Building a Suspension Fork Impact Tester for Science

[@michellesharpe6159]

So, you've made a bike fork guillotine. Love it!

[@TheNinthPhotography]

Happy to see that I am not the only one reminded of this particular device …

[@Pufferfishmaster]

I was just about to comment this but then i saw your comment

[@Herran42]

I saw the diagram and instantly thought guillotine

[@billydoesntexist5061]

@@Pufferfishmaster same!!

[@I-AM-THE-SKIBIDI-RIZZLER]

Pretty much.

[@quincybuickerood3070]

You need something to guide the weight down. This will make it so the weight hits exactly in the same spot each time, not just a similar spot.

[@SethsBikeHacks]

yes, like the one Cane Creek has. Part of the reason I didn’t was lack of ability. I may need to work this out…

[@ghostly07]

good idea but you are probably never going to hit the same spot in the real world

[@YujiSsi]

@@SethsBikeHacks I don't know if it's possible, but I guess you could drill a hole to attach a bar through the weights; and create a guide hole trough out the wood.

[@christiannieman8144]

Or maby even just directly mount the steerer in the clamp

[@MatroniFitness]

You may be able to put some steel or wood across left to right so the force equally distributes up and down. I bet you’re getting some torsional deformity in addition which affects its future deformities

[@nilz6432]

To actually use this as a tester, it needs to be significantly stiffer than the object you are testing. The Wooden platform that you mounted your clamps to will flex and dissipate a lot of the energy, allowing the Forks to experience less Load. Also the Weight needs to hit at the same place every Time, and the Forks sould be stopped from rotating. I could continue with this, but as far as fun and entertainment is concerned, the smeasher works perfect.

[@ThatVoxelBlock]

he might be getting close to patent information if he uses steel

[@falsemcnuggethope]

Maybe he should start testing wooden forks

[@ThatVoxelBlock]

@@falsemcnuggethope like a mediaeval mountain bike forks made with brass accents

[@nilz6432]

@@ThatVoxelBlock Yes, but you would still need a pretty decent Steel beam as a base to act as a counterweight (maybe 200-400 pounds?) or the whole things needs to be bolted to the concreet floor.

[@jamesroscoe7555]

Yep, the cost (and effort) to build this to properly test forks would easily exceed the cost of just buying a good high end fork, but the entertainment value as it is, is priceless! That sticker was hilarrious!

[@curt13g]

Love the video. R&D Engineer here, if you put the fork at the top and tie a rope between the weight and axle then drop the weight, that would result in much higher consistancy in the experimental results and eliminate a lot of the variability in the impact. Could also throw in a strain gauge on the rope to get measuments of how much force is being applied and change the length of the axle/weight rope to alter the force beeing applied.

[@yakwabbit]

As an engineer, I appreciate the the term; 'moment' of truth. Perhaps that should have been the name for this device?

[@mtbrwannabe5484]

I have been watching you from 10k subs. There is still nothing more exciting for me, than to see “Seth’s bike hacks” has posted a video. I had just started to ride a bike again for some fitness, I found your channel, was totally inspired to push myself harder and faster. Then spent a large amount of money on my new whip, you showed me I can fix it myself. Heartfelt thank you for your abundance of inspiration you share all over the world, every time you post a video. Carry my love and strength with you at all times ❤️🤘.

[@daviddoornenbal44]

I used to have that exact same fork on my bike, but it broke after like 5 months of taking heavy flat drop hits from 2 meters and a few jumps.

[@blankidelics]

How did it break?

[@acr_master5594]

what broke on it?

[@40bikes]

@@acr_master5594 bolany forks Pretty poular here in SEA, lowers usually blow out near the arch. Crown cracks.

[@daviddoornenbal44]

By my fork the steerer tube just snapped in 2

[@daviddoornenbal44]

@@blankidelics i dropped a 1m drop to flat and then it made a loud noise and when i came home i took my bike apart and it just broke in 2

[@eddmorrell90]

If you ever get tired of riding with Seth, you can smeash things with Seth! Great video 👍

[@MTB_Rider_96]

Wow, Excellent job on this. I work in an ASTM/ISO professional test lab, and you did a great job on this.

[@aydinatavash9854]

dont fall for the scam

[@amechanicalengineer4088]

It's a good idea and an interesting route to take the channel! I will say, as a testing engineer, some of the design decisions were hard to sit with. I'm glad to hear there are some future revisions coming for the smasher

[@jonahkrynski8001]

Woah! Return of the SMEEEEAAAASH?

[@bmxbandido473]

You’re a genius Seth!

