80% point is (164x0.8) 131 beats per minute. If you ride below this level you should be able to nose breathe, feel no build up of strain in your muscles and be able to talk. Perhaps its:1. Overly tight pressure on the rear wheel is making the resistance too hard - if you get it up to around 20 mph (assuming you can measure rear wheel speed) then is should take around 8-10 seconds to come to a halt. Significantly less than this and you need to ease off the rear wheel resistance/settings on any variable lever/dial.2. That you do need to back off and ride at a conservative effort/cadence (85-90rpm and 65-75% HRmax - that is 110-125. Turbo does not equal higher effort, rather it means you can pedal for more constant periods than in the real world, using less kit, less bike wear BUT it does not test your balance, gear selection or pace judgement as well as real-world riding.3. There may be resistance in the bike such as: bottom bracket bearings; dry chain; worn jockey wheels; dry/damaged rear wheel bearings - all these could make pedalling seem hard work despite not feeling like you are going hard.I would recommend all triathletes get a bike HR max test to set their zones and understand how hard the various levels of effort are.
Happy to help,
Coach Joe Beer
Tri & Cycle coach, Magazine columnist & Author. Proud to be Scott-Sports, PowerBar, Speedo and Rotor brand ambassador - Podcast since '06 bit.ly/JBSTpod