Extremely progressive bike beats modern enduro bike- Mtbr.com
Results 1 to 23 of 23
  1. #1
    mtbr member
    Reputation: chomxxo's Avatar
    Join Date
    Oct 2008
    Posts
    1,732

    Hope Extremely progressive bike beats modern enduro bike

    You may have heard of the Pinkbike Grim Donut already, a half-serious experiment in taking slack/steep geometry to an extreme (57* head angle, 90* seat tube). Well, turns out it's faster than a modern enduro bike.

    https://www.youtube.com/watch?v=-5cVPy2NbL4

  2. #2
    Formerly of Kent
    Reputation: Le Duke's Avatar
    Join Date
    Mar 2009
    Posts
    11,805
    “Would I ride this bike every day? Absolutely not,'' said Yoann after his run on the Grim Donut. ''The way it is right now, the geometry isn't pleasant. When you pedal, you're going to hit them on the ground. And it doesn't corner properly, but it works when you go super fast.''


    Sent from my iPhone using Tapatalk
    Death from Below.

  3. #3
    mtbr member
    Reputation: Renzo7's Avatar
    Join Date
    Mar 2015
    Posts
    313
    Super fun and interesting!

    Sent from my SM-A705MN using Tapatalk

  4. #4
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    1,256
    That was actually fun to watch

  5. #5
    mtbr member
    Reputation: smartyiak's Avatar
    Join Date
    Apr 2009
    Posts
    864
    Quote Originally Posted by Le Duke View Post
    “Would I ride this bike every day? Absolutely not,'' said Yoann after his run on the Grim Donut. ''The way it is right now, the geometry isn't pleasant. When you pedal, you're going to hit them on the ground. And it doesn't corner properly, but it works when you go super fast.''


    Sent from my iPhone using Tapatalk
    I found this line amusing: To be honest, I'm not sure why no one's done this before.
    I would reply: b/c it doesn't work. Sure it's an interesting experiment, but as the quote LaDuke posted, it doesn't really work.

    Maybe not a good analogy, but there's a reason why automobiles are not Indy or F1 cars. In addition to lack of ability to haul groceries, most people would probably kill themselves. But they do work great for: Indy and F1.

    The Grim Donut has a very narrow "optimum performance" window that very few can exploit...or would even want to. I'm sure mfgs have looked "outside the box" and came to the conclusion that one-offs aren't something they're interested in doing.

    But, it's a cool and fun experiment none-the-less.

  6. #6
    mtbr member
    Reputation: jeremy3220's Avatar
    Join Date
    Jul 2017
    Posts
    2,887
    Quote Originally Posted by chomxxo View Post
    You may have heard of the Pinkbike Grim Donut already, a half-serious experiment in taking slack/steep geometry to an extreme (57* head angle, 90* seat tube). Well, turns out it's faster than a modern enduro bike.

    https://www.youtube.com/watch?v=-5cVPy2NbL4
    It was faster in one of two runs. Like Gwin said you have to do a bunch of back and forth runs over multiple days and multiple courses before making any determinations. The Grim Donut probably is faster on certain courses.

  7. #7
    mtbr member
    Reputation:
    Join Date
    Jul 2007
    Posts
    592
    It's like showing up at the Daytona 200 on a Harley Davidson chopper and exclaiming loudly to no one in particular that you will be the most comfortable rider during the qualifying. You won't qualify, but you will be most comfortable.

  8. #8
    mtbr member
    Reputation: chomxxo's Avatar
    Join Date
    Oct 2008
    Posts
    1,732

    Extremely progressive bike beats modern enduro bike

    Quote Originally Posted by MessagefromTate View Post
    It's like showing up at the Daytona 200 on a Harley Davidson chopper and exclaiming loudly to no one in particular that you will be the most comfortable rider during the qualifying. You won't qualify, but you will be most comfortable.
    I think it’s the opposite of that. The Grim Donut is the least comfortable, but the fastest.

