Drop bar - Fit question

[atreya...@gmail.com]

Group , need your thoughts on drop bar fit . I recently bought homer Hilsen ( most recent batch ) . I have short torso but long legs and arms . My height is 5’8.5 ish and pbh is 86.5. I have homer in 54.5 , which has tt of 57.5. I am running a short stem 50mm and nitto m151(75 mm reach) . I am also using nitto lugged seat post , which I understand has a lot of set back.The reach seems to be working fine , however I do find my hamstrings are getting taxed way more than I like compared to my quads especially on climbs in the saddle . My understanding is that homer has a slack seat tube angle of 71.5. Will running a zero set back seatpost help ? Has anybody run zero setback posts on rivs. I understand that general recommendation is to have more set back .

[Joe Bernard]

Since no one with more knowledge than dumb-old me has answered yet: I don't know anything about hamstrings and quads but I do know that is indeed a very setback post you're using on a rather slack seattube. Considering that you're also using a short stem I think you could keep your current reach by shifting your whole body forward. Maybe not a zero-setback post, I'm thinking a Nitto S65 post and 7cm stem.

Joe Bernard

[Joe Bernard]

Dang it, I wish there was a way to edit these things. I'd swap the post first and see what you think. You may end up happy with the reach without changing anything else. 

[Eric Marth]

Before swapping the post, have you tried sliding the saddle all the way forward on the lugged seatpost and trying that? 

[atreya...@gmail.com]

Forgot to mention , the current set up described in my original post I do have the saddle all the way forward.

[Patrick Moore]

Get your saddle position comfortable for pedaling, independently of reach to bar, then choose stem and bar for correct reach. 

Peter White has a good article on proper setup.

On Mar 4, 2022, at 7:14 AM, atreya...@gmail.com <atreya...@gmail.com> wrote:

Forgot to mention , the current set up described in my original post I do have the saddle all the way forward.

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[Jeremy Till]

You also don't mention which saddle are you are using, which in my experience is a key determinant in how much setback you need to achieve through frame and seatpost setback. The Nitto Lugged post was developed by Riv when most of their designs used a 72 degree seat angle, and some people had trouble getting a Brooks B.17 far back enough to be well balanced and comfortable. I've also seen it used to get Brooks saddles in a better position on older steel road bikes with 73 degree or steeper seat angles. Brooks leather saddles have very short usable rail adjustments which is biased towards the rear of the saddle, meaning it can be hard to get it far enough back on bikes with steeper seat angles. However, on the newer Rivendells with slacker seat angles, like your Homer, the lugged post might be overkill.

Personally, I use a zero setback Thomson seatpost on my 59cm Clem H, which, if I remember correctly, also has a 71.5 degree seattube. However, I also use a WTB Pure saddle, which in my experience has a lot more "built-in" setback--it's rails are longer, and more biased towards the middle of the saddle, so I have no problem getting enough setback with that post. If you're currently using a Brooks and the Nitto lugged post, you might try one of the Nitto posts with a more moderate amount of setback (the S65 or S83) before going to a zero setback. 

After many years of trial and error and recently getting more precise about the way I measure and set up my saddles, I've come to the conclusion that I need a similar amount of setback whether I am sitting upright or using drop bars. As others have said, it's best to figure out what that setback is for you before adjusting the reach to the handlebars to get comfortable. If you have another bike that on which you are basically comfortable, measuring its setback and replicating it on your Homer (assuming the same or similar saddles) might be a good starting point.  

Also, setback should be adjusted in conjunction with saddle height. The farther back your saddle is, the lower it should be to keep your leg extension relatively constant. If you're experiencing tight hamstrings, that might be part of it. I've heard fitters say the ratio is roughly 3:1, that is, for every 3mm of increased saddle setback, the seat needs to come down 1mm, and vice versa.  

-Jeremy Till

Sacramento, CA

On Thursday, March 3, 2022 at 8:24:22 PM UTC-8 atreya...@gmail.com wrote:

[atreya...@gmail.com]

Thanks Jeremyfordetailed response.I am usingb17. Though I also have GB Aspin. 

[John Hawrylak]

Like Joe B, I dont know about hamstrings vs quads, but is seems like you are too stretched out on the 54.5cm AHH-MIT, mainly since you are using a very short stem length and a very short reach bar.

Also, a 54.5 AHH-MIT has equal STA and HTA, STA=71.5°.  HTA=71.5° so the bars are coming back to compensate for the slacker HTA (and also to give enough Front Center to prevent TCO).  Therefore, the slack STA is not your problem, the long TT is probably contributing to your being stretched out.

