When I was first building up the bare frame of my 1981 Lotus Excelle mixte, I didn't question the choice of 700c wheels at all. It was quite logical to me, since the switch from 27" to 700c tires is so popular these days due to tire selection and availability. I also had good experiences (although limited) with the 700c tires I chose up to that point. However, over the course of just this past year, I have gained a better sense of how different sizes, widths, and thicknesses of tires affect the ride quality of certain bikes. I know that to me, the 590x37 Schwalbe tires feel fast, balanced, and natural on my old Raleigh 3-speeds, as do 20x1.5 tires on my folder, as do 700x32c Continental tires on an old 10-speed. They're all completely different animals. I was lucky enough to have found those tires on the first try (that is, after discovering that the cheap Kenda/Sunlite tires will never cut it) but that led to me not realizing for a long time what kind of impact an inappropriate tire has on the ride quality.
So, what about the Lotus? At first, the 700x37c Continental Sport Contact tires were actually decently lightweight, but their sheer size somehow made them feel jiggly over bumps. I then downsized to 700x35c Vittoria Randonneurs which were decidedly less jiggly, but due to their incredible, bomb-proof puncture protection, they are actually quite heavy and maybe a bit overkill for Ann Arbor. Although more sure-footed, the ride quality remained somewhat crashy over bumps and the difficulty of accelerating with heavy tires was compounded by the handlebar stem being too long. As a side note about the tires, but not contributing to their removal from this bike, they developed long cracks along the sidewalls. For whatever reason, every bike I have equipped with salmon Kool Stop brake pads gets cracked tires. This does not happen to anybody else. I still don't know why it happens to me. Am I actually supposed to wash the brake dust off after every ride?
Another thing that happened over the past few years was the sudden explosion in popularity of 650b wheels and tires. Previously an outdated French size, the 584 mm bsd tire enjoyed a revival (reportedly almost single-handedly because of Jan Heine) among those who wanted fast, supple tires that still soaked up bumps and could be taken off road. I'm still waiting for this to happen with the old English 590 mm (26x1-3/8") size - maybe I should do something about it. Anyway, I read all about the great experiences people were having with this new trend, but somehow never considered the option for myself. I must have somehow thought that the larger-diameter, skinnier tires would be "good enough" for me to stick with; plus, I was able to buy a ready-made 700c dynohub front wheel at the time.
The decision to switch to 650b came quite suddenly. I don't remember how I arrived to the conclusion but within a couple days, multiple realizations came together and I noticed that it might actually be a great idea. I thought of the possible benefits of all of the changes. Smaller, lighter wheels that can get going quicker, light, supple tires that have great user reviews, a closer-ratio wider-range drivetrain, the ability to tuck the fenders closer to reduce the ever-present toe overlap (maybe), and perhaps keeping my desire for a cyclocross bike at bay if the Lotus could be even more gravel-loving than it already was?
The wheels actually took two attempts to build because someone gave me a slightly-smaller dimension for the wheels and I learned the hard way that my spokes were too short. After that was done, I took the Suntour 14-30 tooth 6-speed freewheel off a ruined 1986 KHS Gran Tour that I had to part out. The 170 mm-long 110/74 BCD Sugino cranks with the 40 tooth chainring remained, but I gave it 30 and 50t rings in place of the bash guard. The range and gear jumps on the freewheel are perfect for commuting and adequate for touring. To explain, well, a 9-speed brifter-equipped drivetrain would have been within my budget and a little more ergonomical, but there are just too many finely-spaced gears to be flipping through when I'm taking off from a stoplight. I like banging gears like a drag racer with my wide-ratio 3-speeds, but they don't have a wide-enough range for the place I'm headed next month. The ratios in a 3-speed hub are also a bit far apart for longer-distance riding where an efficient cadence is more important. The solution was a wide-range drivetrain with more than 3 gears in the back. First, I figured I could go with a dime-a-dozen 7-speed freewheel but that didn't fit on the bike - the hub was too wide and the frame wasn't wide enough. 5 gears didn't seem like enough of an improvement, either. I happened to have the old Suntour freewheel lying around so I cleaned it up and ran it. The bearings are in terrible shape and the smaller two sprockets are worn, so I might be mixing and matching parts with a nicer 14-28 Suntour 6-speed that I have. Anyway, the 30t ring gives me a 1:1, the 40 is perfect for commuting in the city, and on my longer, faster rides with less-frequent stopping, I use the 50 almost exclusively, except on the larger hills. I didn't expect to nail the chainring tooth count on the first try, despite having verification from Sheldon Brown's gear calculator. I am very happy with this setup and I think it is not only a great compromise between a 3-speed and a 9-speed, but also not much of a compromise at all.
