No video

Disc Brakes on a 90's Bike - Converting the Frame to Hydraulic Brakes

  Рет қаралды 15,903

Robert Adair

Robert Adair

4 ай бұрын

I recently converted my old 90's Gary Fisher mountain bike to use hydraulic disc brakes. In this video, I show you what I did to modify the steel frame to fit hydraulic brakes. We take a look at the changes needed for disc brakes and then check out the the forces a disc brake applies to a frame. This is a more in-depth video which uses some original footage from the Gravel Bike build. If you haven't seen the build video, I've added a card at the beginning of this one. I hope you enjoy.
I reference two studies in this video:
Calculation of rear brake power and rear brake work during skidding on paved and gravel cycling surfaces by Matthew C Miller, Aden A Tully, Adam M Miller, Stephen R Stannard and Philip W Fink:
www.jsc-journa...
Construction of a test bench for bicycle rim and disc brakes by Clemens Oertel, DI Heinz Neuburger, and FH-Prof. Ing. MMag. Dr. Anton Sabo:
www.sciencedir...

Пікірлер: 81
@letolollers3729
@letolollers3729 4 ай бұрын
This is the best retro bike modernization ive seen to date, paint job ended up looking amazing as well
@jonathantyler7327
@jonathantyler7327 4 ай бұрын
Couldn’t agree more 🎉
@_MrSnrub
@_MrSnrub 4 ай бұрын
The bike is impressive, but showing your work is just next level. Well done video, and that bike is amazing. Well done.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Thank you!
@bennettturk3206
@bennettturk3206 4 ай бұрын
As a structural engineer who loves tinkering with bikes this was right up my ally.
@peterbedford2610
@peterbedford2610 4 ай бұрын
You can buy pre made caliper mounts from several bike frame builder suppliers in the US. No need to mill your own. I silver brazed mine and added a small gusset. I have over 3000 miles on the frame. No problems at all.
@ericjensen4434
@ericjensen4434 4 ай бұрын
Did not expect the multiphysics analysis! Bonus. I’m doing this same thing to a Giant. Just welded up the brake tabs yesterday. I’m paying close attention to your work. Thanks,
@substrate007
@substrate007 4 ай бұрын
Great video -- really impressed with the FEA!
@TheWillRogers
@TheWillRogers 4 ай бұрын
Whenever someone comes into a forum and asks about converting a 90's MTB to disc brakes by welding in tabs, the top response is something along the lines of "you'll die". It always seemed hyperbolic to me, I'm glad you busted out the FEA on this. I'm wondering what the safety factor on something more modern is, particularly a more all-road frame as opposed to a downhill bike. (deleted part of my comment, reading the linked studies now lol)
@iziashsuklan7057
@iziashsuklan7057 7 күн бұрын
Wow this is great! I was thinking about doing exactly this and to see that someone else has done it before me will be a great reference. Great work!
@RobertAdairWorkshop
@RobertAdairWorkshop 7 күн бұрын
Appreciate it, thank you It was a fun and rewarding project. I'll bet yours will turn out great.
@tipperryan
@tipperryan Ай бұрын
Wow, modifying old mtb frame WITH physics theory. Bravo my friend, sub'd!
@nicozegers
@nicozegers 4 ай бұрын
Very nice work. I made a similar transformation but with an early 2000's alu bike that already had disk mounts. The FEA analysis is interesting, but think I spotted a small mistake in the model. You seem to have defined the wheel axle as a rigid point, but it should be considered as a pivot. that way the seatstay should share some of the deformation with the chainstay, and show less difference between the braced and unbraced cases.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Wow! You are exactly right. I'm not quite sure how I missed that. Thank you!
@BruceChastain
@BruceChastain 4 ай бұрын
really impressed you bothered to run it in FEA software, way to go man
@SebastiaanNL
@SebastiaanNL Ай бұрын
good explanation about the brace, that's what I also said something about in the first video.
