N-1wsletter #9: SRAM Transmission retrofits, 1” headsets, and sealant funnels
Perhaps you don’t *need* UDH after all.
Featured in this week’s tech round-up:
Want to ride more? Considering commuting more.
You (maybe) don’t have to have UDH to run SRAM Transmission.
The Pro’s Closet inches closer to re-opening its doors.
Another helping hand for Scott Sports.
One-inch headsets aren’t dead.
Silca embraces its artistic side.
Fancy funnels for tubeless sealant.
Quick-release valves and pump heads from Schwalbe
A lightweight cassette option for XPLR riders.
Squishy MTB grips to save your hands.
TPU now comes in XXL.
Welcome back, everyone! I hope you all enjoyed a good chunk of time off, and maybe some quality time with friends, family, and your bike, too.
I’m guessing many of you checked out your Strava “Year in Sport” summary at some point in the last few days. It’s been fun to see how much distance I covered and how much vert I ascended – alas, not as much as I’d hoped in both cases. But the figure that stood out most to me is that I logged nearly 1,800 km (1,100 miles) in 2024 just running errands, almost all of which were short trips of less than 15 km (10 miles) round-trip.
Several factors played into this for me.
I’ve got incredible cycling infrastructure in my hometown, as well as generally favorable weather. If I want to ride a bike somewhere in town, I can do so not only safely, but I’ll probably also be dry when I get there. And of course, I’ve got my trusty Urban Arrow e-cargo bike that somehow seems up for just about anything I ask of it.
That said, while all of these are undeniably helpful, none of it is at all meaningful if I don’t muster the motivation to toss a leg over the saddle in the first place.
It supposedly takes just over two months to kick old habits and create new ones, and for many looking to go car-free more often, that means severing the reflex to reach for your keys each and every time you need to go anywhere. Looking at those Strava stats reminded me of a fun experiment I ran in 2011 when I did my first review on an e-cargo bike (a Trek Transport+ with a BionX rear hub motor). I decided then that the only way to properly evaluate the thing was to really dive into the lifestyle, so I committed to going car-free for 30 days straight (in the middle of a particularly snowy Colorado winter, no less).
As it turns out, it was surprisingly easy. For sure, I needed to pay more attention to dressing for the weather, and there were plenty of times it would have been easier to just hop in the car. I should also mention I ran that experiment before having kids. Regardless, I credit that month for helping to change my mindset about the best way for me to get somewhere. Almost fifteen years on, I think it’s safe to say that little experiment took hold as I now regularly go a week (or more) without sitting in a car.
I don’t say all of this so I can hop on my high horse and spout off about how much CO2 I saved over that distance or brag about my environmental bona fides (although it’d be neat to see Strava add some sort of leaderboard for saving carbon emissions). Ultimately, the reason I was excited to see that 1,800 km figure was that it meant I spent a whole heap of additional time in the saddle than I would have otherwise.
I’ve never been big on new year’s resolutions, and they usually don’t work, anyway. Goals, on the other hand, are often more achievable. If you’re going to make one, “riding more” seems like a good pick, and mixing in some more commuting by bike could be a good way to do it. Nope, it’s not always easy, and I’m under no illusions that everyone can feel as safe doing it where they are as I do. But if given the choice of pedaling a bike or sitting in a car, I know which way I’d prefer.
Here’s to 2025.
In the news
SRAM T-Type for older Yetis
SRAM’s Transmission wireless electronic drivetrains took the mountain bike world by storm when it debuted in 2023, partially for its remarkably positive and nearly foolproof shifting – even under full pedaling load – but also for the incredible robustness of how the rear derailleur attaches to the frame. Instead of bolting to a relatively thin piece of aluminum, Transmission derailleurs’ so-called Full Mount design has tabs that sandwich both sides of the driveside dropout. The thru-axle then passes through both of those tabs to add far more strength and rigidity to the whole assembly that you could never get out of a standard hanger, regardless of material or design.
Full Mount indeed offers awesome durability, but it’s only compatible with frames built with SRAM’s Universal Derailleur Hanger – well, sort of. Some folks have devised workarounds for certain frames, such as Reid Fletcher at upstart Colorado brand Biggie Components, who’s come up with a kit that allows owners of older Yetis and Revels to upgrade to Transmission despite those frames not being technically compatible.
The kits are pretty affordable at US$65, although they also don’t consist of much – basically just a CNC-machined acetal (i.e. fancy plastic) hat-shaped spacer, plus an additional washer for the Revel variant. But that spacer allows folks to run Transmission on bikes that weren’t originally meant to use it without having to shell out for a new frame or bike, and without the need for any permanent modifications that would void your warranty.
“I bought my [Yeti] SB130 new and was bummed when T-Type came out,” Fletcher told me. “US$8k for a new Yeti for a new drivetrain is prohibitively expensive. My part reduces the size of the bore in the Yeti frame to the Transmission dimensions.”
Keep in mind that the Biggie Components spacer only adapts the frame to Transmission spec; you still need the Transmission components themselves, not to mention the specific rear thru-axle and a new chainring or crankset (since Transmission uses a different chainline than most other mountain bike drivetrains). And while US$65 might seem like a bit much for a bit of machined plastic, it’s still – as Fletcher keenly points out – a heck of a lot cheaper than the alternative if you really want to run Transmission.
What about other brands of bikes, you wonder?
"I’ve measured all the major brands of bikes to check plausibility but currently only offer these two solutions because of their simplicity,” Fletcher explained. “Most other bikes you need to mill the frame which isn’t possible for most people; the existing hole in the frame is too small.
San Diego machining specialist 5Dev offered retrofit kits for several Specialized gravel models for a period, but despite it still being listed on the web site, it’s since been discontinued, saying it was a major headache in terms of customer service.
“I’m still trying to figure that [Specialized gravel frames] out as I have probably 50+ people worldwide offer to buy regardless of cost.”
Three cheers for creative folks with access to CNC machines.
The Pro’s Closet plots its return
Online retailer The Pro’s Closet announced in early November that it had been purchased by private investment firm Elshair Companies, and barely two months after announcing it was shutting its doors, it sounds like TPC is on its way toward being back in business.
The company recently signed a lease on a new warehouse space in Thornton, Colorado – just north of Denver – and it’s been busy collecting a new stock of used bikes, frames, and wheels that it’ll presumably put up for sale shortly. Photographers are already busy shooting images of incoming inventory, too, and I’d imagine there are other folks frantically scribbling up product descriptions in preparation for launch.
“We're still getting our work stations, cleaning bays, photo studio, and other work areas set up,” read a company blog post from December 23. “We even bought 5G hot spots so we could get internet in the building while we wait for cable.”
In the meantime, the company is still soliciting folks to sell or trade their current gear here.
FYI, there’s no word on whether TPC 2.0 will honor the in-store credit many people hadn’t used before TPC 1.0 went under. It’d of course be fantastic if it did, but it’s important to keep in mind that the rebooted TPC is under no legal obligation to do so since it’s technically an entirely different entity despite the carried-over name and branding.
Either way, let’s see where this goes.
Scott Sports gets a loan
The abrupt end to the pandemic-fueled bike boom has obviously hit a lot of companies hard, particularly ones that had ramped up production in a big way to feed what they’d hoped to be a longer-running buying frenzy. Those brands have not only been forced to pay for lots of additional warehousing they hadn’t originally planned for, but all of that inventory has also tied up huge sums of capital they would otherwise prefer to use for things like research and development, or even just day-to-day operating expenses.
According to the folks at industry trade publication Bike Europe, Scott Sports is the latest major brand to require a loan to keep things moving, to the tune of €160.6m courtesy of South Korean majority shareholder Youngone Corporation – and that’s on top of the €107.1m it had already extended to the prestigious Swiss label.
We’re definitely not out of the woods yet, folks, and 2025 is shaping up to be another rough year. That light at the end of the tunnel can’t come soon enough.
