MTB Sizing

Good morning all,

I am hoping someone can answer this soon, ebay awaits!!!

How do you size a MTB? ie what is the relationship between the seat tube and the size of the rider?

Thanks,

Richard

Wowzers?? Well if it feels comfortable then it's the right size

But on a serious note as frame geometry varies so does the suitability of frame, I'm a tad over 6ft, 33" leg and fairly long reach, and in my collection have 18" Frame, 19" Frame, some sized as Large, one Full Susser in a Medium, I'm sure if you took all the measurements they would all vary slightly, some more than others, however all are comfortable as they are set up for me and my riding style, some have riser bars some flats some have Front rigid forks others with anything between 60mm & 100mm of Suspension Fork travel. You can roughly size against inside leg, reach and height but there are some tall riders who prefer smaller frames than to be sat on a Gate. If you can try before you buy then its a bonus but if you are doing a build from scratch then it may be a case of trial and error until you get that comfortable ride

Jussa,

This relates to a purchase on the bay. Road bikes are a bit easy - subtract 10'' from inside leg measurement (best rough guide) i am wondering if there is an easy method like the for MTB's.

But thanks - i am about your size so i know what would fit me.

Being 6 foot with long legs and short arms, a road bike can be as big as 60cm whereas an MTB can be as small as 17".

Its very easy to make MTBs fit due to the number of different stems available, add a long seatpost and you have a lightweight chuckable trail machine.

Is the measurement of the seat tube different then from a road bike? I am trying to work out a size for a frame for my mate. He is 5'9'' with inside leg of 30''. What would this equate to in MTB frame size?

Or, will almost any frame do - just with a scaffolding pole for a seat post when required?

Thanks Mr Large Cheese

when I bought my marin back in 1992 ISTR it was road less 3-4 inches hence I ended up with 19" frame Marin and ride 22.5-23" road but the marin does feel bit big and prefer a 17.5" in same frame now, the issue is less the seat tube as can adjust seat pin but rather the overall reach and position,

I think it rather depends on make and really endorse the comments above, it's just not that simple.......unfortunately

Thanks for the responses, i think i understand that a rough size and mess about with seat posts should sort it out.

Thanks all, much appreciated.

I start from a base of 5ft10 = 18/19in and work from there

Some companies give their sizes from the centre of the crank to the centre of the seat tube..the same say 19 inch could be measured by another company centre of the crank to the top of the seat tube

Much like a road bike your looking at the two figures..frame size from where to where and the top tube length

Without showing the ebay sale..if your able to say what year and/or the manufacturer then some will be able to give you where that manufacturer measures from

simple rule of thumb for road bike frames is:
1/3rd height in inches
10 inch subtracted from your trouser leg length

for mtb subtract anoither 5 inches.