Builder's Spotlight The Paceline Forum Builder's Spotlight

Go Back   The Paceline Forum > Bike Fit

Thread Tools Display Modes
Old 10-11-2017, 10:25 AM
Blown Reek Blown Reek is offline
Senior Member
Join Date: May 2015
Posts: 243
You really should find out what your ideal saddle height and saddle fore-and-aft position are. Once you've got that, everything else falls into place.

You're doing some big stuff, fit-wise, and your gains might be due to using muscle groups differently, but might not be ideal for you in the long run. Once you know where you're supposed to be, everything is easy from there. For all you know, you might benefit from a zero offset post with a saddle centered on the rails, and having a setback post with the saddle oriented towards the back could be counterproductive, even if it feels good right now. But, you'll never know if you're throwing anything and everything at the wall to see what sticks.

I was first fit about 10 years ago, and that really changed the position that I thought worked for me for the 10 years previous (using the Serotta fit system and SerottaCycle). Of course, after a while when I started to do the frameset-and-parts shuffle, my "ideal" numbers weren't as ideal, since it was more of an "old-school" fit that used the "expertise" of the fitter, and I didn't have the "numbers" to work off of. And since that time, Retul came along and quantified everything for me, and all of a sudden, every "problem" that I was chasing ended (that was about 6 years ago).

Now, since I know the saddle height and fore-and-aft that works for me, I can build up a bike and be within a couple of millimeters of where I need to be (at most). And since that can be a function of the chamois thickness, a couple of mm doesn't matter (as well as the natural movement of the rider on the bike). From there, depending on the top tube length (or reach), I can adjust the stem length as needed. Voila... new bike, same accurate fit.

Go get fit. Someone knows more than you do, and you should listen to then. Then, you can waste your time riding your bike instead of wasting it trying to get comfortable.
Reply With Quote
Old 10-11-2017, 02:14 PM
Wayne77's Avatar
Wayne77 Wayne77 is offline
Senior Member
Join Date: Dec 2004
Location: SLC, Utah
Posts: 1,450
I haven't read all the posts yet, but few general rules of thumb to think about when comparing two already built frames. Perhaps others have already touched on this.

- Don't forget to account for BB drop. If you have two frames with otherwise identical numbers, if one has a BB drop that is 8cm and one that is 7cm, you'll be sitting a little "lower" in the front triangle with the 8cm drop frame (since your saddle height is a constant) that will typically result in 1cm less saddle to bar drop on the bike with the lower BB

- Account for STA. A steeper STA will have a l longer effective reach than a slack STA (if both frames have the same effective TT length). Its counterintuitive but since your setback is a constant, you'd have to move the saddle back to compensate for the steeper STA compared to the bike with the slacker STA. If I remember correctly, don't quote me, but I think a 73.5 STA results in something close to 1cm additional effective reach compared to the same frame with a 72.5 STA.

- Same applies (to a lesser extent) when comparing frames with slack vs steep HT angles. A slack HTA brings the bars a little closer.

- Long story short, when shopping a new off the shelf frame, comparing to another existing frame, a lot of people compare effective TT length and HT height only...without accounting for angles that can change things quite a bit when you add it all up. **note that none of this addresses bike handling impact, ride characteristics, etc. STA, HTA, drop etc definitely have some impact there, but I'm not qualified to make definitive statements there...I'll leave that to frame builders or other experts.

One last thing: I have a spreadsheet that does a pretty good job comparing frame measurements, even plotting the two frames overlayed so you can visually see where the contact points differ. Its not perfect by any means, but it serves as a pretty good initial pass. Can't remember where I got it. A few screen shots attached. If anyone wants it, I'd be glad to email it over...just send me a PM
Attached Images
File Type: jpg screenshot 1.jpg (131.2 KB, 113 views)
File Type: jpg screenshot 2.jpg (88.3 KB, 116 views)

Last edited by Wayne77; 10-11-2017 at 02:23 PM.
Reply With Quote
Old 10-11-2017, 11:39 PM
Clean39T Clean39T is offline
Senior Member
Join Date: Jan 2017
Posts: 2,374
Trials and tribulations of fitting myself

@Blown_Reek and @Wayne77 - thank you for the thoughts...all good stuff. I got in contact today with a local fitter who does both stationary and outdoors sessions as part of the fit. I like what he had to say initially and am going to get together with him next weekend or shortly thereafter. I have used that bike geometry comparison tool, but as was said, without a good starting place in terms of setback and saddle height, it's easy to get lost quick. Hopefully that all gets cleared up soon...

Last edited by Clean39T; 10-12-2017 at 12:43 AM.
Reply With Quote
Old 10-16-2017, 01:46 PM
chiasticon chiasticon is offline
Senior Member
Join Date: Apr 2014
Location: northeast ohio
Posts: 2,439
I see the Campy group off the Peg is for sale. so what's the story? is the Peg going too? did you learn more about what will work for your fit?
Reply With Quote
Old 10-16-2017, 02:19 PM
Clean39T Clean39T is offline
Senior Member
Join Date: Jan 2017
Posts: 2,374
Trials and tribulations of fitting myself

Originally Posted by chiasticon View Post
I see the Campy group off the Peg is for sale. so what's the story? is the Peg going too? did you learn more about what will work for your fit?

Still waiting on my fit, and also have feelers out for a professional HT snip. After 75mi on the Bowman with the extra 4cm drop, it's pretty clear that's a big part of my fit issue on this. If I can't (or don't want to) cut the HT on the Peg, it's getting sold. I'm pretty sure at this point the reach and setback are within range, and it's the drop that is throwing things off...

The group is getting offered just because I have too many spares and likely won't be riding the Peg for a while - doesn't factor into the keep or not decision.

Last edited by Clean39T; 10-16-2017 at 03:56 PM.
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 07:09 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.