    This video also lays out the dynamic between bike companies’ engineers and pro racers. Clearly the pros would be fine if we were all still riding 26” hardtails, as long as everyone had the same thing. The engineers sometimes have to overrule their UAT rejections, so to speak. Perhaps they tone down a radical new design so as not to ruffle feathers. Or, one could be cynical and say that bike companies are just out to sell slightly tweaked new bikes.

    And this cycle repeats itself year in, year out...until the 2030 Grim Donut


    Sent from my iPhone using Tapatalk

  9. #9
    mtbr member
    Reputation:
    Join Date
    Aug 2017
    Posts
    418
    Quote Originally Posted by chomxxo View Post
    I think it’s the opposite of that. The Grim Donut is the least comfortable, but the fastest.

    This video also lays out the dynamic between bike companies’ engineers and pro racers. Clearly the pros would be fine if we were all still riding 26” hardtails, as long as everyone had the same thing. The engineers sometimes have to overrule their UAT rejections, so to speak. Perhaps they tone down a radical new design so as not to ruffle feathers. Or, one could be cynical and say that bike companies are just out to sell slightly tweaked new bikes.

    And this cycle repeats itself year in, year out...until the 2030 Grim Donut


    Sent from my iPhone using Tapatalk
    Or maybe, just like everything else in the area of human achievement, progress occurs over time. Just because the iPhone 11 didn't come out in 2007 doesn't mean there was a conspiracy to hide the goods from the masses.

    We learn new things over time. Getting things exactly right is hard. I have no idea what MTB geometry will look like in 2030, but only in mountain biking is there so much circle jerking about bike geometry and head angles. Motocross bikes which hit gnarlier stuff at higher speeds have settled in at 62-64 HTA and nobody argues about this crap on the MX boards.

  10. #10
    EAT MORE GRIME
    Reputation: 127.0.0.1's Avatar
    Join Date
    Nov 2013
    Posts
    5,467
    0️⃣5️⃣:5️⃣9️⃣
    0️⃣6️⃣:0️⃣0️⃣

    It's Groundhog Day!!
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

  11. #11
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    1,256
    Quote Originally Posted by hesitationpoint View Post
    Or maybe, just like everything else in the area of human achievement, progress occurs over time. Just because the iPhone 11 didn't come out in 2007 doesn't mean there was a conspiracy to hide the goods from the masses.

    We learn new things over time. Getting things exactly right is hard. I have no idea what MTB geometry will look like in 2030, but only in mountain biking is there so much circle jerking about bike geometry and head angles. Motocross bikes which hit gnarlier stuff at higher speeds have settled in at 62-64 HTA and nobody argues about this crap on the MX boards.
    Next we'll have steering dampers in MTB.

  12. #12
    No. Just No.
    Reputation: Circlip's Avatar
    Join Date
    Mar 2004
    Posts
    5,211
    Quote Originally Posted by Fajita Dave View Post
    Next we'll have steering dampers in MTB.
    It's already been done (by Hopey, maybe others also). I tried them on XC bikes in years past. In many situations, I actually liked it.
    Nuke the entire site from orbit. It's the only way to be sure.

  13. #13
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    1,256
    Quote Originally Posted by Circlip View Post
    It's already been done (by Hopey, maybe others also). I tried them on XC bikes in years past. In many situations, I actually liked it.
    After I sent it I started thinking it would be pretty sweet for downhill and enduro lol

  14. #14
    No. Just No.
    Reputation: Circlip's Avatar
    Join Date
    Mar 2004
    Posts
    5,211
    Quote Originally Posted by Fajita Dave View Post
    After I sent it I started thinking it would be pretty sweet for downhill and enduro lol
    I used them a couple of times on my setup for 24hr solo races to settle the quick steering of an XC bike, but retain all its other characteristics of light weight and efficiency. A little less wandering here and there (especially once fatigue was setting in) can add up over 24 hours. The damper weighed about 200g if I remember correctly. Nicely machined. The only real reason I think I stopped using them was that I was having trouble keeping them from loosening. The part of the damper that inserted into the steerer kept the headset tight instead of a star nut arrangement, and it loosened on me more than once during rides and races.
    Nuke the entire site from orbit. It's the only way to be sure.

