Mechanical Disc Brakes

"John Appleby" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Hi,

I've just had a nasty blowout at high speed which has left my front rim in shreds. My front
V-brakes, M950 XTR, are shot (seem to have fallen apart inside). Oh, and my old Pace RC-30 forks
are succumbing to rust.

John - If you're binning the XTR V's could I trouble you for a spare part? Been looking for the
thingie that meshes with the wotsit for a good few years without success, no-one seems able to order
it and its a shame to see the brakes sat doing nothing for want of thingie. Its a round bit that
sits next to the brake stud and has 6 or so 'teeth'. No problem if you're keeping the brakes as
spares - just thought I'd ask.

Quoted message said:

So, I'm considering replacing them with a pair of RC-31s. Carbon doesn't rust...

I owned a pair of these for about 3 months, very nice looking (and nice to ride for the limited
riding I did on them) but the carbon made me nervous.

<Snip>

Quoted message said:

I'm wondering though whether or not this is likely to be substantially better than the V-brakes.

Probably not much difference in overall stopping power but the advantages are with the discs
reliability as well as increased mud and tyre clearance. I'd vote disc.

Quoted message said:

I'm not really minded to put a hydraulic disk brake on, because I'm running XTR M951 brake/shifter
combos which I'm

rather

Quoted message said:

partial to. As far as I know, you need the dedicated brake levers on a hydraulic shifter.

Yep. Fair enough.

Quoted message said:

As an aside, 160mm vs 185mm - is the 185mm necessary? Or just designed for people who are
constantly on the brakes for DH purposes. I mean, I like going down hills, but I also like going
up them...

I am perfectly happy running a 165mm rotor on both my bikes, but I am not the heaviest bloke in the
world and I don't drag the brake all the time. As for the Disc/Q.R. issue - I'm not going there...

Quoted message said:

Thanks in advamce, John

Steve

John Appleby said:

Hi,

The cost is going to be approximately the same (£30-50 more for the disk brake), the weight is
approximately the same (V-brake adapters for the RC-30 weigh about the same as the weight penalty
of the disk), so I think the only question is whether or not the mechanical disk is going to be
substantially better than the V-brake? Oh, and potentially whether the Avid brake will work with
the M951 lever?

As an aside, 160mm vs 185mm - is the 185mm necessary? Or just designed for people who are
constantly on the brakes for DH purposes. I mean, I like going down hills, but I also like going
up them...

Thanks in advamce,

John

Mr. Appleby, I don't think that anyone can tell you that the Avids are substantianlly better than
V's, that is probably a matter of opinion. I can tell you this, I recently made the switch from
V's to Avid mechanicals and for my application I like the Avids better. It was not an issues of
braking power for me, but loss of power and feel on long downhills. It is not uncommon here to
have a 3-5 mile downhill with constant braking. I felt the V pads became soft and hot and had
some loss of control. I do not get that feeling with the Avids (160 mm rotors). They may get
hot, but the feel of the brake is the same at mile one as it is at mile 5. Plus, I will move the
old V's to my fully rigid bike and replace the cantis (I like the cantis, but are more difficult
to set up), so it is no real loss. BTW, you can always replace the Avids on the front wheel and
see how you like that before you fully commit. Good luck.
--
Craig Brossman, Durango Colorado (remove ".nospam" to reply)

Quoted message said:

2) Buy RC-31s without the V-brake adapters, replace the wheel with a disk brake hub and put a
mechanical disk brake on. The Avid Ball Bearing one looks nice.

Avid Mech disks are by far the best mech disk (Not juts my opinion user and mag reviews seem to
think the same) , they have very good stopping power once bedded in. For me they perform far better
than the V's they replaced. Set up is easy due to the fact that they have a system for compensating
for badly faced mounts, fit and forget as long as you use a good set of cables. As for price I
bought both of mine from
chainreactioncycles.comviewproduct.aspOpen ↗ The don't come
in a box as they appear to be ex OEM, but since the real retail is supposed to be 40 quid more each,
who cares. always get nice next day delivery from Chainreaction too no bother.

Quoted message said:

As an aside, 160mm vs 185mm - is the 185mm necessary? Or just designed for people who are
constantly on the brakes for DH purposes. I mean, I like going down hills, but I also like going
up them...

I stuck with the 160 as I vary between 11.5 and 12 stone depending on how much cake and Chocolate I
can eat ;-) No bother stopping at all.

Phil

John Appleby said:

Hi,

I've just had a nasty blowout at high speed which has left my front rim in shreds. My front
V-brakes, M950 XTR, are shot (seem to have fallen apart inside). Oh, and my old Pace RC-30 forks
are succumbing to rust.

So, I'm considering replacing them with a pair of RC-31s. Carbon doesn't rust...

The question that remains, and which I'm unsure of, is what to do with the brakes and wheel. I
have basically two options, I think:

...

Quoted message said:

2) Buy RC-31s without the V-brake adapters, replace the wheel with a disk brake hub and put a
mechanical disk brake on. The Avid Ball Bearing one looks nice.

I have Hayes mechanicals with XTR integrated shifter/V-levers -- for a similar reason. These work
great. Not considerably better at normal braking than Vs; but mud, wet, and long downhills are
dramtically improved. I've heard and read enough good stuff about Avid's that I'd expect the same.

