Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Mountain Biking Mountain biking is one of the fastest growing sports in the world. Check out this forum to discuss the latest tips, tricks, gear and equipment in the world of mountain biking.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 10-06-05, 09:24 PM   #1
Sincitycycler
Senior Member
Thread Starter
 
Sincitycycler's Avatar
 
Join Date: Mar 2005
Location: "Gosh honey, you pass more like Tony Rominger..."
Bikes: 2005 Scott CR1 Pro - 1992 Panasonix Fixed Conversion 60tx20t
Posts: 3,219
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Inseam - 14" = proper frame size?

I saw this at some Mtb site but I forgot what link it was .

Is this a valid system for fitting? According to this formula, I have a 36" "bike" inseam and hould be using 22", which seems pretty big . BTW, I'm 6'2" and use a 61 cm Roadie...

Good fitting guide?
Sincitycycler is offline   Reply With Quote
Old 10-07-05, 12:59 AM   #2
Sincitycycler
Senior Member
Thread Starter
 
Sincitycycler's Avatar
 
Join Date: Mar 2005
Location: "Gosh honey, you pass more like Tony Rominger..."
Bikes: 2005 Scott CR1 Pro - 1992 Panasonix Fixed Conversion 60tx20t
Posts: 3,219
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
bump
Sincitycycler is offline   Reply With Quote
Old 10-07-05, 02:26 AM   #3
Raiyn
I drink your MILKSHAKE
 
Raiyn's Avatar
 
Join Date: Jul 2002
Location: St. Petersburg, FL
Bikes: 2003 Specialized Rockhopper FSR Comp, 1999 Specialized Hardrock Comp FS, 1971 Schwinn Varsity
Posts: 15,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
No it isn't a good guide. You want three to four fingers of room between the top tube and the boys. Try a 19" Also there's no need to bump threads
__________________
Raiyn is offline   Reply With Quote
Old 10-07-05, 09:43 AM   #4
Maelstrom 
Wood Licker
 
Maelstrom's Avatar
 
Join Date: Apr 2002
Location: Whistler,BC
Bikes: Transition Dirtbag, Kona Roast 2002 and specialized BMX
Posts: 16,885
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Actually, if that were a method at all, I would like say -17 or -18. Interesting idea, I am gonna have to play with the idea ...

BTW go try a 19"
Maelstrom is offline   Reply With Quote
Old 10-07-05, 06:43 PM   #5
ChroMo2
Senior Member
 
Join Date: Aug 2005
Bikes: 1997 Schwinn Moab2 cross-country racing, highly modified, rebuilt many, many times. very fast!
Posts: 256
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
a 19" frame would be good, but you would really appreciate a 21" frame. Smaller frames are good for trails. Bigger frames are better for long rides on pavement, they're actually faster.
ChroMo2 is offline   Reply With Quote
Old 10-07-05, 08:25 PM   #6
MasterSezFaster
UareFASTjustNOTfastENOUGH
 
MasterSezFaster's Avatar
 
Join Date: Jul 2005
Location: Amongst the hills in So.Cal.
Bikes: Scott Gambler, Scott Ransom, Bianchi C2C 928
Posts: 391
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ok Sin... did I not answer this for you in another thread?

My bad, I just check and I answered it for a different roadie I, my self, also ride a 61cm roadie but mtb's are a totally different breed.

Here is what I said to the other guy (with some modifacation), "I am 6'2" with a 34 1/4" inseam and 20" would be the largest size I would get and that would be pushing the limit and if I were only going to be on fire trails or well groomed trails. If you will be riding technical trails I would say look into getting an 18" or 19" frame if it will be for XC and a 17" frame if the trails are VERY technical. You need to remember, you do not size a mountain bike like a road bike. They are two totally different animals "

MSF
__________________
MasterSezFaster is offline   Reply With Quote
Old 10-07-05, 08:57 PM   #7
Killer B
THIS BIKE'S 4 U !!!!
 
Killer B's Avatar
 
Join Date: Sep 2004
Location: Western, NC .... (Pisgah, Bent Creek, DuPont)
Bikes: HARO Xtreme X2, K2 Lithium 3.0, K2 Beast, K2 Flyin' Monkey, DiamondBack Accent EX, DiamondBack Axis TR
Posts: 1,272
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
WTF are you posting in the MtnBiking forum if you're a Roadie?

