Saddle discomfort

Just started zwift after buying a zwift ride kickr core combo. Great so far but I’m struggling to understand why I have so much more saddle pain now. I put my road bike saddle on the zwift ride frame and similar measurements but I’m super sore after like 40minutes when I can go 2 hours on my bike.

Is this just because of the lack of side to side motion on a trainer? Would a rocker table help? Thanks.

While some setup adjustments may be beneficial, the essence of indoor training seems to persist regardless of the setup. My Kickr is mounted on an MP1 plate, which is adequate, but after several hours, I start to feel sore; however, when riding the same bike outdoors for five or six hours, I experience no discomfort. Off the records, I combine Aspercreme with Lidocaine and Butt’s cream during some indoor sessions –not joking!

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Rocker plates are good, they do help.

Indoor trainer difference is you don’t move around as much.

I also find it more comfortable to do the steep/hilly routes because I’m putting down more power and less just sitting and spinning (more saddle pressure).

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Assuming you have the fit dialed in the same, a rocker will help, but another factor may be the rigidity of the seatpost and how much it’s extended vs on your bike. Unfortunately it uses a proprietary seatpost so you have no control over how rigid it is. A lot of what people imagine as frame ride quality is actually seatpost ride quality.

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I doubt a rocker table would fix a saddle issue that starts after 40 minutes.

On the off chance your soreness is on your sit bones you may well acclimatize to it after a few rides. I wouldn’t be pushing it though. Take a break before it’s super sore.

Does it feel uncomfortable before it reaches the “super sore” stage? That is the feeling to focus on for fitting it. Simple step 1, make sure you’re sitting on the saddle properly putting your sit bones in the right place. If it’s uncomfortable there then it may not be the right saddle for you.

Pedal for a bit and see if you shift position subconsciously, if so that’s probably the issue. Move the saddle so you can sit on it properly whilst pedalling.

There’s a chance that the increased amount of sweat indoors is making you more sensitive to chaffing. Quality of bibs might affect that too. I have 2 pairs of bibs, one are the good value for money DHB that wiggle used to sell, the others are more expensive assos ones - and the difference is palpable.

It depends where the pain is. If your saddle is pushing into soft tissue most of the stuff that people advise better bibshorts, creams, “move around, stand out of the saddle” are not really fixing anything they’re just working around a bad fit. If you were saying “after 6 hours I’m uncomfortable” sure, but 40 minutes? Your saddle should be comfortable for 40 minutes or, as you say, a couple of hours as is. If you ride across america YMMV.

Typically saddle issues usually point towards a saddle that’s too high rather than too low - but being too low creates issues too.

Saddle position is slightly complicated by having to consider fore/aft at the same time as the height. Simply put, moving saddle up is similar to moving it back and similarly moving it forward is similar to moving it down.

Try to find the right height and then consider if you can sit on the saddle there, if not then you can start to move the saddle fore/aft and height together to keep the same effectively leg length but without having to sit on the nose of it, or off the back.

I’d do biggish sustained power to test even if it feels good with easy pedalling. The fitters will get you pedalling relatively softly but they can see all the angles and some of them have saddle pressure mapping too - and they can tell from that the problems you’re likely to have. e.g When you’re trying to fit yourself the easiest way to tell whether your quads are going to burn because your saddle is too low or forward is to do a seated sustained effort above threshold and see if they burn.

Be aware of the fact that, if you get off the bike, adjust the saddle and get back on it will generally feel better than it did when you stopped because it was sore no matter whether you moved it to the right place or not. i.e if it takes 15 minutes until your knee starts to hurt or your saddle is uncomfortable then you need to test for that length of time. This can be really frustrating and you can waste a lot of time getting off, adjusting, riding for 5 minutes, getting off again, repeating trying to make a bike comfortable.

