Jump to content

Mountain Bike Sizing


Barry Nel

Recommended Posts

Posted

Hi, I am in the process of buying a new bicycle and I have come across a great deal on a Titan Skyrim Elite. The only problem is that the only sizes available are 16" 18" and 20". I am 191cm and on most online sizing guides it tells me I need to get a 21" or 22" bike, will it make a huge difference if I get the 20" version or should I look for a bigger bicycle?

Posted

I would stick to the right size.

 

Sizing plays a big role in being comfortable on a bike and getting an enjoyable experience out of it.

 

I was once forced to ride my wife's bike for a day (mine was in for a repair) she is one size smaller than mine and it felt absolutely horrible.

 

I had ZERO confidence on it and ended up cutting a ride short (pun intended) because of it.

 

Welcome to theHub by the way! 

Posted

Sizing is 100% the most important thing when getting a bike. If you get the wrong size then it doesn't matter how good the deal is, it's not going to be a good deal for you. Wait for the right size....

 

I have made this mistake before, believe me - not worth it.

Posted

Hi, I am in the process of buying a new bicycle and I have come across a great deal on a Titan Skyrim Elite. The only problem is that the only sizes available are 16" 18" and 20". I am 191cm and on most online sizing guides it tells me I need to get a 21" or 22" bike, will it make a huge difference if I get the 20" version or should I look for a bigger bicycle?

Cycling is tough. At times very tough. You as the rider deserve to be comfortable when sufferering. It all starts with the correct size frame, thereafter you tweek the other parts.

If you ride the wrong size frame, you will always have it in the back of your mind. It effect your confidence.

So ja, rather go for your bike size. Its the right thing to do.

Enjoy

Posted

Barry WELCOME to the Hub.

 

 

YES !!  Bike size is THEE most important thing !!!

 

 

When I got back into cycling I bought a bike that "felt right".  A year later I was riding further and harder .. and having the weirdest pains.  Turns out the bike was too small.  Now two sizes larger I am at tripple the distances without any issues.  Seriously expensive school fees !!

Posted

Although I agree with the comments here, I would caution against just looking at a number when it comes to bike frame sizes; especially on MTBs.

 

A 20” from one brand is way different from a 20” from another brand.

 

The biggest size the Skyrim comes in is the 20”, and it may fit you. I would suggest that you get measured up at a bike shop that stocks Titan, and see what they suggest. You could also try and get the sizing charts for Titan (if available), to get some ideas. Some brands however only cater for ‘average’ height riders, and don’t really cover the short or tall guys.

 

At your height, I do however think this will be too small.

Posted

Although I agree with the comments here, I would caution against just looking at a number when it comes to bike frame sizes; especially on MTBs.

 

A 20” from one brand is way different from a 20” from another brand.

 

The biggest size the Skyrim comes in is the 20”, and it may fit you. I would suggest that you get measured up at a bike shop that stocks Titan, and see what they suggest. You could also try and get the sizing charts for Titan (if available), to get some ideas. Some brands however only cater for ‘average’ height riders, and don’t really cover the short or tall guys.

 

At your height, I do however think this will be too small.

 

Ja .... nee ....

 

 

YES - frames sizes differ between brands.  And it is best to use the frame size guide from the brand you are looking at.

 

 

no ... my expensive school fees stem from a bike shop that "sold what they had on the floor" ...  The deal was concluded by the owner himself, a former professional cyclist that SHOULD know about proper bike sizing !! All he had to do was to tell me that he will order in the correct size, and I would have had the correct size 2 or 3 days later ....  Thus my personal experience clouds my judgement, and I would rather trust a specialist bike fitter.

 

 

PS - I know there may be trustworthy shops out there, and I am sure they are as frustrated with this "bad apple" salesman as I am.

Posted

the 16" 18" and 20" refers to the seat tube length and that's not an important measurement to determine that a bike fits you. The reach and or top tube lengths are the most important measurements. So best to check out the bike in person to see if it can fit you

Posted

Hi, I am in the process of buying a new bicycle and I have come across a great deal on a Titan Skyrim Elite. The only problem is that the only sizes available are 16" 18" and 20". I am 191cm and on most online sizing guides it tells me I need to get a 21" or 22" bike, will it make a huge difference if I get the 20" version or should I look for a bigger bicycle?

