Shimano has added a new front derailleur to the 105 5800 groupset and it looks like a straight piece of trickle-down from Dura-Ace R9100 and Ultegra R8000. Could this even be a preview of an unannounced 105 groupset, perhaps called 105 R7000 or 5900?
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Badged the FD-5801, the new derailleur does away with the FD-5800’s long lever arm, which means no more cables rubbing on tyres and potentially more tyre clearance full stop.
It includes the same built-in Allen bolt cable tension adjustment as the latest Dura-Ace and Ultegra offerings, and the awkward JIS-standard cross-head limit screws have also been replaced with hexes.
In addition to these practical touches, the FD-5801 promises — just as R9100 and R8000 did — a new geometry which more closely matches “the force curve of the hand... to reduce effort at the end of shifting."
Claimed weight for the FD-5801 is 98g for the braze-on version (FD-5801-F) and 112g for the band-on version (FD-5801-B), which makes it slightly heavier than the standard 5800 part, which comes in at 89g/104g.
Interestingly, the two FD-5801 variants are just 6g heavier than their Ultegra R8000 counterparts.
In compatibility terms, the FD-5801 is right in line with Ultegra and Dura-Ace. It’s fully backwards compatible with older shifters and cranks (i.e. 5800, 6800 etc.) and riders should see an improved shift action by adding it to their existing groupsets.
Pricing on the FD-5801 is to be confirmed, but we expect it to be very close to that of the existing 5800 derailleur, which retails at £32.99 for the braze-on and £34.99 for the band-on version.
What’s the point of the FD-5801?
When Shimano Dura-Ace 9100 launched last year it came with a host of refinements and upgrades.
The optional integrated powermeter and the bold aesthetic changes grabbed headlines, but from an actual shifting point of view the new front derailleur design was more important.
To accommodate the wider (135mm) rear spacing of disc-equipped bikes while keeping the minimum rear-centre sensible at 410mm, the latest groupsets have slightly wider spaced chainrings and a redesigned chainring tooth profile.
As a result, the new derailleurs required a slightly wider range of movement and a subtly redesigned cage.
According to Shimano brand manager Mark Greshon, the FD-5801 was created primarily to allow bike makers to spec the latest RS510 cranks on their more affordable disc bikes, and it’s not clear if it will actually replace the standard 5800 part completely.
The RS510 is a non-series (i.e. non-groupset) crank that you’re likely to see a whole lot more of in 2018, and it uses the same chainring spacing as Dura-Ace R9100 and Ultegra R8000.
If you want to fit R9100, R8000 or RS510 cranks to your current bike, the FD-5801 is currently your cheapest option for a front derailleur that won’t object to the wider chainring spacing.
Is this really part of a new 105 groupset?
If this is a tease for a whole new 105 groupset, Shimano isn’t letting on. It would certainly make sense, however.
Dura-Ace R9100 was released in 2016 and Ultegra R8000 arrived in 2017, so it would be quite logical for a new 105 groupset to follow for 2018.
Whatever happens, the FD-5801 offers some tangible upgrades over the existing 5800 derailleur and brings the everyman 105 groupset that little bit closer to its more expensive siblings.