The down side is that you'll have disc in the front and V in the rear. Many claim that this is not
problem. I did it for a while and found that it wasn't a problem, but it was annoying -- I couldn't
get the balance between front and back braking as well as when the brakes were the same. Within 3
or 4 months, I had a new rear hub and another Hayes mechanical as father's day and birthday
presents 🙂.

Quoted message said:

As an aside, 160mm vs 185mm - is the 185mm necessary? Or just designed for people who are
constantly on the brakes for DH purposes. I mean, I like going down hills, but I also like going
up them...

I'm pretty sure that the 185 is for downhill. The only times that I'm even remotely worried is
when I'm hauling down a steep mountain road (on the way home 🙂) and I come around a bend and
find a car driven by a little wizzened old lady/man, hugging the steering wheel for dear life,
going 10 MPH... 🙂

David

"John Appleby" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Hi,

2) Buy RC-31s without the V-brake adapters, replace the wheel with a disk brake hub and put a
mechanical disk brake on. The Avid Ball Bearing one looks nice.

I just bought 160 mm avid mech's to replace avid v's that I will use with my existing LX levers. I
should be riding them by the weekend after next I hope. I'll let you know...oh I am keeping my v's
on the back.

I think that normally the v-brake stopping power is fine and 160mm is definately ok for x-coutry.
Disks must be nice for the UK weather, no? especially in the fall, winter and spring....and summer
too I guess.

I never felt the need for disks but I'm getting a great deal on the brakes and wheel and I hope to
ride more over the upcoming wet and muddy months. Maybe get something other than XTR v-brakes? it
doesn't surprise me to see flimsy, overpriced XTR stuff breaking down. I have el cheapo avid v's
that I never had trouble with.

SDC

Quoted message said:

Carbon doesn't rust...

Steel doesn't delaminate.....

Andy Chequer just a thought

Quoted message said:

John - If you're binning the XTR V's could I trouble you for a spare part? Been looking for the
thingie that meshes with the wotsit for a good few years without success, no-one seems able to
order it and its a shame to

see

Quoted message said:

the brakes sat doing nothing for want of thingie. Its a round bit that

sits

Quoted message said:

next to the brake stud and has 6 or so 'teeth'. No problem if you're

keeping

Quoted message said:

the brakes as spares - just thought I'd ask.

I think that's the part that's broken. It fell off the inner piece some time back and I can't get it
to mesh back correctly (I have to bolt it on very carefully). As a result one half of the brake is
pulling harder than the other and I have to compensate with the screws. The brakes aren't pulling
together quite as well as they should as a result and so braking power is reduced, plus pads wear
too much on one side.

Quoted message said:

Quoted message said:

So, I'm considering replacing them with a pair of RC-31s. Carbon doesn't rust...

I owned a pair of these for about 3 months, very nice looking (and nice to ride for the limited
riding I did on them) but the carbon made me nervous.

Well I've been riding a Trek 9900 carbon frame for coming on 7 years now. I'm past the point of
nervous there i guess 🙂

Quoted message said:

I am perfectly happy running a 165mm rotor on both my bikes, but I am not the heaviest bloke in
the world and I don't drag the brake all the time.

As

Quoted message said:

for the Disc/Q.R. issue - I'm not going there...

Yeah hmm I'm left wondering whether the increased power of a correctly setup V-brake might actually
be all I need. I don't have a problem with clearance and I've never had a problem with fading on
the XTR pads.

The only problem is on the rear where I need a booster to stop frame flex, but since my frame won't
take a disc brake on the rear anyhow, I'm not sure if I'll bother.

Thanks for the reply, it's given me food for thought.

Regards,

John

Quoted message said:

I just bought 160 mm avid mech's to replace avid v's that I will use with

my

Quoted message said:

existing LX levers. I should be riding them by the weekend after next I hope. I'll let you
know...oh I am keeping my v's on the back.

Your feedback would be interesting. I shan't be buying just yet, because I have spent too much on my
bike already this month 🙂

Quoted message said:

I think that normally the v-brake stopping power is fine and 160mm is definately ok for x-coutry.
Disks must be nice for the UK weather, no? especially in the fall, winter and spring....and summer
too I guess.

Perhaps; I've never found a problem with V-Brakes myself. I find it's mostly a question of picking
the right tyres for the conditions.

Quoted message said:

I never felt the need for disks but I'm getting a great deal on the brakes and wheel and I hope to
ride more over the upcoming wet and muddy months. Maybe get something other than XTR v-brakes? it
doesn't surprise me to

see

Quoted message said:

flimsy, overpriced XTR stuff breaking down. I have el cheapo avid v's

that

Quoted message said:

I never had trouble with.

Well to be fair, they are the original M950s from when they first came out in 1996 (I think, or was
it early 1997). Anyhow, I can't complain.

I've not got a bad word to say against XTR; I've got some M900, some M950 and some M960. Some 1994
M900 hubs that have never been serviced and still run sweet as anything. The only question in my
mind is this new Hollowform II crankset. I can't really be dealing with £75 for an outer ring when
I can buy a full RaceFace set for £65. Plus the reported poor BB bearing life in early models. But
then I always did think that Shimano were a ripoff on the chainset. So I bought the RaceFace
turbine set and I'm very happy with it so far. Moreover, ISIS looks like it's a good technology
that's here to stay.

Regards,

John