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Need some more help...Sizing question- LONG(10 posts)

Need some more help...Sizing question- LONGcyclejim
Jun 3, 2002 6:49 PM
Some of you may have been following my seemingly never ending saga of the search for my first road bike. I'm getting very close now though! This is rather long and anal so I apologize in advance for ranting on.

I've spent a lot of time riding various bikes and am trying to focus my decision firstly on fit. I started my search after having a helper measure me per the instructions on both the colorado cyclist and wrench science web sites. I started with the following measurements- inseam 36.5in, height 6'2" 1/2, arm length 26.5in, sternum notch to floor 61.5in. I was looking at frames 62cm and above (c to t) due to my inseam and height. Right now I have pretty much narrowed my choices to two bikes: Cannondale CAAD5 built up with Ultegra, or a Jamis Quest.

I test rode the Cannondale CAAD5 in a 63cm size initially and while it fit me decently, I found it a bit on the large side. It just felt "big" & I find my self streched out in the cockpit with a rather long reach to the bar. I also rode the Jamis for a second time today in a 62cm and found it suits me quite well overall. I am comfortable on the bike. I've rode other bikes as well and it seems I like my top tube a bit on the shorter side then I first thought I needed. (Ive taken care to ensure the saddle height is adjusted to allow for the same slight bend of the leg with the pedal down and that the tires are always inflated correctly as well)

I then re checked all of my measurements and found that my inseam is actually closer to 35.5 to 35.75. Not sure how we messed up the first time but I re-did them 3 times to be sure. According to colorado cyclist that puts my frame size at 60.4cm to 60.8 cm (which of course isnt a valid frame size) and Wrench Science says 60cm.

I then decided to give the Cannondale 60cm a test ride to see how it felt. Well, it felt GREAT, pretty much perfect. It feels "faster" than the Jamis and more responsive to me. There was one thing that concerns me about it though:

When in the drops I feel more pressure on my crotch than the Jamis. I think this is because the seat needed to be set a little higher to get my leg extension to the pedals just right but am not sure. Funny thing is the seat tube on the 60cm Cannondale is longer than the Jamis, but overall the Jamis standover is higher than the C-Dale. Below is the geometry data. (told you i was anal)

......... TT length - Seat Tube - Standover
Cannondale 60cm 23.3 24.7 33.3
Cannondale 63cm 23.6 25.9 34.5
Jamis 62cm ....... 23.43 24.41 33.86

Well hopefully I havent totally muddled the issue, I guess the biggest thing I am wondering about is the pressure Im feeling when in the drops on the C-Dale. Is my assumption correct about the higher saddle height causing more pressure? Any other thoughts and advice are appreciated.

Thanks in advance.

Jim
re: Need some more help...Sizing question- LONGjtolleson
Jun 3, 2002 7:02 PM
Could be too large a saddle-to-bar differential has you -- ahem -- riding on the family jewels. As a female rider I won't pretend to analyze the details. It could also be merely a difference in saddles (or whether saddle is perfectly horizontal) between the two bikes.

My advice to most folks is to largely buy for top tube length, assuming that standover clearance is adequate, moving the saddle up and down is a non-issue (unless it is so radically that it puts too much weight forward or back).
re: thankscyclejim
Jun 3, 2002 7:55 PM
I've been hearing that a lot, that is to go mainly for proper TT length and as you said assuming enough standover clearance you can adjust with the saddle. That is great advice. I guess another advantage is that you can go with a smaller frame as long as the TT is right on.

This fit stuff isnt all that easy..its an art. I just got things figured out on my mtn bike...after 3 years! I'm wondering also if the saddle on the C-Dale is partly to blame, although I am currently riding on a Selle Italia Flite on my mtb bike so I should be used to the abuse!

Thanks again.
Most likely because the saddle was set a bit highelviento
Jun 3, 2002 9:33 PM
I am sure someone will disagree with me, but given the wide range of stem length (10~13cm) and rise (-17 ~ +17 degrees) and the great adjustability of seatpost length, probably a 58 cannondale to a 63cm can both fit you (to achieve the same positions of your hands, feet and butt). The only barrier I can think of is that if the fork steerer is carbon, you can't have too many spacers and can't raise the bars high enough. Handling would be a bit different but handling is a matter of personal taste/preference anyway. I am 5'8" and I ride a 54 Trek. I have tried both a 56 and a 52 and both can fit me with a 10cm stem and 12cm stem respectively, and properly adjusted saddle height.

I understand you are anal, but you have to just test ride and decide for yourself, which could take months of frequent riding. Because no one can decide your handling and aesthetic preferences. No matter how much calculation you do now, and how much advice you get from experienced riders, they can't replace your test riding and figuring out your preferences.
Check these.Len J
Jun 4, 2002 4:07 AM
Was there any difference between the Janis & the c-dale in seat to bar drop?

