Heavy, tall... it's all against me

[simonineaston]

At 5' 10" and 9ish stone, I had the build to do well as a rock climber. Not a mountaineer, mind - or a fell walker, but rather I was ideally suited to be a 'crag rat'. I spent years happily following in the footsteps and handholds of the first & second generation of the post war rock climbers.
Wind back far enough to see me at school, struggling to fit in with the predominant sport du jour ie rugby football and the only place I did any good was down along the wing. That is, on the rare occasions the ball made it as far as me. So I'm sympathetic to the notion that body shapes often dictate the sport and when we're shaped differently to what we want to do, there can be trouble and strife.

[irc]

I'd also say that your current bike sounds fine, discs make little to no difference in a road bike. But if you want them, go for it.

I'd argue that this is where it makes a very significant difference, hauling a 136kg (21stone/300lb) rider to a stop!

At 17 stone I find rim brakes perfectly adequate. Does another 4 stone make a big difference. Though in fairness if I was buying a new commuter bike for year round riding I'd probably go disc for wet weather performance.

My suggestion would be that the OP buys a touring bike. The frame is less likely to give issues. If you weigh 17 stone who cares if the bike is a few kg heavier?

[NickJP]

My suggestion would be that the OP buys a touring bike. The frame is less likely to give issues. If you weigh 17 stone who cares if the bike is a few kg heavier?

Agree. The wheels and tyres on a touring bike are also more likely to be suitable.

[Cyclothesist]

My suggestion would be that the OP buys a touring bike. The frame is less likely to give issues. If you weigh 17 stone who cares if the bike is a few kg heavier?

Agree. The wheels and tyres on a touring bike are also more likely to be suitable.

That's a great suggestion. Touring bikes are usually designed with comfort friendly geometry too. As we age comfort becomes increasingly important as an enabler for speed and distance.
Comfort, Speed, Distance - pick the first and get the other 2 thrown in free!
Let me wish you every success TallTeaSipper on your fitness and weight management journey.

[rareposter]

Except that touring bikes are about the least suitable thing for triathlon and the OP is still.up against the fact that the rider weight limit on pretty much any bike is going to be the same 120kg.

Frame / wheels is of secondary consideration to that amount of weight going through a stem or seatpost.

[PH]

Except that touring bikes are about the least suitable thing for triathlon and the OP is still.up against the fact that the rider weight limit on pretty much any bike is going to be the same 120kg.

The 120kg weight limit is common because it's a US standard for road bikes, set by ATSM. If you want to sell a bike with a lower limit then that has to be clear, if you want to sell a bike with a higher limit you have to be able to demonstrate that capability. Up to the rider if they choose to exceed the stated limit, but it's easy to compare two bikes with 120kg limits and see one is more robust than another. The European weight limits also went through some changes a few years ago, I don't know the details but several touring bikes jumped from 120kg to 140-160kg around 2022.
I have no advice for the OP, who has already decided what sort of bike they want. They're hugely ambitious and I understand why they'd look at what tri riders are using, I think if it were me I wouldn't make the assumption that's going to be the best option for a rider of their weight.

[Cyclothesist]

Except that touring bikes are about the least suitable thing for triathlon and the OP is still.up against the fact that the rider weight limit on pretty much any bike is going to be the same 120kg.

...
I have no advice for the OP, who has already decided what sort of bike they want. They're hugely ambitious and I understand why they'd look at what tri riders are using, I think if it were me I wouldn't make the assumption that's going to be the best option for a rider of their weight.

The OP posted looking for advice. Their aim is to finish the triathlon, not compete for podium or a PB. They are aware that their current weight is an issue and are addressing that. I do wonder how an approx 136Kg 1.94m male with a BMI just under 36 would feel perched on the nose of a Tri bike seat. It's quite possibly 'the least suitable thing' for finishing a triathlon for them.
Good on TallTeaSipper for taking on the challenge. I hope they find a suitable bike for the task.