Tech Tuesday - Rotor Straightening

Sep 26, 2011 at 17:16
by Mike Levy  
The argument against using tools: There are a few different companies out there who manufacture tools made specifically to straighten rotors, simply pinching the rotor and acting as a lever to allow you to bend it easier. Some are designed to be used two or three at a time, with one or two holding a section of the rotor in place while the remaining tool acts as the lever. There is even a feeler gauge that allows you to see exactly how far the rotor is out, but nothing works as good as using your bare hands.

There are a few issues with using metal levers (this includes crescent wrenches as well) to straighten rotors, but the first is how easy it is to actually bend the rotor while using these tools. That isn't a good thing? Nope, especially for the home mechanic who might not be doing this repair that often. The extra leverage allows you to very easily bend the rotor too far, making the problem worse than it was when you started the repair. While it would be easy to blame the mechanic and not the tool, some bent rotors only require the slightest amount of force to straighten and some require much more, but a rotor tool can make it difficult to feel the amount of force that you are applying. Using your hands will give you a much better feel for what you are doing, allowing you to make smaller adjustments at each go.

Rotor straightening tools are often quite skinny as well, and applying pressuring to a very focused point on the rotor may do more harm than good. It is often much more effective to use your thumbs to spread the force out as you work the rotor back to straight. The worst case scenario is when so much force is applied by using a rotor straightening tool that it actually kinks the rotor where the tool makes contact, instantly turning it into scrap metal.

But aren't your hands dirty? When was the last time that you cleaned your rotor straightening tools? Your hands have oil on them right now, even if you've just woken up and haven't touched anything yet, which is why you'll want to clean them before doing this job. Getting that oil or grime from your hands onto the rotor will only be detrimental to the performance, so if you are going to try and straighten your bent brake rotor by using your hands you'll want to make sure that they are clean. Very clean. Wash them thoroughly, being sure to rinse off any and all soap that you've used, and then dry them with a towel that you know is clean. Alternately, you can just throw on a new pair of nitrile gloves and be done with it.

Some helpful pointers:
• Much like truing a wheel, this is one of those repair jobs that will only get worse if you try and rush it. Take your time, find the exact place where it needs to be straightened and make very small adjustments at each go. You want to avoid bending the rotor too far or doing it in the wrong place, both of which can cause the rotor to have a wave bend where it is out of true to both the left and right. That's when things can start to get tricky...
• While a small to medium gentle bend in a rotor can usually be trued out with great results, sharper kinks are likely going to be a death blow. Having said that, it certainly doesn't hurt to try and straighten anything.
• The rotor may be out of true in multiple spots, but only work on one at a time to keep things simple.
• The edges of a rotor are usually quite sharp. Be careful not to cut yourself!

What's needed:
• Your clean hands (nitrile gloves help)
• A clean rag
• A sharpie
• Brake clean

n a
Step 1. You first need to identify the exact spot where the rotor is out of true. It is easiest to let the rotor tell you where it's rubbing the brake pads - instead of trying to peer down at the gap between the pads and rotor, listen to the sound it makes when it rubs. You may have to listen carefully, but slowly rotating the rotor through the caliper will tell you exactly where contact is being made.
n a
Step 2. Use a black marker to indicate the exact position and how long the bend is. Only mark the very top edge of the rotor, not the braking surface. This will make keeping track of your progress much easier, especially if there are multiple locations on the rotor that are out of true. If there are multiple places that need attention, concentrate on one at a time.
n a
Step 3. If you need to true the rotor by pushing it in towards the bike, wrap your fingers around the spokes and gently push with your thumbs. Go easy, you'll find that not much force is needed to make substantial changes. If the affected area is long, spread your thumbs far enough apart to straighten it. Apply pressure and then turn the rotor through the caliper to see how effective you've been. Repeat as needed.
n a
Step 4. If the rotor needs to be pulled out away from the bike place one hand at the top of the tire to hold the bike in place and use two or three fingers to gently pull at the rotor. Again, start with only a small amount of force, working your way up to applying only as much pressure as needed.
n a
Step 5. Even though you washed your hands prior to touching the rotor you should still give it a good spray with a brake cleaner to rinse off any oils. Let it air dry.

