Clarify some confusion please re: ascents and turbos

kubeism

Hi all, I've had a good trawl back through but haven't been able to find an answer to this (most likely stupid) question.

I'm looking at getting my first turbo for a few reasons. Mainly to get some level of fitness back and to try and finalise my saddle going forward. I'm fed up being in pain with miles to get back home!

Anyway, I'd pretty much decided on a fluid trainer due to the apparent quietness and smoothness. But regarding hills, obviously in real life you hit an incline, it gets harder, so you drop down gears and grind up it. So therefore I would expect the most realistic replication of this would be a magnetic turbo where resistance increases on a virtual climb and you drop gears on your bike?

Fluid turbos only increase resistance as you pedal harder obviously, so I can't fathom how this recreates a climb? Or does pedalling harder in the lower gears eventually increase the resistance enough to create the feel of climbing?

As I said, I have a strong suspicion that's a really stupid question but I may as well put it out there.

Many thanks all

MiddleRinger

If it's just a basic "non-smart" turbo where resistance increases as you pedal harder and change into harder gears then you'll need to replicated hills by choosing a much harder gear and dropping your cadence too (optional).

If you're using a virtual program such as Zwift, your on-screen speed will drop when you hit a hill, but your actual wheel speed will increase. This is why if you're using a speed sensor the distance/speed recorded with that will never match what you ride virtually on Zwift.

rdt

Kubeism wrote:

Anyway, I'd pretty much decided on a fluid trainer due to the apparent quietness and smoothness. But regarding hills, obviously in real life you hit an incline, it gets harder, so you drop down gears and grind up it. So therefore I would expect the most realistic replication of this would be a magnetic turbo where resistance increases on a virtual climb and you drop gears on your bike?

You are roughly right in what you've written; maybe the following 'tome' will help a bit:

- app-control of trainer resistance requires that the trainer be a so-called 'smart' trainer; 'app-control' means that some software running on a device (phone, laptop, etc) communicates wirelessly with the trainer, telling it what resistance to provide (erg-mode) or gradient to simulate (slop-mode)

- all smart trainers have resistance units that use magnetism (usually in the form of an eddy current brake, or a few use motor brakes)

- but not all magnetic trainers are smart trainers; there are also old skool dumb magnetic trainers, which usually have a manual control clipped to your handlebars to allow the power-curve to be steepened in steps, in a manner that's somewhat akin to selecting slopes (hills) of increased gradient

- all fluid trainers are dumb trainers; these all have a fixed power-curve meaning that to obtain more resistance you have to increase wheel speed (pedal faster / change up gears); there is no additional external control to step-up the resistance (change/steepen the power-curve); these trainers often provide a good simulated feel of riding on the flat, ie. the pedal stroke often feels realistic compared to many dumb magnetic trainers which may feel quite janky in comparison

- many dumb magnetic and fluid trainers can still be used with various training apps, but unlike with smart trainers the apps will not control the resistance of the trainers. Dumb trainers require you to use either: (a) your own bike's power meter, OR (b) wireless rear-wheel speed sensors to tell the apps what speed you're riding at, with the apps then using their prior knowledge of your trainer model's power-curve to estimate your power (so-called virtual power), which may not be so accurate but can still be adequate, depending on your needs; whether using your bike's own power meter or relying on a wireless speed sensor and virtual power, the app experience will not be so immersive as with a smart trainer, but can still be OK, depending on the app

- note also that smart trainers vary a lot in their capabilities, with the pricier ones being much more able than budget priced ones; it pays to do your research so you understand exactly what you're getting for your money and what you aren't

- which app or apps you're intending to use with your trainer will play a part in what trainer features matters most to you; eg. for something like TrainerRoad, immersivity doesn't matter so much, so a dumb fluid trainer like an old skool 2nd hand Kinetic Road Machine using either your own existing power meter or virtual power via a wireless speed sensor can be excellent bang-for-the-buck; whereas for something like Zwift, where immersivity is a major factor, a smart trainer that provides app-control of slope is highly preferable, and where a higher-end more capable direct-drive (rear wheel-off) trainer able to simulate steeper slopes and respond to slope changes rapidly and smoothly may provide a much more enjoyable ('realistic') experience than that provided by a budget priced smart trainer

HTH.

kubeism

Thanks both for the input, especially the 'tome'

That's good info and at least confirms I was on the right track. The sub £200 Smart trainers do get mixed reviews so worth considering if that function is really that important to me.