Mountain Biking - Replacing rotors 6" to 8", possible?

Got a friend who has a bike with 6" disk brakes and want's to change the rotor to 8". Is it possible to change the rotor while keeping the rest of the brake intact? Or does he need to get a whole new disk brake set for a bigger rotor? I'm assuming he needs to get a new 8" brake set but I dont own any disk brake bikes at the moment so i wouldn't have a clue!

Thanks for help.

Got a friend who has a bike with 6" disk brakes and want's to change the rotor to 8". Is it possible to change the rotor while keeping the rest of the brake intact? Or does he need to get a whole new disk brake set for a bigger rotor? I'm assuming he needs to get a new 8" brake set but I dont own any disk brake bikes at the moment so i wouldn't have a clue!

Thanks for help.
I think all he needs is an adapter, and then he's golden.

Normally all that is needed is the 8 inch disk and the adapter. Everything else will work fine. You may have to get some shims to align the caliper to the rotor since the adapter may not position the caliper perfectly and the adjustment range may need help. It really isn't a big deal, takes maybe 15-20 minutes to do the swap.

Normally all that is needed is the 8 inch disk and the adapter. Everything else will work fine. You may have to get some shims to align the caliper to the rotor since the adapter may not position the caliper perfectly and the adjustment range may need help. It really isn't a big deal, takes maybe 15-20 minutes to do the swap.

Shims? What? When you remove and reinstall a caliper, of course you are going to have to realign it to the disk however, I fail to see a need for shims if you know what you are doing and its a non-Shimano brake. For Hayes and Avid you just need a 8" mounting bracket and an 8" rotor. All their calipers up to a 10" rotor are the same.

Can anybody find a link for these adapters? Preferably for Avids?

http://pricepoint.com/detail/12752-115_AVDBR3-3-Parts-158-Brakes/Disc/Avid-Disc-Brake-Adapter.htm

http://www.discbrakeadapters.com/

I think all he needs is an adapter, and then he's golden.

A word of warning though. His fork may not be capable of handling the increased forces of the 8" rotor.

A word of warning though. His fork may not be capable of handling the increased forces of the 8" rotor.

Ditto, also the frame may not be designed for an 8" rotor either.

Thanks for replies. His fork is a Suntour Magnesium to my knowledge, would this be 8" compatible?

Sweet mother of God, no. Unless its some Suntour I have never seen before, no no no no no.

how about a dj3?

how about a dj3?

If it's the 20mm version it should be ok, if the QR version, then no.

Thanks for replies. His fork is a Suntour Magnesium to my knowledge, would this be 8" compatible?
Gotta back seely on this one.
No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! No! A thousand more times NO!

I think we get the point Raiyn... :lol:

I think we get the point Raiyn... :lol:
Really? That's good, because I was trying to show a bit of restraint.

Raiyn - you posted 'No' 326 times, and 'NO' 1 time. You show no signs of restraint ;).

I have another fork for the '6" to 8" changeover'... Marzocchi MZ-3? Possible?

:D

Raiyn - you posted 'No' 326 times, and 'NO' 1 time. You show no signs of restraint ;).

I have another fork for the '6" to 8" changeover'... Marzocchi MZ-3? Possible?

:D


Nein.

Raiyn - you posted 'No' 326 times, and 'NO' 1 time. You show no signs of restraint ;).
:D
I was planning on doing an entire page of them but held back. I kept them all at normal text size to boot

Nein.
Habe Zustimmung, dunke für Ihre Hilfe, ich nie gewusst, dass Sie Deutsch sprechen könnten?

Cool, well it looks like some of the 'cheaper' forks arn't compatable.

Let me guess: RST Gila - NO NO NO? :eek:

Let me guess: RST Gila - NO NO NO? :eek:
I'd say so.

I'd say so.
Damn! How come? Is it that the fork will have play in it? Will it snap? 'Cause I already have a front Juicy 5 with 8" rotors.

Damn! How come? Is it that the fork will have play in it? Will it snap? 'Cause I already have a front Juicy 5 with 8" rotors.
Yes you will crash and burn, crash and burn good :p .

Habe Zustimmung, dunke für Ihre Hilfe, ich nie gewusst, dass Sie Deutsch sprechen könnten?
hey, was ist hier mit dem deutsch los??
i had to recheck twice whether i was reading on one of my German mountain bike boards...