@RobertAdairWorkshop
@RobertAdairWorkshop Ай бұрын
Right on
@thehollows
@thehollows 4 ай бұрын
This is a mod I've always wanted to do. Sadly, 90's MTB frames are scarce where I live. Looking forward to the Kona!
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I’m excited for the Kona build. I got to buy a new rotary table just for that project. It’s going to be awesome.
@WesMacaulay
@WesMacaulay 4 ай бұрын
I’ve got a Brodie Catalyst that’s getting the gravel bike treatment …and this video is fantastic. Really liked the engineering to demonstrate that deflection under unrealistic loading is not even 0.2mm! Those are numbers I can live with. Subbed and thanks for your excellent work!
@lbgstzockt8493
@lbgstzockt8493 4 ай бұрын
Very cool video, I appreciate the fact that you did some FEA to verify your choices, as that is what engineering is all about. I personally wouldn't do all the extra work of welding in a brace for a .5 increase in my safety factor, but I guess that depends on the frame one uses.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Great point!
@AK-oz4ew
@AK-oz4ew 4 ай бұрын
What a great video. The only thing for a "modern" bike would be internal cabling, which is very easy on that frame
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I didn't even think about that. Hmmm. Next project, right?!
@johnnydoe66
@johnnydoe66 4 ай бұрын
I have to agree that the frame looks better than it would have with a brace, and I was one of those who questioned why you chose not to install one. After watching this great explanation, it makes sense that the force applied is really negligible, especially with using a small diameter rotor (160mm). The force would have been higher if you had went with a 180mm, but that's not really needed on a road/gravel oriented bike on the rear.
@user-ue1sg2nr6y
@user-ue1sg2nr6y 4 ай бұрын
Well done. Impressive craftsmanship.
@JohnPilling25
@JohnPilling25 4 ай бұрын
Awesome. Very well explained. Just wish I could weld. Loved the FEA but I'm not a big fan as very minor changes in the boundary conditions can have huge effects on the answers. Love the thru-axles.❤👍👍👍👍👍
@dperreno
@dperreno 4 ай бұрын
About the need for a brace. I completely agree that your setup is fine. Steel frames are very strong, and also in practice the rear brake is only able to take maybe 1/3 of the stopping force before the rear wheel will skid - - physics. The more critical part is the front fork, but I'm assuming you just used a new disc-ready fork? Really cool build!
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Appreciate it, thank you. Yep, you're spot on. This was a disc fork. I did adapt it for thru axles, but native disc.
@silverphoenix10
@silverphoenix10 4 ай бұрын
Just one thing to say, sickly amazing job!
@surrealestateinvestor736
@surrealestateinvestor736 4 ай бұрын
I just did a back-of-envelope calculation and I got a different force on the caliper. Considering mu = 1 (dry asphalt, good tire) and rear tyre normal force Fz = 400 N, the stopping force is 400 N on the lever of 0.35 m (wheel radius). From the torque balance for the brake disc action radius (r= 0.07 m), that is 400*0.35/0.07 = 2000 N!. Looking at the second paper, I see they use mu = 0.5 in which case your result seems plausible but their experiment is in pretty much laboratory condition. I would be afraid that that frame could collapse in that one emergency braking situation when your rear tire bites to a rock in the ground. I am sure you will be fine on normal roads but I would think twice before riding some rougher trails.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Actually, that gives me an idea. What if I'd model the original cantilever brakes and see what forces those applied to the stays under the same conditions? It could serve as a good baseline. The only other idea I have is strain gauges on the rear stays but that is sure expensive and I'm 100% we'll get the same results.
@surrealestateinvestor736
@surrealestateinvestor736 4 ай бұрын
@@RobertAdairWorkshop @RobertAdairWorkshop it surely would be interesting to reverse engineer the original design, just to put it into perspective with yours. But for rim brakes, the braking force might not even be the most significant one. For such thin tube I would definitely also consider the buckling load from your weight but and also from the forces from wheel into axle. Using strain gauges could be a fun project that I thought about myself. You can get cheap ones from china including some arduino amplifier modules. But proper installation, processing the results and calibration could be frustrating. If it was to me, I would simply lock the brake, try to turn the wheel to simulate the braking torque and observe closely the bending of the tube. Btw how did you measure the thickness of the stay tube for your FEM model? Is it the same along the length of the tube? And also what UTS of the material do you use in the FEM?