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Thanks all for the tips.
Initially I had sits bone pain with the zwift saddle but when I put my road saddle on that improved but now it’s that terrible perineal numbness pain. I’ve got it a little better with some micro adjustments but I bet some of it is the rigid seat post like someone mentioned above.
I do get out of the saddle but probably not enough. Some of that is due to doing the 6 week ftp test which is basically always seated so far but also getting used to the virtual shifting. I’m working on timing the shifts so I can have enough resistance to stand but also not come kill my momentum.

Maybe I’ll put my road bike on it this winter and see if I get the same result. Then I’ll know it’s just the nature of stationary trainers without the natural bike rocking motions.

I can ride 8 hours outside with zero saddle pain, indoors I get to about 90 minutes and pain starts, I have a homemade rocker plate for Kickr and I stuck one of those awful gel covers on the saddle but my butt still gets sore but its bearable now.

Besides bike fit, one of the major causes of butt soreness on a trainer, when you are already acclimated to riding long distances on the road, is the fact that trainers pretty much just sit there, i.e., they don’t require you to move around or get off the saddle to accomodate potholes, ruts, gravel, and such. They stay fixed upright no matter what you do. On a normal road you are constantly moving around on the saddle as you adjust for road complexities, plus the bike is constantly moving around underneath you as you pedal and steer. On a trainer, you just sit in the same spot on the saddle and crank away, causing ischemic spots on your backside. Even rocker and motion trainers permit this sit-in-one-spot-and-spin problem, and sometimes even more so because you are using your contact with the bike to muscle it upright instead of steering the bike underneath you, as you do on the road. To fix it, whenever you START to feel an uncomfortable spot, move forward, back, lean on one cheek, or just lift off the saddle a tiny bit to let the blood flow back into the soft tissues. It works even better is you simply remember, every couple of minutes, to keep moving around on your saddle (and handlebars and inside your shoes) the whole time you ride. If you wait for a sensation to cue you, you probably already waited too long.

If your trainer bike doesn’t fit the exact same way your road bike fits, make it so. Poor bike fit is still the premier cause of cycling discomfort.

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Yep, I think this is generally just a band-aid though. I mean, if I ride outside, stop, stand up, move around etc and that’s the only thing that stops the bike being uncomfortable then that’s most likely going to be because my fit sucks and I’m just mitigating it by not sitting on the saddle and pedalling.

So I’d say the opposite of you, if you start to get uncomfortable every couple of minutes then fix your bike fit. Especially if it’s after just a few minutes.

What I find though is that why a lot of these ‘not sitting and pedalling’ things work on the Sunday bun run you end up struggling to ride at pace behind a group if they aren’t all either fidgeting around trying to get comfortable or pedalling through the discomfort.

i.e you have this thing where you can ride solo because you’re dictating the pace, but if something else is dictating the pace well now you drop off the back if you start wiggling around.

It’s like if you do a ride with the D robopacers, they’re pretty slow, and you can easily ride ahead, stop pedalling, unclip to turn on your fan or fetch your towel that you put on the other side of the room. So, sure the wiggling around thing works. But if you ride with the C or B and, whichever or these are at a pace where you’re clinging on then you won’t have time to start wiggling around every 2 minutes. At that point people with a bad bike fit either give up and get dropped or grit their teeth and suffer through it.

That said, if you ride hard enough the suffering you feel from the effort tends to mask other discomfort and pedalling harder probably takes some weight out of the saddle so riding harder can be another band aid around discomfort itself - but it only really works a couple of times a week. The other 5 we’re supposed to be riding z2.

I think it shows how poor bike fitting is though when you discover how many people are uncomfortable unless they’re wiggling around in the saddle every couple of minutes and we pass this “wiggle around” info on to each other on as though its a normal aspect of cycling.

Hi. I’ve been zwifting for around 4 years. I had the same issues. Tried many saddles, none of them made any difference 30 minutes in and I’m feeling sore.
Omirocker plate changed that instantly. My smart bike now moves. For me 100% better

Another vote here for Omnirocker, money well spent if you ride indoors for a fair amount.