[Reelchef67]

Hi I'm looking at upgrading my rear disc to a 203mm disc. I'm almost 200 and want some more bite. My fork isn't rated above 165mm hence doing the rear.
It's an 2006 idrive 5 4.0
I 've just put some new mavic crossride wheels on it if it matters.
Is there any problems with using a larger disc besides the adapter ? Ie frame stress etc??
Erik

 

[David C]

Hi I'm looking at upgrading my rear disc to a 203mm disc. I'm almost 200 and want some more bite. My fork isn't rated above 165mm hence doing the rear.
It's an 2006 idrive 5 4.0
I 've just put some new mavic crossride wheels on it if it matters.
Is there any problems with using a larger disc besides the adapter ? Ie frame stress etc??
Erik

For the rear, it think its part of frame clearance and also stress on the brake mount... But for the front, I think it's really related to the strength of the fork's mounts and to prevent structure stress... I have a FR frame and fork, so 203mm isn't a problem, but on my trail bike, 203mm at the rear is very limit for the frame clearance...

Since I think those frame are pretty tough, and you are 200, 203mm rotor should maybe put less stress on the frame since you will be softer on the brake... But for the fork, you should check with someone that know the fork better, since I don't know what fork you have.

David

 

[Reelchef67]

I've got rock shox j4.. I've check it out already it rated only up to a 165mm

 

[David C]

I've got rock shox j4.. I've check it out already it rated only up to a 165mm

Then I think you should try to get a new fork that accept the biggest brake unless 165mm of steel can still stop you good enough...

But ask your lbs, they should know better about it, unless they are no really into that kind of stuff...

What can I said ?

 

[joe_bloe]

Are you running sintered pads? If not, that upgrade might get you some of the improvement you're looking for.

Sent from my PC36100 using Tapatalk

 

[herb1234]

what brakes? and when were did they last have the fluid changed in them / when were they last bleed?

 

[Reelchef67]

I have tektro Auriga hydro brakes currently. I just bled them last week and filled with Pentosin hcf 7.1( big improvement over the stock fluid)

 

[herb1234]

i would try some better pads and clean/replace the rotor. they should be able to slow you down as you are not that heavy.

as a rule the bigger disc should be on the front as that is most of the stopping is done.

 

[David C]

Also don't forget that the tire can make a huge difference in stoping power and control in the descents...

You can also improve braking effect by moving you body weight to the rear of the bike.

David

 

[Reelchef67]

Thanks guys
I put on the 203 bled everything and cleaned sanded and alcohol cleaned everything.
I also tightened the QR on the front wheel really tight. Seems to have stopped my squeaking. My braking is much better now.
Also scored a fox float rp23 shock in 7.25x 1.75 off fleabay for a great price to replace the stock shock. Which btw was 7.5 by 2.0 even though everywhere online it says it came with a 7.25 by 1.75????

 

[tone22]

I have the same bike. I am 250#'s and am running 185mm rotors f/r on the stock magura juicy will cool stop pads and they work just fine for me. I also run the mavic's so be careful with over tightening the qr on the front due to bearing crush(from experiance). Takes about 3 weeks to get them from mavic. And you might as well contact your local gt dealer and order a couple extra flexbones because they do break, bought mine new in 06 and have gone thru 10 of them. Love the bike and it is definately worth the hassle

 

[Reelchef67]

Thanks for the info, unfortunately I have no local gt dealer. So far Gt has not been helpful at all.
Do you have the original front shock? The Judy J4 ? I'd love to try a 185 rotor , rocks hoc says it is only rated up to 165 rotor..
When you get get flex bones do they come with the barrel nuts that go inside the frame??
Regards
Erik

 

[tone22]

I have the fox vanilla 130mm with the heavy spring. The barrels are sold seperately but unless they are stripped i wouldnt worry about it 2 much. I regrease the pivot points every month and take the flexbone off each time to clean everything up and re loctite the bolts with never an issue