Disclaimer: im not a bike fit pro but i know what i like and not. Also...text wall of death to follow:

 

I sympathise with you as i'm 197cm....with long legs and a shorter torso.

Im super pedantic when it come to fit when i get a new bike because its always a struggle to get comfortable..especially on bikes i know i will be spending a lot of time sitting in the saddle.

 

I get all my new bikes' geometry and draw them out in software to test out different options in stems/risers/stacks etc lol to make sure im making an informed decision. I have all my own measurements too.  im not trusting some bike shop moegoe wanting to make his sales target. :whistling:

 

The online recommendations are off to an extent. They give blanket answers. What they don't take into account is body proportions and new bike geometry and longer frames with more reach....and all the other small nuances that can make a bike fit better.

 

if you have super long legs like me...you will have plenty of seat-post showing no matter what....and thats fine. The problem Comes in when you get something that fits your legs with only 150mm seatpost showing but is too long for you in the reach department. That is almost worst...you will suffer from lower back pain almost certainly from being stretched out. For people our lenght, frame stack is also important...since your you will want to get your bar roughly at the same height for your seat. 

 

The best bandaid-advice i can give you is measure  your cycling inseam first (or get it measured). Using this and the online calculators to calculate saddle height for a MTB will get you a ballpark figure for the distance from the crank or pedal spindle (depending on formula) to the top of the saddle but will not be where you are 100% comfy. But very close..close enough to make an informed decision imo.

I know mine is 860mm from crank spindle to top of saddle using 175mm cranks on a mtb for example.

 

This will give you a better idea of that generic/ambiguous number on frames they use for sizing (18/19/20" , which is basically only the seat tube length)

From there you will at least know how much seat post will be showing on a given frame. 

 

 

 

purely as an example (im not some bike fit pro)...here is how I ended up doing it for my last bike...and I got it perfect for me and the type of riding it was intended for. I can ride this thing for a 100km and not hurt.

 

it is a  is a 510mm XL ( 20") as per the attached geometry.

 

I compared it all and built up to everything using their actual geometry numbers from their sites in cad as mentioned. Treks, giants, Cotics...everything that offered anything I liked in a size close to what i needed.  Even ones like the 23" Spaz Fuse fatty. What this exercise showed me was that the number on the seat tube does not mean too much...

 

If you are not as pedantic...just go throw a leg over the 20" like everybody says. It should be close to the right size for you imo. :D  ;)

post-64325-0-27466100-1560408025_thumb.jpg

post-64325-0-83837900-1560408254_thumb.jpg

post-64325-0-38973800-1560408649_thumb.jpg

Posted

Disclaimer: im not a bike fit pro but i know what i like and not. Also...text wall of death to follow:

 

I sympathise with you as i'm 197cm....with long legs and a shorter torso.

Im super pedantic when it come to fit when i get a new bike because its always a struggle to get comfortable..especially on bikes i know i will be spending a lot of time sitting in the saddle.

 

I get all my new bikes' geometry and draw them out in software to test out different options in stems/risers/stacks etc lol to make sure im making an informed decision. I have all my own measurements too.  im not trusting some bike shop moegoe wanting to make his sales target. :whistling:

 

The online recommendations are off to an extent. They give blanket answers. What they don't take into account is body proportions and new bike geometry and longer frames with more reach....and all the other small nuances that can make a bike fit better.

 

if you have super long legs like me...you will have plenty of seat-post showing no matter what....and thats fine. The problem Comes in when you get something that fits your legs with only 150mm seatpost showing but is too long for you in the reach department. That is almost worst...you will suffer from lower back pain almost certainly from being stretched out. For people our lenght, frame stack is also important...since your you will want to get your bar roughly at the same height for your seat. 