What about in the Bars themselves? Different bars have different distances from top of bars to drops.

Finally, were they the same seats? Were they both set up the same? Remember that small adjustments to seats make a big difference.

As someone else said, you can get a good fit on either of these bikes if you play enough, so the real question is,,, Which bike speaks to you?, which one do you find yourself looking forward to riding? Ultimatly, it comes down to emotion. "There comes a time in the life of every project, when it's time to shoot the engineer & get on with it."

Good luck

Len
ACCURATE geometry comparison....C-40
Jun 4, 2002 5:18 AM
First, ignore the seat tube length, it's meaningless. The critical dimensions are top tube length, seat tube angle, head tube length and frame size (c-t). Standover height is relevant, but only if you're pushing the limit of minimum clearance (2-3cm). The C'dales have a 73 degree seat tube angle, while the Jamis has a 72.5. Because of this difference in STA, the TT lengths CANNOT be compared directly. I've added .7cm to the C'dale TT lengths to compensate for the difference in saddle position. The formula for TT length difference is 1.32 x (cosA-cosB) x frame size.

Here's an accurate comparison of frame size, TT, HT and standover in cemtimeters (no one uses inches). Unfortunately C'dale no longer lists head tube length. Comparing head tube lengths can be tricky, if one brand uses an integrated headset and the other uses a conventional headset. The difference in headset stack height must be taken into account. If you have the bikes available to measure, then it's no problem.

C'dale 60cm, 59.7, ??, 84.7
C'dale 63cm, 60.7, ??, 87.6
Jamis 62cm, 59.5, 19.2, 86

As you can see, the 60cm C'dale and the 62cm Jamis have virtually identical effective top tube lengths. The larger Jamis has plenty of standover clearance (almost 5cm). The 60cm C'dale may be a bit small (vertically) and will require additional steering tube spacers or more stem rise to get the bars up to the same height. This is why it's important to measure the difference in the HT length (plus the headset stack height).

The 63cm C'dale will produce a standover clearance that's toward the minimum acceptable amount, and require a 1cm shorter stem to produce the same reach to the handlebars as the other two frames. On the plus side, the head tube will be about 3cm longer than the 60cm, which will minimize the steering tube spacers or stem rise. 3cm is a very large jump between sizes. IMO, C'dale goofed when they skipped the 62cm size. A lot of folks will find the 60cm too small and the 63cm too large.

As I mentioned earlier, check the saddle height above the top tube for reference. 17cm is about as low as I'd go on this large frame. 18-20cm would be more common (you don't want to look like a Fred). The 62cm Jamis looks like the best fit to me.
Hey! What about the obvious?Matno
Jun 4, 2002 5:34 AM
I'm surprised nobody mentioned this: pressure in your crotch when in the drops comes from seat ANGLE, not seat height. What you need to do, is tilt the nose down until you find a happy medium between upright and in the drops. Too much tilt and your arms and shoulders end up supporting a lot of your weight (not good). Ideally, it should be pretty close to level, but it's really a personal preference. I've also found that my saddle position makes a difference (not where my saddle is relative to the frame, but where my butt is relative to the saddle). I've got a WTB saddle with a "Love Channel" that doesn't extend all the way to the front of the saddle, so sliding back an inch or two almost completely relieves any crotch pressure. Perhaps a Koobi with the split that goes all the way to the front would be the best solution. (I'm still waiting to find a deal on one!)
Yeah, although it's hard to know from here,djg
Jun 4, 2002 6:44 AM
my first guess would be the saddle. IMO, experiments with saddle tilt should start at level--easy to verify with an inexpensive plastic bubble level--and work very gradually (and within a very limited range) from there if level isn't satisfactory. Also, as you and others have mentioned, the saddle itself may be partly to blame: maybe the top is an issue but I'd be looking at the length and flexibility of the nose of the saddle. Also, does the position of the saddle allow for it to be clamped in the center of the rails? If it's clamped at either end it could be rather unforgiving, perhaps exacerbating problems from position on the bike (easy enough to change seatposts if the stock one doesn't work for you).
re: Need some more help...Sizing question- LONGGregJ
Jun 4, 2002 3:24 PM
Colorado cyclist has a little sidebar that no one seems to notice for tall riders; inseam - 27 or 28 cm will give the c-t measure. This puts you on a 62-63 frame.
Get fitted...DINOSAUR
Jun 4, 2002 3:29 PM
In all sincerity why not just find a good LBS who will take the time to do a fitting and listen to you?