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My New Bacchetta Recumbent Bicycle, Part 1
By Cindy of Stone Marmot
April 18, 2019
I've been looking for a replacement for my over 12 years old RANS V-Rex that has at least 55,000 miles on it. It has a 26 inch rear wheel and a 20 inch front wheel. The pedals are in front of the front wheel. The rider sits almost on top of the rear wheel.
Consequently, the bicycle rider is sitting almost as high as on a regular bike. When I'm riding this bike, my head is higher than all cars on the road and about even with the top of most pickup trucks, vans, and SUVs. This means that I can see most all traffic well and they can see me. This is much better than most recumbents, which tend to be much lower, and an important safety feature.
This recumbent also has a turning radius comparable with most regular bicycles since its wheelbase is about the same as most bike. This is because the pedals are in front of the front wheel. Most recumbents have their pedals between the wheels, which results in a much longer wheelbase and bigger turning radius.
I like these features and wanted them in my new bike. I would have gotten another RANS V-Rex (I already have two), but RANS discontinued this model about 9 years ago. The only bike I could find that was close to this was the Bacchetta Giro 20. The Giro 20 has the same wheel sizes and pedal configuration as the V-Rex. It's about 6 inches longer than the V-Rex, so its turning radius is a little wider than the V-Rex. The Giro 20 pedal height is about the same as the V-Rex, but the seat is about 2 inches lower and set up for a more reclined position, but this looked fixable. More information on the Giro 20 may be found here.
I bought the Giro 20 and spent about a month adapting it to my needs. Figure 1 shows my Giro 20 after my modifications. I decided to write this article after I finished my mods, as usual, so I don't have any before or during the mod process pictures and didn't want to disassemble things to show the process. Hopefully, the final assembly pictures are good enough to determine how things were done.
Figure 1 - My new Bacchetta Giro 20 after modification.
The first task was to raise the seat height to be the same as the V-Rex. The seat was originally resting on top of the frame tube clamp. Figure 2 shows the original brackets that fastened the seat to either side of the frame tube clamp. Each bracket was attached to one side of the frame tube clamp with one bolt while two screws attached each bracket to the bottom of the seat. The space between these brackets is 2.75 inches, which is also the width of the top of the frame tube clamp.
Figure 2 - Original seat attachment brackets.
Figure 3 shows the riser I made to raise the seat a little over two inches. It is made from a piece of 3x3 inch aluminum box tube with 1/8 inch thick walls, like those shown in Figure 4. One of the faces was sawed off the box tube section, leaving a U-shaped piece that is 2.75 inches between each leg of the U. The sawed off face was bolted to the outside of one of the legs of the U-shaped piece while a similar 1/8 inch thick piece of aluminum was bolted to the outside of the other leg of the U. Figure 5 shows another view of this U-shaped piece, which is bolted to the frame tube clamp with the same bolts that held the original seat brackets.
Figure 3 - New seat riser installed.
Figure 4 - Examples of 3x3 inch aluminum box tubes.
Figure 5 - Another view of new seat riser.
The remaining face of the U-shaped piece was centered and bolted to a roughly 1x8 inch piece of 1/4 inch thick aluminum bar, as seen in Figure 6. This bar was drilled to match the mounting hole on the seat bottom and screwed to the bottom of the seat with the same screws that held the original brackets to the seat. Note that these screws were countersunk into the aluminum bar like with the original brackets. The bolts that attached the bar to the U-shaped riser were flat head screws that were also countersunk into the bar so they didn't interfere when the bar was bolted to the seat bottom.
Figure 6 - Seat riser attached to aluminum bar which is attached to seat bottom.
This riser fixed the seat height. But the seat was still reclined too far. The bottom sections of the backrest support poles were originally only 13 inches long, which didn't allow the seat back to be raised enough vertically. So I substituted the 19 inch long bottom section poles from my first V-Rex, which I had been cannibalizing to keep my second V-Rex running. These are shown in Figure 7. This allowed me to raise the seat back to the same angle as my V-Rex.
Figure 7 -Seat backrest support poles bottom section.
My first 60 mile ride showed that this bike had the same problem as both my V-Rexes in that the seat would slide down the frame while riding. Figure 8 shows the piece of 1/2x3/4 inch aluminum box tube I attached behind the seat frame tube clamp to stop it from sliding while riding. The back of the tube is bolted through the hole intended for the rear rims brakes (I have disk brakes). The front is held down to the frame tube with a stainless steel hose clamp that is threaded through some scrap wire insulation from a 12 channel audio snake cable to protect the frame tube finish. The front of the stop tube is spaced from the frame tube with a scrap piece of rubber from the sole of a sneaker.
Figure 8 -Stop tube to keep the seat from sliding on frame tube.
This completes the changes needed to get the seat height and angle of my new Bacchetta Giro 20 to be the same as my old RANS V-Rex. The second part of this article series discusses the other changes I made to fit my needs.
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