Have you tried to straighten a rotor this way? Maybe you have a technique you want to share? Tell us about it below.


Past Tech Tuesdays:

Technical Tuesday #1 - How to change a tube.
Technical Tuesday #2 - How to set up your SRAM rear derailleur
Technical Tuesday #3 - How to remove and install pedals
Technical Tuesday #4 - How To Bleed Your Avid Elixir Brakes
Technical Tuesday #5 - How To Check And Adjust Your Headset
Technical Tuesday #6 - How To Fix A Broken Chain
Technical Tuesday #7 - Tubeless Conversion
Technical Tuesday #8 - Chain Wear
Technical Tuesday #9 - SRAM Shift Cable Replacement
Technical Tuesday #10 - Removing And Installing a Headset
Technical Tuesday #11 - Chain Lube Explained
Technical Tuesday #12 - RockShox Totem and Lyric Mission Control Damper Mod
Technical Tuesday #13 - Shimano XT Crank and Bottom Bracket Installation
Technical Tuesday #14 - Straightening Your Derailleur Hanger
Technical Tuesday #15 - Setting Up Your Front Derailleur
Technical Tuesday #16 - Setting Up Your Cockpit
Technical Tuesday #17 - Suspension Basics
Technical Tuesday #18 - Adjusting The Fox DHX 5.0
Technical Tuesday #19 - Adjusting The RockShox BoXXer World Cup
Technical Tuesday #20 - Servicing Your Fox Float Shock
Technical Tuesday #21 - Wheel Truing Basics
Technical Tuesday #22 - Shimano Brake Pad Replacement
Technical Tuesday #23 - Shimano brake bleed
Technical Tuesday #24 - Fox Lower Leg Removal And Service
Technical Tuesday #25 - RockShox Motion Control Service
Technical Tuesday #26 - Avid BB7 Cable Disk Brake Setup
Technical Tuesday #27 - Manitou Dorado Fork Rebuild
Technical Tuesday #28 - Manitou Circus Fork Rebuild
Technical Tuesday #29 - MRP G2 SL Chain Guide Install
Technical Tuesday #30 - Cane Creek Angleset Installation
Technical Tuesday #31 - RockShox Maxle Lite DH
Technical Tuesday #32 - Find Your Tire Pressure Sweet Spot
Technical Tuesday #33 - Three Minute Bike Preflight Check
Technical Tuesday #34 - MRP XCG Install
Technical Tuesday #35 - Stem Choice and Cockpit Setup
Technical Tuesday #36 - Handlebars - How Wide Affects Your Ride
Technical Tuesday #37 - Repairing A Torn Tire
Technical Tuesday #38 - Coil spring swap
Technical Tuesday #39 - Trailside help: Broken Shift Cable
Technical Tuesday #40 - Installing a Fox Float Air-Volume Spacer
Technical Tuesday #41 - Replace the Seals on Your 2011 RockShox Boxxer World Cup Fork
Technical Tuesday #42 - Clean and Lubricate Your Fox F32 Dust Wiper Seals
Technical Tuesday #43 - Thread Locker Basics
Technical Tuesday #44 - Install a SRAM X.0 Two-By-Ten Crankset
Technical Tuesday #45 - VPP Suspension Bearing Service


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Author Info:
mikelevy avatar

Member since Oct 18, 2005
2,032 articles

124 Comments
  • 41 0
 My tip would be to take the chain off and then you can hear exactly where and how hard it is scraping - and of course when you've done a perfect job (no noise).