@senorspiegel
@senorspiegel 4 ай бұрын
Nostalgia! I used that solidworks in college
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Ha! That's where I learned it, too.
@jamesrossdesign
@jamesrossdesign 4 ай бұрын
Looking forward to the 2000 Hahanna!
@BruceChastain
@BruceChastain 4 ай бұрын
man I'm inspired to try this now
@hugomundo4826
@hugomundo4826 4 ай бұрын
Dude, that's exactly what i want to do with an old frame i got. But i'll try to stick weld it because its the only way i have to weld it, hahahaha. Cool video, cool bike
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I mig welded it because I don’t know how to braze. I totally got ya!
@kenychowsf
@kenychowsf 4 ай бұрын
Nicely done sir. Wow great step description.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Thank you kindly!
@y0val
@y0val 4 ай бұрын
looking forward for that kona video 👀
@ravennexusmh
@ravennexusmh 4 ай бұрын
curious, the use IS (not iso) mount because it opens up the options for flat and post mount caliipers, good choice. but the use of a what looks like maybe a IS to PM adapter (that adapter is huge) for a 203mm rotor to locate the mount for a 160mm rotor would remove the options of running flat mounts as the caliper won't be in the correct place. surely using a adapter for 160mm rotor in the first place would of allowed the creation of a IS mount that would suit all brake styles. yes using the BB5 cable brake is good, but just use enough flat spacers under it to account for the CPS washers thoose things usually use.
@jonathantyler7327
@jonathantyler7327 4 ай бұрын
Fantastic work 🎉
@ozzycrazy5183
@ozzycrazy5183 13 күн бұрын
Superbe reconversion du freinage . Je suis sur le même projet sur un cadre acier LOOK . Peux-tu me renseigner sur le support choisi pour le montage de l'étrier . Superb braking conversion. I am on the same project on a LOOK steel frame. Can you tell me about the support chosen for mounting the caliper.
@Musterdavid85
@Musterdavid85 4 ай бұрын
Congratulations on your bike, I liked how it turned out, I really like the on point methodology you explain to us about the FEA! Aluminum frames are another level to modify, right? I've got a cannodale m900 bike which is aluminum, same 90's built, it would be awesome if you could show us how to modify aluminum frames! Im not a welder myself but im eager to know how!
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I did discs on an aluminum 1998 Stumpjumper last year. It was actually easier to do but you're kind of taking your life into your own hands with the brazing. kzfaq.info/get/bejne/rKpho6tpm92nook.html
@thechadwick22
@thechadwick22 4 ай бұрын
Fantastic video! Seriously an underserved subject on youtube a bike forums. I did want to ask if you considered just brazing the bracket onto the stay? Brazing is accessible to more people (a MAP torch from home depot is way cheaper than a tig setup) and certainly strong enough to handle anything i can give it with my grip strength right? Wouldn't have to be as concerned about contaminating a weld and every step would be almost the same except for the filler material.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I think brazing it is probably the frame builders “correct way” to do it. I just never learned to braze so I’m sticking with what I know.
@thechadwick22
@thechadwick22 4 ай бұрын
Totally get it! With the FEA and exceptional thoroughness of your video I assumed it was a strength calculation. I wish I was setup for welding but brazing is super simple (except for the acetylene shortage ha). Getting filler rod of the right type is harder the torching metal until it starts wicking filler in. Great video again and glad it popped up in my feed. Newly subscribed!
