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| Lauf Seigla: Image courtesy of Lauf Cycling |
Okay, so what exactly is the big deal here? Well, first off you should be aware that the differences between "road" and "mountain bike" essentially have been unsaid standards and really- limiters to design over the past 30+ years.
It has only been since around the early 90's that this really all has fell into place, and the economics of the industry have really kept these unspoken standards in effect up until this day. These are the reasons why mountain bike and road bike drive train compatibilities went to wildly different places. It is why you have to get 'gizmos' to make an Eagle cassette work with a Red crank set. Had 'road' and 'mountain' not been kept so separate, this may not have happened, but for reasons of manufacturing ease and lower costs, that is what happened and basically why we are where we are now.
So, road bikes have a set, overall spacing for wheels and bottom bracket width so that road crank sets and wheels can align for the best possible shifting performance. This informs much of the rest of a road bike design, such as tire clearances, how big that your chain rings can be, and more. On the mountain bike side, things have shifted, (pardon the pun) to Boost and "Boost Plus", but start out with the basic widths for axles and bottom brackets, which- again- inform chain ring sizes, tire clearances, and help to make 1X shift better around big, fat MTB tires. (Note: Fat bikes are their own thing, and being niche, are not included here)
Manufacturers and designers have, up until now, been reticent to mess with crossing the lines between "MTB" and "Road" basic dimensional boundaries. However; what Lauf has done here is to push for what is essentially the base dimension for MTB in the crank set/bottom bracket area so that they can get a 29"er tire (700c X 57mm) squeezed into their Seigla without resorting to frame weirdness like dropped chain stays, elevated chain stays, or what have you.
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| By using the 73mm bottom bracket width, Lauf could go big on tire sizes. (Image courtesy of Lauf Cycling) |
Of course, Lauf says this is how it always should have been for gravel bikes. Hmm.....perhaps. But what if Lauf has really only gone 1/3rd of the way to where gravel bikes really should be? Let's see where all of this could lead....
My take is that the Overlock Dimension (distance between drop outs of a frame) that road bikes use, is set for a change again. Disc brakes finally made manufacturers of road bikes move to 135mmOD rear ends, which is where MTB started out as a standard back in the late 1980's as well. But I think that what a few other companies have done should be also done in gravel bikes, (and road bikes, really), and that is to just get on with it and move everything to Boost spacing, which is 148mm through axle. While a few companies are doing this now, this is not adapted to crank sets yet, and so I think matching this up with Lauf's move to 73mm bottom brackets would be wise.
GRX crank sets, (and some others) have already moved the chain line outboard by 2,5mm's, so we are headed in this direction anyway. Getting to a Boost width may turn off some who are worried about the "Q" factor, that distance between the pedals which determines stance of your feet. I think that should only be a racer's concern, and I think it can also be engineered out of being a concern.
What is the third thing? Front wheel spacing. there is no reason at all to stick with 100mmOD for gravel. We should already be using 110mm through axle spacing, and honestly, if we wanted to be radical, I'd go to 142mm front. The difference in wheel stiffness is immense, and gravel bikes shouldn't be hamstrung by making room for suspension forks, so there really isn't much that I can think of that wouldn't work there, but we should at least be at 110mm.
So, Lauf is on the right track, but let's get all of the changes and move forward.
6 comments:
If I could snap my fingers and have all my bikes and wheels upgraded to Boost/SuperBoost (for road & gravel/MTB) I would totally do it! But with all the time and money I have invested in my equipment right now today, I sure hope those changes are a long way off....
Have you seen many failures in narrower spaced disc/11sp wheels? The 'good' spoke tension window is definitely narrower than boost/superboost, but it sort of feels like a throwback in terms of the stiffer-is-better philosophy, and certainly goes against what Lauf seems to be aiming for.
I've tried to pick more flexible components (low cross section rims, thin spokes) in my wheel builds to help with compliance when leaned and can't say I've noticed any downsides...yet.
@Blain - Sorry about that first comment- I thought it was on today's (4/14/22) post on my T-6 Standard Rando SS gravel bike.
But if you caught that before I deleted it, some of what I wrote applies here- That any design for a wheel- the closer it gets to symmetrical- the better - in theory. You have to be careful about any decision based upon hearsay when it comes to failures. You asked if I have seen many failures in 11 speed wheels. That's a far too generalized and 'wide-net-cast' question for me to answer. It also does not take into account what is "failure" and your assumption that I have seen enough 11 speed wheels to make a call with any authority on dished wheel design integrity.
I would rather point you to physics. What does that tell us? I think that we also have to take into account 'how' the wheel is ridden. Is the wheel being misused? Is it poorly built?
You see, your question cannot be answered in simple terms without allowing for misunderstanding, and certainly not in this format, which is too limiting.
I can only point you to the physics and design intention aspect. If the spoke tensions are even- side to side- or close to that, then that wheel, theoretically, is superior. Geared wheels are compromises that would be better if built symmetrically. It doesn't mean that we cannot use them as designed with 'dish' and unequal tensions, but that always should be minimized as much as possible.
@GT - I probably read too much into it. If we're not failing components due to bad hub spacing it seems like stiffer shouldn't be a driving factor for new standards.
It seems like we're due for some research and more transparent data from manufacturers and their marketing teams regarding compliance and/or vibration damping. There's a lot of talk of compliance and comfort, for good reason. Physics would show next to no linear movement of wheel systems vertically (rigid frames, too, for that matter), but there's clearly some felt differences.
@Blain - So, you are wanting my thoughts on how a wheel could be vibration damping? See this coming Saturday's post. This is too much for the comments section.
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