[xiaolin808]

This may be a question a newbie would ask, but as I am only about 2 months back into riding, and these are my first bikes with disc brakes, I figured I'd ask.

I've been debating whether or not to upgrade my brake rotors to a larger size. Stock size on the bike is the 160mm f/r rotors. Should I upgrade the front only, or both? Is the leverage difference between the different rotor sizes noticeable? Or is is just more bling I can add showing off with a huge 203mm rotor?

 

[Kiwiplague]

Depends on what sort of riding you do. XC - stick with the 160's, Trail - 180 up front and 160 at rear, AM & DH - 203 up front and 180/203 at the back.
A 203mm rotor will give much more leverage than a 160mm rotor, but for some applications it can be a bit overkill, but you can bling your bike out if you want.

 

[dunlop2540]

Just stick with 160. 203 is just overkill

 

[LyNx]

What bike and fork do you have? Forks do normally have limitations on the max size rotor you can run, dependent on the intended usage of the fork. Check the manufacturers site to see what's the biggest rotor they say they'll allow and go from there. For me I like to run 180 F/160 R, I ride I guess Trail if you had to put a description on it and I weigh about 185lbs geared to ride, ride a 130/140mm travel bike.

 

[Squash]

There are quite few factors that go into rotor sizing. Things like your weight, the bike, how you ride, terrain, etc. Many people find that a 160/160 combination works just fine. Larger/heavier riders, will often go to a 180/160 set up as will folks that ride terrain where long descents are common, or if you simply tend to experience heat related brake fade often. A 203/180 or 203/203 set up usually comes into play for very aggressive riders, All Mountain, Free Ride, Down Hill, or really heavy riders. Also bigger heavier wheels, think 650b or 29", that carry more momentum usually benefit from larger rotors as well. But it still depends on the rider quite a bit too.

So bumping up rotor size shouldn't be just because you can. Doing so simply adds weight. It should be based on your performance needs. And as LyNx noted, most forks do have limitations on rotor size. The limitations are usually based on manufacturer testing and fork construction. Going over manufacturer limitations can lead to excessive fork flex, and in the case of standard quick release forks may cause the QR to come loose while riding. Not common on most modern forks, but it can happen if the fork flexes enough during braking. Also frames often have limitations, but not for the same reason forks do. Usually it's a size thing. Many hardtails simply don't have the room between the stays for a 180 or 203mm rotor. The chain stays taper in toward the bottom bracket housing on a bike. Depending on the diameter of the tube and/or how steep the taper is, a larger rotor may make contact with the chain stay. Just depends on the frame design.

Personally, I'm a Clyde, 230lbs, and my prefered set up for XC/Trail is a 180 fr/160 rr. I heat up and fade a 160 front on descents and technical terrain way to easily. Plus I need the extra ommf from the 180 front for hauling down from speed quickly enough.

So take everything into consideration before you upgrade. If your 160s work fine for you, stick with em. If you over heat the brakes a fade em out, or ride aggressively enough that you need the extra power then upgrade the front. You can bump up the rear if you really think you need to, but it's usually not necessary. I find that running a 180/180 or 203/203 makes it too easy to lock up the rear wheel. A skidding wheel has lost traction (obviously) and does nothing to help you slow down anyway.

So, your call. If you need to, go for it. If not then leave it be. :thumbsup:

Good Dirt

 

[lightjunction]

Some good advice on here so far. Depends on your riding style and fork/frame limitations. There is a pretty noticeable difference in braking performance for the different sized rotors. The larger rotors have more stopping power, but (in general) less modulation. For all-around XC/AM riding, I prefer 185mm rotors front and rear. If you're only familiar with those 160mm rotors and are looking for more power, I'd recommend at least trying some of the other rotor sizes out.

 

[lew242]

I'm really not sure on this one being so simple as 160mm is for XC, 180 trail/AM, and 200 being DH/FR.

I'm between 180-200lbs depending on time of year. Maybe it's my riding style but when I go do long very steep downhill stretches I find that I put way more power into the front rotor but mostly only before corners and some modulation between them, but actually the rear gets hotter, because it is engaged/partially engaged more of the time, so to my thinking I'd need at least the same rotors front and rear, rather than anything bigger upfront. I also try to modulate my brakes as much as possible to stop them getting too hot. I ride very steep natural rocky trails which I would describe as light freeride/AM and have never gotten brake fade other than using some Tektro disk pull brakes on the road, in an old truck on a hill and riding a Chinese motorcycle down a mountain road with its original brake pads.

