Viewing 40 posts - 1 through 40 (of 56 total)
  • Just fitted my new XT disc brakes and…………
  • sadexpunk
    Full Member

    im a bit underwhelmed to be honest :-/

    was hoping for a real positive snap to the levers when i put the brake on, but they feel a bit 'spongy'.

    levers nearly touching bars too when i brake. i looked at that thread from the other day about the freestroke adjustment, and ive wound the little nut out a bit to make less travel before the pads bite, but they just dont feel how id like.

    ive tried mates brakes before, and had a few of my own to compare, and i like to be able to stop the wheel dead with a skid stop if i want, with the levers feeling like theyve 'hit a stop'. these stop me ok, but i just thought theyd be 'sh*t hot'

    am i expecting too much? does 'better modulation' these days mean 'less ability to skid stop'?

    or do they just need a bleed? (bought new from ribble btw)

    cheers

    bigyinn
    Free Member

    I'd give 'em a good bleed, mine are just not spongy at all. It took a few goes to get them there mind.
    If you've looked at the other threads, you'll know whats required.

    nickc
    Full Member

    but they feel a bit 'spongy'

    this is how Shimano brakes are. I've Goodridge hoses on mine (old Deores, not XT )and it firms them up a bit.

    ahwiles
    Free Member

    put your brake fluid in the freezer over night to get the dissolved gas to 'bubble-out'

    take your time, do it properly. if you don't know how – get a friend who does and give them beer, pizza, and cake.

    clean your pads and discs, don't use spray lube – that stuff = death to disc brakes.

    Frankenstein
    Free Member

    Brake levers going to the bar are not how shimano are!

    Spongy too?

    Air in your brakes!

    You need to bl…

    Don't post pictures like that please. Mod

    Trailseeker
    Free Member

    Yes, I've just changed back from XTR to Hopes, been running the Shimano brakes for about 5 months now (bled twice & used 3 different types of pads) still don't think they're a touch on the Tech Hopes.

    Anyone want to buy some M975's?

    MrCrushrider
    Free Member

    my slx are in no way spongey! have you tried bleeding them?

    when ever i get new brakes i tie wrap the lever to the bar over night or as long as possible to force any airbubbles to one end. seems to solve any issues for me anyway!

    phil.w
    Free Member

    i'm sure someone will say it's how you set them up but i had the same opinion of them. i liked my hopes which had a "solid" lever feel as soon as they bite.

    the XT's that came on a new bike lasted about a month before i ditched them. they would always stop me but just always felt soft in the lever even after bleeding and re-bleeding lots.

    (i've got the old hopes back on)

    sadexpunk
    Full Member

    no, i havent bled them. havent even got any mineral oil yet 🙂

    i havent seen a thread on bleeding them, only that free stroke adjuster thing. is there a 'better than the manual' way of bleeding them? ive got a couple of syringes and pipe if that helps? manual suggests a bit of pipe into a bag.

    the fact that youre saying they shouldnt be like that gives me a bit of hope. ill have to nip and get some mineral oil then. whats the best place to buy that stuff? online? LBS? halfords?

    thanks

    TandemJeremy
    Free Member

    I thought shimano were supposed to be fit and forget and never go wrong? Thats what folk on here keep saying anyway

    donks
    Free Member

    My XT's are as powerful and firm as any I have used and better than most. I have them set up so I only need to pull the lever a fraction and I can stop on a sixpence. It sounds alot like you need to re-bleed.

    molgrips
    Free Member

    I've got XTR from 3 years ago and they are rock solid and very good. Not spongy at all.

    You need to bleed. But bear in mind that it's a bit of a black art because bubbles can be hidden in the system. Think about where bubbles might be – move the caliper around to dislodge them, make sure the lever is the highest point (if there's a loop of hose the bubble will collect there and no amount of bleeding will shift them). Remove brake, place it all in a line (with lever level though), move the caliper around to dislodge bubbles, then let it all float to the top.. then open the top cap and wiggle the lever a bit (but not much) see if any bubbles pop out.