  15. #15
    mtbr member
    Reputation:
    Join Date
    Apr 2005
    Posts
    1,119
    Quote Originally Posted by chomxxo View Post
    You may have heard of the Pinkbike Grim Donut already, a half-serious experiment in taking slack/steep geometry to an extreme (57* head angle, 90* seat tube). Well, turns out it's faster than a modern enduro bike.

    https://www.youtube.com/watch?v=-5cVPy2NbL4
    How about show us a pic of your bike setup so we can all get a good laugh.
    Did you try lowering that saddle about an inch for instant comfort?

  16. #16
    Armature speller
    Reputation:
    Join Date
    Sep 2004
    Posts
    3,609
    Quote Originally Posted by Fajita Dave View Post
    Next we'll have steering dampers in MTB.
    Cane Creek ViscoSet.

  17. #17
    mtbr member
    Reputation:
    Join Date
    Mar 2012
    Posts
    1,256
    Clearly I'm late to this party. I never had much issue with headshake in motocross but putting a steering damper on my dirtbike was a major upgrade. Curious how it would be on a mountain bike now.

  18. #18
    SP Singletrack rocks
    Reputation:
    Join Date
    Aug 2006
    Posts
    1,981
    Honestly that bike with a more normal BB height, and slightly slacker seat tube could be a great enduro race bike for those using it.

  19. #19
    mtbr member
    Reputation: Lone Rager's Avatar
    Join Date
    Dec 2013
    Posts
    9,390
    Yep. I've steering dampers on dirt and road motos...not on an mtb yet. I'm pretty sure I wouldn't want one on the mtb.
    What, me worry?

  20. #20
    EAT MORE GRIME
    Reputation: 127.0.0.1's Avatar
    Join Date
    Nov 2013
    Posts
    5,467
    dampers on mtb were great in the steep head angle 26" days....72.5 degrees style

    but you need them less with better front forks and slacker angles

    they have their place. only time they suck is steep switchback chunky climbs where you need to turn bars quickly between chunks and turns....might make you extra tired fighting the dampening (or if it has an off circuit that's nice) but they'd be great on chundery descents
    "Put your seatbelt back on or get out and sit in the middle of that circle of death." - Johnny Scoot

  21. #21
    No. Just No.
    Reputation: Circlip's Avatar
    Join Date
    Mar 2004
    Posts
    5,211
    Based on my experience using steering dampers for MTB;

    Quote Originally Posted by 127.0.0.1 View Post
    dampers on mtb were great in the steep head angle 26" days....72.5 degrees style
    Correct - even with bikes in the 70-71 range of HA.

    Quote Originally Posted by 127.0.0.1 View Post
    but you need them less with better front forks and slacker angles
    Correct - I wouldn't run one any more, on current bikes that are inherently more stable.

    Quote Originally Posted by 127.0.0.1 View Post
    they have their place. only time they suck is steep switchback chunky climbs where you need to turn bars quickly between chunks and turns....might make you extra tired fighting the dampening (or if it has an off circuit that's nice) but they'd be great on chundery descents
    Correct - although the damping level was adjustable on the Hopey and it wasn't difficult to find a happy medium that made this a non-issue.
    Nuke the entire site from orbit. It's the only way to be sure.

  22. #22
    mtbr member
    Reputation:
    Join Date
    Feb 2008
    Posts
    522
    The fastest bikes in 2030 will be a function of courses in 2030. We've seen bikes adapt to courses, and courses adapt to bikes. So that interplay needs to be noted. I don't see any chance of a 57 degree HTA catching on. What other tech will exist? Will 2 position forks finally work? So 140 uphill, 180 down? Same with XC, will we get a 100 climb, 130 down?

