Monday, December 18, 2023

Musings of an ebike customer

 


When riding the hills recently, upon which I was unceremoniously dropped, I decided that given my advancing years and the apparent immortality of my riding companions, an ebike might be on my radar screen. Of the bikes I considered, all had some common characteristics. All were Class 3 (offering pedal-assist only, which ceases when the e-bike reaches 28 mph in the USA) with carbon fiber frames, mid-drive (bottom bracket) motors, semi-wireless or fully wireless electronic gear shifting, disc brakes and wide tire clearance. All were way on the wrong side of $10,000. There is a myriad of choices throughout the industry; most major manufacturers now offer ebikes and the numbers increase by the month.  However, they are extremely sophisticated (that is, complicated) devices and I believe that maintenance and servicing are issues for the foreseeable future. For this reason, I focused on Trek and Specialized because both are excellent brands which have (hopefully) adequate service outlets in Austin.

 Marketing hype requires the regular introduction of something new and therefore, by implication, better.  Both mountain bikes (1970s) and gravel bikes (2000s) were introduced long after off-road events such as Yorkshire’s legendary Three Peaks cyclo-cross race which dates from 1961 and which used bikes which had many characteristics of their two-wheeled descendants. And now the term “endurance bike” has now been introduced. All this pigeonholing is questionable. Bicycle designers have been experimenting for over 150 years with different frame geometries and components to meet the needs of different riders. “The Birth of Dirt: Origins of Mountain Biking” by Frank Berto is a persuasive account of this phenomenon and should be mandatory reading for anybody interested in the history of cycling, whether a mountain-biker or not. 

 Confusing terminology results in a challenge for any prospective customer and it is necessary to delve into the specifications of a particular bicycle to ensure that you end up with something appropriate to your needs. Using today’s vernacular, I was looking for a “road” bike with limited “gravel” capabilities. This idea is proving popular and some manufacturers are pushing their machines’ dual-purpose versatility, even at the high end.

 Both brands push their own components, Bontrager (Trek) and Specialized with the main exception being the drivetrain which is either Shimano or SRAM, Campagnolo having disappeared from the US market.  I assumed that the e-technology and the hydraulic disc brakes of both brands are equally effective and, in any case, I am ill-equipped to evaluate any subtle mechanical differences between them. Frame geometry is ostensibly more relaxed on a gravel bike but here too, I assumed that the models that I looked at would probably work for me.

 Manufacturers have experimented with various suspension systems initially designed for mountain bikers such as Trek’s IsoSpeed rear pseudo-suspension system (located at the junction of the top tube and seat tube) or Specialized’s Future Shock (front suspension located below the handlebar stem). These innovations are now appearing on road bikes.  Other components such as dropper seat posts have appeared. These allow for quick adjustment of saddle height without requiring getting off the bike but would seem to have little value on a road bike.

 So, what is left to think about? 

 Component dimensions. Both Trek and Specialized pre-determine these for a given frame size. For the perfect fit with a custom frame, one would usually evaluate steer-tube length/bar height, stem length & [WH1] rise, crank length, handlebar width etc. etc. To these, add tire width, depending on the bike’s intended use and saddle width, depending on your anatomy.  The irony is that, except for Trek’s Project One, these multi-thousand-dollar bicycles offer little or no true customization. The only way to make this happen is to take off the stock parts, purchase the components you want separately and then have them installed by the retailer.  The steer tubes come pre-cut from the factory so they can only by shortened ….. goodbye handlebar height.

 Gearing.  There are several methodologies for expressing gear ratios. The one I usually use is calculated thus: divide the chainring size by the sprocket size (both determined by the number of teeth), then multiply by the bike's wheel diameter in inches. The latter is a function of both rim diameter and tire size. Some formulae also factor in crank length but that only changes the results by very minor amounts. One of my custom 10-speed road bikes has a 53/42/30 triple crankset and the other has a 50/34 compact double. My cassettes have varied from 11-23 to a 12-28 resulting of high gears of approximately 120 gear inches and low gears of about 28 gear inches.  However, the introduction of ebikes changes this dynamic as with the pedal assist, the need for very low gears is somewhat mitigated. The most radical innovation in the mountain-bike gearing arena is the widespread introduction of single cranksets with chain rings of 40 teeth or lower and mammoth rear cassettes with up to 50 teeth. These set-ups, colloquially known as a “one-by,” are now migrating to road and gravel bikes.

