Depends on your fun interests and where you live.

If you live somewhere where riding a tri bike as the only bike outdoors would not be as fun (lots of short steep hills and sharp corners and start/stoppin), makes total sense. Or to mix it up on group rides. People have group rides they do with tri bikes fine, but being on the base bar a lot on a group ride isn't the same comfort/feel as a drop handlebar on a road bike.

If you have the money, just get it.

Of course you don't need 2. But 2 does off massive benefits.

I didn't even buy a (true) road bike until after my 3rd. However most of my training is now done on the road bike.

A key part is how you train. Early days then I used to be cycling 26 hilly miles a day with paniers as my commute, then add on a hilly saturday ride on the tri-bike. But over the last 15 years I've favoured a plan around the 'club' saturday ride century all year round, and then December to February (Summer in NZ) will swap to long run Saturday and then solo TT rides on the Sunday ahead of March race.

Throughout the year then add in zwift sessions in the week. And there I mix between road and TT bike - don't like sprinting on the TT bike on zwift races, but equally for the 2hour steady sessions then doing that in the TT position is great for holding position outside.

So to spin your question round, there is not reason NOT to have 2 bikes assuming you use them appropriately (ie don't do all training on one and then jump from road bike to TT bike raceday).

Agree with you on geographic location. I live in the Texas "hill country", and do only have a road bike at the present time. I'm trying to make the case to myself (and to my wife lol), that having the road bike is crucial for training around where we live. But, I also want to be able to step my game up on the triathlon side. Thanks for the input!

Thanks for the reply! It is definitely a tougher pill to swallow to have both, financially at least, but do agree with you that the TT bike would be a better option on longer trainer/zwift rides and to become more acclimated to that position outdoors.

If money not a factor, separate TT and road bike.

TT bikes are just more optimizable for ideal TT-tri position and are built for speed on solo TTs.

Road bikes are great for group rides, hills (you can ride TT bikes on hills, but road bikes are lighter and handle better) and tend to also have less annoyingly-custom parts in the cockpit to replace as they wear out.

There is a big plus to having two bikes at any time even if they overlap in function - when one is out of service, you have another to ride. This WILL happen at some point, so you will be prepared.

Excellent point! This answer definitely hits home and feel like the case could be made for keeping one on the trainer (TT/Tri), and using the other (road) for outdoor rides, at least until 1-2 months prior to a race then likely switch to TT/Tri only for training at that point.

As someone who only races triathlon (I don't do road bike events and only rarely do group bike rides), I could def argue that the even better combo is TT bike, and a permanently setup indoor trainer bike setup (separate from TT bike).

I live in bike-heaven Norcal, but due to scheduling and other life demands, I'm on the trainer at least 2x/wk, if not 3-5x, and quality sessions def occur on the trainer (hard repeats). So I ride my trainer more than my TT bike or my road bike.

I now have a 'broken' Cervelo bike frame permanently living on my Kickr trainer - I used to put my race bike on it, but I had a lot of problems over many years with headset corrosion despite using a lot of towels and covers. (I didn't wrap it all with plastic because I wanted to still take the TT bike out on weekends to ride). Cockpit and headset corrosion is a major issue with bikes that live mostly on the trainer, so take care with sweatproofing if using your race bike on it for a long time without riding it outdoors (deseizes stuck bearings, etc.)

I keep my TT bike on my trainer unless I’m racing or it’s the last 2-3 bigs rides before a long course. If I’m going to steel a day that’s nice out or just want to do Z2 or fun riding, I ride my roadbike. Certainly you do could it one bike, but it’s so nice to have one for outdoor rides and another for focused training and racing.

Holy cow, I had no idea the cockpit corrosion could be so bad on a bike that lives on the trainer frequently, but it definitely makes sense. Duly noted. Thank you for that insight! Is your damaged frame Cervelo a TT bike or road?

That's kind of what I figured I would be doing if/when I get the TT bike. Glad others are doing that as well!

My road bike saves me lots of time.

I use it for commuting, travel, socializing and adventure.

My road bike also saves me money (when compared to my tri-bike or car):
A) It was inexpensive to buy and will be inexpensive to replace.
B) It's durable.
C) It's easy and cheap to repair.

TT Cervelo bike - cracked rear derailleur hanger (non-replaceable), so can't mount a rear derailleur on it. Luckily for me, I mostly use erg mode nowadays from Trainingpeaks plans, so having one gear is fine (for now).

THe corrosion really happens when your bike stays on the trainer for weeks without moving it. Things lock and seize up pretty quick with even tiny amounts of sweat. If you're riding your bike outdoors more than once per week, it fares better, I think the grease moves around more and surfaces stay unfused.

Prior to getting putting my Cervelo on my trainer, I had to do full headest bearing overhauls every year, no matter how much I covered my bike. I could put it off one year, but then by the next year, the headset was noticably sticky and hard to turrn. For fancy TT bikes like mine where the brake cables run through the center of the bearing, this requires a full front brake recabling and cockpit disassembly, which runs $200+ every time.

