Help - Converting v-brakes to disc (MTB)

[raebomb]

Hi folks, needing some help please;

Recently bought myself a hardtail mtb, my first in about 10 years! After reading these forums I avoided buying a £100 lump of rubbish and saved for a bit longer and bought a Giant Revel 3 (now wishing I had saved a bit longer for something better!). It's a good solid bike but it's a bit basic so I would like to convert my rear brakes to disc. The front forks don't have mounts for disc brakes, plus I don't want to spend too much, so just the rear will do for now.

I'd like to know what parts I will need to do this.

I've seen this shimano kit on ebay that comes with rotor, caliper, pads and all screws - http://cgi.ebay.co.uk/Shimano-416-Mountain-Bike-Re...

My brake and gear levers are on the same 1 piece unit so I didn't want a kit that had it's own seperate brake lever.

I then realised I'll need a hub/wheel that will take a rotor, this is where I need the most help as I've never had a bike with disc brakes.
If I buy a hub that i can screw the rotor onto can I use my existing rim and spokes? Would it be easier to look for a preassembled rim that's for a bike with discs?

Sorry if I'm not very clear or using the correct terms, feel a little bit out my depth here.

cheers.

[Theoldfm]

To be honest, you are probably as well just sticking with the v brakes that you already have. The mechanical disks that you are looking at wont really give that much more (if any) braking power than a well set up pair of V brakes.

To change your bike to disks, you will either need to get a new rear hub and rebuild the existing wheel, or buy a new wheel with a disk hub. Either way, the costs are soon going to mount up.

Now hydraulic disks on the other hand are a real step up - the problem here is that you will also need to buy new shifters as you will not be able to use your existing setup.

The other point to consider, is that the majority of the braking force is usually done with the front wheel, not the ear. Putting a disk just on the rear is not such a good idea.

Sorry if this is not what you wanted to hear, but you would probably be beter off putting your bike on ebay and buying one with hydraulic disks already fitted.

[Jonnas]

Wot he said really. Do you need to convert them? Lots of hasstle for little if no return. Save your money and put it toward your next bike......

[raebomb]

Thanks for that, you answered alot of things that were on my mind. I have considered just sticking with the v-brakes as I don't want to waste too much money on a bike that I bought just to get me back in to cycling. Like you say, the costs will soon start spiraling.

I just enjoy tinkering about with things, I need to be content!

Wishing I had just held off longer as for a little bit more money I could have bought a better bike in the first place.

Edited by raebomb on Tuesday 19th October 20:21

[Flippin' Kipper]

It will be an expensive upgrade, and the most cost efficient way to go about it would be to purchase a set such as these http://www.merlincycles.co.uk/Bike+Shop/MTB++Parts...

That would give you disc ready wheels, brakes and rotors for £169.

You would then need a fork with a disc mount, with these coming in as good value at £125 http://www.merlincycles.co.uk/Bike+Shop/Frame++For...

You will then need separate shifter pods, and SLX shifters come in at £40 from the woolyhatshop.

This is all assuming that you have a rear disc mount on the frame, you could then sell your old brakes, forks and wheels to recoup some of the cost.

However, you would probably be better off keeping the V-brakes or selling the bike and buying second hand bike that already has discs.

[raebomb]

Thanks Kipper.

Your post has definately made up my mind, the total cost to upgrade to proper discs front and rear would work out more than the bike itself! I paid £260 for it.

As mentioned above, I don't really ride hard enough yet to actaully need to switch to discs, I just see all these stunning bikes on the net and want to buy bits for my own.

[Flippin' Kipper]

Happy to help. As you say it's not really worth extensively upgrading what is essentially a budget bike. I think what I would do is keep your bike as it is, and save up towards a more expensive bike in the future - this will work out much cheaper than trying to upgrade to the spec you want.

[aspen]

I was going to start my own thread on this topic and saw this one, hopefully Raebomb doesn't ind the hijack as it looks he is sorted!

I have a Trek 4500 with disc mounts that I would like to upgrade from Vs to discs. Initially I went for Vs because I wasn't sure how often I'd be getting out on my bike. It turns out I'm getting out quite a bit and really enjoying it and I think I'd really benefit from discs.

I don't really know much about the options. I'm thinking 180mm front and back. I'm guessing I might need around £250 for decent quality components. Should I go for Shimano? What exactly do I need? Mounts, calipers, rotors, hoses?

Or should I just wait until my next opening on the cycle to work scheme and buy a new bike for the trails and stick road tires on the 4500?

[shalmaneser]

You need disc ready hubs, these have six bolt holes in them and look a bit like this...



If you don't already have them then you'll need a wheelset. Budget about £150 for these.

Discs come in two flavours: hydraulic and cable. If you have separate brake levers and shifters you can use hydraulic brakes. If you have integrated levers and shifters then you can either

- run cable discs, these are not much good, but better than v's
- buy shifters at the same time as you buy the brakes, further adding to the cost.

Best VFM hydros ATM are something like Avid Juicy 3's. They're not as nice as more expensive discs but do the job quite nicely. About £45 each from Chain Reaction Cycles.

[shalmaneser]

In terms of disc size, 160 rear 180 front is standard, and more than enough for everything bar full on DH.

For wheels, shimano hubs on mavic rims are nice, shop around and see what you can find, alternatively something like

http://www.chainreactioncycles.com/Models.aspx?Mod...

is a pretty good price for a pair of wheels for £160.

Brakes: Shimano, Avid, Hayes or Formula.

Go on bikeradar and read the reviews.

[SkinnyBoy]

Alternatively you could get some Magura rim brakes which offer much better braking IMHO than V's and are pretty much fit and forget. There usually a few kicking around on eBay and retrobike for sale.

[aspen]

Thanks for the replies.

Those Maguras look interesting!

I think I'll go with hydraulic discs. Need to do some shopping around.

[aspen]

My hubs are disc ready, so thats a bonus

[hman]

I looked at doing this and then realised that brakes are for poofs.

[raebomb]

hman said:

I looked at doing this and then realised that brakes are for poofs.

haha, brilliant!