@MJennifer
@MJennifer 4 ай бұрын
And now I’m on market place looking for a 90s mtb 😅😂
@bikethelife8639
@bikethelife8639 4 ай бұрын
Last summer I put 27.5" wheels on a 26" frame because they fit and I wanted the bigger wheels. Being a bigger wheel, the whole bike got a bit taller and it felt like I was riding on a tower of a bike. Did you find that this bike felt really tall with the bigger than intended wheels?
@janwillemkuilenburg7561
@janwillemkuilenburg7561 4 ай бұрын
Brilliant! I have one question: would a panic stop cause a peak power that could be higher, and would the calculated safety value cover this?
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
The 984N I calculated is for a situation worse-than a panic stop where there is no slippage. A panic stop would be less than that 984. The calculates FOS does cover max braking.
@prison9865
@prison9865 Ай бұрын
Then you. This is incredibly useful. Also, did you have to mill rear drop out to fit 12mm axle? I'm just about to get my self a classic gt or gary fisher. Cant waiiiit
@RobertAdairWorkshop
@RobertAdairWorkshop Ай бұрын
I had to drill it out 12mm for the axle. If you're alright with me sharing a link to another video, check out the build video. I've started it at the timestamp for the thru-axle mods: kzfaq.info/get/bejne/jaqbjLR5zcXXk4k.htmlsi=6kVaQ2sjjSYYOgUj&t=222
@dadlife8289
@dadlife8289 4 ай бұрын
You're like Bob Ross. Was that a PAPR you were wearing during clear coat
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
It’s a Hobbyaire system I bought back in the early 2k’s to paint a 300zx. Still works great. Draws from filtered shop air.
@StereoDiscoShit
@StereoDiscoShit 4 ай бұрын
Yeah! Waiting for the kona videos!
@magnumpunch
@magnumpunch 4 ай бұрын
🔥🔥🔥
@jimgourgoutis
@jimgourgoutis 4 ай бұрын
Does that FEA package let you do a fatigue analysis?
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
No, sadly, this one is a bit too old to look at fatigue stresses. I’d like to have a modern version but the software is ridiculously expensive for one license. Maybe if I make it big on KZfaq, I’ll celebrate with software.
@jonahwhale9047
@jonahwhale9047 Ай бұрын
Is that flux wire welding? I imagine that if a gravel bike is really being used on gravel, rather than just riding down to the coffee shop, then surely braking forced must be seriously reduced? Does anyone do a hub brake derailleur hub?
@RobertAdairWorkshop
@RobertAdairWorkshop Ай бұрын
Yeah, it's flux core. I'm good enough with it. I have some other videos where you could see me repair my Dodge's frame with it, or make a milling machine with it. Anyway, the braking forces aren't as high as people think, and the stays are stronger than they think, too. I talk about it in-depth at 9:04. I think I remember seeing something like a hub brake on motorcycles many years ago. Not sure if that technology ever went anywhere. Its an interensting idea to take a look at.
@jonahwhale9047
@jonahwhale9047 Ай бұрын
@@RobertAdairWorkshop Thanks. Yes, I've started using one too for running repairs having had so called non-bicycle welding "pros" make total messes of simple jobs, like carrier or bracket repairs. Someone described them to me a "metal hot glue gun" but, so far, they seem to work well enough. I've not been brave enough to use them on frame, for fear of punching holes in the tube walls by using too many watts, or whatever it is. I have no idea of how deep I am penetrating the metal yet, or even if. Thanks for the video. I'm interested in a tri-brake set for cargo bikes or old tandems, ie a rim AND a disc brake, like they used old drag brakes.
@TheSpaceBrosShow
@TheSpaceBrosShow 4 ай бұрын
Where did you get the rivet brake hose holders? :0
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Amazon. Here's the basic link -> www.amazon.com/gp/product/B07DND33HV I had to round the bottom of each with some sandpaper wrapped around a dowel, to get them to sit flat on the frame. I didn't show that in the video.