The correct answer to your question is "Way Big", go figure....
Killer B is offline   Reply With Quote
Old 10-08-05, 01:31 AM   #8
Raiyn
I drink your MILKSHAKE
 
Raiyn's Avatar
 
Join Date: Jul 2002
Location: St. Petersburg, FL
Bikes: 2003 Specialized Rockhopper FSR Comp, 1999 Specialized Hardrock Comp FS, 1971 Schwinn Varsity
Posts: 15,061
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ChroMo2
a 19" frame would be good, but you would really appreciate a 21" frame. Smaller frames are good for trails. Bigger frames are better for long rides on pavement, they're actually faster.
Considering this is the Mountain Bike section and not the Riding on Pavement section one should presume we're not talking about pavement bikes here
__________________
Raiyn is offline   Reply With Quote
Old 10-08-05, 02:07 AM   #9
Sincitycycler
Senior Member
Thread Starter
 
Sincitycycler's Avatar
 
Join Date: Mar 2005
Location: "Gosh honey, you pass more like Tony Rominger..."
Bikes: 2005 Scott CR1 Pro - 1992 Panasonix Fixed Conversion 60tx20t
Posts: 3,219
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Killer B
WTF are you posting in the MtnBiking forum if you're a Roadie?

The correct answer to your question is "Way Big", go figure....
WTF? I want to diversify my riding experience. Yes , even in the desert it gets cooler and I don't like going 25+ mph on my road bike with cold wind blasting in my face and engaging in runny nose heaven.
__________________
"How did all those 'Keep Off the Grass' signs get there?"
Sincitycycler is offline   Reply With Quote
Old 10-08-05, 08:20 AM   #10
MasterSezFaster
UareFASTjustNOTfastENOUGH
 
MasterSezFaster's Avatar
 
Join Date: Jul 2005
Location: Amongst the hills in So.Cal.
Bikes: Scott Gambler, Scott Ransom, Bianchi C2C 928
Posts: 391
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ahhh don't worry Sin, just like in the roadie section some folks here have their head up their ***
No need to justify your self, ask away.

MSF
__________________
MasterSezFaster is offline   Reply With Quote
Old 10-08-05, 08:48 AM   #11
mtnbiker66
Old School Rad
 
mtnbiker66's Avatar
 
Join Date: Sep 2004
Location: The old Mountains
Bikes: Blur LT
Posts: 8,212
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by MasterSezFaster
Ahhh don't worry Sin, just like in the roadie section some folks here have their head up their ***
No need to justify your self, ask away.

MSF
Fer sure.
__________________
Like a circus monkey on a stolen Harley......
mtnbiker66 is offline   Reply With Quote
Old 10-08-05, 09:41 AM   #12
Krazy Koz
enjoy the ride
 
Krazy Koz's Avatar
 
Join Date: Aug 2005
Location: Columbus, Ohio
Bikes: The Ship of Theseus - the only bicycle that I own or have ever owned. It is a bike that I built, with a constantly shifting constellation of parts & frames.
Posts: 74
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Kudos to you for actually taking your inseam measurement; I would say that 85-90% of all people who buy bikes never do this. Once you get your inseam size, all you need to do is plug it into one of the two frame size formulas: one for MTB frames and one for road bikes. To get your MTB size, take your inseam measurement, multiply it by .65, and then subtract four inches from that. Or stated another way:

MOUNTAIN BIKE FRAME SIZE:
(inseam * .65) - 4'' = frame size
ergo,
36 * .65 = 23.4 - 4 = 19.4

Therefore, you should ride a 19'' frame.
Krazy Koz is offline   Reply With Quote
Old 10-08-05, 11:33 AM   #13
ChroMo2
Senior Member
 
Join Date: Aug 2005
Bikes: 1997 Schwinn Moab2 cross-country racing, highly modified, rebuilt many, many times. very fast!
Posts: 256
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Raiyn
Considering this is the Mountain Bike section and not the Riding on Pavement section one should presume we're not talking about pavement bikes here
I ride 90% on pavement. I ride between 3 and ten hours when I ride. My bike is built for real world cross country racing (not a closed circuit) it goes anywhere, anyplace, anytime, and it does it fast! When I go off road I have no second thoughts of my capabilites. I'm 6'2" with a 36" inseam and my 21.5" stumpjumper with ridgid fork took me 135 in a day, 80 miles on singletrack. My bike never gets locked or attached to a car to take it somewhere. By design, my bike can pace many roadbikes and still do trails reserved for dual suspension bikes. My current frame size is 19" front suspension only (to slaughter the trails) I miss having a bigger frame, but since my riding techniques are above average, I have great compensation in my abilites to do on and off road riding.The rider is a big factor in the equation. I don't know what your limits are, but I don't have any.
ChroMo2 is offline   Reply With Quote
Old 10-09-05, 01:02 AM   #14
Sincitycycler
Senior Member
Thread Starter
 
