Markus

"Chunky" is getting a bike (more than likley a 19" Iron Horse Oxide) and he quite likes the look of it.

I get the feeling that the modding bug might hit me. I've been a good boy and have not modded the passat, just don't think it's the same as modding a scooby. Anyway, one of the mods I might make to the bike is to upgrade the brakes to these funky disk brakes.

Now, has anyone done this? if so, what setup did you use and why? how easy is it to do this? How do they fit to the bike/wheel, is there some adaptor kit or something? Do you need a new hub for the wheel, if so, I assume you'd need to respoke the wheel?

Would it be better to get a bike shop to supply and fit the discs than for me to do it myself? (I know I'm no mechanic, but I can fit a dump valve and induction kit to a scoob )

Marin

iTrader: (1)

You will need disc specific hubs - 6 bolt is industry standard although the new Shimano brakes use a splined hub. Either way, you'll need new hubs and the wheels rebuilt to fit them. Also need to make sure your forks and rear triangle have disc mounts on them, if not, no go and there are two different types of mounts depending on the fork manufacturer.

Could end up cheaper to upgrade to a new bike with discs as standard plus it's a good excuse to get a new one too :-)

imlach

Assuming you really feel you NEED disc brakes, as opposed to just modding for the sake of it

Only worthwhile if you do a lot of proper mountain biking on dusty/wet/muddy descents IMHO.

MarkO

Agree with what's been said here. New hubs plus brakes, plus rims, spokes and wheelbuilding costs means it'll probably cost upwards of £400 even for cheapo £70 Hayes or similar. Whereas for £500-600 you can get a decent Alu frame with discs (e.g., the Giant XTC3).

If you ride a lot, on wet decents, discs will make a difference. If you're only a fair-weather rider, they're not all that, compared to a decently set-up set of V-brakes. The main benefits are consistency and ease of use - you get full power braking with a single finger, and they work with a (slightly) untrue wheel - handy to get you home if you have an 'off'.

I wouldn't buy a new bike without discs, but my V's do the job quite happily. If you are going to upgrade, though, I'd recommend Hope mini-monos, Hayes, or the Shimano XT discs which are cheap, easy to set up, and have an excellent feel.

Oh, and don't even consider cable discs. Hydraulic is the only way to go.

mj

usual "shot down&pissed on" Disclaimer applies..

The brakes for the Millenium Wheel are on the rim.

IWatkins

Everything MarkO said except cable disk brakes. I've had no end of trouble wth hydraulic systems (Hopes especially). Went over to using Avid disk (cable operated) and haven't looked back.

But each to their own.

Cheers

Ian

MarkO

You're the only one then Ian. 8 months of working in a bike shop and running a fleet of 50 hire bikes all with hydraulic was proof enough to me that hydraulic is the way to go.

DrJP

Tried to but a Giant XTC 3 or 4 recently, apparently almost all sold out in the UK this year. Bought a TREK instead. I was advised that for my price range approx. £500 that if I bought a bike with discs I'd be sacrificing quality elsewhere. Could be rubbish though

MarkO

Probably right. 600 is about the minimum you can get a decent bike with disc brakes. XTC3 is about the best for that sort of price. Spend any less and something will be compromised (frame weight, etc).

alcazar

iTrader: (2)

Changed my Titanium frame over to discs, (Hope XC's ) about 2 years ago.

Was it difficult? YES! I already had disc mounts on the front, but had to have a new drop out and disc mount made up in titanium , and then welded on at the rear..........about £50 all in, but took me two weeks to organise! (including finding a drawing, getting someone with the right thickness of titanium to cut it out with a hot wire cutter etc etc).

Then I had disc wheels built and sold my old wheels so another £50-£100 there, plus the cost of the brakes.

Setting up was NOT easy, but they now work well except when I forget to back them off a bit in very hot conditions, the fluid expands and they lock on. You look REALLY stupid carrying a bike to find water to cool 'em off!:

Would I bother again? No, probably not, I'd go for XTR or XT V's, and spend what I saved on a better, lighter chainset/cassette etc, (although I already have XT on both).

Alcazar

r32

If your seriously into bikes and ride hard then discs the only option, Hope mini monos, and you donr get any temperature pressurisation.

MarkO

Word of warning. Frames which don't have disc mounts (like mine ) probably aren't built to withstand the massive strains that disc braking can produce. Modern frames usually have stronger (non-butted) tubing on the mount side, to cope with these pressures.

Just welding mounts onto a new dropout could potentially result in snapped frames...

Markus

Thanks for the replies chaps. From the sounds of it, more hassle that it's worth for what I'm going to be doing with the bike, if I get seriously into it all, and I doubt I will (Toronto is not known for it's hilly trails ) then I'll sell the current bike and get a whizzy new one.

alcazar

iTrader: (2)

I had thought of this, and approached the frame builder before doing it. They informed me I'd be OK, as their frame was produced WITH the mounts the next year, with no other mods. They even sent me the drawings, and put me in touch with the company who did the work making their dropouts/discmounts from titanium in the first place.
They had the titanium in stock and the guy I spoke to was a bike nut, so he did the job for me cheap and put it through with another he was doing.