This only applies for when it is the rotor on the REAR wheel Smile
  • 4 0
 good advice!
  • 27 0
 To figure out where the bend on smaller tweaks I use a dry erase marker and draw a single line on the actual braking surface. spin the wheel once or twice, and then the parts that hit the pads are rubbed away, so you can see exactly where and how much needs to be bent and in which direction. Obviously don't go nuts colouring the whole surface, and wash with alcohol immediately apres le repair. works great for the finicky fixes.
  • 9 2
 Hahahah Just imagined a Nyan Cat Running trough the rotor lol

But it is a quite good idea to mark the rotor!
  • 1 5
flag georgy291 (Sep 28, 2011 at 2:26) (Below Threshold)
 then your wheel is prob on wrong
  • 1 0
 Next time my brakes start playing up they'll play the nyan cat tune!
  • 9 0
 what i tend to do is take the rotor off, lay it on a completely flat level surface, and from there, i can tell which sections are out of true because they're not lying flat.
  • 1 0
 I do the same and take to it with a rubber mallet, but on trail I use my fingers, I'm just happy he uses brake clean, I have been using it since I started riding discs and I was always concerned that perhaps mtb pads deteriorate from this as I never saw anyone else use it. great to know!
  • 3 17
flag pinityoufairy (Sep 27, 2011 at 1:53) (Below Threshold)
 this is such a cop out from tech tuesday but actually quite useful and I'm always a fan of cavalier repairs
  • 6 0
 Shouldn't you be applying the brake cleaner to a clean cloth, and then the cloth to the rotor, to avoid spraying other parts? Also worth pointing out you need to wipe clean the rotor to remove the brake cleaner residue?
  • 3 0
 indeed makes sense, brake cleaner is highly corrosive and kills the grease on all parts
  • 90 11
 What I do is this:

