I am 5'11' and I have a 86.4 cm PBH. I currently ride a Long Haul Trucker which is similar to an Atlantis and I chose a 58cm. I use 175mm arms now and ride with Crank Bros. 50/50 pedals and Tevas mostly, skate shoes or my Redwing boots. I have a shorter reach than most and I use a 90 mm stem length. I could probably ride a 60 or 61 Riv frame depending on the model and the tire size. I use Schwalbe 700x47's on my Trucker so the 58 cm works nicely for me. I think your saddle height indicates a 59-61 being right in the ballpark. I think you might be making it a little too complicated. Its only 2 cm difference or 20 mm which is less than 3/4 of an inch. In my mind if you can stand over a given frame size with your tire preference and you can get the bars where you want them then that is what you are looking for. You should be able to get your bars high enough with either size all the way from 58-61. You just might need to use a Dirt Drop stem with the smaller sizes but they are stronger anyway so...........it sounds like you know what works. Other bikes with higher bottom brackets and skinnier tires aren't a good comparison and serve to cloud up the subject (unless you want one of them) I think you just need to look at the standover and the bar height and distance to the bars regardless of the frame style/brand and just use your measurements to get you wherever you want to be. More post, less post, long stem, short stem, these are just aesthetics when you get right down to it since there is easy adjustment built into quill stem bicycle frames. I think you just want to avoid the extremes. For instance riding a 55 cm or a 67 cm.
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 -~----------~----~----~----~------~----~------~--~---
