I’m just wondering if upgrading cheap Shimano M-447 brakes (with M-510 levers) to SLX system would make a noticeable difference to breaking power/bike control?

Not much. There isn’t that much difference between them. The low level Shimano brakes are pretty good.

Possibly – i’m not familiar with the brakes you have but suspect they aren’t the servowave type, which is an advance. Will it be like day and night – no; IMHO shimano brakes are all very good, and the ones you have are not totally dissimilar in technology to those that would have been labelled as XT a few years ago, maybe just slightly cheaper machining / more weight. And they stopped us just fine.

If you want more ‘power’, what size rotors do you have?

From what I understand it’s the current Deore and up that are the good un’s? With that being the case I think the upgrade you suggest would make a fair old difference. Happy to be proved wrong though.

probably not.

If you can, try installing larger rotors and adapters, and get some fresh brake pads. But first, check your existing brake pads – are they organic?

some of the less expensive Shimano brakes come with softer organic pads, and the brake may be designed only for organic pads due to inability to deal with higher heat generated by metal sintered pads

If the brake can handle a metal sintered pad, this offers more “bite”, especially in wet weather.

Typically increasing the size of the rotor (i.e. 160mm to 180mm) makes 20% difference to the leverage the brake has.

If you’re going to upgrade to better Shimanos, probably no real need to go higher than Deore level. I have Deore on one MTB, and SLX on the other and in outright braking power terms there’s not a noticeable difference. Deore’s can be had very cheaply

Im pretty sure that Deore and lower Shimano brake sets come with resin pads and discs that are stamped for resin pads only. So depending on your current rotor size and adapters, you could fit bigger harder rotors that would take sintered pads and see how you get on.

you wont be wasting money, as if you still want to upgrade the caliper and master cylinder then you will still need the rotors and pads!

I replaced the rotors ages ago (SLX ones) and I run sintered pads. I don’t normally complain on the brakes, however I found that on long steep downhills it requires a lot of pressure applied on the lever to lock the rear wheel – I can feel the lever becoming much firmer and kind of pulsates (very mildly though).

I tried using a set of those Shimano brakes on a Lakes epic and they were terrifyingly bad.

Currently using SLX and they are in another league.

Unless you’re only pootling around, I’d say it’s an excellent upgrade to make.

My girlfriend has got the M447 on her Trek and I’ve got SLX on my Bfe.

I wish I could tell you to save your money but there’s quite a big difference in stopping power. The M447 seem to have a really gentle, wooden, bit point which I’m not used to and they just don’t grab as hard on the rotors.

Mine are so much sharper and grab much harder for less effort. They were very cheap from Planet-X as well, less then £140 including rotors, mounts etc.

Above SLX yeah, there’s not much difference but from personal experience (I own and use both sets) I’m thinking of another set of SLX for the girlfriends bike.

I found that fitting Nukeproof Enduro pads to similar brakes (M-395) gave a massive improvement in power, feel & wear. Even though the disc rotors are stamped for resin pads only, they seem to be coping OK. (Hardened discs for these brakes are now obsolete, I believe, but are / were available on ebay)

Be slightly wary of ‘partial’ upgrades (e.g. bigger discs only), as I believe that the higher spec Shimano brakes use a narrower ‘track width’ on the disc – the pads on your existing caliper would overhang each side of the rotor track.

Got old style SLX on one bike and new Deore on the other, both excellent , very little to choose between the two. You might as well go for the Deores as they are about £65 both ends without discs.

I had exactly that combination M447/M510 on my first bike, and as I got better and faster I found that I didn’t have the confidence going into corners/obstacles that they’d stop me – sort of a time lapse between spotting the need to brake and pressing the levers and starting to slow down (I’m 100kg kitted up by the way).

I replaced them with SLX and there was quite a big difference (and yes, still resin pads and same size rotors – so it was all in the brakes themselves) and I now have much more confidence to approach corners/obstacles fast in the knowledge the brakes will wipe off the speed when needed.

Just my experience, but happens to be with exactly the combination you have, and are looking to upgrade to, and I say – yes, it makes a big difference!

Can’t comment on Deore as I haven’t used them. Have XT on another bike and they’re same as the SLX.

Depends what you’re looking for, I have a set of what you have, I believe they would be Acera or Alivio level stuff in a groupset?

Currently running a pair on my HT and with 180mm rotors and some soft compound pads from Superstar they are excellent….are they as good as the Deore M615s on my other bike?….just different i’d say, both lock up easily enough, the Deores perhaps requiring less effort and have more ‘feel’ but this can be subjective.

The Deores are definitely lighter and the lever arrangement is smaller and comes with reach adjust….I’m building a FS for spring and have Zee’s on order purely because (I’m vain) and have never tried 4 piston brakes, I’ll let the forum know if they’re worth the cost or whether a £65 set of Deores is about as good as braking gets…which would be slightly depressing thinking about it!

As above really, I wouldn’t bother going above Deore. They really are excellent brakes for the money.

They felt better than the XT’s that had on my big bike. One of my mates found the same…his Deores felt better than the SLX on his other bike.

For the money you really can’t go wrong. I’ve just increased the size of my rotors and they’re pretty powerful.

and I run sintered pads

You need to make the following decision: Do I want better performance or longer pad life?

Personally I’ve stopped using sintered pads as, as you’ve found the performance drop is’t worth it. I’ve accepted that I’ll have to change my pads a bit more often, but I’d rather have the stopping power.

I bought a Deore a few years back as an emergency spare and the performance was amazing. I couldn’t find fault with it, plus the lever shape was perfect.

TBH, a rebleed and new pads will make all the difference unless you want shinier bits (Hope) and/or little dials to adjust the bite point (Hope/Shimano XT), if you simply want to pay a bloody fortune for spares (Formula) or you like inconsistent braking performance and enjoy screaming obscenities at an overcomplicated bleed process (Avid).

was thinking about getting zee’s but at twice the cost of Deore’s really not sure now.

I have Deore M610’s, mate has XT 785’s and i really can not tell the difference apart from his looking slightly tartier.

Deore M610’s are £98 at Merlin Including Rotors and adaptors. Bargain 🙂