-1 remove bent rotor
-2 set aside
-3 install new, unbent rotor
-4 hang old rotor on garage wall for decoration
  • 6 0
 i just use 99% iso as it is easier to come by and evaporates nicely
  • 1 0
 so is it okay on organic brake pads? because to be honest I use an auto grade product and douse my caliper while the rotor spins, grey crud comes out and I wipe my rotor with a cloth. My pads wear fast but then I feel that's more to do with my riding and as I generally ride alone I have no one to compare ware rates with. I noticed in the picture above Mike uses a special sram product, does anyone here disagree with an automotive product?
  • 2 0
 Nah I don't disagree with an automotive product as long as it is the right product for the job.
  • 6 0
 It really depends. I work in a automotive repair shop and we have brake cleaner here that melts plastic. You CAN buy less harsh versions of this stuff that will be safe on bikes. But they are not all created equal. Hell, if you have your brake rotor off the bike you can use the agressive product all you like. It wont hurt metal. But as a rule of thumb I do not use automotive products on my bike. Isopropyl Alcohol is all you need to properly clean a brake rotor.
Also, oldfaith, I would not douse the whole caliper like that, especially with brake clean. You risk the cleaner getting into the piston/caliper interface (bore) .......I just dont think its a good idea. Also, it will soak into the pads and the stuff you are using could have ingredients that wont evaporate out.
  • 1 0
 Thanks!
  • 1 0
 Meat hooker! I laughed out loud when I read your comment, that's EXACTLY what I do LOL.
  • 2 0
 okay,, i have been doing this the same way as they said.. sometimes with hard bends.. i took a bacho to fix it..i ride trials with a rear mono trial brake.. my discs get nackered from time to time,.. i would be poor if i had to buy a new rotor each time,..
the brake cleaner is not so good for your brakes.. it DOES leave a residu..(some brands more than others..i found one good brand we have @ work.. it is normally the cheap house brand) i believe in alcohol too which is said above aswell..
since i do not get to high speeds i really feel the deteriorating braking power of using brake cleaner,. (note alcohol does make the brake fade too, but it lasts only a very short time ! ) if you do use brake cleaner.. i found out paper towels work great.. and they are disposable,,.
NOW CHECK THIS >>>
what i have seen some time ago ..baffled me !
my mate took 2 hammers,,. found the bend in the rotor and using the WOODEN end of one hammer against the disc and hitting the hammer part with the other.. on the lower part of the arms of the disc.. IF i am correct ! if the bend is inwards (to the wheel) hit the out side and vice versa,, he tapped his disc straight in no time,. i practiced it at home with a soon to be replaced hope trial disc.. which i ended up using for 4 months longer or something..cause i got it straight !
it works great.. start with small taps.. dont try to bend the disc arm ! just frighten it and it will return to its original form !
with bend rotor surfaces this does not work.. than use the method as noted somehwere here to.. take rotor off the wheel.. lay it on a flat (glas table !) surface to check the bends..and mark them,, take it OFF the glas table, and whack it straight on a flat piece of wood with a rubber or metal hammer.. note the hammer surface must be clean and smooth !
use a wooden surface so the impact of the hammer can go somewhere,.
  • 2 1
 why would you worry about getting hand oil on your rotors? as long as you wipe it off you'll be fine, besides, im sure a lot worse things get on your rotors and such while your riding.
  • 5 0
 In twenty years of being a bike mechanic, I've trued all kinds of things by hand - chainrings, wheels, rotors, even frames. When something's bent bad enough to need straightening, there's no harm in giving it a go. The important thing is to be honest with the customer, and realistic about the chances of the part staying straight and not breaking. At home there's much less to worry about, because the amount the shop's going to charge you to straighten a rotor will be very close to the price of a new one, unless they do a half-arsed job, which of course you can do yourself. Useless tips:
1 - A clean paper towel obviates the need for cleaning the rotor afterwards
2 - Rotors can have some really strange complex bends. Circular items exhibit more stiffness in the direction of the bend, so learn to feel for that resistance with your fingertips.
3 - Know when to give up. Especially in the shop, I hate to see mechanics spending two hours trying to save a fairly cheap part.
4 - Rotors aren't necessarily straight even right out of the box, so you might end up straightening it even if you buy a new one.
  • 7 0
 Park actually makes a pretty dang good rotor truing fork that works quite well and I use it quite often at my bike shop.
  • 6 0
 Very good tech tuesday, something most home mechanics should know how to do.
  • 2 0
 This was how I've been doing this for years. When I was just researching for some tips in straightening rotors a few years ago, all I could find is how they suggest to use adjustable wrench in bending the rotors. Still, I opted to use just my hands so as not to mar nor overbend the rotors. Glad to know I am not the only one who believes so.
Big Grin
  • 2 0