    IIRC Shimano instructions tell you to do this rather than faff about with pumping etc. If you do the pumping the lever and operating the bleed valve thing, any bubbles in the hose will just keep floating up, no matter how much fluid you put through.

    Frankenstein
    Free Member

    I have 975 XTRs, XT's and LX's setup myself and you have to patient if you're bleeding the shimano way-takes a while but solid.
    Even bled some XTRs from users on here too as they were struggling and thats before a setting off on a trail.

    I do hate using shims on shimano calipers but it could be sticky pistons causing rub. Otherwise fit and forget (except that pads need a little bed in)

    epicsteve
    Free Member

    I thought shimano were supposed to be fit and forget and never go wrong? Thats what folk on here keep saying anyway

    I'm convinced Mr Shimano must have shagged you and dumped you at some point. Either that or you'd heard he votes Tory…

    I've got a mix of Hope and Shimano brakes on my bikes (plus Julies on one of the others) and the XT and XTR's definitely have more modulation than some others (which is probably a good thing), but they definitely leave you in no doubt of their ability to lock the wheels if required. I've got Deore's on several bikes and, when set-up properly, they can be very sharp indeed. The Hopes are somewhere in between.

    While I like the Hopes I have I still prefer Shimano and stick to those now. The most expensive brakes I own are Hayes Carbons and I when I took them off, replacing them with some old Deore's, I regarded that as a huge upgrade!

    reggiegasket
    Free Member

    as said, spongeyness is a function of air in the system, not the design of the brakes themselves.

    TandemJeremy
    Free Member

    Just having a laugh steve. Second post on here in recent days with issues with shimano brakes but people still say they are faultless. Fit and forget and never need anythng doing to them.

    I dislike shimano for the disposable / planned obsolescence philosophy but I fully accept that they make functional products at a very good price – there is a reason they are so big!

    nickc
    Full Member

    I dislike shimano for the disposable / planned obsolescence philosophy

    Like their hubs presumably? I mean, a few ball bearings and some grease occasionally, curse them and their long lasting ways…

    re brakes, just because the levers have some 'give' in them, don't mean they've got 'issues'. It's just they way they seem to come. If you want them firmer, then do something about it, they work fine, it's just an individual taste thing…IME.

    sadexpunk
    Full Member

    just about to go buy some oil, and checking the instructions to make sure ive got all i need. 2 lengths of tubing and a syringe should be fine i reckon. but…… the instructions give 2 methods.
    'adding oil and bleeding air at the reservoir tank' where it seems its just a bag and bit of tubing needed, and let oil drain into bag.
    and 'adding oil and bleeding air from the caliper using a syringe' where it seems that you have to piush oil up into the system, instead of topping up in the reservoir.

    which ones best? (its not recommending you to do both is it???)

    BadlyWiredDog
    Full Member

    people still say they are faultless. Fit and forget and never need anythng doing to them.

    People are just describing their own experiences aren't they, which is what forums like this are all about.

    My experience of Shimano XTs and SLX too is that they're a bit fiddly to bleed initially, but once you've done that, they're pretty much fit and forget except in sub-zero conditions when they tend to stiffen up, possibly someting to do with the seals. Am I supposed to invent faults with them just to keep you happy? 😉

    bigyinn
    Free Member
    bigyinn
    Free Member

    TJ I dislike shimano for the disposable / planned obsolescence philosophy but I fully accept that they make functional products at a very good price – there is a reason they are so big!

    I'd agree with their number of gears, but they hyro brakes are pretty much cross compatible across the range. From the original M755s right up to the latest SLXs.

    hora
    Free Member

    Reading thread with interest….

    I rode my new XT's at the weekend too. They were either almost too the bar (trapping my fingers) or too far out so I was almsot slippin goff gripping them.

