Mechanics Quick Question Thread [Ask Questions Here]

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Mechanics Quick Question Thread [Ask Questions Here]
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flag R-M-R
Posted: Sep 10, 2019 at 22:24 Quote
nojzilla wrote:
Have you ever ridden one?

Oval yes; Absolute Black no.

I've used a couple shapes of oval and played with the timing. Maybe my biomechanics would adapt after a year or so and I would prefer oval, but it seemed to be worse than round and I wasn't willing to play the long game to see if oval would eventually work out.
flag naptime
Posted: Sep 10, 2019 at 22:53 Quote
I can say, with only trying AB.. the difference is immediately noticable. Its definitely a smoother cadence which with clips, I find better. I wouldn't say so with flats. The extra 2th effect. I'll also say is definate, the first ride I was in my usual cogs for the line an I quickly tired myself. Like I was in to hard a gear..

Weather that's better for overall performance could be debatable but, I personally think they do what they say on the tin.

P.S I'm old enough to remember the old shimano biopace that where the same concept but flawed in desighn
flag Duderz7
Posted: Sep 10, 2019 at 22:58 Quote
R-M-R wrote:
Duderz7 wrote:
Nobble wrote:
Many shops won't clean contaminated rotors for two reasons:

1: It doesn't always work well, depending on how much it was ridden while contaminated and what it was contaminated with. The shop can't guarantee that the problem is 100% fixed. I wouldn't want to charge a customer without knowing I had fixed the problem the paid me to.

2: Its usually time consuming, no big deal if you're a home mechanic. If you're a shop, it either eats up your already mediocre profit margins or it costs the customer almost the same as a new rotor.

Reason 1 combined with Reason 2 means it's usually better to just replace the rotor. Just take the old rotor home, clean it yourself and keep it as a spare.
Automotive disc brake cleaner that is residue free works perfectly. Has never let me down. My favorite brand is berrymans. I've even had success cleaning contaminated pads with if they're not completely soaked. As far as from a shop stands, I agree. It's best not to leave something, like brakes especially, to chance and end up with an unhappy customer.

Here's the MSDS for Berryman Brake Cleaner: it's 95% - 99% acetone!
I suppose that's why it works so well then.
flag R-M-R
Posted: Sep 10, 2019 at 23:22 Quote
Duderz7 wrote:
R-M-R wrote:
Here's the MSDS for Berryman Brake Cleaner: it's 95% - 99% acetone!
I suppose that's why it works so well then.

I looked up a few other cleaners people were debating on another forum. Exactly the same: acetone and a little propellant. Acetone is a damn fine solvent and not very toxic. Love that stuff. Just keep it away from epoxy (ex. thermoset carbon).

Some other brake cleaners contain a mix of chlorinated solvents and other volatile organics. They may work even better, for all I know, but yikes.
flag watch123
Posted: Sep 11, 2019 at 8:39 Quote
nojzilla wrote:
I can say, with only trying AB.. the difference is immediately noticable. Its definitely a smoother cadence which with clips, I find better. I wouldn't say so with flats. The extra 2th effect. I'll also say is definate, the first ride I was in my usual cogs for the line an I quickly tired myself. Like I was in to hard a gear..

Weather that's better for overall performance could be debatable but, I personally think they do what they say on the tin.

P.S I'm old enough to remember the old shimano biopace that where the same concept but flawed in desighn

Ok, thanks for all the advice, definitely more interested in it now.
flag hyroller80
Posted: Sep 11, 2019 at 9:21 Quote
just installed new Shimano XT 4 piston brake set. The brake pads rattle badly when not under braking. Obviously not felt when climbing, but when descending even at slow speeds they rattle. Vibrations are felt through the entire bike and its very noisy and uncomfortable. Under braking everything is silent and works really well.
I have tried stretching the springs out between the pads....but that didn't make any difference. I've also been advised to try advancing the pistons before putting the pads into the caliper, but have yet to try that. Any other bright ideas on how to eliminate the pad rattle ?
flag R-M-R
Posted: Sep 11, 2019 at 9:27 Quote
hyroller80 wrote:
just installed new Shimano XT 4 piston brake set. The brake pads rattle badly when not under braking. Obviously not felt when climbing, but when descending even at slow speeds they rattle. Vibrations are felt through the entire bike and its very noisy and uncomfortable. Under braking everything is silent and works really well.
I have tried stretching the springs out between the pads....but that didn't make any difference. I've also been advised to try advancing the pistons before putting the pads into the caliper, but have yet to try that. Any other bright ideas on how to eliminate the pad rattle ?

Pads are little things that weigh a few grams and can move only a few millimeters. If you can feel it throughout the whole bike, something more serious than pads is loose.
flag watch123
Posted: Sep 11, 2019 at 18:19 Quote
Any insight into how essential it is to have the heat shield installed on SRAM Code brakes? See page 7 of the manual for the exploded view.

Edit to follow up in case anybody else sees this and wants to know the answer. Apparently it is important, keeping the brake pads in line.
flag Owensven
O+
Posted: Sep 11, 2019 at 22:39 Quote
Would an ethriteen LG1+ downhill chainguide/bashguard fit comfortably on my 2018 nomad (30t chainring) without causing any clearance issues

Thanks
flag seraph
Posted: Sep 11, 2019 at 23:28 Quote
Owensven wrote:
Would an ethriteen LG1+ downhill chainguide/bashguard fit comfortably on my 2018 nomad (30t chainring) without causing any clearance issues

Thanks

Most likely, it should fit fine.
flag thedad71
Posted: Sep 12, 2019 at 2:56 Quote
I have just bought a bike used, very happy with it so far but a question. It has 160mm pikes reduced to 140mm. Would all the recommended settings for rebound, pressure etc. Still apply or do I need to adjust for less travel? E.g. increase pressure by about 13% as that's roughly the travel I have lost? Or am I reading too much into this?
flag JohnyBoy
Posted: Sep 12, 2019 at 3:24 Quote
thedad71 wrote:
I have just bought a bike used, very happy with it so far but a question. It has 160mm pikes reduced to 140mm. Would all the recommended settings for rebound, pressure etc. Still apply or do I need to adjust for less travel? E.g. increase pressure by about 13% as that's roughly the travel I have lost? Or am I reading too much into this?

I run shorter travel forks a bit harder than longer ones and never look at the recommended air pressure. Just set the sag you want and work it out from there.
flag Blackmetalgoat
Posted: Sep 12, 2019 at 15:47 Quote
hi guys , ive got my dhx rc4 recently serviced but noticed that it is leaking oil form under the rebound knob , does anyone know what my problem is ?
flag cyberoptixs
Posted: Sep 12, 2019 at 18:23 Quote
Blackmetalgoat wrote:
hi guys , ive got my dhx rc4 recently serviced but noticed that it is leaking oil form under the rebound knob , does anyone know what my problem is ?

I would say you have a leak under your rebound knob Wink
flag Duderz7
Posted: Sep 12, 2019 at 19:05 Quote
Blackmetalgoat wrote:
hi guys , ive got my dhx rc4 recently serviced but noticed that it is leaking oil form under the rebound knob , does anyone know what my problem is ?
How long ago was it serviced? If you just got it back is possible a touch of oil was hiding under the rebound knob and wasn't noticed until it got some dust on it. Try cleaning it up and see if it continues.

 


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