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Discussion Starter · #1 ·
i'll be ordering some Avid BB7s soon and because i weigh 225#s i was considering an 8" front disc. However will the added stopping torque of the 8" disc reduce modulation? id prefer modulation over raw stopping power. any advice?
 

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Good Q

My guess would be that the caliper design has more to do with modulation than rotor size. Hopefully someone in the know will come along and give a more definitive answer.

BTW-a word of warning about 8 inch rotors-you may void the warranty on your fork unless it is specifically made for 8" rotors. I'm using 7" rotors on a fork designed for 6", and I haven't had any issues, in fact a lot of people run larger rotors without a problem. Just wanted to toss that out.

Bob
 

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HuffyMan said:
i'll be ordering some Avid BB7s soon and because i weigh 225#s i was considering an 8" front disc. However will the added stopping torque of the 8" disc reduce modulation? id prefer modulation over raw stopping power. any advice?
Modulation shmodulation.. 225? Don't even consider - go for at least 8". That's quite a mass to stop. Go easy on those carbs unless you are r e a l l y tall, or just ride more.
 

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Go

200mm up front (203mm for Avid) and a 185 in back. I have the same setup and I'm 6'4" @240.

Rob
 

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What fork?

What fork are you riding?

At your height and weight, an 8" rotor is a great thing to have. I should know. (6'4" 230 here) Do it if your fork will allow it.
 

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Discussion Starter · #10 ·
hrm looks like its pretty cut adn dry, eh? theyll be on a RS Reba SL. i read through the manual and i can't find anything where it limits what size disc to use. It just says use disc brakes according to their manufacturer's spec.
 

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32mm stanchions

HuffyMan said:
hrm looks like its pretty cut adn dry, eh? theyll be on a RS Reba SL. i read through the manual and i can't find anything where it limits what size disc to use. It just says use disc brakes according to their manufacturer's spec.
The Reba has 32 mm stanchions and the web site considers it to be an All-Mountain fork. Avid's web site says that the 185 mm (7 inch) disc brake is for use with "Extreme" riding and the 203 mm (8 inch) is for use with "Downhill".

Again, I'd say you're pretty safe in using the 7 inches, and as others mentioned, you could probably get a way with the 8 inches, but again, voiding the warranty on either product would be my concern if you went with larger than 7 inches.

Copello mentioned going for "at least 8 inches". Should you find the disc brakes with the elusive 9 inch or 10 inch rotors, I say buy 'em. You'll probably be the only guy on the boards that owns a set. :rolleyes:

I hope this helps.

Bob
 

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sorry sorry,

Call_me_Clyde said:
The Reba has 32 mm stanchions and the web site considers it to be an All-Mountain fork. Avid's web site says that the 185 mm (7 inch) disc brake is for use with "Extreme" riding and the 203 mm (8 inch) is for use with "Downhill".

Again, I'd say you're pretty safe in using the 7 inches, and as others mentioned, you could probably get a way with the 8 inches, but again, voiding the warranty on either product would be my concern if you went with larger than 7 inches.

Copello mentioned going for "at least 8 inches". Should you find the disc brakes with the elusive 9 inch or 10 inch rotors, I say buy 'em. You'll probably be the only guy on the boards that owns a set. :rolleyes:

I hope this helps.

Bob
Darn, meant 7", 7" not 8". The inch/metric thing got me there.
Sorry for misleading there for a while. The 8 in 185 confused me. 8" is indeed more for DH and will put a lot of load on a Reba. A 185, 7", is still a major upgrade from a 6" and should suit you fine.

Sorry
 

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No biggie

copello said:
Darn, meant 7", 7" not 8". The inch/metric thing got me there.
Sorry for misleading there for a while. The 8 in 185 confused me. 8" is indeed more for DH and will put a lot of load on a Reba. A 185, 7", is still a major upgrade from a 6" and should suit you fine.

Sorry
Couldn't resist busting your shoes a bit. No harm, no foul.

Bob
 

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copello said:
Humbly taken with my tail between the legs..
If I only had a dime for every time I had to walk away humbled, I'd be a millionaire. Read the tag line at the end of my post and that should put it all into perspective.

Bob
 

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thread hijacker asks- What bad can happen by running too big a rotor on a fork? I have a marz MX pro ETA and want to run 7" disc. Manual says 6 inch limit.


Thansk and sorry to poster....
 

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HuffyMan said:
i'll be ordering some Avid BB7s soon and because i weigh 225#s i was considering an 8" front disc. However will the added stopping torque of the 8" disc reduce modulation? id prefer modulation over raw stopping power. any advice?
On a XC / light trail bike, the 185mm/160mm combo should work out just fine. Especially if you're looking for more modulation. I think most QR forks advise against using 200+mm rotors.
 

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el_chupo_ said:
thread hijacker asks- What bad can happen by running too big a rotor on a fork? I have a marz MX pro ETA and want to run 7" disc. Manual says 6 inch limit.

Thansk and sorry to poster....
My guess would bee the extra torque could crack the lowers, or caliper mount on the fork, if left unchecked the crack could lead to a really nice face plant when it eventually breaks all the way.
 
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