Disco Newbie

[Colin]

Hi All,
So, for my new project, I've got an Oz Frame,  a 5th Element air shock and a Maverick fork up front and I want discs...............

So I need a disk adapter for the rear.........
RDS Hammerhead obviously.......... or are these easy enough to knock up yourself? Anyone got any drawings they could send me?

I've never had any dealings with discs before, so the first question is what make and size discs do I get?

The Whyte 2006 website lists Hope Mini MONO M4's 180/200 as the standard fitting for the Maverick fork(I guess the 200 goes on the front...?) or for 2007 the Avid Juicy Carbon, 203mm Front Rotor, 185mm Rear Rotor.

What do you think of these?

what size (Min/Max) disk will fit on the back of an Oz?

What size disk is the Hammerhead designed to fit? - Callum?

what exactly dictates what size disk you can fit onto a fork? I guess it's obviously how far the caliper ends up from the axle, but how can you tell the size of disk that the fork will take without any adaptors?

Confused? I am !!! <GRIN>

Col.

[willem]

Col,

Unless you plan on some pretty radical trailbiking, 6" rotors are just fine. And when you have a breakdown you can swap out front/back or with another bike.

Going to a 7" up front looks cool and usually uses the same caliper (unless you have post mounts), but it requires a different adapter to mount to the IS holes.

I now ride bikes with Shimano mechs, Avid mechs, and my new bike has Juicy's. The Juicy's are great but are essentially a "black box" to me. If they need bleeding, it's off to the LBS. The bleed kit has two syringes that get used simultaneously. Yikes!
So... my inclination is to lean toward mechanical calipers. And, if it's going to be mechanical, it's got to be Avid BB7's.

I've heard some folks say the Hayes mechs are good, but not always. NOBODY doesn't like Avid BB7's. They just plain work.

If you can get Aluminum plate, a bandsaw, and a drill, you really should make your own adapter from a Simon or OP pattern. I think Matno has one too...

Cheers,
Will

[jimbo]

what exactly dicates what size disk you can fit onto a fork? I guess it's obviously how far the caliper ends up from the axle, but how can you tell the size of disk that the fork will take without any adaptors?

Confused? I am !!! <GRIN>

Col.

I'm not familiar with the Maverick except that I know that they use a propriety hub.

General rules:

The fork manufacturer will tell your what the max size rotor their fork is rated for.

Most brake calipers have adapters to fit the various rotor sizes but you need to know what kind of mounting standard the fork uses.

Step 1.  Determine max rotor size the fork is rated for and don't go over that size.

Step 2. Determine the size of rotor you want.

Step 3.  Determine the type of disc mounting stardard the fork uses.

Step 4.  Buy the adapter from the brake manufacturer for the rotor size and fork mounting standard.

[Sprucey]

Hi Colin,

Sprucey here. Long time member and lurker on this site and based down in Gosport on the South Coast. I own an Oz and also own and internet based mail order bike company so I hope my advice will be worth while and unbiased.

First and without a doubt, discs are the only way to go. No arguament. I could never imagine going back to V brakes and will never ever own a moutain bike without disc brakes again.

Mechanical discs.
the budget option - you can still use your existing V brake levers and you will gain most of the advantages of discs. However, they are not as powerful as the cables compress and cable still get gritty and dirty and filled with condensation in the winter so you will still need new cables and outers at least twice a year if riding regularly in typical UK winter condions. These days there are great hydro discs out there at price points not much higher than mechanical operated disc brakes. eg Shimano Deore fully bled kits.

Hydro disc.
Defintely the way to go - largely fit and forget. First, don't worry about bleeding them. Most come fully bled and you should not have to touch them from year to year if set up properly. Bleeding is actually easy and the twin syringe method as employed by Avid and Formula (who designed the AVID brakes) is relatively clean and simple. (We even use it on other brakes such as Hopes).

I fitted a Hammerhead to the OZ and it works - does what it says on the tiin and you even get the correct sized drill - what more do you want. Plus, Callum is a gentleman, knows what he's talking about and a good guy to deal with.

Sizing depends on several factors:-
Your weight. Your typical ridng style and terrain. Your fork model (and it's warranty conditions!)

For UK Conditions and general XC ridng - if you are light (12 stone or less) then go for 160 each end. If you are heavier or ride more aggressively, go to the Alps or regularly ride the Welsh/Scottish trail centres then go 180/160 F/R.

I am 17 stone and ride 180/160 on my XC bike and 203/180 on my all mountain Scott Ransom which I take to the French alps many times a year. My Oz has 180/180 F/R (I prefer a more powerful rear as I can feather the power on more subtly - its known as modulation).

Lastly, some forks impose a disc rotor size limit in their warranty conditons - check what maverick say about max rotor size?

As for makes to go for, that is a very personal thing. I use Hope Mono M4s on two bikes and old style Minis on the other.  i am about to get a set of the new Greg Minaar ltd edition Formual One brakes to try.

Most of my staff ride the Formula Oro - a very light & powerful brake and well regarded with good spares support etc.

The Avid juicy range are very similar to the Formula Oros.

