have I overlooked any important measurements?

[Bob Ross]

My bike's in the shop for at least a week awaiting a replacement part. Fortunately the LBS gave me a loaner bike...and it's kinda nice! I was pleasantly surprised to find that there were no fit issues in going from my bike to this loaner; other than having to raise the seat 2cm, it's been pretty darn comfortable.

Perhaps even more comfortable than my bike!

So I thought I'd measure all the important dimensions & compare them to my bike when (if?) it gets back from the shop, see if there's anything I could refine.

Here's what I've measured so far:

- Top tube length (from head tube to seat tube, c-to-c)
- Stem length (from head tube to handlebar, c-to-c)
- Reach (seatpost/saddle attachment to handlebars @ stem)
- Seat tube height (from bottom bracket to top tube, c-to-c)
- Seat tube height (from bottom bracket to seatpost binder clamp, since, having a sloping top tube, this is quite different from the previous c-to-c measurement)
- Inseam (pedal axle at 5:00 position [crank parallel to seatpost] to top of saddle)
- Standover height (floor to top of Top tube, averaged over its length)
- Width, depth, and drop of handlebars (c-to-c)
- Drop (from top of saddle to [virtual] top of handlebar)
- Crank length (pedal axle to bottom bracket, c-to-c)

Is there anything else critical I should compare to my current ride to make sure nothing's dramatically different? Do I need to be concerned with STA, or rake/trail, or wheelbase? I'm not really worried about how handling compares, just my fit in the cockpit.

Thanks.

 

[Kestrel12]

I would add seat set back from bottom bracket. For me this and saddle height are the most important measurements

 

[Bob Ross]

I would add seat set back from bottom bracket.

How exactly would I measure setback? Distance from a (virtual) vertical line perpendicular to the ground & passing thru the bottom bracket, back to the point where the saddle rails clamp to the seatpost?

 

[Guaps]

At the top of this page (http://www.parktool.com/repair/readhowto.asp?id=130) there is a diagram you can print out that has all the major measurements you can take and a place to record them. It's pretty useful...

 

[Kestrel12]

How exactly would I measure setback? Distance from a (virtual) vertical line perpendicular to the ground & passing thru the bottom bracket, back to the point where the saddle rails clamp to the seatpost?

Set back is generally the distance between the bottom bracket and front of the saddle. Although if the saddles on two different bikes are somewhat different measuring to the centre of the saddle is more effective

 

[PeterF]

My bike's in the shop for at least a week awaiting a replacement part. Fortunately the LBS gave me a loaner bike...and it's kinda nice! I was pleasantly surprised to find that there were no fit issues in going from my bike to this loaner; other than having to raise the seat 2cm, it's been pretty darn comfortable.

Perhaps even more comfortable than my bike!

So I thought I'd measure all the important dimensions & compare them to my bike when (if?) it gets back from the shop, see if there's anything I could refine.

Here's what I've measured so far:

- Top tube length (from head tube to seat tube, c-to-c)
- Stem length (from head tube to handlebar, c-to-c)
- Reach (seatpost/saddle attachment to handlebars @ stem)
- Seat tube height (from bottom bracket to top tube, c-to-c)
- Seat tube height (from bottom bracket to seatpost binder clamp, since, having a sloping top tube, this is quite different from the previous c-to-c measurement)
- Inseam (pedal axle at 5:00 position [crank parallel to seatpost] to top of saddle)
- Standover height (floor to top of Top tube, averaged over its length)
- Width, depth, and drop of handlebars (c-to-c)
- Drop (from top of saddle to [virtual] top of handlebar)
- Crank length (pedal axle to bottom bracket, c-to-c)

Is there anything else critical I should compare to my current ride to make sure nothing's dramatically different? Do I need to be concerned with STA, or rake/trail, or wheelbase? I'm not really worried about how handling compares, just my fit in the cockpit.

Thanks.

When you say more comfortable, what do you mean. More stretched out? smoother pedalling? hands? saddle?
There's comfort based on better fit, but there's also comfort based on ride characteristics of frame materials, head/seat angles or rake.

 

[alfeng]

My bike's in the shop for at least a week awaiting a replacement part. Fortunately the LBS gave me a loaner bike...and it's kinda nice! I was pleasantly surprised to find that there were no fit issues in going from my bike to this loaner; other than having to raise the seat 2cm, it's been pretty darn comfortable.

Perhaps even more comfortable than my bike!

So I thought I'd measure all the important dimensions & compare them to my bike when (if?) it gets back from the shop, see if there's anything I could refine.

Here's what I've measured so far:

- Top tube length (from head tube to seat tube, c-to-c)
- Stem length (from head tube to handlebar, c-to-c)
- Reach (seatpost/saddle attachment to handlebars @ stem)
- Seat tube height (from bottom bracket to top tube, c-to-c)
- Seat tube height (from bottom bracket to seatpost binder clamp, since, having a sloping top tube, this is quite different from the previous c-to-c measurement)
- Inseam (pedal axle at 5:00 position [crank parallel to seatpost] to top of saddle)
- Standover height (floor to top of Top tube, averaged over its length)
- Width, depth, and drop of handlebars (c-to-c)
- Drop (from top of saddle to [virtual] top of handlebar)
- Crank length (pedal axle to bottom bracket, c-to-c)

Is there anything else critical I should compare to my current ride to make sure nothing's dramatically different? Do I need to be concerned with STA, or rake/trail, or wheelbase? I'm not really worried about how handling compares, just my fit in the cockpit.

Thanks.

The wheels & tires ...

• spoke count & lacing / rim type (low profile, semi-aero, aero)
• tire size & PSI

And, yes, frame geometry (and, frame material) CAN make a difference in the ride.

Also, the saddle ... plus, handlebar shape & tape AND the position of the levers on the handlebars.

 

[Bob Ross]

Just to clarify: by "comfortable" I'm referring to my physical comfort, especially in my neck & shoulders, both while riding and after I get off the bike. The ride quality of my bike is much more enjoyable than this loaner bike: it rolls more smoothly, more effortlessly, there's not as much road chatter going into my butt, etc. So I'm pretty confident this is a fit issue rather than a frame material or ride characteristic issue.

And it's not so much that my bike is uncomfortable or that this loaner is much more comfortable, it's just that this is the first time I've ridden another bike that didn't feel conspicuously different the moment I got on it. (Usually when I rent a bike or borrow someone else's or test ride one from the LBS I can tell within seconds "oh, I'm too stretched out" or "this saddle is too low" or "this handlebar drop is killing me!") And if anything, my neck & shoulders hurt less on the loaner than they do with my bike, so I want to see if there are any critical measurements regarding my position on this bike that aren't yet dialed in on my bike.

Thanks for all the suggestions so far. The Park Tools Road Position chart is really handy. And I found a good explanation on how to measure setback from the Competitive Cyclist Fit Calculator.

Now all I need is for my bike to come back from the shop, dammit!

 

[PeterF]

Just to clarify: by "comfortable" I'm referring to my physical comfort, especially in my neck & shoulders, both while riding and after I get off the bike. The ride quality of my bike is much more enjoyable than this loaner bike: it rolls more smoothly, more effortlessly, there's not as much road chatter going into my butt, etc. So I'm pretty confident this is a fit issue rather than a frame material or ride characteristic issue.


I ride on the hoods mostly and I like the bends of the bar to form a parallel line from bar tops to hoods. Hard to describe, but my Ritchey WCS ergo bar forms a a perfect union with my Campy hoods. I can instantly tell on a bike if the hoods aren't positioned right or even if the bar is set at the wrong angle. Other than that and saddle postion/tilt, I think you have it covered.