 

The best bandaid-advice i can give you is measure  your cycling inseam first (or get it measured). Using this and the online calculators to calculate saddle height for a MTB will get you a ballpark figure for the distance from the crank or pedal spindle (depending on formula) to the top of the saddle but will not be where you are 100% comfy. But very close..close enough to make an informed decision imo.

I know mine is 860mm from crank spindle to top of saddle using 175mm cranks on a mtb for example.

 

This will give you a better idea of that generic/ambiguous number on frames they use for sizing (18/19/20" , which is basically only the seat tube length)

From there you will at least know how much seat post will be showing on a given frame. 

 

 

 

purely as an example (im not some bike fit pro)...here is how I ended up doing it for my last bike...and I got it perfect for me and the type of riding it was intended for. I can ride this thing for a 100km and not hurt.

 

it is a  is a 510mm XL ( 20") as per the attached geometry.

 

I compared it all and built up to everything using their actual geometry numbers from their sites in cad as mentioned. Treks, giants, Cotics...everything that offered anything I liked in a size close to what i needed.  Even ones like the 23" Spaz Fuse fatty. What this exercise showed me was that the number on the seat tube does not mean too much...

 

If you are not as pedantic...just go throw a leg over the 20" like everybody says. It should be close to the right size for you imo. :D  ;)

I found this site rather helpful http://pedalforce.com/online/bikefit.php?osCsid=45a9070871d9664e2e80a7cc04627361

 

you put in your measurements, and if you want the measurements of the bike you're looking to get and it will give you seat heights and stem lengths etc.

Posted

I found this site rather helpful http://pedalforce.com/online/bikefit.php?osCsid=45a9070871d9664e2e80a7cc04627361

 

you put in your measurements, and if you want the measurements of the bike you're looking to get and it will give you seat heights and stem lengths etc.

i used all those websites to cross check. They all differ slightly depending on what algorithms/formula they use. I worked with the average between a few and used that number. in the end I ended up dropping my saddle by about 10mm from recommended to be 100% comfy over longer distances.

 

this is also a good-ish one

https://www.competitivecyclist.com/Store/catalog/fitCalculatorBike.jsp#results

 

and this was a huge help too to see how certain things affected geometry...like going rigid vs 140mm fork in my case...and what fork lenth i needed to keep bb drop to a minimum.

 

i know its a bit more hardtail specific though:

https://www.bikegeocalc.com/

Posted

Hi, I am in the process of buying a new bicycle and I have come across a great deal on a Titan Skyrim Elite. The only problem is that the only sizes available are 16" 18" and 20". I am 191cm and on most online sizing guides it tells me I need to get a 21" or 22" bike, will it make a huge difference if I get the 20" version or should I look for a bigger bicycle?

Simple calculation is take your inseam length x0883 that is your saddle height from BB to top of saddle. Now you can subtract about 1.5-2cm from that length 

 

 

 

Now you have the length you will need from the BB to the saddle rails. 

 

Subtract the bike seat tube length and you can see what length seatpost you will need. 

 

The longest seatpost you can get EASILY is 400mm but only 300 is usable.

 

 

 

Now you can see IF you can even get the correct seat height on a frame. If you are approaching limits then you know it is to small.

 

 

 

For example I need a seat height of 740, now if a seat tube is ANYTHING shorter than 440 then it will not work for me as I will not get the correct seat height even with a 400mm seatpost. 

 

 

 

Now there is also the Top Tube. The smaller the frame the longer stem you will need. MTB does not like stems longer than 100mm these days.

 

 

 

You can also look for online fit calculators that will ask you Height, arm length etc etc and the map out a recommended bike geo for you

Posted

the 16" 18" and 20" refers to the seat tube length and that's not an important measurement to determine that a bike fits you. The reach and or top tube lengths are the most important measurements. So best to check out the bike in person to see if it can fit you

Agree with you but you can get a seat tube so short that you can not get the correct seat height even with the longest seat post you can find

Posted

Agree with you but you can get a seat tube so short that you can not get the correct seat height even with the longest seat post you can find

 

 

YEs true but I'm sure a 20" seat tube will accommodate a 400mm seat post for a tall rider

Archived

This topic is now archived and is closed to further replies.

Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout