From ten paces away you might not see the differences between DT Swiss' new FR 541 rim and a lot of the other ones in the brand's line up, or from other brands for that matter. Once you have them in your hands, it's still somewhat tricky to pick them out. It's black and round, right? So it may be easy to pass off all this fanfare for a new rim as marketing and angrily scroll down to the comments.
But the thing is, DT Swiss has a reputation as being the go-to company for all things wheel related. So when they release a new product, it's usually good to sit up and take note.
FR 541 Details
• 29" & 27.5" diameters
• 28 or 32 hole
• Welded rim construction
• For use with PHR washers and nipples
• 30mm internal width
• 569g in 27.5", 606g in 29"
• €89.90, $150.90 US
Zooming further in, their existing downhill rim, the FR 560, is a damn good rim that still sees its fair share of action at the World Cups. But DT Swiss saw room for improvement in it.
However, for a very long time now, downhill racers have been using the company's EX 471 and especially EX 511 rims. The EX series of rims uses a slightly different rim profile to the FR 560, which allowed racers to play around with tire profile and support. It was also a lighter option than the FR 560, saving precious grams from a pretty important extremity on the bike. Rotational and unsprung mass are two areas that can have a profound effect on changing the way a bike rides.
But not everyone is a World Cup racer, and many a hobby rider who looked to the professionals to inform their buying decisions also took the EX 471 and 511 as their rim of choice for use on downhill bikes.
Strictly speaking though, the EX 471 and 511 aren't downhill rims. They're even listed under the Enduro section of the brand's website and many people looked past this in order to run the same components as Loic Bruni, Troy Brosnon and Vali Holl, perhaps ignoring the context that a World Cup team might have a few more spares on hand for when a rim gets damaged...
The EX 471 and 511 rims have been around for almost a decade now, and this has given DT Swiss a solid amount of experience to build on for the new rim development, with the new FR 541 using the EX 511's rim profile and PHR system as a base to build from, but with some small but important changes to improve in the three main areas of impact resistance, pinch flat resistance and weight.IMPACT RESISTANCE
Rim denting is often the main cause for needing a new rim. Aluminum rims are great for bending rather than detonating under impact. But past a certain point it might compromise the tubeless seal with the tire, incur a pretty hefty flat spot or bend, or, even worse, crack.
Significant amounts of material, in the context of a rim, were added to the flange hook giving it a taper at the top. This angle, coming from the taper in the case of the FR 541, isn't a new concept, but it does align the rim shape better with the impacts coming into it. It also simply gives the rim more material to resist impacts in the first place.
More material was added to the belly of the profile, where the spokes exert their force. More material here bolsters the strength of the rim when the spokes are pulling hard during big energy impacts.
PINCH FLAT RESISTANCE
A section view of the FR 541, in black, compared to the FR 560, in grey, shows the differences in rim profile as well as really highlights the flange hook design.
That flaring out of the rim's flange hooks also increases the contact patch between the rim and tire. When the tire is bottomed out on the rim, more area drops the risk of the tire pinch flatting, something that DT Swiss tested in collaboration with a leading tire brand. The result is a 17% increase in pinch flat resistance compared to the FR 560 rim.
The rim inner width follows the EX 511 at 30mm and sits right where rim widths have stabilised in recent years in conjunction with tire profile design.LIGHTER WEIGHT
While adding weight helped the strength, DT Swiss also managed to shave 30g out of the rim profile when comparing it to the FR 560. Making the rim well ever so slightly thinner. Imagine, fractions of millimetres on a section drawing translate to quite a few grams once you sweep that profile 360 degrees.
Joining the extrusion profile together is done by welding, which DT Swiss say is the most resistant process for aluminum wheels. And on all DT Swiss welded rims, it's nigh on impossible to spot the join if you don't know where to look.
Weight was also saved compared to the FR 560 by ditching the eyelets and moving over to the brand's PHR system in the nipples and washers that is already commonplace on the EX 511.PHR WASHERS, NIPPLES & WHEEL BUILDING
Pro Head Reinforcement is a combination of rim, washer and spoke shape that increases the load bearing surface of the nipples, reduces localised stresses and acts as a ball joint to automatically align the nipples with the spoke, reducing the risk of spoke failure or the rim cracking.
In the way that the PHR system is a meeting of individual parts, the rim is only one part in the bigger system of the wheel. Quality wheel building is something that DT Swiss put a lot of emphasis on, with their focus on spoke tension. For DT Swiss, the key to a well built wheel that lasts is on building it as close as possible to the maximum given spoke tension, something that is even printed on the rim stickers, while keeping the deviation of tensions to a minimum.
The ability to tune the wheel characteristics then falls on things like the spoke geometry and lacing pattern rather than the spoke tension. Thinner spokes, for example, can give more flex in the system while still allowing the wheel to be built to a high tension, ensuring a good lifetime of the wheel.
Spoke tension is a can of worms sure to be opened in the comments, and hopefully something that we might dive deeper into in the not too distant future, if we can line up the lab time.
Small details like the rim stickers mean that the FR 541 has options for customization and keeping the rims looking fresh for their lifetime. The rims come with red decals out of the box, with gold, chrome and black options also available. That ability to take the rim stickers off might also come in handy for some of the competitor sponsored racers at World Cups who were spied running DT Swiss rims.
The new FR 541 is available immediately and is priced at €89.90 or $150.90 US.
In the way that the EX 511 has been the go-to rim for many a racer and hobby rider alike, the new FR 541 does have some big shoes to fill. But it might just be the one able to fill them.
We picked up a set of FR 541s laced to 240 hubs with slightly thinner Competition Race spokes at the World Championships in Les Gets. DT Swiss wheels out of the box are built extremely well and so it was only suitable that their wheel building wizard Sven built them to the same high standard that anyone buying a DT Swiss wheelset would get.
With Champery open well into fall and plenty more steep leaf surfing options open after that, we'll report back in a few months with a full review on the new FR 541 rim.