    Xylene
    Free Member

    When mine go spongy. I just level the levers pop the caps and give them a good pump, leave it for five, pump again, leave for five, repeat a third time and they have always firmed up.

    Now I've said that I bet it all goes tits up.

    zangolin
    Free Member

    Good source of tube for bleeeding is your local RC model shop. Silicone fuel line is just the right size for little Shimano bleed nipples etc. Few quid for a metre or so.
    Halfords do a nice little 7mm combi spanner for them little nipples also

    molgrips
    Free Member

    Think about it. Bubbles want to rise, right? So if you squirt oil into the bottom (and catch it coming out the top) you'll take all the air out with the oil.

    I seem to remember it saying something abotu leaving the bubbles to rise up then putting more oil in the bottom…

    bigyinn
    Free Member

    Seriously follow the suggestions, it may take a few goes to get it right, but they'll come good.

    phiiiiil
    Full Member

    which ones best? (its not recommending you to do both is it???)

    I used to use the fill-up-the-reservoir method, but the last time I bled my XTs I did it from the caliper up instead, and it seemed a lot less hit-and-miss (are there any more bubbles to come out? Should I do one more "fill reservoir / squeeze lever / tighten bleed nut / release lever" cycle? When do you stop?). Just drain the current fluid out of the caliper, start pumping new fluid back in, stop when the reservoir is full, job done.

    tails
    Free Member

    they need bleeding for sure try bottom up bleeding if you can, mine where exactly what you want from new!

    http://www.gravity-slaves.co.uk/?a=427 this can be done without the kit

    ahwiles
    Free Member

    sadex – this sounds like your first 'bleed' – it will go wrong i promise.

    but that's ok, it's all part of the fun of learning, the very first thing you need to do, when you think you're ready to go, is take the brake pads out, and put them in a different room – and close the door.

    you're not allowed to open that door until you've finished.

    before you start, are you sure you haven't just got oil on your pads/discs ? shimano brakes are a bit more squidgy than others – i like this, other people not so much.

    one of the great things about shimano brakes is,the mineral oil, you'll end up with it all over your hands, but it's mineral oil so it's fine.

    do this with dot fluid and 2 days later your skin falls off in sheets.

    i use 2 syringes – a big one attached to the calliper at the bottom the push lots of fluid through, and a little one at the top to draw off the excess as it flows into the reservoir.

    there's a lot more to bleeding than just pushing a bit of oil through, you need to make sure you 'access' all of the air-traps – this is not easily explained here…

    hora
    Free Member

    When mine go spongy. I just level the levers pop the caps and give them a good pump, leave it for five, pump again, leave for five, repeat a third time and they have always firmed up.

    Now I've said that I bet it all goes tits up

    The pumping doesnt bring up the level of the oil to overflow?

    pypdjl
    Free Member

    but once you've done that, they're pretty much fit and forget

    No brakes are "fit and forget", they all go wrong every so often. You might argue that shimano are better than most, but the difference is certainly not as vast as people tend to claim in brakes threads.

    BadlyWiredDog
    Full Member

    No brakes are "fit and forget", they all go wrong every so often. You might argue that shimano are better than most, but the difference is certainly not as vast as people tend to claim in brakes threads.

    Do you actually understand what 'pretty much' means?

    pypdjl
    Free Member

    Yes, see your reply to TJ. "people still say they are faultless. Fit and forget and never need anythng doing to them." This is clearly not true in general. I realise that you didn't say they were absolutely fit and forget, but I assumed the context would have been sufficient that I didn't need to go to tedious lengths of quoting.

    hora
    Free Member

    Responde se vous plait!

    When mine go spongy. I just level the levers pop the caps and give them a good pump, leave it for five, pump again, leave for five, repeat a third time and they have always firmed up.
    Now I've said that I bet it all goes tits up

    The pumping doesnt bring up the level of the oil to overflow?

