Wow. You should get a tune-up and have your bike checked out! Handlebars being loose (I'm assuming you meant the stem was loose and the wheel steered on it's own) could do some SERIOUS damage.

Anyway, my advice is: if you're scared, hold off. Clipless pedals = no biggie because if you're new to them you can just unclip your foot well before you need to stop and you'll be fine. However, if you get them and you're nervous you won't enjoy it, will ride your bike less, etc.

Oh! I got it fixed that day! They also did a total check-up and said everything was fine (breaks, etc). I can't get it fitted because it's not my bike. I'm getting myself a new bike for my 30th birthday (Sept 25th!) and I'll get that one properly fitted. I think this one is a bit tall for me.

Added bonus for tris - you can wear the same shoes for run and bike legs, so fast and easy transition!

Very true.

You've got two problems here. One is bike safety and the other is your equipment.

Can I suggest that you not really worry about any equipment advice from your Team In Training "coaches". In my experience, Team In Training draws a LOT of new riders/runners/etc. like yourself. Who know nothing (understandably) about basic bike safety and unfortunately the "coaches" are wannabe-athletes who really don't know much of anything. They herd their groups through a training program, and keep you motivated to keep up your fundraising (which, really, is all that Team In Training cares about), and that's about it.

If you're on a mountain bike, clipless pedals won't help you one little bit.

Find a good local bike shop, and let them advise you about equipment.

Your fear (again, understandable) is because you don't know the basics of bike safety. I really encourage you to find a bike club (again, your bike shop can probably help you find one) and take a safety and road-riding techniques class. You'll learn so much more than Team In Training will ever tell you.

Ride safely.

Possibly true, but the up pull is only one possible benefit of clipless pedals. I have flat pedals (with pins) on my mountain bike and clipless on my cross bike. It is much easier to spin a comfortable cadence and pedal in circles with the clipless pedals. I only pull up when I'm standing and accelerating from low speeds.

Ever sprint (even for a stoplight)? Or have to power up a short, steep pitch? Or bunnyhop a pothole? These things can all be done on platforms, but I feel much more secure with my feet securely attached to the pedals.

I appreciate your comments but I did want to clarify that both of my coaches have been doing triathlons for years. They are not "wannabe-athletes." My head coach is doing the World Championship Ironman in October - and it's not his first Ironman. They've barely talked about fundraising (to the extent that I wish they would more - we have to raise $3,500). I'm also one of about 3 people in our group of about 10 who normally come to the group trainings who have never done a triathlon or marathon or a century and a half bike race.

I think the experience you have with TNT is probably different for every chapter - so maybe I lucked out. :)

In any case, I DO have a local bike shop I love called Big Shark and they helped me when I first got on the bike (and they don't upsell at all). I got my helmet, gloves, tubes, etc. Then when my bike decided the handlebars needed to be really loose, they fixed it and gave it a safety inspection for free. They told me just to come back when I got my new bike - which I plan to, in September. Yay for a hybrid that's not 3433232 pounds! :)

Shimano, and some others have an adjustable retention rate , so back that off
and the cleat will release from the pedal rather easily, if you remember to do it.

It might make sense waiting some then.

At least, it wasn't a UPS/FedEx mail box. Those are much harder!

26 miles is a short bike ride. You really might not need to worry about clipless for such short rides.

This makes sense.

The advantage of clipless is not huge. It would make more sense changing the bike before worrying about using clipless pedals.

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Clipless pedals might be necessary to be competitive or for an ironman, but they are not at all necessary for what it appears you are planning on doing. It isn't clear that there is any good reason to complicate your life right now with clipless pedals.

I suspect that the biggest benefit of clipless is that it makes high cadence easier.

What you can do is get have a reasonably knowledgeable person help you set up/fit the borrowed bike to closely fit you - then you can reset the bike to its current setup when you return it. Nothing you do insetting the bike up for you fitwise is permanent - a couple tools and a bit of elbow grease and you can reset anything you have changed.

Seriously, if you really want to change things, just mark the pieces you change with tape/grease/etching and/or measure the current set up, then write it down. A couple months from now, pul out the piece of paper and there you go.

Riding a bike that is "too tall" is not only uncomfrotable, it can be dangerous (esp for guys and that danged emergency stop onto the top tube).

Personally I think that pedal retention systems should only be used by people with a bit of experience, who can ride on autopilot. When starting out, riding on the road takes up a lot of metal capacity as well as physical.
Autopilot means that you have enough spare brain capacity to observe, predict and classify the dangers, prioritise them and act accordingly. Experienced riders do all of this mental activity on autopilot so they can enjoy the view as well.
If you want a pedal positioning system suitable for a newbie, fit some mini toeclips without straps.

Most riders who convert to clipless have a few clipless moments when something happens and they dont have the reaction to unclip.

At every major event I've been to (marathons and bike rides) where TNT groups are present, it is really apparent that they haven't been taught anything about safety or etiquette. They don't know "rules of the road" and they ride/run in large packs doing very unsafe things. This is why I really do recommend that you find a bike safety class on your own. It will help with your fear of riding, and it will make you a better rider.

And if your coaches are triathletes, their advice will be to do everything like a triathlete would. Since you're only moving up from a mtn bike to a hybrid, you will still be way below their level of equipment and performance. So take any advice they give you with a BIG grain of salt.