Cane Creek teams up with Richard Sachs and Wilde Bikes for classic headsets
Just about every steerer tube these days uses an external diameter of 1 1/8” or 1 1/4” – either straight or tapered. However, there are also heaps of older bikes out there with 1” forks, and Cane Creek wants to make sure those folks are still being accommodated. The company has long offered its workhorse 40 Series headset in 1” diameters for both threadless and threaded fitments, but it’s now handing off distribution of the higher-end 110 Series variants to a couple of OE partners.
Richard Sachs Cycles will now be your primary point of contact if you want a threadless 1” Cane Creek 110 Series headset, which features classically shaped 7075 aluminum external cups, Cane Creek’s “ZN40” zinc-coated steel angular contact cartridge bearings, and a rubber lip seal built into the crown race. They’re only offered in black, but they can be purchased with or without “RS” laser etching for US$120.
If you need or want a 110 Series headset for a 1” threaded steerer, you now need to head over to Wilde Bikes. These are offered only with Wilde’s laser-etched branding, but they’ve available in both silver and black, and include three 5 mm spacers (one keyed, two non-keyed). Retail price is the same at US$120.
“Back in August, we received a request from Jeff Frane of Wilde Bikes to make EC30 threaded headsets (for threaded 1" steerer tubes),” Cane Creek product marketing manager Will Hart told me. “We deemed this SKU not worth stocking and selling ourselves due to its extreme niche for small builders, so we proposed that Jeff purchase an entire MOQ [minimum order quantity] from us and we would pass along all requests of this headset to him. He would be the sole dealer of them.
“Curiously enough, one month later, we received a very similar request from Richard for EC30 threadless headsets in 110 Series level. Again, the potential sales numbers are small enough that we can't justify stocking these here, so we gave Richard the exact same proposition that we gave Jeff. He accepted. His product shipped the week before Christmas. Though it's lasered like a 110, these headsets are using the ZN40 bearing out of our Forty Series. Just made the most sense here.”
Kudos to Cane Creek for keeping these things in production.
Silca encourages gambling – sort of
Silca has partnered with California artist Chris McNally for a limited-edition run of its HX-One tool kit. The kit includes the same items as the standard version: a set of polymer-coated S2 tool steel hex wrenches (from 2-10 mm), a set of S2 steel Torx wrenches (from T8 to T30), a 6 mm-to-1/4” bit adapter, and four S2 screwdriver bits (PH1, PH2, SL4, and SL5), all housed in a beechwood storage case with a magnetic clasp. The Artist Edition one, however, features a case with laser-etched graphics penned by Chris McNally.
Unusually for a limited-run art piece like this, retail price for the Chris McNally edition is US$125, which is exactly the same as the regular HX-One – not exactly inexpensive, but neat that there’s no premium upcharge for the fancier wrapper.
Here’s where the gambling comes in: Silca is only offering sixty of these kits, each with laser-etched graphics penned by McNally. But of those sixty, there will be ten kits hand-painted by McNally himself, and randomly mixed in with the lot.
Ordering one of the McNally-edition kits will guarantee you the fancy graphics (while they remain in stock, of course), but it’ll be a game of chance whether you end up with a painted one.
Who wants to play?
TL;DR review: Straz Components Sealant Funnel
I’m a pretty big fan of small brands and/or sole proprietors that come up with clever solutions for common problems. Tim Straz of Straz Components is just one of those folks, and he recently reached out to me about his Sealant Funnel.
Currently, there are two preferred methods for adding sealant to your tubeless wheels and tires: you either inject it through the valve stem with some sort of syringe-type device, or you pop off a section of tire bead and pour it straight into the casing. Both techniques work, though the former can be prone to clogging and the latter can be kind of a pain.
Instead, the Sealant Funnel is designed to screw straight on to a Presta valve stem (with the core removed) so you don’t have to disassemble anything: just pre-measure your sealant in a graduated cup or something similar, and pour it in. That’s it.