    U31
    Free Member

    When mine go spongy. I just level the levers pop the caps and give them a good pump, leave it for five, pump again, leave for five, repeat a third time and they have always firmed up.

    Now I've said that I bet it all goes tits up

    The pumping doesnt bring up the level of the oil to overflow?

    No its what's known as " Burping"
    Combine burping with tying the levers close to the bars over night and while transporting the bike to the trail..

    sadexpunk
    Full Member

    right, ive read the thread linked to above and theres a few good ideas there, but also some stuff i dont quite understand.

    i get the impression that the 'from the caliper up' method is best so thats what ill do.

    1

    Try using an elastic band or toe strap to pull the levers in to the bar and leave it, sat upright on the floor, overnight.

    sat upright. what does that mean? lever pointed up? or reservoir level?

    2

    both are now tied up with the caps off over night.

    so the top cap need to be off when you cable tie the lever?

    3

    Another thing i discovered is to gently pump the pistons out and gently push them back in, but have the lever reservoir cover off, seems to shift stubborn clingons at the lever hose union.

    why? maybe i just dont understand the workings of the brake or an open system, but how does the top being off help? doesnt air go on top of the diaphragm whether or not the top is on?
    and is that simply take the top and diaphragm off, then pull lever with no spacer between pistons, so they come out? then push them back with tyre lever or something?

    4

    Turning the freestroke ajuster screw anticlockwise allows the cam roller attached to the end of the master cylinder to travel further into the wave slot machined into the lever. This ensures more fluid is displaced per degree of lever travel until the cam moves back across the wave slot to the power side, effectivly increasing leverage once the pads are in contact. It absolutly does work and has a marked effect thats like night and day. Trouble is, the instructions are flakey, the grafix can be percived to be backwards, and not everybody understands how to adjust them correctly.

    wtf?? 🙂 told you i just dont understand how they work. thats the key i think :-/

    5

    Ellaccy band and burping work wonders.
    Pads out/ pistons in while bleeding from calliper to lever, then top cap on while still injecting.. then as you nip up the bleed nipple a gentle push on the lever to send a little fluid out

    whats burping? and i still dont understand the relevance of when you put the top cap on

    why cant brakes just play nicely!! 🙂

    rootes1
    Full Member

    if you learn to bleed car and motorbike brakes then this bike stuff is a doddle…

    key tips that apply to all.. away make sure bleed points are at highest point, even it that means removing/adjusting position the caliper and lever to reorientate (shimano can't account for the calliper position on every frame design)

    make sure the calliper pistons are fully back – force them back into the housings and hold them there – block of wood and card etc

    force fluid through, actuate slowly so as not to froth fluid and air..

    always tightened nipples whilst still forcing fuild through so when lever is half pressed tighten nipple as you finish the stroke.. this stops air getting back in.

    make sure hoses are as short as they can be and avoid loops etc

    if you can you syringe / vacuum pump to draw fluid through the system.

    Never let the res go dry whilst bleeding and make sure you expel any air from res.

    and sometimes if you are having a bad day stop, and then re bleed later / next day as things settle etc

    sadexpunk
    Full Member

    at the moment ive just cable tied the lever to the bar. with the top cap off, but diaphragm still in place.

    is this right? or does the diaphragm need to be off as well, to leave the fluid open to air?

    U31
    Free Member

    Cap can be on while cable tied, though while it is off remove the rubber and squeeze the levers in and out gently, and watch the air come out

    BadlyWiredDog
    Full Member

    No brakes are "fit and forget", they all go wrong every so often. You might argue that shimano are better than most, but the difference is certainly not as vast as people tend to claim in brakes threads.

    What do you find goes wrong with Shimano brakes then? Just interested, I've run about six sets over the last ten years or so from the original four-pot XTs through to the latest version and SLX, bar the occasional sticky piston they've all been extremely reliable, which is more than I can say for various mates' squealing Hope set-ups 😉

Viewing 40 posts - 1 through 40 (of 56 total)

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