Why do 2 sets of identical brakes not feel the same?

mac_man

My current bike has Tektro Auriga Comp hydraulic discs. 180mm rotor on the front and a 160mm rotor at the back. Bike is only 2 months old.

My son just got a 9 month Rockhopper with the exact same Tektro brakes. This has 160mm rotors front and rear.

The braking force on the Rockhopper just doesn't feel as strong. Mine stops on a sixpence whereas the Rockhopper doesn't seem to. The brakes feel kinda spongy. The rear brake more so.... slam it on and even downhill the wheel hardly locks up.

Bike itself is absolutely mint with barely a scratch on it. Guy I bought if off reckons it's done about 350 miles in total with only about 50 offroad. Can well believe that given the condition its in.

Is their anything to adjust on them? Could the pads need changing? Or have they not even bedded in properly yet

bomberesque

if the lever feels spongy then a bleed is needed

if that doesn't fix it, then the pads could be contaminated in which case they'll need changed. how worn do the pads look (how much material is left on them looking from the side)?

Also, check the disc, if the brakes have been overheated (perhaps the previous owner tried a DH course and dragged his brakes) then the braking surface of the disc may look black and shiny, as the metal has been annealed. This will affect breaking. Take a piece of emery cloth and sand the breaking surface, should come up as good as new.

mac_man

Cheers

Will check the above points.

How easy is bleeding the brakes? There's a 'how to' in the manual showing syringes and stuff (I think). Will I need some new oil?

_Ferret_

Tolerances in the brake
different wheels
tyres brake mounts
bedding in time
bad condition
disc condition
there is a long list of possibilities
But the points given above are the best to check first

bomberesque

for bleeding you will need the correct kit and a bottle of brake fluid (not sure what yours use, either DOT 5.1 or mineral oil ... probably DOT) The kit will come with instructions, but there are some youtube vids that maybe usefull and no doubt Park tools will have some advice (actually, I'm not sure about that as I don't think they do bleed kits but still worth a look)

however, tbh it's quite messy and can be easy to get wrong so unless you really want to do it yourself, there's no shame in paying your LBS to do it for you. At least get a quote from them. I now bleed my own brakes but made a mess of it the first few times.

Maxticate

Tektro Auriga Comps use mineral oil as brake fluid.

mac_man

LBS have quoted £20 to bleed both brakes. price incl the new oil.

no idea if that's a good price or not.

BlackSpur

mac man wrote:

LBS have quoted £20 to bleed both brakes. price incl the new oil.

no idea if that's a good price or not.

Yes that is a good price.

I would say that pads are the most likely issue though, either different compounds or one set is contaminated etc.