Well worth 20 minutes of your time as the guys from PB put a massive change from current geometry on the hillside. No spoilers from me.
Saw that yesterday, not disappointed after the long wait for the video.
Watched it last night - ace!
Shame this was done by an online publishing team rather than a multi-million pound bike company, but fair play to them, and also the factory that made it.
Just the right amount of stupid! 🙂
I like that saying "we've stumbled across the right amount of stupid".
Snap!
It is an interesting idea but the shape just looks all wrong - how that frame hasn't snapped at headtube is impressive...it just looks all wrong. The fork is almost angled so the traditional seals and bushings aren't going to run smoothly as they aren't really going up and down but sliding at a forced angled.
I've not seen the video yet but will watch it - the above is just my uneducated thinking - especially watching the amount of flex produced in the slow-mo bottoming out videos of suspension bikes.
An interesting idea, but looks like it will fail dramatically. Hopefully the video proves my thinking completely wrong!
It's brilliant, highly entertaining and i really like Mike L, a bike nerd who see's the funny side of being a bike nerd
edit: quick someone copy Dick's comment before he watches the video
Who else wants a bottle 'oldeer now?
It is an interesting idea but the shape just looks all wrong
Would you have said the same thing ten years ago about today's bikes? I would have....which is kinda the point of the experiment.
It is an interesting idea but the shape just looks all wrong – how that frame hasn’t snapped at headtube is impressive…it just looks all wrong. The fork is almost angled so the traditional seals and bushings aren’t going to run smoothly as they aren’t really going up and down but sliding at a forced angled.
I’ve not seen the video yet but will watch it – the above is just my uneducated thinking – especially watching the amount of flex produced in the slow-mo bottoming out videos of suspension bikes.
An interesting idea, but looks like it will fail dramatically. Hopefully the video proves my thinking completely wrong!
Certainly one of the most STW posts ever.
Singletrack have previous in this area of course - they made their own bike years before this.
Bollocks to the bike, I want the mini at the start!
Interesting vid, wonder on the side loading on the fork bushes...
I wonder if dropping the head tube height to help pick up the bb height slightly would help
It's very good at one thing seemingly.. As Yoaan says, you wouldn't want it as your everything bike (or words to that effect)
Everything is a compromise for a bike that performs well everywhere. They could just as easily make a frame that excels at climbing,but is rubbish downhill....maybe.
Cool experiment and I'm glad they did it. It'll be interesting to see what we are actually riding in 2030.
The guy testing it reminded me of the scuba instructor from Along came Polly.
An interesting idea, but looks like it will fail dramatically. Hopefully the video proves my thinking completely wrong!
Are you so sceptical of bridges, aeroplane wings not snapping and the existence of helicopters?
Grim Donut huck to flat about 3 mins in.
I feel like the Trust fork might actually come into its own with a bike like that.
Levy does like his Trust fork. Hmmm.
I could be wrong but I think the Grim has already had a Trust on it, just for extra Ugly.
It's really entertaining, I don't think for a minute they actually thought it would be any good, and YB's comments were super interesting. Also I shall be referring to it as a bottle older from now on.
I could be wrong but I think the Grim has already had a Trust on it, just for extra Ugly.
Only in photoshop IIRC
I enjoyed Yoann's laugh when he saw his time - genuinely contagious, I found 🙂
Very entertaining and I’m amazed it worked as well as it did. Some of the comment from both mike and yoaan are brilliant
Nope, I trust the engineers that have spent the time learning and working out the right stuff...but as this has been done without all that (from what I can see from the various videos and articles on it), then I'm more sceptical.
Side loading was the terms I was after not the up and down bit.
Video looks good...does support Chris Porter's chat about longer bikes being faster as well, that bike seemed to make a decent dent in the 'standard' bike time on that run they filmed.
As I said, it doesn't make sense to me, but I'm not trained or skilled in this area (I have enough problem trying to get my leg over the bike!), so happy to see it being ridden and used, but the front end does look like it'll be ripped off without much impact!
Noticed Chris Porter's name in the credits too.... he actually did this for real (albeit bit more seriously) five years ago.
The issue with too much side loading isn't going to be an issue all the time, how often do you huck to flat. Surely the head angle will mean the fork can compress backwards more and "get out the way" of oncoming obstacles, kind of like the theory behind high pivot points for rear suspension
Only in photoshop IIRC
Makes sense, there has to limits after all...
I knew it would probably work well!
I’ve made a business from ignoring convention and pushing the boundaries with audio products. People are just so stuck in their ways!
Regarding the forces on the fork, we ride our bikes forwards so impacts are rearwards most of the time - that’s why high pivot rear suspension works so well. With that 57 deg head angle you’ll have 20% more leverage on a huck to flat than with 63 deg HA. Is 20% a big deal?
Look what Paul Aston has built after 15 years of pushing the boundaries with non DH bikes:
https://m.vitalmtb.com/features/Ultra-Long-210mm-Travel-Enduro-Machine-Is-This-the-Ultimate-MTB,2947
57 Degrees!!
That was a fun video. Its a really cool idea.
If they dial back the stupid just a touch they might really be onto something.
Ultimately though, you really need to be a good rider benefit from that style of bike.
I'm on a LLS trail bike with a 65 degree HA and I keep having to remind myself to get my weight more forward.
If I rode the Grim Donut I'd be spat out the side on the first corner.
That's a highly entertaining video, Mike Levy's enthusiasm is properly infectious - don't think I've ever spent 20 mins watching a review of a bike I've no interest in owning!
Been waiting for this video for a while, love ridiculous projects like this!
Bollocks to the bike, I want the mini at the start!
I mentioned to Levy in the PB comments about how ridiculous that bike would look carried by the Mini and we got into a conversation about how it wouldn't fit on his rear mounted rack. Ended up talking about Mini's for a bit and about how strap-on racks can separate the roof from the rest of the car, he spotted the tell-tale signs of that on his car and now he has a seasucker as in the vid!
My little claim to fame.
It is an interesting idea but the shape just looks all wrong – how that frame hasn’t snapped at headtube is impressive
It certainly doesn't look conventional! But in terms of the headtube, not really, you have to consider which way the forces are acting, unless you slowly hit a huge huck to flat, then it'll be fine.
Genius. Loved both of those videos.
“I’m on a LLS trail bike with a 65 degree HA and I keep having to remind myself to get my weight more forward.”
You wouldn’t if your bike had longer chainstays!
“unless you slowly hit a huge huck to flat, then it’ll be fine.”
As I said above, 20% more leverage than with a 63 deg head angle. It’ll fine full-stop.
Crumbs. Never occurred to me it was possible for the chain to slap the ground on landing.
The grim tagnut?
the head angle means that flat hits (like the huck to flat) there's a lot of sideways load on the bushings - so they perform badly - but whilst riding along and hitting a log the force comes from the front - it could easily be that angles like that are more perpendicular to the force hitting the wheel and thus actually work better (same for the force going through the headtube)
but as this has been done without all that (from what I can see from the various videos and articles on it), then I’m more sceptical.
They did the FEA and the rig testing on it according to the vid.
Im sure Cy talked about it in his lectures at Sheffield (10 years ago?). The loading in the CEN test for pulling the fork forward is actually mimicking a landing so hard your legs would buckle.
Podcast discussing it here
https://www.pinkbike.com/news/the-pinkbike-podcast-episode-23-grim-donut-2-is-live.html
Here you go,
The CEN test is 1200N pulling horizontally away from the rear axle, 50,000 times.
At 2012 geometry (yes slacker will be a bit less) that was 50,000 9G landings to flat.