Lets assume you are too stretched out. Your options are:

1  Get a seatpost with less setback, see below

2  Push the saddle all the ways to the BACK of the saddle rails to move the saddle forward.  This can give you 2 to 4 cm or more depending on the saddle used (a B17 is at the low end of the range, 2.4cm.  

3.  Move the bars UP to either at saddle height or above it.   This is a small effect and based on the 71.5° HTA,  the distance you move BACK (x) is either  

0.335 x y,    where y = the VERTCAL distance the bars are raised, y is in CM and x is in CM

0.317 x Z,   where z = the DISTANCE ALONG THE STEM QUILL the bars are raised,  z is in CM and x is in CM

If you move the bars UP 2cm the bars will come back 0.67cm or 6.7mm, not a lot

 If you are too cramped, then just increase the stem length or get a longer reach bar like a Noddle.

RBW gives the following seatpost setbacks (in mm) on their SEATPOST tab

Nitto Lugged:           40

IRD Wayback           10 to 50

Paul                           26

Nitto S83 (2bolt)     20

Nitto S65 (1bolt)     18

Assuming the RBW values are consistent (reflecting the relative setbacks of the 4 posts), then replacing the Nitto Lugged post (40mm) with a

      S83 or S65 (20mm either) will reduce your REACH to the bars by 2.0 cm.

     A IRD Wayback will reduce it by 3.0cm at the minimum setback setting.

     A zero setback post will give you 4.0cm closer to the bars

This saddle movement may be enough.  Seatpost are not cheap to experiment with

I think you are 2 to 4 cm too stretched out from what you said.

We can calculate the center of saddle to center of stem clamp or end of bars for the 54.5 AAH-MIT and compare it to a bike you have and which you are comfortable, essentially transferring the fit to the 54.5 AHH-MIT.   For example, Assuming your Saddle Height (SH) is 76cm (PBH-10), then a 54.5cm AHH_MIT has 57.4 cm between the seatpost center at 76cm SH (no saddle) & the center of the stem quill bolt (bars LEVEL with seatpost at SH), from the 71.5° frame angles,  Let me know if you want to try this.

John Hawrylak

Woodstown NJ

[deepak atreya]

Thanks everyone for such detailed response . I ended up swapping VO grand cru stem from Atlantis , which I believe is 30 mm stem .  I also switched back to 7 mm stem and almost leveled saddle and handlebar ( may be a cm higher ) . I think this is working out fine . I guess reach was never a major issue but set back was . I will ride it for few more days and if it works get an s83 so that VO can  go back to Atlantis . Attached is photo of current set up and reach . Thanks everyone! 

Cheers ,

Deepak

On Mar 5, 2022, at 07:42, 'John Hawrylak' via RBW Owners Bunch <rbw-owne...@googlegroups.com> wrote:

Like Joe B, I dont know about hamstrings vs quads, but is seems like you are too stretched out on the 54.5cm AHH-MIT, mainly since you are using a very short stem length and a very short reach bar.

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[Patrick Moore]

One more thought on saddle position and stem and bar position (and therefore stem length and bar shape). I described on reason why saddle position ought to be set independently of bar position, namely that you want a certain fore/aft and up/down relation of hips and thighs to pedals for comfortable and efficient pedaling. But there is a second reason that is as important: you need sufficient saddle setback so that your torso muscles can support your upper body; a saddle too far forward causes your weight to fall on your hands, arms, and shoulders -- perhaps counter-intuitively, a saddle too close to bar means more pressure on hands.

On Thu, Mar 3, 2022 at 9:24 PM atreya...@gmail.com <atreya...@gmail.com> wrote:

Group , need your thoughts on drop bar fit . I recently bought homer Hilsen ( most recent batch ) . I have short torso but long legs and arms . My height is 5’8.5 ish and pbh is 86.5. I have homer in 54.5 , which has tt of 57.5. I am running a short stem 50mm and nitto m151(75 mm reach) . I am also using nitto lugged seat post , which I understand has a lot of set back.The reach seems to be working fine , however I do find my hamstrings are getting taxed way more than I like compared to my quads especially on climbs in the saddle . My understanding is that homer has a slack seat tube angle of 71.5. Will running a zero set back seatpost help ? Has anybody run zero setback posts on rivs. I understand that general recommendation is to have more set back .

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Patrick Moore

Alburquerque, Nuevo Mexico, Etats Unis d'Amerique, Orbis Terrarum