 Tire width.   Back in the day, I used to run 19 mm tires at 120 pounds pressure. Ouch !!!  Now the trend is towards wider tires at much lower pressures. Road tires are typically 28 or 32 mm whereas gravel tires are in the 35 – 45 mm range. As a roadie, one important issue for me is not how wide a tire I can get on the supplied rims but what the safe minimum width is.

 Handlebars.  Road bike bars are usually quite aggressive in geometry. Gravel and endurance bikes have a lower drop and sometimes use a flared design, not dissimilar to the Rene Herse “randonneur” style. Without trying them, I do not know if I would have a strong preference.

 SPECIALIZED

 Historically, the company has used the following nomenclature: S-Works = Premium line (carbon frame manufacture and high-end components), Turbo = ebike, SL = Super Light and EVO = short for Evolution which represents a design or technology upgrade, usually, but not always, applied to their mountain bikes.

 On their current website, Specialized listed three ebikes of possible interest to me: (1) the S-Works Turbo Creo SL, identified by the manufacturer as a road bike, (2) the S-Works Turbo Creo SL EVO, identified as a gravel bike and (3) the most recent addition, the S-Works Turbo Creo 2 which claims to be a road/gravel “combo”.  All three are 1x12: Specialized no longer offer any high-end ebikes with a double chainring.

 The Creo SL and the Creo SL EVO are being discontinued, replaced by the new Creo 2 which, as mentioned, is being sold as a road and gravel multipurpose bike. However, I think that the Creo 2 strongly leans towards the gravel community: it comes with a single 44-tooth chainring, a 12-Speed 10-50 cassette, flared handlebars, and a dropper seat post. It is supplied with massive 47 mm tires although the rims will accept any in the 28-47 mm range. The drivetrain is SRAM’s fully-wireless Red eTap AXS.  Thus Specialized no longer offer a high-end, road ebike although some dealers still have a limited number of the now discontinued Creo SL and Creo SL EVO models.

  TREK

 There were two bikes on the current Trek website that were of interest: (1) the road-specified Domane+ SLR 9 and (2) the gravel Domane+ SLR 9 AXS.  In the company’s nomenclature, the Domane is the series name, the + indicates an ebike, SLR = "Super Lite Race", the 9 indicates a carbon frame (c.f. the 7 which is aluminum) and lastly, AXS (= “access”) which is SRAM's component integration system that connects the electronic components and software.

 The two frames are identical in terms of frame construction and geometry. Both use the same motor, the TQ-HPR50 which is rated at 50 Nm, 250 watts maximum continuous rated power and 300 watts peak power. The wheels/rims are the same though the SLR 9 comes with 32 mm road tires whereas the SLR 9 AXS comes with gravel-suitable tires of 40 mm width. Both models come tubeless but the rims can take tubes.

 The primary difference between the two is that the Domane+ SLR 9 uses the semi-wireless Shimano 2x12, Dura-Ace Di2 drivetrain with 52/36 teeth chain rings and an 11-34 cassette. The Domane+ SLR 9 AXS uses the fully-wireless SRAM 1 x 12, RED XPLR eTap AXS single drivetrain with a 42-tooth chain ring and a 10-44 cassette.

 Trek’s Project One boutique program offers full components customization: chainring size (within a 36 – 46 range on the SLR 9 AXS), steer tube length/bar height (limited), stem length, crank length, handlebar width, tire width, saddle width etc. can be individually specified. And there is a huge range of color options, for a price.

 AND THE ANSWER IS …….. ?

 Given that my “need” for an ebike is not urgent, I will wait to see what the manufacturers introduce for the 2024/2025 model years.  If either Specialized introduce a true road version of the S-Works Turbo Creo 2 and/or Trek introduce a “one-by” 1x12 version of their Domane+ SLR 9, then the market will become even more competitive.

 


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