@TheSpaceBrosShow
@TheSpaceBrosShow 4 ай бұрын
@@RobertAdairWorkshop Awesome, thanks! Ive welded tabs on an old schwinn and I'm excited to put these to use too
@viktor1511
@viktor1511 24 күн бұрын
Hello there, could you by any chance send me the 3D-Model of the frame you created for the video? Step or any other type would be fine, but SLDPRT highly appreciated, as I use SolidWorks myself. Would be great and save me a ton of work. It doesn´t have to be perfectly my own frame, but I need a model of a retro-mtb-frame for an upcoming project. It would be great, if you could help me out on that. Kind regards Viktor (btw. If it if it makes a difference to you: I did not just find your channel while searching for a 3D-Model, but am an active viewer, and just remembered, that you made this model in this video before starting to create my own one)
@RobertAdairWorkshop
@RobertAdairWorkshop 24 күн бұрын
Hey! I'd be happy to send you the Solidworks file for the frame. Send me an email and I'll attach it to my response. Its in SolidWorks 2006 so hopefully it'll still be compatible.
@Speedy.V
@Speedy.V 4 ай бұрын
Max tire size?
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
700c x 40. I talked about it in the original build video. That gives 8mm at the stay bridge. kzfaq.info/get/bejne/jaqbjLR5zcXXk4k.htmlsi=dsn5uc-Sn0hriI5d&t=1179
@Speedy.V
@Speedy.V 4 ай бұрын
@@RobertAdairWorkshop oh. Yes thanks. So 40c on a wide 27internal rim would be the frames max. That would probably bulge it out to 41 or almost 42. Ever thought about putting in some 42c ? Or would that be bad for your type of riding in muddy areas?
@wheelzandgillz
@wheelzandgillz 4 ай бұрын
Dang man it sounds like you could tweak your compressor settings a little, seems like the first word of your sentences is getting cut off, anyhow great stuff!
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
Probably the noise reduction I use to try and cut down on the background noise from my workshop heater. I didn't notice til you mentioned it. I'll see what I can do for the next one.
@doncrescas
@doncrescas 4 ай бұрын
Very impressive. I wish there was an easy way to properly face brake mounts and tabs. For the home mechanic the tools are out of reach.
@jettaphi1e
@jettaphi1e 4 ай бұрын
I wish I was your neighbor!
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
You might be if you live in Denver, Colorado.
@jettaphi1e
@jettaphi1e 4 ай бұрын
@@RobertAdairWorkshop Rural Maine for me! Thanks for the videos, keep up the good work 👍
@Imagine2035
@Imagine2035 4 ай бұрын
Converting from rim brakes to disc brakes is really dangerous due to the different forces exerted on the frame. It can e. g. easily lead to fork failure.
@RobertAdairWorkshop
@RobertAdairWorkshop 4 ай бұрын
I don't think you watched the video. Look at 8:52. I talk about, just that, for at least 5 minutes.
How to cycle with less effort. Bicycle bottom bracket maintenance
13:19
building a dobsonian mount for skywatcher 200p 8 inch newtonian telescope
1:37
AMATEUR ASTRONOMY ARIZONA
Рет қаралды 184
OMG what happened??😳 filaretiki family✨ #social
01:00
Filaretiki
Рет қаралды 10 МЛН
Fast and Furious: New Zealand 🚗
00:29
How Ridiculous
Рет қаралды 48 МЛН
Converting a 90's MTB to disc brakes - 1992 Mongoose Switchback
21:26
1990's Gary Fisher Gravel Bike
21:53
Robert Adair
Рет қаралды 312 М.
Thru Axles on a 90's Bike - Converting the Frame for Thru Axles
11:33
Rear Brake Mount for my GRAVEL BIKE // Paul Brodie's Shop
27:43
paul brodie
Рет қаралды 33 М.
90's Cyclocross Bike restoration into a Gravel Bike
19:36
Velofil
Рет қаралды 46 М.
The Difference Between GOOD and BAD Carbon Fiber Bike Frames!
17:53
Jourdain Coleman
Рет қаралды 91 М.
The Correct Answer on Disc Brakes vs Rim Brakes
4:11
Phil Gaimon
Рет қаралды 110 М.