Also, I used 180s before on an older bike admittedly only using Hayes Stroker Rydes, but I found them too on/off and preferred the modulation of running them with Avid 160mm rotors.

Also if you run floating rotors, icetec rotors, have the new Shimano finned pads or use high quality Sintered (or metallic) pads, surely that tech would help dissipate heat better. So these days surely it could be argued with more modern technology in braking systems that going bigger than 160mm is maybe more of a psychological factor, other than for extreme aggressive DH/FR?

Having said all that I still feel I want to change up to 180/180 front rear icetec rotors, partially for the performance, also for an experiment, and then for that bling factor.

 

[RaveOn]

I just went from 160/160 to 180/160 because I was looking for an even feel. For me, the 160/160 felt a tiny bit out of balance.

Its relatively cheap to swap. Rotor and caliper bracket (180mm)

This is less of an issue if you are sub 160lbs

 

[xiaolin808]

Thanks for all the great advice.

What bike and fork do you have? Forks do normally have limitations on the max size rotor you can run, dependent on the intended usage of the fork. Check the manufacturers site to see what's the biggest rotor they say they'll allow and go from there. For me I like to run 180 F/160 R, I ride I guess Trail if you had to put a description on it and I weigh about 185lbs geared to ride, ride a 130/140mm travel bike.

I have a Jamis Dakar Sport that is pretty much stock. 750mm bars, Intense System4 2.25 tires are the major upgrades. The fork is dead and I'm looking to replace it with a Fox Talas 36(travel is about 150-160), cause I'm getting a good deal on one. The reason I was wondering about the upgrade is because i have to change the hub from a QR to a through axle hub.

There are quite few factors that go into rotor sizing. Things like your weight, the bike, how you ride, terrain, etc. Many people find that a 160/160 combination works just fine. Larger/heavier riders, will often go to a 180/160 set up as will folks that ride terrain where long descents are common, or if you simply tend to experience heat related brake fade often. A 203/180 or 203/203 set up usually comes into play for very aggressive riders, All Mountain, Free Ride, Down Hill, or really heavy riders. Also bigger heavier wheels, think 650b or 29", that carry more momentum usually benefit from larger rotors as well. But it still depends on the rider quite a bit too.

So, your call. If you need to, go for it. If not then leave it be. :thumbsup:

Good Dirt

The type of riding I do. I guess you would consider it downhill. We climb up the mountain and ride down. It's nowhere as serious as the videos i've been watching, but they're good inspiration. My weight is about 180-185.

Having said all that I still feel I want to change up to 180/180 front rear icetec rotors, partially for the performance, also for an experiment, and then for that bling factor.

Maybe that's the direction i was thinking when i started this thread. Except i only wanted to change the front rotor.

I just went from 160/160 to 180/160 because I was looking for an even feel. For me, the 160/160 felt a tiny bit out of balance.

Its relatively cheap to swap. Rotor and caliper bracket (180mm)

I don't think it's about balance for me, just wondering if the upgrade was worth doing since i have to change the hub. But i may find balance when the change is made. :cornut:

 

[Colorado S14]

I am a bigger guy and love the 180/160 setup on my bike. The front brake provides 70%+ of the total braking force on a bike and I think a staggered setup provides not only better balance but better thermal stability and less fading. I have a 5" trail bike and the 180/160 setup has been perfect for trail riding and for the few times a year I head up to Winter Park and just go downhill all day.

 

[jeffscott]

160/160 combination works just fine. Larger/heavier riders, will often go to a 180/160 set up as will folks that ride terrain where long descents are common, or if you simply tend to experience heat related brake fade often. A 203/180 or 203/203 set up usually comes into play for very aggressive riders

I use a 203 fornt and a 160 rear....I was cooking both (160/160) pretty regularly on downhills and got fed up with the brake fade....

So I figured just go to 203 on the front and save a nickle as compared to 180/180, or 203/203....and I didn't want to lose the modulation on the rear for real steep and slow dives...

Just another combo to consider. 230/160

 

[LyNx]

Just remember that your bike was designed around a certain usage and fork travel, going beyond that can be dangerous, so be careful. Just saying as from what I found your old/original fork was a 100-130mm travel and you're saying you're going for a 150-160mm travel fork, also your intended usage for this frame isn't I think what the manufacturer had in mind - seems maybe you want a burlier frame if you want a Talas 36 for your riding. As to your original question with your weight I think 180/160 would work fine, but AFAIK the Fox 36 can easily do a 203mm rotor.