[@jonahtillman9499]

I have an XCR 32 in my mtb and it still hasn’t been upgraded because it doesn’t need to be upgraded. I’ve replaced my bars, seat, tires, brakes, and cranks, but man, the suntour forks and freakin indestructible. They’re a bit heavy, but the cheaper we can get people into mtb the better!🤘🤘

[@carlwilliams3488]

The XCR is loads better than that XCM, XCR has an alloy steerer, air spring, rebound damping and alloy stanchions. It's the first half decent fork in the Suntour range. My wife has one on her Cube Access, it isn't much different to the Raidon on my sons Voodoo Bizango really, but I haven't torn either down to compare them so I would think the damper in the Raidon wil be better.

[@amiramz]

so i just remembered i noticed on several of your vids you were wearing a Winder Towing tshirt... just imagine how cool a colab vid with Matts off-rod recovery could be :) just putting it here... awesome vid! thanks bro

[@WestCoastMountainBiker]

I think the weight should have a flat bottom. That might already make a difference in the way the impact treats the fork as well as how the deflection will be if any.

[@andresgargut]

I was going to suggest the same

[@timmyreeves4546]

Netflix series I would watch it on repeat lol. This is one of the most entertaining KZbin channels I've seen thanks so much please keep them coming 🙏 👍

[@bladesageproductions326]

Love the video maybe you could make a budget guide rail by rigging up some brake cable vertically on both sides of the weight and attaching the weight to it with small carabiners or eyelet bolts or attaching some short pipe to the weight to guide it I love your videos where you engineer and build stuff, you're quite good at it and it are relatable at the same time.

[@WeekendPirate]

The mad bike scientist is at it again!

[@cozmo4694]

The smasher could be improved in many ways, but i think a guide for the weight would benefit it the most. You should be able to add one with thick linear rods and bearings, linear rails (you can find big ones used from cnc machines for cheap) or v slot wheels but then you would have to build the frame from v slot extrusion

[@whitmankwok1034]

Just finished our 3rd helmet impact test rig at KAV and we learn something new each time.

[@benjaminblakemore9704]

DEAR BIRM PEAK, HERE IN NEW ZEALAND, UNFORTUNATELY IT HAS BEEN A CRAP SKI SEASON AND MT RUAPEHU IS IN RECEIVERSHIP. THIS WOULD BE THE MOST EPIC MOUNTAIN BIKE FACILITY BRO!! CHAIR LIFTS ETC.... I THOUGHT OF BIRM PEAK YOU COULD HELP MATE!! DONT LET THIS DIE, KINDEST REGARDS BEN FROM NZ 👌😎😜

[@Marvthegrate]

I particularly love the look on Oscar's face at 0:35 with captioning turned on.

[@ThugZ3r0]

just great idea, that definitely needs some upgrades. you totally got our respect because you mentioned problems with that version

[@SamSalty]

Seth goes above and beyond on everything and it is great. Customised sticker like what the hellllll!

[@f--lg1hu]

I can't wait to see what is to come in the future.

[@joshallen1846]

How many squares of toilet paper do you use to clean your Tallahassee?

[@brycebonilla4288]

Hey Seth, you should try tapping screws into the metal pipe that holds the fork that screws into the steerer tube, so that the fork does not deflect or come loose

[@mdturbo764]

"Honey! Look what I built! Its a guillotine but with a weight instead of a blade so its only 2/3 as dangerous and so it will be perfect for our kid! Their gonna love it! - Seth's final words before death by wife using his own creation "The Smeashotine"

[@benjaminjessop3429]

Seth! Please do a video on the camera gear you use and how you make your videos. What gear would you suggest for a beginner with a price range? What different types of products are available and what are they best used for?

[@xB0BBYx073]

Hi Seth, just wanted to let you know. In the Philippines, there are a lot of BOLANY Fork users because of its price. And one of my friends uses it on his MTB. It is great way for me to share this video with him. I can't wait to see this fork in action on the trails. Thanks for this one. Great vids btw.

[@wasifzihan4662]

As a to be mechanical engineer and a diy crafter I praise the effort seth. But it would be thetter if the weight had a angled point which would hit the fork, also, you can build a guide for the weight to come down precise everytime with the sideposts as guide rails.. And the steer tube clamping vice would fare better if they were mounted to a hard surface, The wood would create dents and lose energy

[@Littleweenaman]

I love this channel overconsumption is the best!!

[@evan24pen]

A quick and dirty way to guide the weight down might be a set of long, heavy duty drawer slides mounted on both sides with a middle frame to hold the weight and keep them square as they descend. Excited to see the modifications!

[@sotoboxios]

THE SMEASH STICKERS ARE BACK !!!