The Magura brakes come with a 5 yr leak proof guarantee and are appearing on more and more bikes as original equipment (the Marta SL is supplied on lots of the new Specialised Stumpy FS bikes).

Shimano make great performing, reliable brakes and good prices (as mentioned) the Deore is hard to beat on price) but spares are not readily available - if you do have a prblem its replace the whole caliper as seals and caliper pistons are not available as spares. Sounds bad but complete calipers re not expensive and it doesn't happen often - they are very reliable.

So, I hope that helps?

Any problems drop me a mail.

Sprucey
Mark Spruce
www.ukbikestore.co.uk

[Colin]

Thanks,

Sprucey, cheers mate, so a 180 will go on the back end OK?
I'll probably go with 200 at the front and 180 on the back then?
I weigh 200lb (14.25St) kitted out for riding, so medium stopping power required I think? I would class myself as an XC rider but the Oz project is to create a 6" travel bike fore and aft so that it might inspire me to try some bigger hits and steeper downhills. But nothing too mental, I'm getting too old and sensible!

I like the look of the Avids but also was attracted to Magura Julie's but are these good enough? But Marta/Louise's seem a bit overkill?

I love my Magura HS11's on the XP-X they have never let me down or needed any maintenance in 10 years!

The RDS Hammerhead looks the biz, but I've got taps and drills so supplying these with the kit is a bit redundant for me! Come on Callum do me a deal, or can I swap you a 856 Pivot kit for one? <GRIN>

I might go for Shimano (XT probably) as I need to replace the shifters and levers but can't seem to see a set that includes everything I need.....(levers, rotors and calipers.)

hmmmmm...........more comments please!

Col.

[jeffhop]

have a word with simon about the maverick forks, he had them on his whyte, ill second the avid mech brakes i rate them higher than my hope xc4 with a +20mm kit each end. ive got 170mm - 150mm hope xc4 on my oz, 180mm - 160mm avid bb5 on my recoil and 160mm hayes sole f&r on my hardtail. if you wanted i could trace round the rear disc mount that simon made on my oz and email you that. so you could probably make your own.

[Colin]

OK, thanks for the help so far fella's! It's now when the problems really start!
A pair of Avid Juicy Carbon Disc Brakes is on it's way to me!


Just a mere 203mm Front & Back, I expect that'll tear the poor old Oz apart won't it? (I may reduce the rear to a 180, what do you think?)

Sprucey,
will the A2Z - RETRO FIT BIKE MOUNT
Fit on an Oz? (I guess not or you would have used one?)
http://www.ukbikestore.co.uk/acatalog/info%5fa2z%5fdm%5funi%2ehtm


The fun continues...........

Col.

[Simon]

200mm is all you will ever need on the Mavericks in the UK. I had M4'S with floating rotors,more power than I ever needed, genuine one finger braking most of the time.
You will need a hammerhead adaptor or make a copy
its a proven design that no one appears to have any
issues with.
 

[Old Proflexer]

ahhhh - nice to see a man on a mission -

with disc's on a k2 carbon - who needs viagra?

OP  

[willem]

Hydro vs. Mechs... a fascinating debate that Colin is going to add some additional flavor to.

Juicy Carbons are some awfully sweet brakes, and certainly appropriate for a carbon bike. (No kidding who needs Viagra with that set up. To steal a line from another current thread, "My beast has a four inch Chubby." ?)

I've now had my Juicy's for 2 months and my front brakes have are dragging miserably. I was going to just ride through the dragging and hope the pads would eventually wear down. However, I can't take it anymore. I've got to take them to the shop for a bleed job.

If they were mechs, I could use my opposable thumbs and fix the problem in roughly 3 seconds.

With great advances in technology come great repair bills. !@#$#$%^

Will

[shovelon]

. (No kidding who needs Viagra  "My beast has a four inch Chubby." )

I've got to take them to the shop for a bleed job.

I could use my opposable thumbs and fix the problem in roughly 3 seconds.



Will

Dude, if I read between the lines?:-)

Will

[willem]

Dude! I didn't write that!
I think our friends across the pond speak different English than we do... Who named the bleedin' fork Chubby in the first place? Especially with only "4 inches of stroke"!!!

Good engineering, bad marketing.

[Old Proflexer]

Willem

what kind of dragging are you getting?  

If it's consistent, might just need to shim the caliper in or out at the mount.  if it's a spin cycle drag, i've had to shim rotors on a trueing stand as the facing on the hubs were not 90 degree flush (bontrager hubs).  used tin foil to do the shimming.

if the caliper is not releasing, maybe just pull it apart and clean it up

maybe this will help, maybe not - we should return this thread to Colin.

OP

[willem]

Thanks OP - I'll check it out

Colin - sorry for the diversion... Make sure you don't hang your Juicy fitted bike upside down on hooks. I understand this can create bubbles in the fluid.

Will

[wylyman]

Hey all cable brake users.  I have the bb7's and my rear brake cable was having some serious stiction Issues to the point where they were freezing up completely.  So I went to the local shop and the guy sold me some Boeshield T9 lube.  I disassemble the housing, cleaned and sanded the cable and applied a good amount of the lube and now they are better than new.  I am definately impressed with this stuff now my brakes almost as nice a the hydros.