Damn! How come? Is it that the fork will have play in it? Will it snap? 'Cause I already have a front Juicy 5 with 8" rotors.
You're running a substantial risk. Granted you're a small guy so that will buy you time, but 8" in a RST is BEGGING for trouble

hey, was ist hier mit dem deutsch los??
i had to recheck twice whether i was reading on one of my German mountain bike boards...

Haha. I'm so dodgy (http://www.freetranslation.com) :p

That free translation is very good. Its amazing how it works so good.

Anyway, lucky blue made this thread. I had a friend today telling me about putting a 8" rotor on his front end, i straight out said "NO", it won't work. And for some reason he did not believe me and he's going to the other side of town to get a 8" disc for his bike and the guys at the bike shop will just say that it won't work. It will be funny :lol:

That free translation is very good. Its amazing how it works so good.

Anyway, lucky blue made this thread. I had a friend today telling me about putting a 8" rotor on his front end, i straight out said "NO", it won't work. And for some reason he did not believe me and he's going to the other side of town to get a 8" disc for his bike and the guys at the bike shop will just say that it won't work. It will be funny :lol:
It will go on. His fork won't hold up to it, but it will go on just fine

It will go on. His fork won't hold up to it, but it will go on just fine
Really? Well it is true that his fork won't hold up. Its like no-name brand.

Really? Well it is true that his fork won't hold up. Its like no-name brand.
Unfortunately yes. If it has tabs you can put an 8 on it with the right adapter. It's just not smart to do so on a fork that's clearly not rated for it

Unfortunately yes. If it has tabs you can put an 8 on it with the right adapter. It's just not smart to do so on a fork that's clearly not rated for it
This might scare you Raiyn, but i think his discs are no-name as well. :p

This might scare you Raiyn, but i think his discs are no-name as well. :p
<shakes head
Friends don't let friend's ride junk man.

On the bright side his turd brakes probably won't generate enough power to cause him any harm. It would most likely balance out to a decent set of six inchers which hopefully even a piece of crap fork can handle

Aint his bike a Mesa GSD?

Aint his bike a Mesa GSD?
Yep something like that, Schwinn....Quality = K-Mart

I'm presuming that the Aussie Mesa GSD isn't the same one we have here in the US?
http://www.schwinnbike.com/products/bikes_detail.php?id=417
Not that putting a 8" rotor on a Manipoo Six is smart either, but it's not exactly no name

From their site...


Hayes mechanical disc brakes brings name-brand disc brake performance to this exceptional bike.

:lol:, he must have the '04 ;)

I'm presuming that the Aussie Mesa GSD isn't the same one we have here in the US?
http://www.schwinnbike.com/products/bikes_detail.php?id=417
Not that putting a 8" rotor on a Manipoo Six is smart either, but it's not exactly no name
Im pretty sure he has the 04 model. This is what happened when he bought the bike....sorry to go off topic a bit but yeah. He got the bike cheap for $400AU, they usually sell around $900AU i think, but yeah his friend exchanged parts, and my friend thought that they were all the same stuff, so he ended up with the no-name forks and discs.

I think the 04 Schwinn Mesa GSD usually came with a SR-Suntour fork and Hayes MX-2 disc brakes.

:lol:, he must have the '04 ;)
If it's the same spec as the US '04 version it's an SR Suntour XCP-70. It's the perfect fork - If you're making a lamp that is

I think, but yeah his friend exchanged parts, and my friend thought that they were all the same stuff, so he ended up with the no-name forks and discs.
.Sounds like your friend rides the short bus to school
http://img364.imageshack.us/img364/1882/shortbus12nd.jpg

:roflmao:

Blue Neon mentioned the MZ-3 a page back.

Why is this fork a bad idea? Would you take a stock EXR over it?

No, i will not leave you alone with this question. But im sure it will continue to go unanswered :p

Edit: Crap, didnt check the date and just pulled up an old thread. Easy on the smackdown, i was severely beaten as a child :eek:

You're running a substantial risk. Granted you're a small guy so that will buy you time, but 8" in a RST is BEGGING for trouble
Well, seeing as this thread is revived all I want to say is I've gotten a 6" disc and I'm waiting for the adapter now. :)