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GETTING FIT ON MY 1ST ROADBIKE ???PLEASE HELP(9 posts)

GETTING FIT ON MY 1ST ROADBIKE ???PLEASE HELPRPM M
Jul 4, 2001 4:51 PM
I RECENTLY HAVE BEEN ON A QUEST TO PURCHASE MY 1 ST ROADBIKE I HAVE BEEN RECEIVING CONFLICTING IMFO ON PROPER FIT I AM 5'7 1/2 AND HAVE A 31 1/4 INSEAM WHEN I WALK INTO SHOPS THEY USUALLY THINK I AM, A 52 OR 53 HELL I EVEN HAD ONE GUY TELL ME I WAS A 49???????? HOWEVER WHEN I PICKUP A BIKE SUCH AS A 54(CANNONDALE,CAAD 6)I LEAVE @ 3" UNDER THE TIRES..THEN THEY MOVE ME TO A 56 AND THERE IS @ AN 1"-1.5" when I sat on the 56 as I looked down across the bars I did not see the front hub...any input would be appreciated.....RM
re: GETTING FIT ON MY 1ST ROADBIKE ???PLEASE HELPfuzzybunnies
Jul 4, 2001 8:39 PM
One problem you could be running into is the actual size of the bikes can vary from company to company. An example would be that someone who rides a 53cm trek would ride a 51cm raleigh. Each company uses a different point of reference on the seat tube to do thier measuring. A 56 seems like it might be a little large though depending on your perportions you might need to go for something a little taller to get a proper reach. Something that can be adjusted with a stem to some extent. If they don't have a size you feel fits and they're trying to get you on something you don't feel comfy on go to a different shop. TTFN
re: GETTING FIT ON MY 1ST ROADBIKE ???PLEASE HELPHighgear
Jul 4, 2001 9:08 PM
Bike fit is the most important part, the bike is second. Stand over hight is not the way to fit a bike. The first step is to set your shoes up correctly ( I presume you are using clipless pedals) , ball of the foot over the pedal axle to 4mm forward of it. Second would be to find your correct saddle hight and setback. After this you you dial in your bar hight and reach. Your saddle hight should be as high as you can go without reaching for the pedals. You will have a very slight bend in the knee when the the pedal is at six o'clock. Now you move on to the fore and aft placment of the saddle. Sitting on the saddle in the spot you will be riding in, foot at six o'clock, pedal level (have someone help you with this) drop a plumb line from just under the kneecap, it should line up with the center of the pedal axle to one cm behind it. Moving your saddle forward will shorten the saddle hight, moving it back will lengthen it, so you will have to recheck the hight if you do move it. When all is done, it would be nice that the seat post carriage is centered on the rails of the saddle. If you find that the when it's all set but the saddle looks too far forward you will need a frame that has a steeper seat tube angle or vice versa. Now once this is set you move on to finding what your drop will be from the top of the saddle to the top of the bars along with what the reach will be from the tip of the saddle to the center of the bars. I'm tall and ride with a 10cm drop, typical flat back race position. You might not be comfortable at that. Try to see how low you can go and still be comfortable. This will be the deciding factor in what size frame you will need. The smaller the better. If you pick too big of a frame, you won't be able to drop your bars down enough or if you pick a too small of a frame you will end up with too many spacers under your stem. Now that you have found your correct drop, you look to find your correct reach. With your hands gripping the the tops(not the levers,the bars) bend forward till your forarms are parallel to the top tube ,your humerus or upper arm should be at about the same angle as the head tube. This will be brought in by changing stem lengths. Now that all this is said. You don't want a 140mm stem on anything under a 62cm frame and you don't want a 90mm stem on anything over a 50cm frame. What I'm trying to say is that you have to find out what top tube length you'll need and using a stem to correct a wrong top tube length is totally wrong, it throughs off your balance on the bike. The best way to dial in your frame size is to find the best shop around that has an adjustable frame jig like the serotta sizecycle and have a well trained person set you up. Bring the saddle you will use on your bike and have them mount it on the jig. You will have to pay for this fitting but it is money well spent. Bike fit is very complex but with time and understanding it's a worthful gole. I will try to post below some web sites that will help you. Good Luck
re: GETTING FIT ON MY 1ST ROADBIKE ???PLEASE HELPmackgoo
Jul 4, 2001 11:39 PM
Just one comment, for the plumb bob job, shouldn't the pedals be at 3 and 9 o'clock?
Yesdavidl
Jul 5, 2001 6:39 AM
Poster referenced 'cyfac' - check item #10: says the crank arms are parallel to the floor when taking this plumb bob measurement.
Oops, it was late at night. Drop the plumb line from the knee-Highgear
Jul 5, 2001 6:39 AM
when the cranks are at 3 o'clock and the pedal is level with the ground. Sorry
Fit linksHighgear
Jul 4, 2001 9:28 PM
http://www.bsn.com/Cycling/ergobike.html http://www.cyfacusa.com
CAAD 6 for your first bike?! I wish I had that much money...(nm)Mabero
Jul 5, 2001 6:39 AM
your inseam isn't 31-3/4".....C-40
Jul 5, 2001 5:50 PM
I'm 5'-7" in height with a 32-5/8" inseam. I ride a 55cm frame, with a standover height of 31.3 inches, which gives me a little over 3cm or 1-1/4" standover clearance.

The standover height on a 56cm C'dale is right at 32 inches, which is more than your stated inseam. Maybe these guys don't even know the size of frame they have you trying. The standover clearance you've described for the 56 sounds like a 54 to me. If in doubt, take a tape measure with you. The standover height of a 54cm should be about 31-3/16".

At your height, a 54 would probably give the best top tube length, but standover clearance shouldn't exceed 4cm or 1-5/8 inches for guys our size. If you really need the 56 to get the standover clearance to less than 4cm, you will probably need a stem length of 90mm or 100mm to reduce the reach.