 

[xiaolin808]

Just remember that your bike was designed around a certain usage and fork travel, going beyond that can be dangerous, so be careful. Just saying as from what I found your old/original fork was a 100-130mm travel and you're saying you're going for a 150-160mm travel fork, also your intended usage for this frame isn't I think what the manufacturer had in mind - seems maybe you want a burlier frame if you want a Talas 36 for your riding. As to your original question with your weight I think 180/160 would work fine, but AFAIK the Fox 36 can easily do a 203mm rotor.

I realize the fork is kind of overkill, but i'm getting a pretty good deal, and i don't think i want to pass it up. I know i'm not going to use it more than the bike can handle. The extra travel should push my center of gravity back, so as not to pitch me over the bars. I really appreciate the insight, thanks.

I am a bigger guy and love the 180/160 setup on my bike. The front brake provides 70%+ of the total braking force on a bike and I think a staggered setup provides not only better balance but better thermal stability and less fading. I have a 5" trail bike and the 180/160 setup has been perfect for trail riding and for the few times a year I head up to Winter Park and just go downhill all day.

I think i'm gonna go with the 180/160 avid g2 combo, and i'm gonna change the rear rotor to one that's a little more slotted/cross drilled to help with the fade. I have a set of avid g2's on my hardrock, those don't fade on me.

 

[LyNx]

It's the stress it can put on the headtube, that's what I'm talking about. Don't see any sort of gusset reinforcement on the headtube/downtube junction and looking at more recent models of that bike they're coming with 100mm a fork, so something tells me doing a 150mm would not be good. I suggest you contact the manufacturers directly and ask a question - remember when guys where doing similar to the early Trance, using 120,130, 140mm forks on them and someone asked Giant and they chimed back in that it was OK to go to the 140mm fork, no warranty voided and everything would be fine.

I realize the fork is kind of overkill, but i'm getting a pretty good deal, and i don't think i want to pass it up. I know i'm not going to use it more than the bike can handle. The extra travel should push my center of gravity back, so as not to pitch me over the bars. I really appreciate the insight, thanks.

 

[DarkKnight369]

This may be a question a newbie would ask, but as I am only about 2 months back into riding, and these are my first bikes with disc brakes, I figured I'd ask.

I've been debating whether or not to upgrade my brake rotors to a larger size. Stock size on the bike is the 160mm f/r rotors. Should I upgrade the front only, or both? Is the leverage difference between the different rotor sizes noticeable? Or is is just more bling I can add showing off with a huge 203mm rotor?

Its a matter of physics...the further out from the center of the wheel, the easier it will be to stop. I am ~295lbs and ride a 29er. 160mm came with my bike and the stopping power is weak and I burn through pads like crazy. I am going to upgrade to 203mm. However, if I took that same size on 26" wheels, it would be easier to stop and I probably would only need to go up to 180mm.

 

[xiaolin808]

Thank you everyone who replied to this thread.

You guys gave some really good insight into the questions that i had. Glad i stumbled upon this site to have soo many good peoples that help guys like me who don't really know what they're doing.

 

[POAH]

my forks can take 203mm so I put 203mm on - upgraded the discs on my wifes bike to 203mm too cause it looks bling lol wither I actually notice any difference between the 160 and 203 is another matter but it does look nice

 

[vichila]

if i have hayes storker trail and i want to upgrade my rotors do i need a hayes rotor or any rotor will do?
do they have specs for the caliper that says which type of rotor it ca work with?

 

[xiaolin808]

if i have hayes storker trail and i want to upgrade my rotors do i need a hayes rotor or any rotor will do?
do they have specs for the caliper that says which type of rotor it ca work with?

Check out this link, might be helpful.

MTB hydraulic disc brakes head-to-head: Avid vs. Hayes | Mountain Bike Blog || SINGLETRACKS.COM

 

[TheeSuperUberV]

What bike and fork do you have? Forks do normally have limitations on the max size rotor you can run, dependent on the intended usage of the fork. Check the manufacturers site to see what's the biggest rotor they say they'll allow and go from there. For me I like to run 180 F/160 R, I ride I guess Trail if you had to put a description on it and I weigh about 185lbs geared to ride, ride a 130/140mm travel bike.

Thanks for fork limitation/max rotor size info