Alls I had to do was find a welder, and there just happens to be a guy near me who does welding in alloy for motorsport, and in titanium for the aerospace people.

Everyone I approached was so helpful and intrigued with what I was doing.

Alcazar

the moose

I've been using Hope hydraulic discs for the last 2 years now, and have never had a problem. They're a little cheaper than they used to be, but as MarkO says, the costs more than outweigh the benefits if you're starting from scratch. Certainly the case that unless you use your bike hard in the wet/mud, Vs are fine.

Then again, I prefer the feel of discs and wouldn't go back. Oh, and they look good too - chicks love discs. Or was that scars?

Mark Miwurdz

That's what I used to think - then I tried them. Now I wouldn't be without them.

Cheers
Kav

the moose

I had Hope Minis, but now I've got M4 Monos I'd not go back to them. Ridiculously powerful and incredibly subtle - there's certainly no excuse for locking the front wheel, other than user error.

Markus

Little update for you. The 'oxide' I was meant to be getting had not been shipped so got a great deal on a 'warrior disc' which, amongst other things, had hayes disc brakes on it.

Must say I'm rather happy with them, cable operated and not had a problem yet, think they need a slight adjustment at the front, so will do that later.

Once again thanks for all the advice on this.

unclebuck

You've already got disc brakes - 26" ones, front and rear. If you can lock the wheels then they're as powerful as you need. I don't see why people feel the need to spend hundreds of pounds on unnecessary 'bike jewelry'.

Dougster

Specialized Epic Disc and I cannot fault the excellent hydraulic brakes that came standard!! Amazing stopping power and feel, giving great rider confidence.

MarkO

Hmmm. Presumably that's why people spend hundreds of pounds on 6-pot braking systems for their Scoobs then, despite being able to lock up the wheels with the OEM brakes?

Just because you can lock the wheels doesn't mean you're getting maximum braking use/efficiency/easy/performance. What it probably means is that your brakes aren't being modulated correctly and you need some new tyres.

You don't see why, because you've clearly never ridden a bike with disc brakes. If you had, you'd know that moving from traditional rim-based caliper or 'V' brakes to discs is probably the biggest performance upgrade you get make to your mountain-bike. In fact, I'd say that most peoples' riding would benefit more from an upgrade to discs than from moving to a full-sus bike.

The main benefits of hydraulic discs over conventional rim-based brakes are:

o Consistency - disc brakes act almost precisely the same regardless of riding conditions (dry/wet/mud/snow ), whereas with rim-brakes the first 1/2 to full revolution with the brakes applied is usually spent clearing the mud & water off the rim, before any decent braking effect starts.
o Ease of use - discs require far less strength to get the same level of braking performance than even V-brakes. I find that by the time I've completed a 15-20 mile ride with lots of decents on my bike (which has XTR V-brakes), my hands are sore and knackered, whereas on the bikes I've ridden with discs, it's not an issue.
o Accuracy - it's far easier to modulate discs to give precisely the required braking power. Cable-based brakes aren't so consistent and usually just require a big yank to work, even if they're perfectly set up.
o Lack of day-to-day maintenance - setting up V-brakes is a royal PITA. To get good power, quick response without having the pads drag on the rim is tricky - particularly if your wheel's even slightly out of true. Discs don't require this - I've seen people with discs come off the hill with wheels that are rubbing the frame, but they still had consistent braking so could ride home rather than walk. Discs also don't wear your rims out, requiring a wheel rebuild every year or two.
o Power and Performance - without question, discs are massively more powerful than any rim based brake. This means you can brake later/harder into the corners, making you quicker overall.
o Longer pad wear - having worked in a bike shop last year, I've had first-hand experience that disc pads last far longer (3-4x) than rim pads, despite only costing 50-75% more. In wet/muddy weather, I've seen people get through a set of V-brake pads in a single 2-hour ride.

The only real disadvantages of hydraulic discs are that the initial cost is fairly large compared to rim brakes, and every now and again they might need bleeding through. Having said that, spending £20 on labour at your local bike shop once a year is no big issue, IMO.

UB, I'd suggest you get out and try a bike with a set of hydraulic discs before you start making wild, inaccurate and (frankly) daft claims about 'bike jewellery'.

the moose

I'll back up the ease of use point - Mrs Moose did a week in Les Gets last year, and was amazed at how little her hands hurt, even on the big decents. This was on a (very) stiff hardtail with just an 80mm SID on the front, but with Hope Minis fitted.

Having ridden the same courses on a similar (but Magura HS33-braked) bike, my hands were in bits; I could barely pick up the bike for cramp.

MarkO

Could've done with discs today at Glentress - it was so muddy I had pretty much zero braking for most of the descents....