AASQ #142: Why are manufacturers shifting Increase frames from 52mm to 55mm chainlines?

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We’re preserving it quick and candy this week, joined by Julian Litterst, Advertising Supervisor at Scott Sports activities to debate why an increasing number of of the large body producers are shifting their Increase (148mm x 12mm) spacing mountain bikes from the usual 52mm chainline to a 55mm chainline.

2022 Scott Spark RC & 900 XC trail mountain bikes, light fully-integrated cross-country MTB, XCO jump

Our man, Cory Benson, ripping on the brand new 2022 Scott Spark which now runs a 55mm chainline. Watch the complete evaluate right here. c. Scott, photograph by Daniel Geiger.

So, what’s up with 55mm chainlines on 148mm bikes? The business settled on 52mm a couple of years again. Now Shimano says 55mm is the way in which to go and Trek’s all-in with the revamped Prime Gas (55mm chainline not simply with Shimano cranks, but in addition SRAM and E13). I simply can’t imagine 55mm within the lowest gears may be good for a sequence.

Julian Litterst, Scott Sports activities: 55mm chainlines current no downside in any respect for the chain, cassette, and chainrings. This variation has been examined on the world cup circuit for nearly two years now. With main groupset producers stating that the rise in width is the way in which ahead, we’re assured that their merchandise are being designed to work completely on this state of affairs.

2022 Scott Spark RC & 900 XC trail mountain bikes, light fully-integrated cross-country MTB, complete

The 2022 Scott Spark 900 Tuned AXS XC bike’s 55mm chainline offers room for as much as 2.6″ tire clearance in addition to the huge 40T chainrings that Nino races on across the widely-space PF92 backside bracket.

From a body engineering standpoint, even tiny will increase in clearance on this crucial space can considerably assist with body energy, stiffness, and/or tire clearance. We’re all the time preventing for area within the space across the widest level of the tire and the chainring. To maneuver to 55mm, due to this fact, presents a great alternative for us to progress the efficiency of our frames.

2022 Scott Spark RC & 900 XC trail mountain bikes, light fully-integrated cross-country MTB, mudd detail

How does chainline have an effect on Q-Issue, and is that this one thing body producers take into account?

Julian Litterst, Scott Sports activities: Q-factor has elevated a few mm, however within the close to future new crank improvement goals to regulate the Q-factor for these adjustments in chainline width, due to this fact shifting again to the narrower measurements. With these adjustments coming by, a 55mm chainline will due to this fact set up itself as the usual sooner or later with any potential downsides having been corrected for.

hyper spark dangerholm scott sparkrc white dream built schmolke carbon seat post

Dangerholm’s staggeringly lovely construct of the “Hyper Spark”, a sub 10 kg full construct – see stratospheric spec record right here.

Editor’s Observe:

We additionally despatched the reader’s query out to Travis Ott, the Advertising Supervisor at Trek Bikes. He mentioned “it’s actually a conference dictated by the drivetrain producers. Anytime the drivetrain producers can provide us a pair extra mm in that crucial space for tire clearance and pivot junctions and bolstering chainstays, we’ll take it each time.”.


The Trek Prime Gas XC Bike (now pushing into the Path class) has additionally moved to a 55mm chainline for this mannequin yr

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