For the cockpit, I found a Nitto Technomic stem that was tall enough so I could bring the dirt drop bars to a comfortable position. It had a 70 mm run instead of 110 as well so I could slide the saddle back for optimal power output. Luckily, the Technomic also came with a 26.0 mm clamp diameter to fit the dirt drops. However, I kept riding the Lotus for the remainder of the school year and decided that the 48 cm bars were too wide so I found a pair of Origin8 handlebars in 42 cm, also with a 26 mm clamp diameter. These bars are also humped on the lower front quarter, much to my delight. The tape is Fizik Superlight in some shade of gray to match the saddle, but the saddle had since faded even more since I bought the tape, and the tape was darker than I had thought. I also figured out how to "flip" the wrapping direction at the brake levers like the professionals do to minimize the risk of unraveling, but I somehow did it two different ways and one side ended up using more tape.
Both of the SunRace shifters are actually non-indexed left side shifters for triple cranksets since the right hand ones are indexed for 9-speed cassettes. Luckily, I found someone who sold these individually since I couldn't manage to land any of the nice old Suntour bar-ends before other people bought them. However, they do have a one-direction ratchet just like the old Suntours do. I like that. I find that the downward curve of the shifters make upshifting slightly more difficult and less precise, but downshifting is great. I've gotten used to them over the past 200 miles (a little over a week) so this is a no longer an issue.
After I moved the brake levers onto the new bars, I noticed that the right aero lever was about to tear itself apart. I have no idea why this started happening right then because it was fine to ride before. Anyway, I used the chance to get some slightly nicer Tektro levers, similar to what I have on the Lenton. The new hoods are also much nicer to ride on. The Origin8 bars were not only much lighter than the Nitto Dirt Drops, but they came with indentations to route cables. With some help from my friend Nikolai, I found a way to take advantage of all of the cable tracks with the cables from my bar end shifters without creating weird pressure points. All of the cables run where minimal pressure is applied, inside the "finger knuckles," if you will.
The tires are Panaracer Col de la Vie 650B, chosen not only because of their low price and medium-depth tread, but also because I was unsure if a wider tire would have fit in the bike. They are nominally 1.5" wide as opposed to the more popular 1.75. I think now that the 1.75" tires would also fit. For brakes, I used the "Schwinn Approved" Weinmann calipers that came on my '72 Speedster. The rears fit just fine, but the front required a reach so long that I had to file the opening on the caliper downward by a few millimeters to move the brake pads further down. I may even have to file the top side of the brake pads as they wear down and get a larger footprint. The brakes are predictably weak, but they do the job for now and are more powerful than what I'm used to on an old Raleigh. I may upgrade to Tektro calipers one day, if they make ones long enough (other than the R985A).
I attached bullet terminals to the lighting system as well as to the computer wire because I wanted to be able to disconnect all wiring for easy removal of the fork during a headset overhaul. I have a different Herrmans headlight with a working standlight that I will be installing so I don't have to roll the bike back and forth at night at a stop light.
Since the 700c fenders I used previously were now too large in radius and too narrow in width, I took the aluminum fenders off one of the late '60s Falter Star Rider bikes that had 26" wheels. These fenders fit the bike perfectly, visually, but it took a bit of wrangling to get the rear to conform to the shape of the bike. I also drilled a hole to fit one of the reproduction Raleigh reflectors just because I like them.
It may be a bit hard to see in the photo due to the shiny parts, but the fork only had one fender eyelet on each blade and the fender needed two. I used the axle retention washers that came on my Takara, turned them to point upward, and used them to hold the upper fender braces to the axle. This very small hack works extremely well and I am more pleased about it than I should be.
The Brooks Cambium C17 saddle has treated me very well over the past year. I still think it is a bit on the stiff side, but its shape, weather resistance, traction, and appearance are pretty much perfect for me. This saddle does not grow more uncomfortable during a day of riding like my other modern saddles do. There are very small signs of wear on the canvas covering, but seeing that it has covered just over 1000 miles at this point, I am very confident in its longevity.
After another spirited 200-mile shakedown period, which I will cover next, I am extremely happy with how the Lotus turned out and pretty convinced that it will stay in more or less this configuration for a long time.