 I like the tips presented but I have to tell everyone to avoid using brake clean, especially automotive brake clean in an enclosed environment. Brake clean is a very toxic substance and is supposed to be used ONLY with full skin protection and supplied air, if you are going to use it please use it outside or find an alternative. I find most citrus degreasers easily clean rotors without the toxic side affects of many brake cleaners, and there are other such products available. We all bike, we all care about our health, so please make sure you read the warning labels on such products before you use them.
  • 1 0
 Ooooops......just used a crescent wrench and it worked but came out a little squirrely. wish this article came out before i tried to repair - United Airlines bent the crap out my new spendy shimano ice-tech rotor. [ Air Canada didn't on the way up to Whistler ].
Shimano mechanic at last weekends Tara Llanes Classic said same thing - "use your hands first". Shoulda woulda coulda. Got it close enough, but from here i'll be taking Mt-Bike-E's advice - Vice and 2 pcs of Oak. .....And perhaps fewer beers.
  • 2 0
 They also break guitars. expensive taylor guitars
  • 2 0
 Funny UA guitar vid.
Just tried straightening the botched rotor again. This time by hand as shown here. Sweetness, success. Thanks Mike Levy @PB!
  • 1 0
 Automotive Disc brake cleaners normally contain rust inhibitors. These do not affect the braking force on cars and trucks etc as the heat generated is much higher so they burn off any residue, but can greatly reduce the effectiveness of Disc Brakes on a bicycle.
  • 1 0
 I just want to clarify for everyone he is NOT putting lube on the rotor a the end there. I can't tell you how many people came into the shop I worked at this summer with squeaky brakes that stopped working after they lubed their rotor...
  • 2 0
 pretty good article, truing rotors is definitely part of the mountain biking game for me. just FYI the mysterious and dangerous oils on your hands (sarcastic) are not going to hurt your brakes
  • 1 0
 I was picking my way down a tight, steep, rocky bit of trail and my right handle bar clipped a tree, and I went down. After I picked myself up and determined there was no damage to my body, I did a cursory check of my bike, and the rear wheel wouldn't spin. My 160mm ice-tech rotor was severely bent. I removed the wheel, and after several unsuccessful attempts at straightening the rotor, I grabbed the top of my tire and with two fingers I pulled as hard as I could on the top of the rotor, and it didn't bend at all. Then I used three fingers. It wouldn't budge. I wrapped a rag around my fingers, and I cranked as hard as I could on the top edge of the rotor where it was bent, but I didn't succeed in bending it back even a millimeter. I had to remove the rotor from my wheel, so I could ride back to the trailhead. It looked to me like the spider arm was bent inward where the bend in the rotor was. I tried to get a Park rotor straightening tool right next to the spider arm and bend the whole thing outward, but the spider arm didn't budge, and the rotor bent, making a mess of things. I can't believe I ever spent $60 on a rotor! In my experience, those rotors aren't easy to bend by hand.
  • 1 0
 My front rotor was so warped that both pads had to be retracted out of the caliper "gap" to prevent the rotor from hitting the pads (the rotor was almost hitting the caliper housing). I tried using my fingers but it did not do much if anything. I finally got a 12" Crescent wrench and with my hand on the very end of it I started bending the rotor where it touched the pad (inside or outside pad), as I got it more straight I moved both pads in, and then repeated bending the rotor where it touched the pads. Took ~15 min. to get the rotor perfectly straight!!!!!
  • 1 0
 My approach is similar but i dont use brake cleaner. I never had a problem with just clean hands. After i get the rotor almost perfectly straight i try to find a spot with a long down hill track were i use a moderate bracking for as long as i can. The idea behind this is that once you get the rotor hot it will straighten it self. It works for me.
  • 3 1
 This is a very useful tip because rotors go out of "true" (bend) easily, but if you are looking for perfection, your LBS will (should) have a rotor gauge which will give extremely exact numbers for them to tweak it.
  • 3 2
 Exactly. A proper shop with have the tools to get it bang on, but this is really for the home mechanic who might be a bit hesitant to start bending away. Nothing to be scared of!
  • 7 0
 Yeah, especially because if you make a mistake, you can correct it by simply bending it back, you won't screw it up for good.
  • 4 0
 Funny you put this article up because not to long ago I was out riding with some friends and I crashed and ended up tacoing a 6" rotor in the back of my bike (don't ask how it's beyond me haha) so I decide to take my rotor off so that I can keep riding just with my front and I look over and my buddy is trying to be a hero and bend the rotor back haha it was almost bent at a 90° angle... Just goes to show that some people lack the common sense that these articles instill onto others! Great article!
  • 1 0
 My rotor is untrue and its really annoying because i have to set up my brake really loose (pads for from rotor) to stop it from braking without me doing anything. I tried to bend it back, but no matter how many times and how hard i pull, it just gets back to its bent position. You seem to be using a skinny rotor, mine is a thick Hope floating disc rotor... Any tips ?
Thanks
  • 1 0
 This only works if your rotor is slightly out of true... if it's really warped then you just have to admit defeat and get a new one.