Each Sealant Funnel is 3D-printed and while US$18 might seem like a lot for a little hunk of “engineering plastic”, it’s at least a reassuringly thick and Straz uses a pressed-in brass insert for the threads. It’s a sturdy-feeling piece of kit that I expect will last for a good long while. The exterior of the funnel is also knurled for easier handling, and the internal volume (30 mL) is marked on the inside in case you don’t feel like measuring beforehand.
Overall, the Sealant Funnel works as intended, and it’s honestly a little surprising just how much quicker and easier it is to use this compared to the two existing methods. You seriously just remove the valve core, attach the funnel, and pour in sealant. Straz has designed the funnel such that the opening is no smaller than the inside of the valve body, so unless you’re using a fluid that’s unusually thick and chunky, there shouldn’t be any issues here; all the sealants I tried flowed through the valve body just fine.
Cleanup is even super easy. The funnel forms a decent seal on the top of the valve stem so you don’t have to worry about leaking, and because sealant tends to bead up on the slightly rough surface, almost nothing sticks to the inside once it flows into the tire. Just give the funnel a quick wipe (or rinse) afterward and you’re done.
That all said, the Sealant Funnel does have some quirks.
The brass insert is a high-quality touch, but it only engages five or six threads, and it’s designed for valve stems that are threaded all the way to the end. There are quite a few valve stems that have smooth ends of various length (such as Reserve, Vittoria, Schwalbe, and Roval, just to name a few) and the Sealant Funnel either has a hard time getting a firm hold or won’t thread on at all.
“The original design for the Funnel had longer thread engagement, which could have worked for several of the products you mention,” Straz told me. “In my field testing with shop mechanics, they mostly service and sell Stan's and Muc-Off valve stems, and they are installed in a wide variety of rim profiles. Quite often, they had 10 mm or less thread to work with and that is how I landed at the current thread length. My focus has been on fully threaded valve stems to start, but I foresee offering a version to accommodate unthreaded designs in the future.”
Perhaps a push-on design using a couple of o-rings would work? I also wouldn’t mind if the funnel was a little taller. It can’t get much wider since it otherwise wouldn’t fit on wheels with higher spoke counts, but even most road tires these days require more than 30 mL of sealant. Something more like 40 or 50 mL seems like it’d be more practical to me, perhaps with molded-in tick marks at 10 mL increments for easier volume estimates.
“I have considered making the funnel a larger capacity, but there are three reasons I settled on 30mL,” Straz told me. “The first is spoke interference, which is a problem as wheel size gets smaller and spoke count goes up. The second is most initial sealant volume guidance from manufacturers is based around a 30 mL interval (60 for road, 90 for gravel, 150 for MTB). The third is to encourage riders to top-off and maintain their sealant. Add 30 mL every three months to keep things fresh. This should be routine maintenance.”
Ok, Tim, fair enough. Consider me a fan.
In the works
Schwalbe Clik Valve
Schwalbe received all sorts of accolades at last year’s Eurobike show for its intriguing Clik Valve system: a quick-release pump head and valve stem design that works exactly the way you’d hope it would given the name. The Clik Valve pump head snaps on the corresponding Clik Valve stem to inflate, and when you’re done, you just pull it back off: easy as pie (although as my friend – and certified pie expert – Amy would attest, making a great pie isn’t actually all that easy).
I recently received some production samples, and Clik Valve really does seem to be as straightforward as it’s made out to be. There’s little effort involved in either attaching or removing the head, it doesn’t leak, and the parts don’t seem subject to undue wear. Schwalbe even says Clik Valve offers 50% greater airflow than a conventional Presta valve, which would be a boon for tubeless setups.
Schwalbe has thankfully designed Clik Valve to be retrofittable to existing parts. The valve stem replaces a standard Presta core and is as plug-and-play as can be, while at the pump end, you can either purchase a complete head that attaches to a bare hose or an adapter head to work with your existing pump. Schwalbe has adapters for Schrader and Dunlop valves, too.
