I have the same PBH as you and use and SH of 77. My Romulus is a 61 center to top, and I run the bars even with the saddle, give or take a little. I also ride a De Rosa that is 59 center to center, probably a 60.4 center to top. Getting the bars even with the saddle requires a technomic (non deluxe) with lots of extension on the De Rosa. The Romulus fits perfectly. I thought about getting a 59 Romulus, but Rivendell said get the 61, and I'm glad I listened. With a Technomic Deluxe, I can get the bars well above the saddle if I want. I have about an inch of standover clearance. Comparing Riv frames to "standard" frames is a bit complicated in that you are dealing with bb drop, upsloping top tube, and an extended head tube. My take on the sizing range factor (especially with the Atlantis) is choose a smaller frame when using way fat tires to maintain standover.
On Apr 16, 11:49 am, jim g <yoj...@gmail.com> wrote: > I'm trying to figure out the right frame size for a possible next > bike-project. I want a "Rivendell fit" with bars about level with > saddle, and somewhere around "a fistful" of seatpost showing. I'm > about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike > shoes; preferred crank length is 172.5 or 175mm. Saddle height on > current bike is comfortable at ~77cm. > > I'm reading Riv's fit guidelines > athttp://www.rivbike.com/article/bike_fit/choosing_a_frame_sizeand am > finding some confusing points. Starting from "How to Size any Bike, > Including Ours", they use an example PBH of 85cm, and suggest that a > corresponding saddle height is 75cm -- or 10cm less than the PBH. So > far, I'm OK with that: my saddle height is around 10cm less than my > PBH (especially accounting for my shoes). > > Next Riv suggests that a good bike size is saddle height minus 15cm. > In my case, that's 86cm - 15cm = 61cm, or accounting for shoes, 87cm - > 15cm = 62cm. Again, I'm in agreement with that: Most non-Riv 62cm > frames I've straddled have been a bit "snug" but not overly so in > standover height -- that is to say, the top tube touches but not > dangerously so. And I could definitely fit on a 60cm frame, but I'd > need a taller quill stem, or some extra spacers in a threadless setup, > and of course there'd be more seatpost showing. > > Now, on to the next section on Riv's page: "Sizing Rivendells (the > bikes we design)".... If you look at the frame-size chart they > provide, for 86-87cm PBH measurements, they recommend 59-61cm frame > sizes! Here's where I'm confused -- most Riv frames have a lower BB > than a typical/average frame, up to 1cm lower. Most of Riv's sizing > theory says something like "you can straddle a bigger one-of-our-bikes > than one-of-theirs", so I've always thought that a correct Riv size > would be 1cm larger than a "typical" frame size (and by typical frame > I mean 1980's UJB steel frame or similar). Taking the previous frame > size result of 61-62cm, that'd put me on a 62-63cm Riv. HOWEVER that > chart points to a 59-61cm Riv frame for my body size -- which is > SMALLER than the first recommended "normal" size, and frankly sounds > too small! > > For example, the 61cm AHH has an 8cm BB drop and standover is just > under 87cm -- that'd maybe be slightly too big for me (no clearance, > since it's the same as my shod PBH). I guess the "Riv Size = usual > size + 1cm" formula doesn't directly apply to the AHH because the > larger tires cancel out the added BB drop? The 59cm AHH frame has > 85cm of standover, which seems about right (about an inch of PB/TT > clearance)...BUT a friend of mine rides this size, and he's always > been on shorter/smaller bikes than me...so a 59cm sounds too small > somehow. > > In contrast, the 61cm Atlantis has a standover of 85cm, so that'd fit > me with the right clearance. Why that frame would fit but the > same-size AHH wouldn't, isn't clear to me -- looking at their > geometries, both have the same BB drop, similar size tires, the same > seat-tube angle, and both have slightly-sloping top tubes. > > The Legolas frame is more typical since it has a standard 70mm BB > drop. (Ignoring the fact that it's intended as a CX bike, which might > indicate more-than-usual SO clearance) I could ride a 62cm size since > its standover is 86.2, but clearance might be tight. The next smaller > size is 59cm with 84.3cm standover. > > The Quickbeam frame is also fairly "normal" with a 73mm BB drop. The > 62cm frame size has a standover of nearly 87cm (too big), but the 60cm > size's SO is about 85cm. > > Now let's compare those data points with a fairly typical non-Riv > steel frame: A Surly Pacer (level top tube, 72.5-degree seat tube > angle, 72mm BB drop). The 62cm frame size has a standover measurement > of just under 86cm, and the 60cm size's SO is 84cm (based on 700x25mm > tires). Riv's Rambouillet frame has similar values at the same sizes. > > Overall, it sounds like I could ride a bigger Pacer frame than most > Rivendell frames -- which seems utterly counter-intuitive to me, since > most Riv frames have lower BBs! > > If anyone has a PBH of 86-87cm, I'd be very interested to hear what > size frame(s) you've chosen (both Riv and non-Riv) and why. > > Thanks! > -Jim G --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en -~----------~----~----~----~------~----~------~--~---
