Looking at the geometry chart, I do believe there's a couple errors. For the two smaller sizes they have the same reach with different effective top tubes and the same seat angle. As you point out the 61 is indicated as having a shorter reach, despite a longer effective top tube and the same seat tube angle. The only time you should see this variance is when there's a different seat tube angle. The 61 will feel like a longer reach, because you wont need to bring the stem up as high, and it will be coming back as it goes up (2mm back for every 7mms up).
Maybe enter all the numbers in this stack/reach calculator with a favorite reference bike that you own and love: https://www.bikegeo.net/ The standover could be another trade off depending on use. I don't mind a higher standover on a road bike I only ride in stretchy cycling clothes. I would mind it on a commuter that I ride in non stretchy jeans. Also, the seatpost is one of the better places for a bike to provide compliance since it isn't triangulated, so a shorter seatpost can feel a bit harsher. Finally, I'd really recommend optimizing for the toptube length you prefer, rather than picking on any other factor/recommendation. Bikes that fit feel better to me, and I always tend to decide that my bikes that feel better look right in the long run. Grant seems to be something of a marvel of fitness and fit adaptability, so there could be other considerations besides pbh that could contribute to your relative sizing preferences. On Saturday, September 27, 2025 at 8:03:01 AM UTC-6 maxcr wrote: > For me, the 61 Gallop prototype felt long even with Albatross bars. I’m > 5’11” with long legs: 90.5pbh and I wouldn’t size up again. > > I think it comes down to your proportions and your preferences > (handlebars, handlebar height, etc). > > You’ll be able to make either work but sizing up isn’t always the answer. > > Max > > On Sep 27, 2025, at 9:51 AM, John at Rivendell <[email protected]> wrote: > > Get the 61cm! > > > > > On Friday, September 26, 2025 at 9:12:19 AM UTC-7 Mike Gillespie wrote: > >> I’m considering a Charlie purchase for this round of frames. At 5’11” >> and a PBH of 86.5cm I’m in the middle of the sizing range for the 57cm and >> just over the lower limit for the 61cm. After seeing the attached photo of >> Grant’s ride on a Blue Lug blog, I’m considering going with the 61. >> According to the blog post, Grant’s PBH is 85cm, and he’s actually under >> the lower sizing recommendation of 86cm. >> >> From the geometry chart it appears the greatest difference between the 57 >> and 61 frames is increased stack height (+4.9cm) with only minor increase >> in reach. The effective top tube increase is only 1cm. Meanwhile, the >> reach calculation shows an actual decrease of 0.7cm. (This seems >> counterintuitive to me and I’m thinking it’s a typo, or am I wrong)? >> Regardless, I’m intrigued by Grant’s setup and wonder if there’s any >> downside that I’m missing. Any recommendations? >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "RBW Owners Bunch" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/rbw-owners-bunch/tzjrP3_z2uI/unsubscribe > . > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/rbw-owners-bunch/620b3604-26de-4ed1-8fe9-8433d342481fn%40googlegroups.com > > <https://groups.google.com/d/msgid/rbw-owners-bunch/620b3604-26de-4ed1-8fe9-8433d342481fn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/73d67e21-2137-4644-8fd6-b0449546baf3n%40googlegroups.com.
