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My new Ride(19 posts)

My new Ridespc15
Oct 26, 2002 11:58 AM
After lurking for several months on this page, just wanted to share a pic of my new bike with everyone. I had to wait a bit to get it, beacause of the paint, etc....It's all worth it now. Thanks to Mike at Maestro UK for being so helpful and delivering to me the bike I have been dreaming about for a couple of years.
here is the picturespc15
Oct 26, 2002 12:00 PM
Very nice...biknben
Oct 26, 2002 12:12 PM
I like the colors too. Nice mix of bare metal and paint.

BTW, what's hangin from the seat post clamp/saddle?
Very nice...spc15
Oct 26, 2002 2:08 PM
It's a braided thread; colorful. One of my riding buddies 7 year old daughter spent a couple of hours on each of them...Kinda like friendship bracelets for a bike....
Very nice.look271
Oct 26, 2002 3:09 PM
Like the colors. You did a nice job matching things. Good choice on the wheelset-they'll last you forever.
The new Invisibike 4000???biknben
Oct 26, 2002 12:02 PM
Sorry couldn't resist. It's always good to hear about someone getting their dream bike. Try posting the pic again, we'd like to see it.
Niiice! Out of curiosity...jtferraro
Oct 26, 2002 12:04 PM
what size frame is that(c-t) and what's the length of the TT? Lastly, what size stem is installed? The reason I ask is b/c I've heard the Colagno's have shorter TT's, which usually allows the user to utilize a longer stem. I'm sure different models vary, etc. but was just curious.

Thanks,

-Jeff
geometry chart...C-40
Oct 26, 2002 12:48 PM
http://www.trialtir-usa.com/2003-colnago/colnagoinfo/colsizecharts.htm

This website has the Colnago geometry chart. The geometry is the same on all models. Colnago top tubes are as long or longer than most in the smaller sizes and become shorter compared to some other brands in sizes 58cm and above.

Small Colnago frames also have steep seat tube angles, which effectively lengthens the top tube by about 1.2cm per degree. For instance, a 55cm Colango with a 74 degree STA and a 54.3cm TT length has the same effective top tube length as a 55cm Litespeed, which has a 73 degree STA and a 55.5cm top tube. Why? Because the saddle must be moved back by 1.2cm on the Colnago to produce that same KOP position on both bikes.
geometry chart...divve
Oct 27, 2002 4:37 AM
I can't say that I fully agree with your assessment. Shorter people usually have comparatively shorter femur lengths and smaller feet. A steeper STA compensates for that by placing the BB comparatively farther back and subsequently positions the knee angle more optimally. If you'd set back the seat it would diminish the steeper geometry. Although I'm sure in some cases it would be necessary.
the bike positioning the rider???C-40
Oct 27, 2002 8:00 AM
I've never heard the theory of the bike determining the rider's position. The steeper STA will indeed change the "nominal" position of the saddle when it's centered on the seatpost, but most people establish their riding position by measuring a specific relationship of the knee to the BB. To obtain that position on a bike with a steeper STA, the saddle must be moved further back, which increases the reach to the bars. The article is referring to one specific rider using different frames, not multiple riders that may have differing dimensions.

In comparing the 52 and 53cm Colnagos, the BB is not "moved back" by the change in STA, the saddle is moved forward. The BB is the always the stationary point of reference in any geometry chart. If you read the chart, you'll note that the chainstay length is 1mm shorter and the front center dimension is 1mm shorter on the 52cm. Both add up to a .2% change in the wheelbase.

A Colnago seatpost will provide at least 3cm of adjustment in the saddle position. This is equivalent to more than 2 degrees of change in the STA. It's there for a reason, to allow riders to obtain the desired position relative to the crank. Increasing the STA by a fraction of a degree merely limits the maximum amount of available setback. If the STA is close to an appropriate value, the saddle won't be slammed all the way back on the post.
the bike positioning the rider???divve
Oct 27, 2002 10:45 AM
First, I wasn't replying to that article, but to your STA theory. If bike designs don't determine rider's positions than road bikes, mountain bikes, Tri bikes, TT bikes, etc., would all have the same geometry. Amongst the reasons for varying geometries in smaller bikes aside from function, size, and handling, are changes due to human body proportions in less tall people (men in this instance). Bodies do not simply grow taller in equal amounts spread over the limbs and torso. For instance taller people tend to have proportionally larger upper legs and arms in comparison to shorter people. You can clearly see that in normal road bike designs by comparing the STA, top tube length to seat tube height ratios, and seat to handle bar drop. As a frame gets larger the top tube becomes smaller in relation to the seat tube, the angle of the seat tube is usually slacker, and the seat to handle bar drop increases.