I can see the appeal of Clik Valve if you only have one or two bikes in your household, but even at the modest retail prices Schwalbe has set here (such as US$13 for a pair of Presta valve converters, or US$17-20 with a pump head), things would add up quickly if you’ve got a whole bunch of bikes to switch over – and let’s not forget that Prestacycle’s fantastic Pro Presta Head offers similar snap-on/snap-off functionality that works on existing valves.
That all said, the Presta valve design is still about a hundred years old now, so maybe we’re overdue for a significant step forward.
I’ll convert a couple of bikes to Clik Valve and will report back once I’ve got some more time in on them.
Garbaruk gravel cassette
I’ve been spending the last few weeks on a Mondraker Arid gravel bike equipped with SRAM’s new Red AXS XPLR wireless electronic drivetrain, and the groupset been awfully impressive: excellent shift performance, more range than other XPLR variants, and the superior ergonomics of the latest Red E1 levers. The new cassette is also wonderfully lightweight with its fully CNC-machined construction, but since Red is now 13-speed and the other AXS groupsets are still 12-speed, there’s no option to mix-and-match if you’re running Force, Rival, or Apex and want to indulge your inner weight-weenie.
Polish brand Garbaruk has an option if you’re open to an aftermarket cassette with CNC-machined construction similar to that fancy Red setup but in the more common 12-speed format for wider compatibility. It uses the same 10-44T spread as the Force-level XG-1271 cassette, but the actual weight is nearly 100 g lighter at just 279 g – not bad considering the somewhat reasonable US$305 asking price – and the aluminum backplate/sprocket is even offered in eight different anodized colors.
But how well does it shift? And will it hold up as well? I’ve just installed my test sample, so stay tuned for more.
Zen Ride FLO mountain bike grips
I know of countless mountain bike pros who prefer riding barehanded with paper-thin grips – all in the name of “bar feel”.
I am not one of those riders.
Maybe it’s my delicate hands or my propensity for comfort, but I’ll happily trade some precision for a bit of strategic cushioning and ergonomic shaping. A buddy of mine swears by his Rev Grips, which use an array of swappable elastomeric inserts between the grip body and locking collars to help keep trail buzz from numbing your hands, and upstart brand Zen Ride now offers its own take on the concept called FLO.
The FLO features a single inboard locking collar matched to an outboard elastomer that sits between the floating grip body and the end of the bar. According to Zen Ride, this provide the FLO grip with just a hint of movement – and damping – to improve hand comfort and control. But whereas the motion in the Rev Grips is more rotational, the FLO grips movement is akin to having extra-flexy handlebar ends. And instead of co-molding a grippy exterior to the fiber-reinforced plastic shell, Zen Ride uses a tacky grip tape that can be replaced when worn – kind of like a tennis racket.
Zen Ride sells pre-taped FLO grips for US$60 per pair, or US$30 if you’d prefer to tape them yourself. Actual weight is 80 g per pair.
I’m intrigued. Fingers crossed the trails stay reasonably dry this winter so I can give these a proper go.
Hack of the week/tech tip
I’ve been a proponent of tubeless wheel-and-tire setups almost since they were introduced. Yep, they’ve occasionally been problematic (especially early road systems, which just weren’t ready when they were initially introduced), but the relatively minor hassle has paid big dividends for me in terms of reliability. I can count on one hand the number of times I’ve had to install a tube during a ride in the last 10-15 years, and just about every bike in the household is so equipped: road, gravel, MTB, ‘cross… even my kid’s mountain bike tires are tubeless.
But I’ve just made an exception.
I’ve been converting my fat bikes to tubeless almost since I started riding them. Punctures aren’t all that common on snow so there’s minimal upside to running sealant in that sense, but there’s a big benefit in weight savings. A pair of fat bike tubes can run upwards of a full kilogram (2.2 lb!), and that’s on top of the 1.5-2.0 kg (3.3-4.4 lb) per tire that you’re already struggling to keep spinning around. Even accounting for the 200-250 mL of fluid you need to add in each tire, running tubeless saves about 600 g in total, and you don’t need to be a diehard weight weenie for that to seem appealing.