Sincitycycler's Avatar
 
Join Date: Mar 2005
Location: "Gosh honey, you pass more like Tony Rominger..."
Bikes: 2005 Scott CR1 Pro - 1992 Panasonix Fixed Conversion 60tx20t
Posts: 3,219
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Krazy Koz
Kudos to you for actually taking your inseam measurement; I would say that 85-90% of all people who buy bikes never do this. Once you get your inseam size, all you need to do is plug it into one of the two frame size formulas: one for MTB frames and one for road bikes. To get your MTB size, take your inseam measurement, multiply it by .65, and then subtract four inches from that. Or stated another way:

MOUNTAIN BIKE FRAME SIZE:
(inseam * .65) - 4'' = frame size
ergo,
36 * .65 = 23.4 - 4 = 19.4

Therefore, you should ride a 19'' frame.
Thanks!
__________________
"How did all those 'Keep Off the Grass' signs get there?"
Sincitycycler is offline   Reply With Quote
Old 10-09-05, 03:18 AM   #15
Brian
Senior Member
 
Brian's Avatar
 
Join Date: Nov 2004
Location: Between the mountains and the lake.
Bikes: 8 bikes - one for each day of the week!
Posts: 16,683
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Krazy Koz
Kudos to you for actually taking your inseam measurement; I would say that 85-90% of all people who buy bikes never do this. Once you get your inseam size, all you need to do is plug it into one of the two frame size formulas: one for MTB frames and one for road bikes. To get your MTB size, take your inseam measurement, multiply it by .65, and then subtract four inches from that. Or stated another way:

MOUNTAIN BIKE FRAME SIZE:
(inseam * .65) - 4'' = frame size
ergo,
36 * .65 = 23.4 - 4 = 19.4

Therefore, you should ride a 19'' frame.
If it were only that simple. Based on my experience selling bikes, and my own experience with the bikes I currently have, there is no simple formula. If I've got 4 bikes ranging from a 15" to a 19", I don't see how your forumla is valid. Of course, that variation can be applied to my inseam as well. Are you measuring pants, or are you measuring your body? My Old Navy jeans just touch my shoelaces. My Armani slacks measure about 2 inches longer, with a proper break at the cuffs. The only way to properly determine your frame size is to check the standover on the actual bike you're going to buy. You'll also need to check for proper reach and leg extension. And plenty of people choose the wrong size.
Brian is offline   Reply With Quote
Old 10-09-05, 04:50 AM   #16
dirtyamerican
KGB Style
 
dirtyamerican's Avatar
 
Join Date: Aug 2005
Bikes:
Posts: 158
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Raiyn
No it isn't a good guide. You want three to four fingers of room between the top tube and the boys.
Assuming all bike frames have the same standover height and geometries, which they vary by a lot!
dirtyamerican is offline   Reply With Quote
Old 10-09-05, 07:15 AM   #17
MasterSezFaster
UareFASTjustNOTfastENOUGH
 
MasterSezFaster's Avatar
 
Join Date: Jul 2005
Location: Amongst the hills in So.Cal.
Bikes: Scott Gambler, Scott Ransom, Bianchi C2C 928
Posts: 391
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
19" is your starting point. Try bikes between 17" and 20". Here is where mtb's are like roadies, the different geometries will affect what size frame you get as well as the terrain you are going to ride.

An example would be, a large framed RockyMountain RMX has the same standover hight as a large Kona StabPrimo but the top tube of the RMX is very short compared to the Stab because one is more of a racer(the Stab) and the other is more for big hits. Now if I go get on my XC bike (Bianchi CaŠl 8800 48cm/19") I have very little standover compared to either of the others and a longer tt.

As with the road bikes, you need to ride as many different bikes as you can to find the "right" one for YOU. You may even get a bike on the larger side. I have a buddy that races semi-pro xc (constantly places in the top 10) and does a lot of 24hr events, he is 5'9" (not sure about his inseam but he does not have long legs) and rides a 20" bike. He uses the same bike when we hit the jumps and drops. Just pointing out it will be what you feel most comfortable on.