[@thefuzzbl]

This looks like a fun toy and looks cool in a video but its little more than that. + Its no where near stiff enough + There is a reason machines like this use linear guides, you need to control how and where you impact the fork/product. If you look through the ISO testing standards there are also very specific drawings for how the impact surfaces are machined + You need to clamp the fork as it would be clamped on a bike. With those orange clamps you're clamping in the middle of the steerer, this is not realistic + You need some way to measure the data. This would ideally be the total displacement during the test, permanent displacement (after the test), and acceleration of the carriage. From there you can calculate anything else that you may need I would be happy to advise you a bit on future projects like this, I have designed and built out many machines that are used in the industry

[@elrictdb]

I really enjoyed this video, like you took pains to stress, version 1 has some flaws but you still made an awesome tool to learn something to pass on to new bike owners and your viewers. I'm dying to see the next one already because "upgrading" to a cheap air fork from stock Suntour coil is something alot of budget conscious people are definitely going to think about. A home built rig is never going to be flaw free (perhaps bolt some steel on to help reduce some flex if it's very excessive), but I do believe that the data will be useful in helping come to conclusions about fork suitability....like I was amazed that the zoom hydraulic brakes you used recently actually stopped a bike /shock'n'awe!

[@rabonour]

This is vintage Seth's Bike Hacks level of sketchiness... love it.

[@Nitrodozer]

It's crazy to think I've been watching you for about six years now!

[@carlwilliams3488]

I've used Bolany cassettes a number of times when doing budget 1x upgrades. They are excellent VFM and have all worked well so far. Better quality that the Sunrace I purchased.

[@zacht017]

Hey seth. Something you could try to fix your issue with the box limiting the amount of deflection the forks have is you could add a second rope and pulley and pull on a angle with the weight tentioning the rope only a few inches before it hits the ground. That way the sky is the limit for how far the fork can bent. Hope that is helpful. 🤙

[@antonioZaRasFiNaLbOsS]

You're actually lefty! Wow i didn't know that. That's awesome!

[@christianhb3314]

Thanks for looking out with this sweet sweet *Chefs Kiss* content Seth. Con mucho mucho amorrrrrrrr

[@gustavobaquedano6992]

I hope you never stop making videos you’re awesome

[@Anonymous-jm3mg]

You should use or build a bow hunter's quick release and replace the pin. Also, have a strike plate that your kettle ball hits that is implemented into the base that falls evenly. Next time you build your base, put pvc tubing or steel tubing in your wet concrete where your clamp bolt holes are going through, just to save yourself the headache of drilling holes. Looks good though and I appreciate your videos. I'm nobody, by the way and am probably wrong about everything I suggested.

[@hardwoodswisconsin4871]

Idea for your smasher, run the kettle-ball through large pvc or similar pipe to guide the decent. Drill holes in the pipe to view the weight drop. Good luck 👍

[@Anderson_999]

Now we just need a Berm Peak express video of you smashing random stuff in the smeasher

[@baronvonrichthofen2021]

Interesting idea, and I have a couple of contents and questions on it. First the questions: why do you want to hit the fork from the front? That’d be like riding into a wall. Yes it’s good to test the perpendicular strength but in practise that’s a force you only see in exceptional situations. My other question is, how do you quantify the force on the steering tube section? It’s actually not too complicated with newtons laws. As for the comments (or considerations): Assuming no alloy characteristics, steel is 3 times as strong as an equivalent object in aluminium. This means you can use a tube that’s a lot thinner from a strength perspective. However, with tubes, the wall thickness matters. if the steel tube is three times as thin as an equivalent aluminium tube, it’s actually more likely to buckle. It’s also less stiff. In addition, steel is much tougher than aluminium. This means it flexes less before it breaks. This means that for the same force, if the force is high enough to break steel, it might not break aluminium, as the aluminium flexes more. (Actual specs you can find for specific alloys from manufacturer websites). What that means for the fork, is that the fork should be placed much higher in your construction to cater for that flex. You can also make some predictions of breakage, soo you can estimate the weight you need to break the steering tube. (Again a few laws from mr Isaac N). Super interesting project! I look forward to seeing more!😊😊

[@code3xiv]

No need guide rail. Just a plank with hinges on the other side that rest on top of the fork. The pivoted hinging plank only go one direction which is down/no side slant. Thats good enuf.

[@sebastiana.345]

Hi seth 1: love the content. 2: you haven't made a tips/tricks video in a while and maybe im dumb but I can't find a video for the essentials for a solo ride, as someone who started riding solo once I got to college I forgot some important things on my first ride and I think it would be a cool video to make.

