This past Fall I had an opportunity to test the new Transition Sentinel and was mighty impressed by it. While lurking around the Transition Outpost in Bellingham, Washington my wandering eyes noticed a bike that very much piqued my interests, but at the time I wasn’t really supposed to see it. Fast forward a few months and I’ve been fortunate enough to spend a good chunk of time on the latest e-bike from the PNW based brand – the new Regulator. Available in both CX and SX models, I have been romping around on the former for the last couple of months. These new bikes both utilize the latest Bosch Performance Line motors nestled into Transition chassis that are all new from the ground up. The CX model that I tested features a larger 600wh battery and more powerful 85nm motor, whereas the SX model has a 400wh battery and 55nm motor, with a substantially lower weight and proportionally pared down frame.
The Regulator CX fits squarely into a budding category of full power e-bikes that generally weigh a few pounds less than the prior crop of full power bikes. To be sure the weight loss can vary depending factors such as category, battery size, spec, etc. While this class has yet to be aptly named, the substantial weight loss is partly accomplished via a new generation of Bosch motors as well as by improved integration, such as forgoing quickly removable battery packs and wired sensors, amongst other things. Anyhow, read on for a deeper dive into Transition’s e-Sentinel…
Details
- Bosch Powertube 600 wh Battery
- 250 wh range extenders for M-XL as aftermarket
- 85nm Torque
- Carbon fiber frame
- Size Specific chainstays
- Mixed wheels only
- Small, Medium, Large (tested), Extra Large
- 160mm front travel / 150mm rear travel
- 170mm fork compatible – up to 160mm rear travel with a 65mm stroke shock
- Flip chip lower shock mount for geometry adjustment
- 180mm post mount rear brake
- 47.2 lbs – our scale, Large / (49.2 lbs claimed)
- Lifetime warranty on frame
- $8999 USD / $12,699 CAD
Starting with the frame’s silhouette, the Regulator CX features the same industrial design as most of the recent models from Transition. Interestingly this bike doesn’t use a sleeved cable routing. Transition’s rationale is that it adds substantially to the downtube diameter and increases weight slightly. Compared side by side to a Santa Cruz Vala – which utilizes the same battery/motor – I can confirm that the Regulator CX’s downtube is quite a bit smaller and thus it looks more like a regular MTB, aesthetically speaking. The angular look of the tubing helps with this as well. Regardless, I had no cable rattle and the routing is straight and because it has no sharp bends cable actuation is very smooth. So while it may make maintenance slightly more complicated, I have no real complaints.
Flagship RockShox suspension was a hit for certain. The new Charger 3.1 damper in the latest ZEB sees a broader usable range of damping adjustment as well as a bit less harshness, compared to the Charger 3.0. I added one additional volume reducer (making two in total) plus a ZEB fender and called it a day. Out back I have to say that I am absolutely floored with the latest Super Deluxe Ultimate and its new highly adjustable Linear XL air can. Transition worksed closely with RockShox so the shock is tuned to land right in the middle of the range in terms of both positive and negative volume reducers, so riders have ample room to experiment in either direction.
Motor rattle from Bosch’s old systems have officially been put to death with the new Performance Line. There quite simply is no unwanted noise from this new motor, other than a fairly quiet hum on the climbs. The power transfer is silky smooth and when you let off the pedals there is no unpleasant cut-out or jerky feeling. Everything on the power side is about as seamless and natural as one could want from an e-bike.
Touching on some of the Bosch related bits, clockwise from top left: The charging port cover seemed like it could be overly minimalist – its magnet closure isn’t that powerful, but I haven’t had any issues after quite a bit of riding and charge cycles. The top tube mounted display is very simple and well thought out – each of the 5 bars represents 20% of the battery life. Each bar changes color when it is halfway cashed – representing 10% marks. If your bar mounted “mini remote” dies or breaks, you can still change modes with the +/- button at the bottom of the top tube display. Next, the remote itself is minimalist, slick and intuitive with good ergonomics. It uses a CR1620 battery. The remote features light activation, walk mode and most importantly toggles through the 4 riding modes. Lastly, gone are the annoying magnets on the brake rotor – the new rear wheel sensor goes under the valve and engages with the motor as it passes by near the bottom bracket. No more wires running through your bike’s back end!
Shimano’s XT drivetrain is a smart pairing that likely helps save some costs on a flagship e-bike. While I personally think that SRAM is well ahead of Shimano these days – and I do love the wireless Transmission drivetrains – one benefit with Shimano drivetrains is how well they shift under power as well as their high level of durability. So no complaints and no issues here. Transition is pushing the envelop on crank length here – the SRAM crankarms pictured above are only 150mm long! While this took a little getting used to initially, I did grow quite fond of how they improved clearance during technical climbing, although that does come at the expense of some human powered torque.
