Regular aerobic exercise is definitely of value for preparing for a big ride.
Spin is a good preparation in conjunction with some outdoor rides, but it is not a substitute for riding your bike on the road.
The feel of the bike, the balance, the momentum, and the environmental and traffic factors will have an effect on your fitness as well, some of which may be purely mental.
If time is limited, try spin 2-3 days a week, and build up your endurance, but also do at least one longer outdoor ride each week.
If you're riding 50 miles, you need to plan to be on the bike for 3-5 hours when you do the actual ride.
Build up to where you can handle 3 hours on the bike easily, and you'll do fine.
bicycles.stackexchange.com/users/1259/zenbike
Yes and no. Spin classes do help with overall aerobic fitness.
There are shortcomings:
the first thought occurring to me is "bike handling".
You can do spin classes blindfolded.
An actual ride means controlling the bike in various situations.
Secondly in a spin class, the "rider" determines the difficulty.
Actually riding, the difficulty is determined by the environment.
The upshot is that spin classes are good for aerobic fitness but other skills require different practice.
Spin workouts in general?
A good thing.
I do spin workouts during the dark, wet, and cold Pacific NW winters.
Spin workouts do wonders for your cardiovascular endurance.
So, you have that covered.
However, spin workouts generally last 45 minutes to an hour.
A long ride is typically longer than that, so little to no help.
Another thing in spin workouts is that the instructor will have you increase the resistance for "hills"; believe me, it never matches reality unless you really ramp up the resistance.
Another thing, is that spin instructors often don't have actual experience in riding a real bike on real terrain; so not sure that it helps unless the spin instructor is actually a cyclist.
Take away?
Usually ramp things up; of course depending on the spin instructor.
...Spin "class" is NOT a "class"...
it's a workout...
bicycles.stackexchange.com/users/None/
In my experience the saddles on gym spin bikes are often a little more plush than a typical "real" bike saddle.
Thus, one part of your body that you will never train, no matter how many spin classes you attend, is your butt's ability to tolerate a bike saddle for 50-75 miles.
I believe the only way to train your butt to sit without significant discomfort on a real bike saddle for 50-75 miles is to sit on a real bike saddle for a significant number of miles.
Several times.
I took a coworker on an easy, flat 25-mile route, and he was not accustomed to being on a bike saddle for that long.
By the time we got back, he was effectively riding on one cheek, because the saddle was paining him so.
His speed had slowed to a crawl.
bicycles.stackexchange.com/users/3985/Zippy The Pinhead
If you don't have much experience on the bike, in a long event, be ready for pain in your hands, wrists, shoulders, back, and bottom.
Especially if your bike fit isn't perfect.
I ride 50-100mi per week (mostly road, some mountain), and my first spin class was really hard for me.
I think the reverse is true as well; a good spinner may find that actual road riding is more dynamic and challenging.
Try to get as many road rides in as possible.
bicycles.stackexchange.com/users/6363/Jeffro
Spinning is fine if it's a long session but no substitute because your 100Km race is an endurance test for your muscles.
So as others have said hydration is more important than your time.
Do the spinning but make sure you've ridden the 100KM on the real bike at least once before you do your trip.
Just so you'll know what's coming.
Hope you enjoy it!
bicycles.stackexchange.com/users/4023/HCAI
For anyone training for a big bike ride I would recommend the following.
Go out once a week and do a long ride increasing the distance by ten per cent a week.
Do a shorter ride during the week, and if you can fit some interval training in on a spin bike that really helps with stamina.
A pyramid climb with some interval sessions straight after.
After one of your training sessions preferably the longer ride
I did some squats, lunges and single leg deadlifts.
This really helped my climbing ability.
All the hills I dreaded became mere blips, not just physically but visually.
I did the ride London and a ride in France which was shorter than the London one but hilly.
bicycles.stackexchange.com/users/31391/Lol
its appropriate.
i do spinning every winter.
great training, really pushes me.
you'll do fine as long as its not a competitive event and you can ride your own pace.
50-70 miles is not that long if you're on a racing bike.
as others said: dont expect it to be too comfortable tho.
cycling is an endurance sport, after all.
I'd say do some riding too.
it's almost summer in the northern half of the world.
perfect time for some relaxed riding.
if you dont like that, then why even bother going to the event?
if you do like it, then youll probably enjoy it more than sweating in some overheated gym class.
its also good (pleasant and safe) to be familiar with your bike and riding, cornering etc when you ride in big groups.
bicycles.stackexchange.com/users/4154/Tim Zwart
I need to train for an upcoming bike ride and i wanted to see if attending a spin class 1-2 times a week (45 min course) would be appropriate way to prepare for a long bike ride (50 - 75 miles)
Does spin class prepare you for a long bike ride?
bicycles.stackexchange.com
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bicycles.stackexchange.com/questions/9226
bicycles.stackexchange.com/users/2005/leora
Spin classes are good for aerobic fitness but they are no substitute for riding your bike on the road. The only real way to train for a long race is to ride long distances on the bike. Gradients are harder on the road than in a spin class and you have to get your body used to spending long periods of time in the saddle. Moreover riding a bike on the road requires balance and awareness that you do not get in a spin class. Spinning is useful for building up aerobic fitness and endurance, but does not teach important skills skills like road awareness and controlling the bike in different conditions. Spinning classes are usually shorter than long rides and simulated hill climbs are usually easier than the real thing. Stationary bikes are usually built differently with a more comfortable seat, so you may not be used to a long ride on an unfamiliar bike. Keep up the spinning classes, but try to introduce progressively longer outdoor rides too. Think about hydration more than the finishing time.
Spinning is useful for building up aerobic fitness and endurance, but does not teach important skills skills like road awareness and controlling the bike in different conditions. Spinning classes are usually shorter than long rides and simulated hill climbs are usually easier than the real thing. Stationary bikes are usually built differently with a more comfortable seat, so you may not be used to a long ride on an unfamiliar bike. Keep up the spinning classes, but try to introduce progressively longer outdoor rides too. Think about hydration more than the finishing time.