Second, I don't agree that the BB is a stationary point in any geometry chart. Again, when you compare a small frame to a large one you'll find that the BB center to front wheel center increases (in some frames more pronounced than others).

Finally, In my opinion you're putting too much emphasis on the KOPS thing and loosing sight of a frame geometry as a whole. The relation of knee to BB or pedal axis isn't really what it's about, as far as legs go that is. More important are the angle relations of the hips, upper leg, lower leg, and ankles. For instance your knee angle could increase to a less comfortable or optimal angle if you have very large feet, even though your knee relation to pedal axis is in the ballpark according to KOPS.
I give up...C-40
Oct 27, 2002 1:07 PM
We're obviously on opposite sides of a pointless argument. If you find a geometry chart that doesn't use the BB as the main point of reference, post the website or manufacturer. I'd like to see it.

I haven't said a word about the many variations of body size and how they affect the needs for a particular frame geometry. All I've said is that the guy who wrote that fit article doesn't understand frame geometry and how to achieve the same position on a slightly different size frame. It's an extremely simple thing to do.
I give up...divve
Oct 27, 2002 2:15 PM
No need top give up:)

I see now what you meant by stationary point of reference and I admit I misunderstood that.

In a nutshell, I'm basically only disputing the specific piece below that you posted earlier. My reasoning is that a steeper seat tube is usually beneficiary for smaller people. From what I understand in your reply you're basically saying that the Colnago seat tube is too steep and you have to compensate for it by moving your seat farther backward.

"Small Colnago frames also have steep seat tube angles, which effectively lengthens the top tube by about 1.2cm per degree. For instance, a 55cm Colango with a 74 degree STA and a 54.3cm TT length has the same effective top tube length as a 55cm Litespeed, which has a 73 degree STA and a 55.5cm top tube. Why? Because the saddle must be moved back by 1.2cm on the Colnago to produce that same KOP position on both bikes."
you're close...C-40
Oct 28, 2002 5:17 AM
I wouldn't argue at all that a steeper seat tube is generally beneficial for a smaller rider. Most brands follow this logic, except LOOK, which continues to produce small frames with a 72.5 degree STA.

I'm not saying that The Colnago STA is too steep (I ride a 54cm Colango C-40 and it fits perfectly). I've also owned the Litespeed in the example. The point is that both bikes can provide the same fit, but the Colnago requires (and Colnago offers) a seatpost that allows the saddle to be moved back to the same position as can be attained on the Litespeed. Once the saddle is in the same position relative to the bottom bracket, the reach to the bars is the same as the Litespeed.

The real point is that there's a common misconception that Colnagos have short top tubes. In sizes below 58cm this is not the case.
Thanks for the link...jtferraro
Oct 28, 2002 6:42 AM
It looks like a Colagno would fit me much better than a Trek, as the 56cm frame has a 55cm TT, whereas the Trek's 56cm frame(c-t) has a 57.1cm TT!!

Maybe my next bike will be a Colagno! =)

-Jeff
Niiice! Out of curiosity...spc15
Oct 26, 2002 2:15 PM
Jeff:

It's a 59 C-T. It has a 56.9cm top tube. The stem is 120mm. I have read several articles about the fitting of these bikes and it was recommended to have a shorter top tube and a longer stem so one could stretch out along the frame.....

this is an interesting article about it...

http://www.bikesportmichigan.com/reviews/colnago.shtml
That article makes you want to run and buy one nmBruno S
Oct 26, 2002 9:05 PM
lots of misconceptions in the article...C-40
Oct 27, 2002 4:43 AM
The guy that wrote this article considers himself an expert at bike fitting, but doesn't understand geometry well enough to determine the real differences between a 53 and a 52cm Colnago.

The author believes that a 1cm smaller frame made a day or night difference in the feel of the bike. What baloney.

If he'd taken the time to analyze the geometry chart, he would have found that the smaller 52cm frame actually had a 2mm longer effective TT length, after the saddle is adjusted to compensate for the difference in STA. Despite this, he put a 10mm longer stem on the bike. Guess he didn't realize that he was increasing the reach by more than 12mm in total.

This is first time that I've heard complaints about not being able to get the bars low enough. From the pictures, it looks like the bars are close to 5 inches below the saddle. Not that there's anything wrong with that, but it's more extreme than most folks can tolerate. He says he's not using any spacers, but there's appears to be something under that stem. He's also using an 80 degree stem. Using a 73 degree stem would have lowered the bars more than the shorter head tube on the smaller frame.
Interesting......spc15
Oct 27, 2002 2:34 PM
I never realized the smaller frames had such a porportionally different sized TT.

In sizing my frame I looked primarily at the top tube lengt/setback knowing that I have been comfortable with a 120mm stem(effective 69cm reach)...worked for me....ymmv, of course..