    Like others, I don't think it's right to say it's 'faster'. One, super steep B.C. descent with no pedaling, piloted by one of the best bike handlers on Earth is not representative of anything else. It's a one-off.
    It was fascinating, but no illuminating.

    The Grim had the following measurements:
    HA 57
    SA 83
    Reach 500
    CS 450
    BB drop 30 (with 155 cranks)

    What will be the most aggressive in 2030? I'm guessing:
    HA 60
    SA 80
    Reach 490
    CS 445
    BB drop 10 (with 165)

  23. #23
    mtbr member
    Reputation: chomxxo's Avatar
    Join Date
    Oct 2008
    Posts
    1,732
    Quote Originally Posted by euro-trash View Post
    The fastest bikes in 2030 will be a function of courses in 2030. We've seen bikes adapt to courses, and courses adapt to bikes. So that interplay needs to be noted. I don't see any chance of a 57 degree HTA catching on. What other tech will exist? Will 2 position forks finally work? So 140 uphill, 180 down? Same with XC, will we get a 100 climb, 130 down?

    Like others, I don't think it's right to say it's 'faster'. One, super steep B.C. descent with no pedaling, piloted by one of the best bike handlers on Earth is not representative of anything else. It's a one-off.
    It was fascinating, but no illuminating.

    The Grim had the following measurements:
    HA 57
    SA 83
    Reach 500
    CS 450
    BB drop 30 (with 155 cranks)

    What will be the most aggressive in 2030? I'm guessing:
    HA 60
    SA 80
    Reach 490
    CS 445
    BB drop 10 (with 165)
    Those are your predictions and they're worth considering, here's mine, with an XC focus.

    Up-to-date size Large XC bikes such as the mainstream Specialized Epic have a 470mm reach with a 70mm stock stem. I predict that size L will have a 490mm reach in a couple of years, not a decade. A 50mm stem is a better starting point off the shelf. You can extend or shorten the stem 20mm to fit. This is where bikes should've been starting from decades ago, and a stem is pretty pointless otherwise.

    Secondly, following up on the moto comment. 67.5* HTA is the current up-to-date XC standard. I predict it'll be 64* by 2030. This seems to be a proven head angle by motocross and enduro bikes as being aggressive, but not too slack.

    Seat tube angle of 80* seems reasonable for 2030, but I'd suggest adding 20mm to the reach numbers by the time that happens.

    Chainstay length; I think we're beyond thinking that we need to tuck up the back wheel to give a shorter overall bike length, so it is what it is. Longer is faster, no prediction here.

    BB drop; as a tall guy I think short cranks are a real PITA, as I still ride 180s. I'd predict that by 2030 the default crank length on bikes will be 170 instead of 175mm, and hopefully that's as far as we'll take this trend; BB drop of 5mm.

    Last prediction: mullet bikes aren't wild enough. By 2030 there will be carbon 36er bikes marketed to the gravel grinder, marathon, and downcountry segments. Fully rigid will be adequate for most racers, but hardtail and FS will be available. There are already production carbon 36er wheels, so this isn't that far off.

Similar Threads

  1. Help with A-C heights on modern forks and modern frames
    By Blatant in forum Shocks and Suspension
    Replies: 6
    Last Post: 04-25-2020, 12:47 AM
  2. Specialized Beats
    By wnlab in forum General Discussion
    Replies: 8
    Last Post: 10-14-2015, 08:37 PM
  3. Replies: 31
    Last Post: 05-06-2013, 08:11 PM
  4. Specialized beats...
    By hysteriamk2 in forum Riding Passion
    Replies: 2
    Last Post: 07-03-2011, 04:48 PM
  5. Sync Video to Music Beats - Advice?
    By ray.vermette in forum Videos and POV Cameras
    Replies: 3
    Last Post: 05-10-2011, 01:59 PM

Members who have read this thread: 166

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT MTBR

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.