MSF
__________________

Last edited by MasterSezFaster; 10-09-05 at 09:45 AM.
MasterSezFaster is offline   Reply With Quote
Old 10-09-05, 08:58 AM   #18
Sincitycycler
Senior Member
Thread Starter
 
Sincitycycler's Avatar
 
Join Date: Mar 2005
Location: "Gosh honey, you pass more like Tony Rominger..."
Bikes: 2005 Scott CR1 Pro - 1992 Panasonix Fixed Conversion 60tx20t
Posts: 3,219
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by MasterSezFaster
19" is your starting point. Try bikes between 17" and 20". Here is where mtb's are like roadies, the different geometrys will affect what size frame you get as well as the terrain you are going to ride.

An example would be, a large framed RockyMountain RMX has the same standover hight as a large Kona StabPrimo but the top tube of the RMX is very short compared to the Stab because one is more of a racer(the Stab) and the other is more for big hits. Now if I go get on my XC bike (Bianchi CaŠl 8800 48cm/19") I have very little standover compared to either of the others and a longer tt.



As with the road bikes, you need to ride as many different bikes as you can to find the "right" one for YOU. You may even get a bike on the larger side. I have a buddy that races semi-pro xc (constantly places in the top 10) and does a lot of 24hr events, he is 5'9" (not sure about his inseam but he does not have long legs) and rides a 20" bike. He uses the same bike when we hit the jumps and drops. Just pointing out it will be what you feel most comfortable on.

MSF
__________________
"How did all those 'Keep Off the Grass' signs get there?"
Sincitycycler is offline   Reply With Quote
Old 10-09-05, 09:35 AM   #19
hooligan
Just give'er.
 
hooligan's Avatar
 
Join Date: Nov 2003
Location: SF Bay Area
Bikes: 04 Scrap
Posts: 1,898
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
It's whichever feels good. Test ride the bikes.
hooligan is offline   Reply With Quote
Old 10-09-05, 11:22 AM   #20
stapfam
Time for a change.
 
stapfam's Avatar
 
Join Date: Jan 2004
Location: 6 miles inland from the coast of Sussex, in the South East of England
Bikes: Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
Posts: 19,915
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by Raiyn
No it isn't a good guide. You want three to four fingers of room between the top tube and the boys. Try a 19" Also there's no need to bump threads

The 3 to 4 fingers is the best way to measure, but a 19" from one manufacturer will be different to a 19" of any other manufacturer. Get the 3 to 4 fingers and then check out top tube length and reach to the bars.

(Thinking Kona that have an extended seat tube above the Top bar and a longer reach than most)
stapfam is offline   Reply With Quote
Old 10-09-05, 12:59 PM   #21
Krazy Koz
enjoy the ride
 
Krazy Koz's Avatar
 
Join Date: Aug 2005
Location: Columbus, Ohio
Bikes: The Ship of Theseus - the only bicycle that I own or have ever owned. It is a bike that I built, with a constantly shifting constellation of parts & frames.
Posts: 74
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Expatriate
If it were only that simple. Based on my experience selling bikes, and my own experience with the bikes I currently have, there is no simple formula. If I've got 4 bikes ranging from a 15" to a 19", I don't see how your formula is valid. Of course, that variation can be applied to my inseam as well. Are you measuring pants, or are you measuring your body? My Old Navy jeans just touch my shoelaces. My Armani slacks measure about 2 inches longer, with a proper break at the cuffs. The only way to properly determine your frame size is to check the standover on the actual bike you're going to buy. You'll also need to check for proper reach and leg extension. And plenty of people choose the wrong size.
Measuring your body part, from the bottom of your foot to the bottom of your pubic bone. I would certainly hope that nobody would take a look at the tag in their pants and go to the bike shop hoping to get a good bike fit. I wouldn't argue that anyone should simply trust an abstract number over their own experience on a bike. However, I would argue that frame size has become standardized to a large extent and while there are differences between the geometry of one bike and another, I would also say that those differences are smaller than the similarities (except with Kona and Fisher bikes, I've noticed).

A formula will not give you a size for every bike in every circumstance, but it will give you a starting point, and one that will more than likely get you pretty close to your size.

Big caveat: I would say that the formula I presented is what I use for trails. For downhilling, freeriding, and hucking you are going to want an even smaller frame.
Krazy Koz is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 11:16 AM.