MTB vs Road Bike Sizing

[Limitseeker]

12 hours ago, King_Crispy said:

Where you based?

Somerset West

[Limitseeker]

2 hours ago, shaper said:

At 1.78 I would be inclined to say you are a 54 or medium, but best going to get a frame size fit done.  Some bike shops will be able to do this and there are some fitment centres you can go to like cyclefit in JHB? You do not say where you are located.

As for the 70.3 in June, as a triathlon coach, you only have 15 weeks until the race, so you need to be already training all 3 disciplines as well as clocking up long kms on a bike, whether a MTB or once you have a road bike

All I am aiming for is a to make it to the finish line in one piece ahead of cuttoff time. I’m not too worried about the ride or the swim. It’s the run that worries me, because I hate the discipline, and this is where I need to focus.

I have been a MTBer for more than 20 years, and riding long distances is not an issue, ditto with swimming. Have been doing +-2400km a month (2x 80-110km rides each weekend with shorter HIIT sessions in the week), and at least 2 1.2km+ swims a week. But virtually no running. But yeah, running off topic now

[Frosty]

Took me 20 weeks (on a structured plan) to be able to run 21.1Km (in under 2 hours) having little to no running background prior to being chased in the army. I probably could have hacked it in less time, but certainly wouldn't have been enjoyable or I may have injured myself

• 0-5k in 8 weeks
• 5-10k in another 6 weeks
• 10-21k in another 8 weeks.

[TNT1]

17 hours ago, Longbarn Killer said:

You will probably be borderline between a M and a L as with your mtb. 

Measure your inside leg and x 0.65 to get an approximate size. 

52 = S

54 = M

56 = L

The above is classic sizing. Lots of road bikes now days have sloping top tubes which may have different sizing. 

But if you aim for the S, M, L, you will at least know what to aim for. 

How about a 55cm?

 

Also, are the measurements taken to the center of the top tube, the top of the top tube or, heaven forbid, taken at the top of the seat tube if there is a mast?

 

Also for c-c and c-t measurement, are the actual on the sloping tube, or virtual to a "straight" top tube?

Edited February 16, 2022 by TNT1

[LuckyLuke]

Always buy one size smaller frame, just get a longer stem, you never know when you have to pull a supertuck for the win and find out your ass doesnt fit between the toptube and the saddle...😅