I found Hope floating rotors especially hard to bend back, which is annoying as they're twice the price.

See here for a cheaper alternative: superstar.tibolts.co.uk/product_info.php?products_id=455
  • 1 0
 Mine isnt very bent, just slightly but it still touches the pad if i try to set my brake up properly, the rotor doesnt need replacement, but its really stiff so dont manage to bend it back out. Should i try to get extra leverage ?
  • 1 0
 maybe you can find someone who does forged iron stuff (fences, gates, bars etc) ask them to heat it and correct the warp for you.
  • 2 0
 Ha non merci. I dont have any friends who can do that and if i go to some stranger they will either refuse or ask for me to pay a little something, i'll keep trying maybe perseverance will pay off
  • 1 0
 Bin the floating rotor, you will be forever trying to get it straight, and when you do it will get knocked out again, they are more hassle than they are worth. remember they arn't attached the the centre (hense floating) so is very tricky to get any leverage. You are trying to get a thin ring of metal flat, not easy.
  • 1 0
 Yeah but i cant afford a new one... And the red looks good with my bike haha thanks for the advice though
  • 1 0
 hmmm...
  • 1 0
 if worse comes to worse use two rotor truing tools, to lever against each other, and give er' hell
  • 1 0
 you could just get a GOOD bike mechanic to fix it?
  • 1 0
 Im pretty sure you could consider me as a quite good bike mechanic, i always get to what i want, but the rotor is just reaply stiff and wont bend. Besides this doesnt require much skill, just control the strength with wich you pull/push the rotor. A GOOD bike mechanic couldnt do much more, the only advantage he would have is tools but i dont think they would be very useful, pull with your hand or with a tool, the rotor just doesnt wanna bend back in shape
  • 1 0
 bend it back at the spokes of the rotor and it will will go if its being stiff like that but use the adjustable wrench trick or the parktool
  • 1 0
 Will try. Thanks !
  • 1 0
 make sure you have centred the caliper properly first, on hopes you need to set the rotor in the centre of the caliper not the centre of the pads. Just not on the bent bit! You should have centre markings on the caliper to help, the pads then will centre themselves after a few brakes, then check and adjust the rotor again. Good luck. If you get nowhere then take it to a good mechanic and tell him you'll buy him a beer if he can get it running true. Smile oh and don't try and bend the centre of the rotor! Just the braking surface, I'm guessing freeride5 didn't pick up on the fact that you have a floating rotor.
  • 1 0
 Thats what i thought too with the brakimg surface, because im pretty sure the center of the rotor is nice and straight, its just the floating bit thats bent, but i thought i might give it a try because it didnt seem to work when bending braking surface. My caliper and pads are well centred, i dont have a hope brake btw i run a mechanic avid BB7, i just have the hope rotor. Apart from being bent the rotor is quite damaged anyways so i might change it anyways, but cant afford it yet so i'll just try and get mine straight, myself ! If i do it myself i'll have learnt it and it will be free, i work on my bike alot and am pretty good mechanic and i keep learning on my own, i dont like having to go to someone who can do it for me
  • 2 1
 make a small line a the top edge of the rotor surface with a marker, very small.
go ride a round for a few minutes without using your brake,
MAKE SURE YOU DONT USE YOUR BRAKE!!! Smile
then you put the bike on the stand. where ever there is no line is where you bend it.
if the line is still there ride more.
works for me, makes it easy to find the spot
  • 1 0
 I think a tool is only as good as the hands that drive it, so if you are to use a tool the first time to try to true a rotor, it would be better to use the tool on an already useless rotor to get the feeling of the amount of strengh needed to be applied. There are for sure bends that can not be corrected just by hand, but I agree that Mike's right on suggesting the use of hands for the diy job.
  • 1 0
 all i can say is : if it works using tools - it works ! and if it works using your hands [ or a combination of ] then, it works ! However, i agree that if you are looking to keep the rotor, it may be better to repair it with the 'right' tools and, an emergency repair if it works by using yer bloody teeth or a sledge hammer , then...well, you get my drift :-)