TRP’s DH-R EVO brakes are a tried and true option. These brakes were recently updated with an all new lever (*not pictured above) and became the “EVO PRO”. That brakeset didn’t manage to make it on my sample bike, but production Regulators will ship with them. Regardless, the powerful calipers remain the same and the 203mm front and rear rotors offered more than enough fade free power at a lower weight and with better modulation than SRAM’s Mavens. Another very smart spec in my opinion.
Left – the mounts for either a standard water bottle or a 250wH range extender are sleek and sturdy. Right – you can see the upper and lower hardware that passes through the downtube to secure the battery. Dropping the motor and removing the battery is about a 20-30 minute job. If you were to do some air travel with this bike, that would be necessary and mildly annoying, but very much worth the weight savings and reduced noise. Also of note, the Regulator CX doesn’t have a downtube shuttle guard but you could always add this.
Up front the cockpit featured a clean cable routing and a nice mix of parts including all time favorite handlebar – a 35mm rise OneUp carbon bar paired with a 40mm ANVL stem that has a few millimeters of rise. Props to Transition for thinking of us riders who like a tall front end! *Note: OneUp EDC lite tool not included.
For seating, the dropper post travel is scaled with frame size. The OneUp V3 dropper is very light and highly adjustable, with smooth action and excellent durability. My size Large shipped with a 210mm travel version which was more than enough for me at 6′ tall. The updated lever features a grippy and comfortable paddle and as well as 3 inboard/outboard adjustments. Lastly the SDG Bell Air III saddle is a notable upgrade from the in-house ANVL seats that Transition’s commonly featured in the past.
Transition features their own in-house upper chain guide, which did a fine job, and just to the right of it you can see the singular geometry adjustment – a high/low flip chip in the lower shock eyelet.
Frame features, clockwise from upper left: The accessory mount under the downtube is a must have for anyone who’s been spoiled by downtube storage. My personal kit features a big CO2 and inflator, a tire lever, plug kit, boot and full size tube, with room to spare. Transition’s new cable management system is very dialed. It makes for easy side to side brake lever swaps and the bike also ships with blank covers for tidy, sealed coverage when using an electronic dropper post and/or drivetrain. Next, there is a nifty little cover that prevents the main pivot from accumulating junk in a bad place. Lastly, the new “pillowtop” chainstay protector is more substantial than past versions and thus does a much better job of quieting chain slap.
DT Swiss handles wheel duties with the e-bike specific H1900 wheelset. The wheels are reinforced to handle the additional weight of an e-bike and have hub hardware designed to manage the increased torque from a motor. I’ve had no issues with them thus far and have found them to be quite tough, while offering a stiff and responsive ride. They aren’t exactly exciting but they get the job done at a reasonable weight and cost.
Putting a bow on things, the new Schwalbe Radial tires are featured front and rear in the new Albert tread pattern, which is considered an all rounder. They’re predictable and work very well in a broad range of conditions while rolling along pretty quickly. I appreciated having an ultra soft compound up front and a soft compound out back – extra traction where it counts and durability where it matters most. The trail level casings are reasonably sufficient, but some riders will surely want to opt for a gravity casing out back given the added strain that e-bikes tend to put on tires.
Transition Regulator Geometry
On the trail with the Transition Regulator
It’s safe to say that I’m a blank slate regarding this new class of e-bikes, so I was very curious how dropping a few pounds of weight off of a full power e-bike would feel on trail. I’ll get into the ride characteristics in more detail further down, but the first thing that struck me about the Regulator CX in particular was just how silent it is. I’ll just come right out and say that this is not only the quietest e-bike I’ve ridden – it’s also the quietest mountain bike I’ve ridden to date. Going down rocky sections of trail just sounds like punching pillows. There is no noise from chain slap, no cable rattle (even with 4 of them) and above all, no motor rattle either. On the climbs, the motor’s sound is also far more subdued compared to everything else I’ve ridden. Once I started to get used to the oddly quiet nature, it then occurred to me how much this bike reminded me of the new Sentinel. It truly did come off as a quiver killer, do-it-all bike.
Starting with suspension, this is a bike that has Transition’s trademark pop. Boosty and easy to get off the ground, it is very confident in the air – despite weighing 15 pounds more than a Sentinel. However, on past Transition models this poppy feel did come at the expense of mid stroke compliance and things could feel a tad on the harsh side in rough sections of trail. Kinematically, what changed with the new Sentinel is how it managed to keep that pop and support yet it became more compliant in the mid stroke, and with less hang up and pedal feedback on square edged hits. Well, those same magic kinematics have been seamlessly grafted into the Regulator’s DNA.
