hello everybody

i'm planning to buy a merida reacto as my first roadbike but i'm not sure about the size.

I'm 179cm tall and my in seam is 82cm

here's my bike measurement according to android apps:



here is merida reacto geometry and sizing



my friend said it better to take 1 size smaller for a road bike. i tried to sit on size 50 bike..but i think it looks small for me. your opinion is very much appreaciated

I would start with getting the effective top tube dimension (or just plain top tube for the Reacto?) as close as possible. You might want to try a more detailed fit calculator like the one at the competitive cyclist website and focus on getting close on the top tube dimension.

You should double check your cycling inseam measurement. It is not your pants inseam. The fit calculator at competitive cyclist gives you one way to measure it. Using a 1" thick book and a wall works just as well, you don't need the level that competitive cyclist uses.

If I had to guess, I would think the bike in the photo is a bit small for you. However, I can't really be sure from a single photo, and also you may have to adjust saddle for correct setback. It is more important for you to try riding a couple of sizes (I would try a 52cm and 54cm) and seeing how the bikes feel in real use. If your torso is fairly long (which your measurements seem to indicate), the 50cm frame with the 535mm top tube would probably be a bit cramped/small.

what you on already ? I pick the 'vitrual' top tube length the size is a relationship to the length
factory designers choice.

you want a fast never sit up posture , or something less 'balls-to-the-wall' and sit up more.

that looks too small-short.

thanks Igualmente

according to different websites i may need size bike with ett 54-56cm depending on my height. some even say i need ett 56-58

my cyclist friend says that measurement for aerobike is different from conventional road bike. is it true?

the ett for the bike above is 535mm (size 50). it does look smaller. but the seller said if i buy the bigger size, i have to lower down the seat post and i will look awkward. the problem is the seller is only a dealer. he doesnt have every bike size..

I think how you want to use the bike is an important question. How do you plan on using the bike? Will you be using the hoods and drops like a typical road bike (not adding any kind of aero/tri bar), or, do you plan on adding aero bars?

The Reacto 5000 is a bike designed to be aerodynamic and with an aggressive racing position, but it doesn't really look like it is an aero bike in the sense of being used for time trials or triathlon.

Yes, its not tt bike or triathlon bike. It is a roadbike with allegedly aero frame. I think i ll use it more on flat road. This is the size after i remeasure my in seam. It seems like it falls between size 52 and 54.. I'm not sure which one to choose

Yes, without good help at a bike shop and all the sizes available to try, it can be hard to choose.

At least we know the 50 is probably the wrong bike.

I can't really say for sure what you should do, but at least you are between two sizes. Ideally you would get good advice from someone at a bike shop and be able to try both 52 and 54.

A last thing I will note: the 52 has 10mm less reach to the handlebars, but it also has a lower front end (19mm less stack). It might put you in a more aggressive position (which for some is good, for me would be bad because I'm not that flexible). However, you can always change the position of the handlebars a bit by changing the stem.

this is me riding Lapierre xelius 400 size 52.. looks not that cramp like merida size 50

it was from different shop. the seller said lapierre size 52 is my size.. here is comparison i made between merida and lapierre of the same size.. i quess if i can fit lapierre size 52, merida size 52 also will fit me right? looks like the geometry is not so difference..

[TABLE="width: 515"]
[TR]
[TD][/TD]
[TD]Lapierre
[/TD]
[TD]LarMerida
[/TD]
[/TR]
[TR]
[TD]Seat Tube Length **
[/TD]
[TD]520.0mm
[/TD]
[TD]520.0mm
[/TD]
[/TR]
[TR]
[TD]Top Tube Length *
[/TD]
[TD]550.0mm
[/TD]
[TD]545.0mm
[/TD]
[/TR]
[TR]
[TD]Stack
[/TD]
[TD]551.0mm
[/TD]
[TD]540.0mm
[/TD]
[/TR]
[TR]
[TD]Reach
[/TD]
[TD]382.0mm
[/TD]
[TD]390.0mm
[/TD]
[/TR]
[TR]
[TD]Head Tube Length
[/TD]
[TD]150.0mm
[/TD]
[TD]139.0mm
[/TD]
[/TR]
[TR]
[TD]Head Angle
[/TD]
[TD]73.0°
[/TD]
[TD]73.0°
[/TD]
[/TR]
[TR]
[TD]Seat Angle
[/TD]
[TD]73.0°
[/TD]
[TD]72.0°-75.0
[/TD]
[/TR]
[TR]
[TD]Chain Stay Length
[/TD]
[TD]408.0mm
[/TD]
[TD]405.0mm
[/TD]
[/TR]
[/TABLE]