So, assuming everyone is straight up, tools work, and no tools work - moving on......
  • 1 0
 So first problem you are touching the rotor with your hands which have different oils on it and letting that rotor pass through the caliper so now you run the risk of fowling your brake pads and on an xo brake those run around 30 dollars canadian. Secondly you run the risk of cutting your hand. I would suggest purchasing a park tool DT-2 sprayed with some rubbing alcohol. Admittedly using the tool takes some skill but thats what practice is for. You solution has too many opportunities of running other things and causing more problems.
  • 2 0
 Please can we have video tech tuesdays back its so much easier to hear and see someone doing it at the same time and also i miss the cock ups at the end Razz
  • 1 0
 I have a red marker. Will that be a suitable substitute for the black one suggested? Only joking, top tip, thanks. I've always used an adjustable but will give the man hands technique a whirl next time. Cheers.
  • 2 0
 I simply use the tool that parktools designed for this.. But then again im running floating know so havent used it on own disks...
  • 3 0
 yah you go ahead and use your fingers to bend the rotor, im going to use my parktools rotor straightener
  • 1 0
 I like seeing the back of a new carbon Trek Session....does this mean a full review soon??? Also great article, I hate the sound of breaks rubbing. Goes to show that if needed you could true a rotor on the trails.
  • 1 0
 Try to fix the Shimano Xt Discs or Hopes like that ;p i got my XT bent a bit and that was a hell of a fight to repair it... but i did it after 6 hrs of fight it was like a new one ^^
  • 2 0
 hope disc a very easy to bent back in to shape if you got floating disc
  • 1 0
 Mine wont give up, it will stay bent the other way no matter how hard i pull...
  • 1 0
 there's your problem your pushing to hard got did it gradauly otherwise it just bend other way like you said if it carrys on just take it to your lbs
  • 1 0
 No it doesnt bend the way i pull. I have done it gradually, but it just always gets back to its bent form, it doesnt get unbent or bent back the other way
  • 1 0
 do it better, youre obviously doing it wrong or it would be working wouldnt it?
  • 2 0
 How do you wanna pull wrong ? I pull the opposite way of the one in which its bent, when i pull itbends the way i want, but when i let go it just gets back to its bent shape
  • 1 0
 I gave up on my xt disc... I put it up against the wall with my other written off discs... Got a hard bump on the disc when bike fell over and the aluminium part got bent (black colored part of the disc), tried fixing it for 4 hours, gave up. Guys if the middle part is bent its game over... (i could be wrong, if there is a special tool for this type of disc)
  • 3 0
 How the hell did they get their hands on a Session 9.9 already!? I work at a Trek dealer and we can't even get it yet. lol
  • 1 0
 how did they manage to already bend a rotor?!
  • 5 0
 Well Avid rotors are usually never straight in the first place lol
  • 1 0
 hahaha good point! thats actually why im looking at this, in regards to my bent G2 Clean Sweep 160mm
  • 3 1
 how do you think bud. probably because theyre the media trek doesnt individually give a shit about every dealer theyve got they care about media
  • 1 0
 I just did this lol. On a pair of hayes rotros that are like 3 years old. I d still ratger buy new ones though but thats just me. My rotoars were soundidng like wahles moaning lol.
  • 2 2
 im sorry but surly once the rotor builds heat up again it will return back to the state it was ie back to the memory that it had from being bent so this is just a quick fix not a proper one ?
  • 2 0
 No, they are not made from the material which you are implying - that's pretty hi tech stuff. This metal will not retain any such properties. Whether bent or straight, heat applied will not return it to it's prior position. Also, Rubbing Alcohol (isopropyl) is a fantastic brake pad/rotor cleaner. It's probably what 's in the spay can.
  • 2 1
 If it had memory like that, it would never bend in the first place.
  • 1 0
 but if it was bent when hot that would make it bent and then to return to the shap eafter