I’m used to the additional hassles of tubeless, but I’m not sure it’s worth it in this instance. Unlike bikes that are ridden more year-round, fat bikes tend to sit for months on end. As such, unless you want to end up with a solid mass of latex come winter, you need to drain old sealant at the end of the season and add fresh sealant at the beginning. And given the roughly 500 mL you need each time, things not only start to get messy, but also a little expensive.
I’ve been waiting years for someone to make TPU inner tubes in fat bike sizes, and that time has finally come courtesy of Chinese accessory brand RideNow.
They’re remarkably lightweight at barely 100 g apiece, though also rather pricey with a full retail price of nearly US$50 each. That said, they also seem to always be on sale for less than one-third of that, and assuming the sale price is the actual price in perpetuity, that not only makes these a lot lighter than running sealant, but less expensive, too.
Fat bike season is only just now kicking off here in Colorado so to be clear, I haven’t yet had a chance to evaluate the RideNow TPU inner tubes’ reliability myself. But online reports suggest the brand may have purged the QC demons that haunted it earlier on in its TPU inner tube journey, so fingers crossed I won’t literally be left out in the cold on my next Tuesday night group ride up in the high country.
I still favor tubeless overall, but in this instance, this alternate just seems to make more sense.
ICYMI: Tubeless sealant calculator
There’s been a bunch of talk about tubeless in this newsletter, so I guess I’d be remiss if I were pass on the opportunity to remind you of a recent post if you didn’t catch it the first time.
Deciding out how much liquid sealant you need to run is a decidedly fuzzy topic, with most manufacturer-supplied guidelines offering only vague ranges. I’ve instead put together a calculator that determines how much you should run based on your actual tire width and diameter measurements, and you can read all about it here.
And that’s a wrap for the first n-1wsletter of 2025! A couple of quick notes before I sign off:
Barring any unforeseen hiccups, I’m hoping to publish this coming Tuesday morning my review of that Stinner Carrizo Select steel gravel bike I previewed a couple of months ago. I won’t give away too much now, but given that I usually am not a massive fan of mid-grade steel frames, let’s just say the Stinner has been a very pleasant surprise.
I also want to announce a schedule change, too. Tech newsletters will continue to be free to all and published weekly on US Friday mornings, but paid-only posts will no longer be posted on a rigid Tuesday morning schedule. They’ll instead come at you a little more haphazardly whenever I feel they’re ready, and my goal for 2025 is also to have more of them than just one per week. Some of those additional posts will probably be a little shorter than my usual 3,000-4,000-word tomes, but hopefully you’ll still find them interesting.
And finally, shame on me for not mentioning this before the holidays, but if you’ve been happy enough with n-1 to recommend it to your buddies, keep in mind you can also gift a subscription to them, too. You can choose a monthly or annual gift, both of which can be purchased here.
Alright, that’s it for real now. See you all next week.
Really enjoy getting your newsletter! It’s interesting to read that you are investigating TPU for fat tires, I went in the opposite direction and use TPU instead of tubeless in my road tires. So much less hassle and even more reliable (so far) than trying to use sealant. FWIW, I use 30mm Grand Prix at about 55-60 psi. The variation in tubeless ready wheel dimensions/tire fitment from brand to brand was my breaking point and I haven’t regretted making the change.
Hi James - thanks very much for the sealant calculator (and the newsletter!) Since I'm using tubeless for both gravel and MTB, it was helpful to me to have your calculator also use inches (and why not, fluid ounces).
I've set it up here: https://docs.google.com/spreadsheets/d/1uuWcmA2gwDc_EaME1SjihY0z-H9FEZM3Nt_LW5376U0/edit?usp=sharing
(you still enter width in mm, but it autoconverts to inches. For MTB, you just guesstimate in mm until you get to the right width). Hope you find it useful (esp. for those chunky boi fatbike tires).