Worth upgrading rim brakes to disc?

nbuuifx

On a Rockhopper with rim brakes, is it worth fitting some hydraulic disc brakes?

The frame looks to have disc brake mounts as does the rear wheel

cooldad

Or just buy a bike with them already on. As decent brakes will cost more than that bike is worth.

But in answer, decent hydraulics are streets ahead of Vs.

billycool

Yes - disc brakes work better. Some basic Shimano brakes would do a good job.

steve_sordy

Even cable disc brakes are much, much, better than rim brakes on an mtb.
But hydraulic disc brakes are the way to go, virtually maintenance free.

bobbydigital

You might as well, they are a good upgrade and I 'd say they were pretty cheap.

I got some m505 brakes for £22 posted on the bay, they work really well, maybe another £10 for a set a disc and you are good to go.

https://www.ebay.co.uk/itm/shimano-deore-brakes/254020940732?hash=item3b24d3f3bc:g:ZfsAAOSwa6NcDtdq:rk:6:pf:0

This could be a cheap upgrade but you need to know the length of the hoses so they fit on your bike.
You can cut hoses down if needed though, with the right parts and tools.

nbuuifx

Thanks for this,

Would the 535s posted above be a direct fit? (providing hoses are the correct length?)

Also how do I know what size discs would be best? Does it matter if I mix makes?

cooldad

Depends on the fittings on your frame and forks. Brakes look like post mount. The bike you were looking at look like IS mounts, so would need adaptors.
For the type of bike and riding you mentioned, 160mm would be more than enough.
Make of rotors makes no difference as long as they match the size of the adaptors /mounts etc. And wheels, either 6 bolt or splined.

cougie

+1 on this. Either live with what you have or get a new bike. Upgrading is an expensive and tricky business and you may end up with worse brakes.

nbuuifx

Thanks for the info. I think I'll stick with the v brakes to start with. It just seemed an obvious upgrade given that all the mounts are there. I have a spare set of wheels with rotors on too so just need the brakes themselves for now. I'll keep my eye out for some sub £20 disc brakes. I'll don't think I'll buy new pads for the v brakes, so when these wear out I'll make the jump to disc if I haven't before then.

You are right that I the bike is IS mount. The 535 ones above were post mount so I would need adapters but I take it that is fairly straightforward?

I like messing with bits like this too, as you learn so much from it! I find my chances of fixing things at the road side is much higher if I've put the bits on, or had to replace them before!

ednino

Yes, in the wet and mud disc brakes are 10000 times better

bobbydigital

The shimano calipers are POST mount and your frame is I.S (International standard) so you would need

Post to I.S mount 160mm adapters

Shimano call them - FS MA F160 - the front and rear are different, the 160 is for 160mm disc so if you had 180mm disc it would be a F180.

https://www.ebay.co.uk/itm/160-180mm-Front-Rear-Disc-Brake-Adapter-Caliper-Post-Mount-PM-to-IS-Standard/283218168156?epid=1081963134&hash=item41f11e495c:m:m6XICK3Vi1GNTmwgGOs4Siw:rk:2:pf:0

nbuuifx

I ended up getting some 535 disc brakes so just need to figure out the fitting. I have some spare wheels with 160mm calipers. So I just need the is to post mount adapters.

Are the ones in the link correct for both front and rear? Are they definitely the right way. As in are they for putting post mount brakes on an IS frame?

The Rookie

Depends what size discs are on the wheels, and they are........?

nbuuifx

The discs are 160mm

nbuuifx

Right, I got the adapters and the brakes and they all seem to line up pretty well.

The only thing I am missing is the bolts that bolt the caliper to the adapter. Do I need to buy any particular special ones or would any bolt do?

cooldad

They need to be the right size - thread and length.

nbuuifx

cooldad wrote:

They need to be the right size - thread and length.

I realise that, they are a M6 thread. Allen head. The adapter to frame bolts are 18mm long and that looks about right for the calipers.

What I meant by my question was do they need to be any particular material or a certain tensile strength? Can you just buy the bolts easy enough? I had a quick search but struggled to find them but then I might not be quite searching for the right thing

bobbydigital

Normally for the fork the top bolt is longer as it needs to travel more distance due to how some of the adaptors line up.

They want like £3 a bolt when it's listed as Shimano original brake bolt, rip off.

M6
Over all length 25mm
Thread end to bottom of washer 17mm

Try here - https://www.ebay.co.uk/itm/M4-M5-M6-M8-A2-STAINLESS-STEEL-ALLEN-BOLT-SOCKET-CAP-SCREWS-HEX-HEAD-DIN-912/221307549544?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D55148%26meid%3Dec5fe34c70f041478f1b5ac8b99bbbdb%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D221307549544&_trksid=p2045573.c100505.m3226

https://www.ebay.co.uk/itm/M3-M4-M5-M6-M8-M10-DIN-912-HIGH-TENSILE-CAP-HEAD-ALLEN-BOLTS-BLACK-SOCKET-SCREWS/191631586181?hash=item2c9e21f385:m:mgHPnAAtMgQYYslnUgRPuYw:rk:11:pf:0

nbuuifx

Excellent, thank you

nbuuifx

It has taken a long time, it is on the wife's bike so never quite made the priority list 🤣

However I've finally done it. I wish I'd done it sooner! It didn't take long at all. Simple plug and play bolt on solution. The front brake is spot on the back brake works but is a bit soft so probably needs bleeding. Even soft it is a lot better than the old brakes.

Thanks again to those that helped! I can't believe all the bits have been sitting on the garage shelves for 18 months!

steve_sordy

One thing you might not realise, seeing as this is your first foray into disc brakes. The pads and discs need "bedding in". If you don't do this the brakes will never be as good as they can be. You should be able to stand the bike on its nose with little effort, and I'm not joking!

https://www.youtube.com/watch?v=BWQxGzHQZVU

nbuuifx

steve_sordy said:

One thing you might not realise, seeing as this is your first foray into disc brakes. The pads and discs need "bedding in". If you don't do this the brakes will never be as good as they can be. You should be able to stand the bike on its nose with little effort, and I'm not joking!

https://www.youtube.com/watch?v=BWQxGzHQZVU

Thanks for this. I do have disc brakes on my MTB as well but am constantly learning! These are all second hand parts that have gone into my wife's bike so hopefully don't need much bedding in but will use it on my MTB as I have just put new pads on that one.

Thanks again!