Disc Brake - ?

[nappyt]

Originally Posted by mechmann

heavily disagree. it all depends on what kind of riding you do. if you are beach cruising, no difference. if you are trying to keep up with me, you better have big rotors when you need em.

I noticed between my old 6" rotors and my new 7" rotors a big difference when it comes to stopping a clyde my size.

[cjwally]

Oh, I definately realize the benefits of running a larger rotor up front....That is why I am trying to change it out. For longer and techier decents, I am looking forward to less brake fade and more power... Currently, the 160 up front isn't hacking it for me...

[CalEpic]

Using a big lever as your first option is asking to snap the screw heads off. 1st try breaking the threadlocker by a nice love tap with the hammer while your twisting. 2nd option is the heat. (you'll need to be careful of the seals in the hub) You can get an impact driver if it's really stuck. Repeat the cycle. I doubt penetrating oil will help with threadlocker.

When putting it back together chase the threads with a tap and die to clean then up then use the blue loctite not the red.
Bring a growler over if you need help

I used to work on boat engines that lived in saltwater. stuck bolts on a bike are nothing.

[Chewyeti]

bigger rotors dont make you stop faster.

They do a few things-
Better Heat dissipation
Better Modulation

Heat dissipation
A larger rotor has more surface area. More surface area exposed to the moving air around it will help keep your brake rotor cooler. Cooler brakes lead to less brake fade (from too much heat). Cooler brakes stop better and dont fade

Better modulation.
using the formula for tangential velocity (the speed at the edge of the rotor), V = rw
where v = tan velociity, r = radius of rotor, w = angular speed.

so for the same wheel rotation (same w) the tangential velocuty goesup by a factor of r (or goes up with the increase in radius)

so a taller rotor will move through the brake pads alot faster.
you will wear out pads faster due to this increased speed, but you have a larger braking moment, which will enable you to modulate the brakes better,

AA

[SAR_boats]

Uh, I just think bigger rotors look cool.

Seriously tho. does the tangental arc equation take into account (what seems like) the larger leverage that a larger rotor has in relation to a wheel than a smaller rotor?

If you think of the contact area of the tire with the dirt as the load and the axle as the fulcrum and the area where the pad contacts the rotor as the force then it would stand to reason that a larger rotor would have a larger leverage ratio than a smaller rotor.

I am not sure about this so any of you brainiacs feel free to chime in.



Oh and as to the original topic:

Using a torque wrench as a breaker bar will blow the calibration.

Use heat and and a SMALL impact wrench to get the bolts off (ideally an electric one b/c they are easily modulated and put out less torque than air powered)

Basically- Listen to CalEpic

[bjammin]

Originally Posted by mechmann

heavily disagree. it all depends on what kind of riding you do. if you are beach cruising, no difference. if you are trying to keep up with me, you better have big rotors when you need em.

...oh brother.

[bighit8]

Hey Craig,
You might try an impact driver, if the bolts are not to rounded you can hammer in the right size Allen head and just heat it up a bit. I think cheweti covered most of it. Worse comes to worse I have some screw extractors!

[bighit8]

By the way the IPA was good, thanks. If I had known I would have tried to help you out.

[bjammin]

Originally Posted by mechmann

bring that out to Fontucky beesh!

I wish I could J. I just need Santa to re-direct a Demo 7 to my house.

[Rockinthecasbah]

Increased size adds better modulation in my opinion but you get alot more noise on regualr moutend 203's, centerlocked 185's you should be ok , if your a weight wennie then bigger is not better. Me and chewy kept smokin are 6" rotors so we went to 203's which was too big chewy is down to 185's and love them after he got his caliper issiues out of the way. I'm back to 8's on my big bike and 6's on my Dj/4x bike its all about what feels right.

[allison]

Originally Posted by bjammin

I wish I could J. I just need Santa to re-direct a Demo 7 to my house.

Wait til summer/fall 08. Mebbe they'll be cheaper!

[bjammin]

Originally Posted by mechmann

oh so that means you can't race super D and XC??? puuuleeeez!

OK, your on!
I down for SD and XC!

Originally Posted by allison

Wait til summer/fall 08. Mebbe they'll be cheaper!

Yeah, by then I shouldn't be so house poor anymore.

[dirttorpeedo]

Originally Posted by Chewyeti

in auto clubs we say "heat, beat, repeat"

you may need to heat it up to break down the thread locker (only a little heat!), try some penetrating lube and let it sit for a bit, and lastly a little force. with a torx bit installed on your socket extension, give a few light taps. This force may be enough to break down the thread locker bond.

DONT use heat on your wheels you stand the chance of ruining the bearing if its a sealed set up.or an overhaul if not.if you can get a TORX bit into a socket you can push down on the bolt while turning it. so it hopefully wont strip it inside or slip.

[BrewMaster]

Dumb question here, when replacing a rotor, are there other options besides TORX head screws? I hate those things and I would rather use hex screws, but not sure if that is an option. Thoughts?

[2wheel_lee]

Originally Posted by BrewMaster

Dumb question here, when replacing a rotor, are there other options besides TORX head screws? I hate those things and I would rather use hex screws, but not sure if that is an option. Thoughts?

TORX bolts are far superior to conventional hex bolts because they will allow far more torque before stripping the heads than hex bolts.

[jschwart73]

Easy way to heat a screw to help coax it out without heating up the entire component is to hold a hot soldering iron to the screw/bolt for 30 seconds or so.

[cjwally]

I had an idea, so I headed over to ACE and picked up a torx bit for my socket wrench. Long story short, the torx screws came right out. Problem solved!

Total cost - $2.99

[bighit8]

Originally Posted by BrewMaster

Dumb question here, when replacing a rotor, are there other options besides TORX head screws? I hate those things and I would rather use hex screws, but not sure if that is an option. Thoughts?

Yes you can go to Mc Fadden dales and get the right thread and pitch in allen or what ever you choose.They have aluminunumnum, and steel,ect......

Originally Posted by cjwally

I had an idea, so I headed over to ACE and picked up a torx bit for my socket wrench. Long story short, the torx screws came right out. Problem solved!

Total cost - $2.99

Were you using the screwdriver type before? A good 3/8 or 1/4 socket set is nice to have. Over my years as a mechanic I estimate over 7000$ in assorted sockets alone.

[92se-r]

Instead of stripping the torx by putting a long breaker bar on it, use vice grips and grab the side of teh head and loosen it that way.