[@thestrengthfactory.]

I don't know why, but this is entertaining.

[@tslaforest]

Thanks for the science lesson! Nice to see other people push the limits of parts. Maybe a frame stress test is next?

[@knordberg]

I love the way Seth says "smash". LOL

[@emoneydev8684]

Nice, I need one for fun

[@kw6919]

Perhaps replace the Stem Tube holding pipe with a PVC Pipe that can actually flex to hold the stem lightly to keep it from rotational deflection. Just a thought.

[@myprelove6818]

Hi seth, Big big love from philippines. i've been your fan for a month.

[@Stickman550]

My favorite thing about this video was the amount of times seth said "smash"

[@aarongreen9014]

Seth is now the dignified Whistlin Diesel of bikes.

[@JH-tc3yu]

Comparing anyone to that jackass is more of an insult than a compliment

[@classydays43]

I have one of those Bolany forks on my bike. Needless to say, it runs alright - I'd say a little better than the Suntour fork that originally came with it given that the air is more responsive. You could say it's basically an air version of the Suntour. The only problem, however, is that none of the parts are replaceable, such as that damper cartridge given that they are made differently for every single fork. Even the dust wipers and other seals have no equivalent replacement. Being a cheap fork you can run it to the ground and buy a new one, even re-oil it once in a while to keep it running nicely, but it bothers me that the "company" doesn't have an online parts store to keep their product reliable. The reason why bike manufacturers use the Suntour, I think, is because Suntour has a longer history of testing and runtime compared to Bolany. Those heavy steel bits mean the Suntour will last for years under normal riding conditions with little maintenance. I get that most riders hate them, but it's hard to argue against their durability for beginners crashing regularly in to rocks and trees.

[@mOkz312]

“sounds sketchy but stick with me” Sketchy is why we stick with you Seth

[@mikemarion2154]

I have the BOLANY 27.5 with remote lockout on my ebike. For my purposes it's good so far. But the dust seals are super hard and scratch the stanchions. Good too see it held up to the insane abuse that Seth could throw at it.

[@itzmrfizz]

Great job! One thing that would of made things a lot easier on you is to set the through bolts before you pour the concrete, or set them into the concrete so you don’t have to drill all the way through. Good looking tester though.

[@derrickquintal]

Another absolute Smeasher of a video Seth!

[@michaeltorres6109]

That fork is popular here in the Philippines. Low quality specially the stanchion. Easy to break and also arch. Can't wait for another test. Be safe on using it on your bike. Keep safe

[@gerp9p788]

could you maybe show us your whole garage and stuff? would love that

[@SkiRidesMTB]

They've done a bunch of shop tours on the channel.

[@michellesharpe6159]

He seems to do one almost every year, and they get better every time.

[@SkiRidesMTB]

@@michellesharpe6159 They also moved houses twice and kept adding to this shop. It doesn't really seem like they've added much to the shop in the last year.

[@mdrochford]

All this talk of guide rails, but I want to see more of Seth’s Revel Rail. NBD and then radio silence was quite the tease.

[@macha2133]

I think one big improvement may be adding guiding rail to weigth. 1. Safety: Weigth won't fly off like now we can see in 10:12. 2. Accuracy: It will provide the weigth will hit exactly at the same place every time. As a bonus I may recommend tying doubble fisherman knot to end of the paracord, it should be big enougth not pass pulley. Cheers!

[@marylloyd7755]

It needs to pass the pulley to drop the weight.

[@macha2133]

@@marylloyd7755 then longer cord and stopper knot

[@charlesc3664]

It would be cool to test out carbon bars on their smash strength, I’d imagine only thing to change is the clap method.

[@blondiejoe]

This might be your most hilarious project yet. You should collab with Project Farm make the most accurate destroyer of things. Or just keep smeashing

[@neotim5]

Thank you for your content, made me go out and ride my dusty thing again

[@domenfatur2018]

NEW VIDEO LETS GOOO THE

[@hokiturmix]

No tires but the instability and the turning may simulate real life better than a rigid one!

[@jsrocker248]

I think if your trying to hit close to true machining as the one they have at cane creek, then maybe using like a used at-home gym system and just retrofitting it into a smasher. 1. Already has a rail system with added weights that you can then increase or decrease weight for testing rails 2. Depending on the specific type, there are ones that are steel (mostly older versions) that can withstand the added punishment 3. Adding steel planks on the side where the seating is located and adding the kettlebell with a guide should minimize the necessity to come up with something from scratch 4. The post where the seating would be on could be then fitted with the clamps with some U-bolts since the seat is usually smack middle of the machine There's also some other stuff that would be taken into consideration but I think that outweighs the cons and assuming you get a good used affordable gym system, why not But then again, just my 2 cents, probably something easier and simpler out there

[@aervinreyaguillon2616]

I've seen many bolany forks here in philippine and they sell it for only 2,000php around 35usd. I seen also many broken arch of that fork even though the trails is for xc with minor jumps.