The first question I asked Transition was “Can I long stroke the rear shock and throw a 170mm fork on this thing?”…The answer was Yes, but the more I rode it, the less I found myself leaning in that direction. It’s nice to have options, but in stock form the suspension is so good that I doubt I’ll even want to go down that road. I found myself using all of the travel fairly often but never once felt a harsh bottom out, so this bike makes excellent use of what it’s got, travel wise. My point is that if you’re thinking you might need a little more than 160mm/150mm, you can have it but you might not need it. Speaking of options, with a 27% progression rate, the Regulator CX – like most Transition bikes – lands right at the mark where it plays nice with both air and coil rear shocks. One last suspension related aspect worth pointing out is that I didn’t notice any funky behavior during heavy braking or under mass transfer of any kind. While I don’t have any numbers on brake jack vs. squat, it was an afterthought and the bike was very neutral while offering loads of traction. To put a bow on things, I think the suspension is about as good as it gets.
As far as geometry is concerned there is an interesting mix of factors – some are quite progressive and some are slightly conservative. That doesn’t mean the bike is paradoxical or confused by any means though. For example the choice of 150mm cranks are on the bleeding edge, but a somewhat higher bottom bracket and a slightly steeper head tube angle isn’t pushing the long/low/slack envelope – rather that geometry ensures that the Regulator CX is a well rounded, utilitarian rig…It’s nimble in the slow, awkward bits and you can just keep hammering the pedals through the jank due to the increased clearance. Striking a nice balance it still remains sure footed in the steeps and unfazed by high speeds.
Another aspect of the geometry I appreciated was the fairly long chainstays. When dedicated mullet bikes first started popping up many of them were a bit too short out back and they suffered from some instability and an unbalanced feel. With a long-ish 450mm rear center in the low position the Regulator CX remains plenty stable, yet still manages to excel in the corners in part due to the smaller rear wheel. Despite the roomy back end, I’ve found that it was surprisingly easy to manual – requiring less effort than any other e-bike I’ve ridden to date. All in all, the Regulator CX is very comfortable in a wide variety of terrain – from tame, mid-grade flow trails to steep, haggard nasty sections. Lastly, as far as climbing goes, the 77.7º (low position) seat tube angle is aggressively steep. This is one of only two bikes which I’ve ever found myself sliding the seat rails back on. It’s very natural and easy to get your weight forward and blast up sections of steep, awkward climbs, while still being comfortable just cruising up fire roads at mellower grades.
As far as the battery is concerned, 600wh is ideal for a broad range of rides. I could go out on a very long ride exploring in the back country and if I’m smart about when I use the higher power modes I can still get a very big day in. It’s also got more than enough juice to blast a bunch of laps on jump trails climbing back up exclusively in Turbo mode. I doubt I’ll ever personally need the range extender, but it’s nice to have that as an option, although it will mean that you’ll likely need to carry a hydration pack due to it supplanting the water bottle. Personally I’d prefer this approach and a lighter overall package when compared to something like the new and similarly laid out Trek Rail, which has an 800wh battery, but tips the scales closer to the 53 pound mark. Most of the time I just don’t need that much battery and like the lighter weight and thus nimbler and more enjoyable handling of this layout. To each their own – but that’s just where I stand on the matter.
Overall
When wrapping things up, it’s always important to cover value and how a bike rates in that area. At $8,999, the Regulator CX scores high marks, relatively speaking. It has an excellent spec with very little to pick apart, and when contrasted with similar models from other boutique brands it offers a lot of bang for the buck. On the other side of the coin, you might be able to find a similarly spec’d bike for a little less money from a consumer direct brand, but there is some hidden value that goes along with buying a Transition. The frame has a lifetime warranty, comes with excellent support and it’s also easy to quickly get a broad range of spare parts, searchable by model, at a very reasonable price – even including touch up paint…If the $8,999 price tag is a bit steep but you do like the sound of this bike, it’s worth considering the Deore model, which comes in at $6,999. And if you don’t need quite as much power or battery, perhaps the SX model is also worth a look.
All told I couldn’t be happier with this bike. The new Bosch system is stunningly good but the main takeaway here is that the Regulator CX’s strengths aren’t derived solely from the latest and greatest German engineered Bosch motor. The sum of the parts is what makes this bike really go. It is fantastically well thought out – from the geometry to the suspension to the frame features. Personally, I think an e-bike should be very well rounded and utilitarian as I have wide ranging needs from it. I want a rig that feels like a normal bike when hammering out a few fast paced laps on jump trails when there is only 45 minutes to sneak a ride in. However, I want it to be equally comfortable and capable on big epic rides, awkwardly bopping up moto trails and exploring new routes on unknown terrain. It also needs to get the job done on digging missions and power me up the trail when I’ve got a 20 pound camera bag on. The Regulator covers that broad range of demands better than anything else I’ve ridden and does so with ride characteristics that are very close to that of a regular mountain bike, all while doing so in a freakishly quiet manner. I’m past due for a new e-bike and this just might be the one…