  • 1 0
 I guess if you're on a really long DH run and you bail.... it would have to get very hot to permanently bend.
  • 2 0
 When I have a bent rotor, I go to PricePoint.com and order a new one for $12
  • 1 2
 Good to know that I was doing it the wrong way... I lost my use-brute-force-on-expensive-stuff virginity while straightening a rotor on a local "DH" race. I was doing it by pushing away the brand new rotor using my foot in SPD shoe, having spokes of my deemax wheel as support...
  • 1 1
 When my rotors need more than a quick alignment I remove them completely & put them between 2 pieces of smooth oak & press them in a vice. Its quick & easy and they come out true.
  • 1 0
 that doesnt work, not that ive tried. i just know it doesnt. the fact that you think it works means you dont know whats going on. if somethings bent, you have to bend it back past straight to counter act the bend. clamping it between anything straight will only bring it straight for as long as you hold it, then it will just flex back to the original amount of bend think about it
  • 1 0
 this is how I've always straightened my rotors...works very well. and saves money on buying new rotors..and buy other bike parts with the saved money
  • 1 0
 i would encourage folks to check the wheel for true before trying to bend the rotor. the wheel can have an effect...
  • 5 1
 If your wheel is untrue, it has no effect whatsoever on the rotor.
  • 5 0
 I've seen this mistake before... I think he's talking about a QR wheel that's dislodged slightly. The first thing you notice is the brakes are rubbing, but actually the axle is crooked. Remember, - always start with the basics and work your way to the more complicated.
  • 1 0
 Oh ok i see what you guys mean now, check that the hub axle is well placed in the frame... That of course will have an effect. The thing is that the way psychobiker1 said it, it seemed like he was talking about an untrue wheel rim... Which has no link at all with rotor problems.
  • 4 1
 Agree - psychobiker1 either is wrong in his statement or just bad at communicating.
  • 1 0
 I spin the wheel backwards so there is no noise from the hub, unless you run a crankstopper
  • 1 0
 because its fair and stuff that you have a carbon session to just mess around with, we should all get a turn Smile
  • 1 0
 Very helpful tech tuesday as its a job that anyone can do and with the right know how can be done right. Thanks
  • 1 0
 Don't forget that brake cleaners make your stoppers useless for the first few corners.
  • 1 0
 if you use iso alcohol you can just light it on fire. looks cool tons of fun and there is nothing on the rotor
  • 1 0
 Wish you could favorite articles (like we do for photos/videos) so some day I could use this as a guide.
  • 2 0
 Good idea Mike. Maybe tweet it in the meantime? I do that for stuff I want to "bookmark" and share later... BTW - you could also bookmark it in your browser, but I know, that's sooo 1999. Smile
  • 4 3
 Please make a video out of it!!!
  • 11 2
 I'm not sure how he could get any clearer with a video? He's been pretty precise...
  • 4 0
 Yeah but tech tuesday videos are so enjoyable and hypnotising !
  • 1 0
 thank you, this came just in time the squeaking was driving me crazy!
  • 2 1
 I just use shimano rotors, avid rotors suck
  • 2 0
 theyre all the same bud. they all come from the factory slightly off, or totally fine, its pretty random. its not like anybodys got some amazing frigging rotor producing technique that makes one brands rotor more awesome than anyone else. and you should use the rotor that lines up for your pads braking track
  • 1 0
 Thanks Mike! This is the best way I've ever tried straightening rotors!
  • 1 1
 I am bored. I think I have made 3 comments on this page. and who knows how many likes and dislikes
  • 1 0
 what happened to the tech tuesday vids? aint seen a new one for ages now
  • 1 0
 I do this!!!
  • 1 0
 Where is the videos
  • 1 2
 Is this Aaron Gwin's WC Session 9.9? I would think he would just get new rotors all the time
  • 1 1
 you lick it off!!!
  • 1 2
 How would you recomend getting feces out of a rotor?
  • 1 0
 You are such a moron shishka. Stay gangster ya poser f*g.
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