[@caledfwlch]

Return of the “SMEash”

[@neon_necromunda]

great job on the tester you'd get more accurate results clamping directly to the steerer or even bodging a headtube mount.

[@Agent-Ate]

Great video Seth! I have an idea for a video, BMX bike vs Berm Peak. I think that this would be very interesting because you have many jumps, and you have past BMX experience. I also wonder about how Airbag trail would work with the BMX bike. Seth, if you don’t feel comfortable or don’t want to do this, then you don’t have to. I know that you have done a video about this on a real trail, but Berm Peak is not a normal mountain bike trail.

[@RCandSR]

So creative and entertaining!😂

[@samueldeter9735]

5:01 man it was probably just me, but boy was I eyeing that closed garage door on your initial test

[@elgiedeleon4393]

Keep on creating interesting, meaningful, informative, straightforward, helpful and honest contents! Did I just become a bit too redundant? Anyways! Great job!

[@tomkang9272]

the steer tube needed to be locked down so the fork wont rotate and also the fork needs to be held up higher. other than that great testing on the forks !

[@kanethomas6998]

I miss the videos of you building sick trails in the woods.

[@rupedog]

Nearly 2.5m subs.... wowzers 💪👏👏

[@steezmuffin]

I cant stress enough how much better your channel has been since you ditched the bike sponsor

[@Rin-oo9pf]

Hem.. am I the only one thinking that one of Seth's modifications is a blade instead of a weight? In a queen of hearts fashion?

[@Callsign_Zion222]

Seth! Can you please do a review on the Sur-Ron X or the Segway X260? They're an E-Moto, these are a cross between an MTB and a Motocross bike. I think it would be an awesome addition to your fleet! they actually use the same DH forks used on, well... DH bikes!

[@vladamirtepes5567]

@Berm Peak Needs a piece of I-beam with a 2x4 track to guide it so it hits consistently and stops the fork from rotating instead of the kettle bell but I like the idea.

[@scmstr]

As a non-engineer, this fixture makes me... Anxious.

[@AppleJack76]

So many engineers are shaking their heads right now. I learned absolutely nothing.

[@oleksiykolesnykov339]

I have a weird nostalgia of sorts for “smeash”, amazing

[@bpnw3816]

I love this new videos but i'm sure we all miss back on Berm Creek when he didnt have the tools or proper way to build features and it was always so sketchy! Love it though!

[@profanityriot2537]

The most common issue with Bolany fork is the crown and the arch can break easily, others may have issue with the lockout system, it doesn't work properly in the long run. That's why I prefer my clients to buy SR suntour forks instead of cheap and garbage forks

[@thisisabsolutelystup]

Congratulations on the workers comp machine

[@Porter3]

Love on of those air forx love the videos

[@MTBNewMexico]

I’ve been waiting for this video :) I was hoping for it

[@originaljws]

seems like you need a more "standard" headset setup to keep the steer tube from sliding/banging around in the clamps. The 2 clamp setup you have seems unnecessary, you could use a pipe (or cut off head tube) sized to fit the top of the steer tube with a bushing instead of a bearing and a normal topcap (perhaps with an expanding plug instead of a fangled star nut). At the bottom you could use a similar setup (bottom of head tube, bushing) or a simpler "yoke"/cradle to act as the fulcrum. +1 to guiding the falling weight...maybe garage door tracks or sliding closet tracks? Something to keep the force in the Z alignment.

[@natr8301]

i had a very similar fork to the baloney. during one quite bad nose case the valve where you pump the air in blew off couldn't hold air once re attached.

[@Jack-cy8qg]

Hi Seth! My name is Jack and I’m from Nova Scotia. I really love your videos and my Dad and I decided to build a bike trail in our back yard! Do you have any ideas on what we should build for new bikers?

[@NonLegitNation2]

A friend of mine just got this exact fork for his e-bike 2 weeks ago to replace the heavy stock coil fork.

[@outoffocus875]

those stickers really give it a personality

[@FelixgreenYT]

I suggest some kind of flat plate at the bottom, to give a flat even hit off the weird rounded surface. It's not repeatable enough on the impact.

[@heathb4319]

I learned something today and i enjoyed the video. I learned how not to make a smasher :) Love you brother, keep it up.