On May 5, 3:53 pm, Grant Petersen <gr...@rivbike.com> wrote: > > It seems to me that because of the long top tubes most of Rivendells > > frames are not designed for drop bars. With the long top tubes you > > need bars that come back towards you to provide a comfortable reach. >
Not here. I've read that article several times in the past. > UnSo! Terribly, terrifically unso. > > The Top Tube Ruse in RR--40/ 41? talked all about that, but I realize people > come and go and land late and may skip over or miss, but basically, it's > like this. Forgive lack of detail in these explanations: > > Shallow seat tubes neutralize long top tubes. We have shallow seat tubes. > Shallow seat tube angles may somewhat reduce the effective top tube length--but they certainly don't "neutralize" the long top tubes found on the larger Rivendell bikes. For every one degree shallower(=smaller numerically) the seat tube angle is on a Rivendell frame compared to someone's current bike, the Rivendell frame will reduce the effective top tube length by approximately 1 cm. For instance, if someone has a road bike that has a 73 degree seat tube angle, a Rivendell frame with a 72 degree seat tube angle will reduce the effective top tube length by 1 cm. > > Higher bars super-'eutralize long top tubes. We're the Cosmos champs in that > cat. > > As bars get higher, your arms become more horizontal, and that makes them > longer (effectively, not literally). > Well, intuitively that doesn't seem like it would make a very big difference over the short distances involved when raising a stem. And my calculations verify that the "longer arm effect" is trivial. For example, if I buy an A. Homer Hilsen and I raise my bars 4 cm higher than on my current bike in order to get the bars even with the top of the saddle, how will my reach to the bars be affected? There are two effects: a) Raising the stem height will bring the bars closer to me by some horizontal distance. By how much? With a 72.5 degree head tube on the Hilsen, if I raise the stem 4 cm the bars will get 1.20 cm closer to me. However if I buy a set of Nitto Noodle handlebars, they have 1 cm more reach than every road bar listed at Colorado Cyclist (including the bars on my road bike). So raising the stem height in conjunction with using Nitto Noodle bars on the Hilsen means the bars will only get .20 cm closer to me. In addition, if I just raise the bars 4 cm on my current road bike which has a 73.5 cm head tube angle, the bars will get 1.14 cm closer to me. The Hilsen can only do .06 cm better. And with the Nitto Noodle bars on the Hilsen adding 1 cm of reach, the bars on the Hilsen will actually be .94 cm further away from me than if I had just raised the bars on my road bike. That is not the direction I want to go in. b) Rivendell reader #41 points out that as the bars get higher your arms get longer (effectively). But by how much? If you wear a size 44 coat (longish arms), and you raise the bars 4cm, my calculations show that your arms will effectively get longer by .06 cm. If you have shorter arms, say size 22 coat (impossibly stubby arms), you can double that--your arms will effectively get longer by .13 cm. A 67 cm A. Homer Hilsen has a 65 cm effective top tube. My current road bike has a 62 cm horizontal top tube. I would like to try a shorter reach and a more upright position to see if that will cure the lower back and shoulder/neck fatigue I suffer on long rides. How am I supposed to neutralize the 65 cm top tube on the A. Homer Hilsen? I don't understand how any of the things you mentioned accomplishes that. Ideally, I would like to ride a frame with only a fistful of seatpost showing and the bars even with the top of the saddle. I think when only a fistful of seatpost is showing that indicates an "expanded" frame or a frame designed with an upright position in mind. According to my opinion, when a high rise stem is needed to get the bars even with the top of the saddle, that is an indication that the frame is sized just like every other road bike sold today. Thanks for reading, happy -- 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-bu...@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.
