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· Registered
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Discussion Starter · #1 ·
I've visited four bike shops lately and got a wide range of suggestions concerning bike sizing. I'm 6 feet 1 inch, 200 lb and am currently riding a 20 year old 25" frame Trek. I'm looking for a decent road bike and I'm hoping to get the bars about level with the seat. (I'm 46 and my back isn't what it used to be).
One shop suggested a 63cm Trek Pilot, another shop suggested the Large Giant OCR3 or a 58cm Canondale, the third shop thought either the 60cm Trek 1500 or the 58cm Trek Pilot and my favorite shop insisted the XL Giant OCR3 was right for me.
The XL Giant needed about a two inch spacer to gete the bars up to seat level. Would that be normal or should I be able to find a frame that fits wihtout such modifications?
Any suggestions on how to figure this all out. Since I only buy a bike every couple of decades I'll be living wiht my decision, either right or wrong, for a long time!

· Premium Member
15,996 Posts
"Compact" frames like the Giant offer a lot of flexibility for playing with your size.

To get the seat height and bar height level on a road-geometry frame will probably take some rise, but many think it's best to accomplish this with a riser stem instead of lots of spacers.

Two inches = 50mm = a lot of spacer. See if they won't swap you out for a stem that goes up a bit.

· Registered
10,161 Posts
post some dimensions.....

If you can get a fairly accurate saddle height measurement, from the center of the crank to the top of the saddle, along the center of the seat tube, then it's pretty easy to predict the head tube length and stem rise that will be required to produce a given handlebar height.

Getting the bars up to the level of the saddle could be difficult without a very high rise stem, since a normal road bike setup has the bars 5-10cm lower. A 100 degree stem will raise the bars about 5cm above horizontal and a 107 degree (73 flipped up) will raise the bars over 6cm.

As you gain riding experience and you hopefully gain some mid section strength and fitness, it's likely that you will want the bars lower.

The proper frame size should be based mainly on your cycling inseam, which dictates your saddle height. With the desire for high handlebars, a shop might suggest one size larger than normal, but this will reduce standover clearance and increase the top tube length (requiring a shorter stem). The various brands all have different methods of measuring "frame size". To avoid confusion, take a take a metric tape measure with you, then you can compare the head tube length and standover height of the suggested frames. The manufacturer's website also have complete geometry charts on the models you have mentioned.

FWIW, the Giant in the XL size should have a HT that is as tall or taller than any of the others. If a lot of spacer was under the stem, I suspect the stem was not in the flipped up position. Bikes are initially assembled with the largest allowable amount of spacer. The amount of spacer, the steering tube length and the stem angle are things to be fined-tuned during a fitting. If the shops that you visit don't offer a serious fitting, with the bike mounted in a trainer, then they aren't very good shops, go elsewhere.

Here's a link to some fit basics:

· Registered
21,834 Posts
Do your homework

Measure your inseam: stand against a wall with your feet 6 inches/15 cm apart. Push the spine of a 1 inch/2-3 cm thick book into your crotch with significant pressure, and measure the distance from the book spine to the floor. Your saddle top to pedal axle should be 108-110% of the inseam measurement.

Here are several frame fit calculators.

For adjusting the fit of the bike, there are roughly five starting points:
1. Seat height (top of saddle to center of pedal axle) at 108-110% of inseam.
2. Saddle parallel to ground.
3. Saddle fore/aft adjusted so that a plumb bob from the bony protrusion just below the kneecap passes through the pedal axle when the cranks are horizontal. This is known as KOPS (Knee Over Pedal Spindle)
4. Front hub axle obscured by the handlebars when riding in your "regular" position (drops, hoods, or tops).
5. Top of handlebars 1 to 4.5+ inches below the top of the saddle depending on your flexibility and size.

These are all starting points for "average" proportioned people, and many folks like to move away from these starting points as they learn what makes them more comfortable, powerful, or efficient. For example, the KOPS position range is typically +1 to -2 cm, depending both on your personal physiology (long femurs tend to push the saddle back) and pedaling style (spinners move the saddle forward, pushers move the saddle back). You want to get the fit of the frame as close as you can, then do minor adjustments with the stem, seat post, saddle position, etc.

A lot of this is personal comfort, and we all tend to adapt to a given position over time. For example, a given stem length may be right for you, but it may feel long at first. I use the "handle bar obscures the front hub" rule for my fit, but others claim better position (for them) with the hub in front of or behind the bar. Plus, if you look down without moving your head, you get a very different view than if you tilt your head to look at the front hub. I'm 6' tall and ride with 11.5 cm drop from saddle to bar, probably more than most people would like but fine for me. Some are suggesting zero drop from saddle to bars - it's about comfort, efficiency, and aerodynamics. No calculator is infallible, so look at the different results you get to see where there is consensus among them. I would suggest riding some miles (over 100 total, and over 500 would be better) and see if you adapt to a given position. There are no hard and fast rules, just general guidelines, when it comes to these things.

Just as important as your size is your flexibility. If you have a stiff lower back, you may not be able to lean over and stretch out as much. If you are very flexible, you may get away with a longer top tube, with the stem in a lower position. Over time on the bike, too, you may become more limber, or at least become accustomed to being lower and stretched out. So, your first 'real' bike may not be anything like what you will want 5 years from now.
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