I have 2 very similar TT bikes. One is on the indoor trainer almost 95% of the time and a few out door rides. The other is for racing with all the "race stuff".

Its my 3'rd "set" of bikes.

I've got two and feel like it's a good balance.


Gravel/Road Bike: Used during the offseason when the weather isn't great, for group rides, or when I just generally want a break from the TT bike. I'll also keep this bike on the trainer during the season for shorter indoor rides during the work week.

TT Bike: Ridden most of the time during the season and especially during race specific prep and workouts. My TT bike also sees some trainer time during the off season.

I also enjoy the mental break from riding one bike too much. And having two also makes it easy when one goes down for maintenance.

The N+1 rule of bikes.

I now have my old road (2002, superceded in 2017) bike permanently on the trainer, and yes rust is an issue - I now use a waxed chain to stop the rust if I've been away with work a few weeks and it's not moved otherwise it tends to be fully rusted. I also use one of the tacx triangular sweat cover things, but to be fair not really sure how much it really catches. The frame is certainly rusting, but then it was in some places before it became the indoor bike. Now much more apparent around the BB though, and tend to need a new GXP BB every 18 months or so. To be fair my new road bike also has pretty rusted bolts on the stem- I suspect combination of sweat when climbing and salty spray when riding in the rain along coastal roads.

Then currently alternate the TT bike on and off the trainer, but in a couple of months when the new TT bike arrives the old Argon will live on for a second decade of life as the trainer TT.

So for pure tri, then 4 bikes is a minimum requirement.

N+1 = Brilliant haha. Love that. I think everyone's given me quite a lot to think about. I am stuck for a bit until I can sell the current road bike, or somehow win the lottery overnight.

Just gonna throw out that IMO unless you're planning on serious road racing, the best bike combo would be TT and gravel bike. Get yourself an aero gravel bike like an exploro or aspero, and it's a fully functional road race bike if you put road tires on it, but then can also run wide tires for either some mixed pavement and gravel or just to be super comfy on the pavement. It'll just be a touch heavier and probably not quite as fast as a true race machine, not that it probably matters for 99+% of the people on this forum.

Don't get too hung up on needing to buy the latest/greatest (ie most expensive) bikes. My first TT bike was UKP600 in 2003. That carried me through to 2012 when I bought my E-114 in a run out sale. That's the one that I'm still using (10sp, SRAM S80 wheels which were the 2006 Zipp 404 mold). My first road bike was NZD700 (about $350USD at the time) and became known in the club as Lazerus for the fact that it wouldn't die. A couple of bunch ride crashes, many Cat B races, including some placings all done with the 9sp shifters and alloy wheels. Ok, was 'noodly' when I was sprinting and maybe did cost me some places, but what did that matter? Was only competing in local/regional events, wasn't going to make my millions on the scene (biggest prize money NZD20 for second in a Crit behind a pro mtb er that scared the crap out of me when he did a tail whip over a speedbump as I was following his wheel.

I have invested in quarq power meters that I've moved across bikes, coaches and then always prepped the bikes as best I could, so top tyres, latex tubes, good quality clothing to be comfortable and basically just rode lots.

And then also just marvelled at the revolving door of carbon that was on the saturday rides - people that change bikes every year.

Just a tri bike would suffice but can one have too many bikes? ;)
I think a variety of bikes is the best.
I use my road, tri and mtb just depending on the workout, time of year of how I feel.
Where I live the roads arent great for TT bikes so I actually do most training on my MTB on the road or my road bike. Maybe once or twice a week in season on the TT for key sessions.

useful article that stands the test of time.

https://rappstar.com/...es-need-a-road-bike/

I can only speak as to having ONE. No road, mtb, gravel or cross bikes. Just a tri bike. If I need to head up a 16 or 20% grade in the mountains, guess what I use? Not a road bike...just a 2010 Cervelo P3. I'd say you only really need a bike to bike...doesn't matter which. Unless, you are training specifically for one of those sports that requires that sort of bike to compete with--as specificity does matter. Since I don't race any of the bike races that require anything but a tri bike...I only need one.

It does limit me though in that I am unable to do any sort of draft legal type tri/duathlons though...

To each their own. I find my road and gravel bike much more fun for everyday riding then my TT bike

I gotta admit - I set up my TT bike fairly aggressively - that low head position is definitely not an enjoyable ride by any stretch. But it's fun to go fast!

No question though that an aggressive TT position with a low head position are not exactly a comfy ride. Even if I do it for hours on end.

Again, I wouldn't know, I only have one. Had a MTB in college but I swiftly ended its life with a crash at the bottom of a hill...turns out some tree trunks are actually rotted enough to soften the crash like a crash pad...but still bend the frame. Had it been a living non-rotted tree, I may have ended myself. Anyhow, it would be nice to have a road bike for sure...but those dang budgets just don't allow for multiples. Buy one, sell one. That's how it goes!