Size

[Glasgow44]

Hi again

As part of my shopping quest for an adventure road bike, at the weekend, I went to one of my local bike shops and had a look at the following bike:

https://www.merida-bikes.com/en/bike/138/silex-400

I tried out a 50 and a 47. The guy in the shop said that a 50 would be too big and indeed it was. He suggested a 47. When I was standing over the 47, my groin did touch the top tube, I queried this with the salesman and he said that if I was to go lower to the size 44, then my saddle height would be too high. I know that the rule of thumb is that ones “bits” shouldn’t touch the top tube but mine do on all my bikes! I also had an interesting chat with another guy in a different bike shop who said that sometimes the trade off is that the correct frame size means that you have to touch the top tube as sizing down would be sizing down just too much.



What do you think?

I'm roughly 5'5/5'6

Thanks in advance

J

 

[Slick]

I know my Lbs tried to convince me to go to a smaller frame with a larger stem but I wasn't convinced. They reckoned it was the modern way of sizing bikes but I still prefer comfort over what a salesman thinks.

 

[Slick]

Also, geometry changes over so many spectrums when you are discussing bike size, one size certainly doesn't fit all when it comes to manufacturers differences.

 

[Cycleops]

When I was standing over the 47, my groin did touch the top tube, I queried this with the salesman and he said that if I was to go lower to the size 44, then my saddle height would be too high. I know that the rule of thumb is that ones “bits” shouldn’t touch the top tube but mine do on all my bikes!

J

Trouble is that can vary with the ambient temperature .

 

[SkipdiverJohn]

Trouble is that can vary with the ambient temperature .

So in Africa you need a smaller frame to clear your bigger bits, whereas in Scotland the cold means you can size up a bit!

 

[vickster]

Ride them, don’t just stand over. If you can’t, go somewhere else

 

[Deleted member 1258]

Hi again

As part of my shopping quest for an adventure road bike, at the weekend, I went to one of my local bike shops and had a look at the following bike:

https://www.merida-bikes.com/en/bike/138/silex-400

I tried out a 50 and a 47. The guy in the shop said that a 50 would be too big and indeed it was. He suggested a 47. When I was standing over the 47, my groin did touch the top tube, I queried this with the salesman and he said that if I was to go lower to the size 44, then my saddle height would be too high. I know that the rule of thumb is that ones “bits” shouldn’t touch the top tube but mine do on all my bikes! I also had an interesting chat with another guy in a different bike shop who said that sometimes the trade off is that the correct frame size means that you have to touch the top tube as sizing down would be sizing down just too much.



What do you think?

I'm roughly 5'5/5'6

Thanks in advance

J

I'm simular hight to you and I'd go for the 47. I've got a Genesis flyer and a Eastway and they are both 47's, whats the top tube length, I cant find a sizing chart on the page you linked to.

 

[Spiderweb]

I’ve never sized a bike based on ‘privates’ clearance, size is imo about the length of top tube/reach.

 

[Glasgow44]

I'm simular hight to you and I'd go for the 47. I've got a Genesis flyer and a Eastway and they are both 47's, whats the top tube length, I cant find a sizing chart on the page you linked to.

Here is the link:

https://www.merida-bikes.com/en/bike/138/silex-400

 

[vickster]

So it's a 47cm seat tube but 55cm TT? How tall are you? It gives a guide at the bottom if the geometry table, 47cm good up to about 5'10 (from 5'5ish), 50cm about 5'9 up
It's got a v slopey TT which will affect stand over if you're up by the bars for some odd reason

Go ride the 47, 50 far too big if you're not likely to get any taller

 

[Deleted member 1258]

Here is the link:

https://www.merida-bikes.com/en/bike/138/silex-400

The 47 would be too long in the top tube for me as would the 44, strange geometry.

 

[Spiderweb]

Really odd geometry. The XS frame has a top tube length which you would usually see on most medium sized frames.

 

[SkipdiverJohn]

I’ve never sized a bike based on ‘privates’ clearance, size is imo about the length of top tube/reach.

In the case of a bike used for long leisure rides I wouldn't worry unduly about standover as you won't be dismounting too frequently. However, if you're riding in cut & thrust urban traffic or playing around on gravel/in woods, then a bit of clearance allows a safety margin for mishaps and unplanned sudden stops. BB height can make a noticeable difference to standover, even on supposedly same-sized frames. I've got two 23" Raleighs that have to be ridden with more care than my others the same size because they have high BB's
Modern sloping geometry frames are a real pain for sizing because the lower standover means a small rider can still straddle a frame with way too long a reach, whereas in the old days, with proper steel frames measured in inches and horizontal crossbars, if a bike was tall enough to make you sing like a soprano you would choose a smaller size which would usually have a shorter TT and therefore avoid over-reaching. It's physically possible to mount a lot of modern bikes that are wildly mis-sized for the rider, without the horizontal crossbar there to act as a sanity check.

 

[youngoldbloke]

I'm 5'5". I would go for the 44cm, but have quite short legs -780mm floor to crutch.

 

[Deleted member 1258]

Really odd geometry. The XS frame has a top tube length which you would usually see on most medium sized frames.

The 47 has a far longer top tube than my Genesis which has a 47 seat tube.