Ask the experts

Shimano brake experts. I have an SLX M675 brake. A while back, on a day when I was bored and looking for completely unnecessary bike maintenance projects, I decided to attempt to clean/lube the caliper pistons because I noticed one was extending more smoothly than the other. Well, I managed to pop out one of the pistons. Got everything back together, but the brake has been rubbish every since. For a while, it would be tolerable so long as long the bike was ridden frequently. Then the bike sat over the winter (and through the spring even). Braking power now is comparable to, or maybe even less than, the amount of deceleration you get from going from pavement to grass. Lever feel was okay, but decided to do a bleed anyways. That didn't help. Swapped pads. That didn't really help. Cleaned pads and rotors, that didn't really help. Swapped to another set of pads, that was slightly better. Took said set of sintered pads, baked 'em under a heat gun to maybe get contaminants out... that made them tolerable, though a bit noisy. But then bike sat a few days and they're back to nearly useless.

Do I:
- Try some other kind of troubleshooting with what I have (a variety of sintered and resins pads and some spare rotors and bleed supplies)
- Order a new caliper and hope that there isn't anything weird in the lever that would be causing this
- Just get a whole new brake

Quote:

---

Originally Posted by jackstraw

Help! Tell me what's wrong. Fox Performance 36 fork. Makes a sound like its losing air during the rebound motion. Sounds like pumping a bike pump not hooked up to a tire. Quick short burst. Hard to hear for sure, but it may be coming from one stanchion only.

---

They make noise. Notice a decline in performance?

Quote:

---

Originally Posted by radam

Shimano brake experts. I have an SLX M675 brake. A while back, on a day when I was bored and looking for completely unnecessary bike maintenance projects, I decided to attempt to clean/lube the caliper pistons because I noticed one was extending more smoothly than the other. Well, I managed to pop out one of the pistons. Got everything back together, but the brake has been rubbish every since. For a while, it would be tolerable so long as long the bike was ridden frequently. Then the bike sat over the winter (and through the spring even). Braking power now is comparable to, or maybe even less than, the amount of deceleration you get from going from pavement to grass. Lever feel was okay, but decided to do a bleed anyways. That didn't help. Swapped pads. That didn't really help. Cleaned pads and rotors, that didn't really help. Swapped to another set of pads, that was slightly better. Took said set of sintered pads, baked 'em under a heat gun to maybe get contaminants out... that made them tolerable, though a bit noisy. But then bike sat a few days and they're back to nearly useless.

Do I:
- Try some other kind of troubleshooting with what I have (a variety of sintered and resins pads and some spare rotors and bleed supplies)
- Order a new caliper and hope that there isn't anything weird in the lever that would be causing this
- Just get a whole new brake

---

Sounds like you buggered the caliper seal and it's leaking fluid onto the pads.

Quote:

---

Originally Posted by HAB

Sounds like you buggered the caliper seal and it's leaking fluid onto the pads.

---

x2

New caliper at minimum

I want to lower the gearing on my cross bike. Currently at 46/36t with a 11-26t 10spd cassette. Looking to go to a 11-36t cassette. It's a 2013 with Sram Re, that derailleur only takes 28t. Was looking at picking up a Sram GX 10spd derailleur with medium cage and to accommodate the new cassette. Can I shift a 2020 GX derailleur with Sram Red from 2013?

Quote:

---

Originally Posted by radam

Shimano brake experts. I have an SLX M675 brake. A while back, on a day when I was bored and looking for completely unnecessary bike maintenance projects, I decided to attempt to clean/lube the caliper pistons because I noticed one was extending more smoothly than the other. Well, I managed to pop out one of the pistons. Got everything back together, but the brake has been rubbish every since. For a while, it would be tolerable so long as long the bike was ridden frequently. Then the bike sat over the winter (and through the spring even). Braking power now is comparable to, or maybe even less than, the amount of deceleration you get from going from pavement to grass. Lever feel was okay, but decided to do a bleed anyways. That didn't help. Swapped pads. That didn't really help. Cleaned pads and rotors, that didn't really help. Swapped to another set of pads, that was slightly better. Took said set of sintered pads, baked 'em under a heat gun to maybe get contaminants out... that made them tolerable, though a bit noisy. But then bike sat a few days and they're back to nearly useless.

Do I:
- Try some other kind of troubleshooting with what I have (a variety of sintered and resins pads and some spare rotors and bleed supplies)
- Order a new caliper and hope that there isn't anything weird in the lever that would be causing this
- Just get a whole new brake

---

I have had a similar experience with my Shimano Zees over the last two seasons. They work great all season, then the bike sits for a few months over the winter, and when I want to ride again the brakes hardly work. A bleed helps the lever feel, but doesn't help the brake slow you down. After trying many, many things this spring, including sanding rotors and pads, soaking each in brake cleaner, and cooking off contaminants with a torch, the only solution I have found is new pads and rotors. I expect I will be able to finish out the season with great braking performance, only to have the brakes mysteriously suck next spring.

If you have a set of pads and rotors that have never been near this bike, maybe try those. Otherwise my only advice is to get new pads and rotors at a minimum, and probably new calipers.

Now for my own issues, concerning suspension on my Canfield Riot:

1. My 2018 Fox 36 FIT4 Factory whatever fork has generally not been great since I got it. I can choose between massive fork dive when I touch the brakes or push into a berm, or having all trail chatter transmitted directly to my hands (I have chosen the latter). It has had a tiny amount of bushing play* for a while, but on my ride yesterday I noticed a pretty significant clunking-around when I was climbing up a moderately rough trail, i.e. while loading and unloading the fork with hardly any force. I think this is excessive bushing play*, but I guess it could be something else.

What amount of service is worth doing on this fork? A Grip2 damper is just over $300, whereas pretty decent new or lightly-used forks can be had for around $500. I am having a hard time getting in touch with my very busy bike shop, but I guess a bushing and seal replacement will be around $150 (and a significant wait time).

*i.e. I can hold the damper side fork leg, lock the front brake, and rock the bike back and forth; and I feel some clunking or knocking inside the fork leg.

2. I have a little play in my suspension linkage, which can be felt by holding the seat tube and rocking the bike side-to-side; I can see the rear triangle moving side-to-side relative to the front triangle. The movement is maybe 1mm. I replaced the bearings at the end of last season, all the links and axles seemed fine. Should I care about this?

I'm on the fence between MT Trail Sports and Curas and could use a shove.

Formula rotors are normal (1.8mm) thickness, correct? I know I'd need to get the thicker rotors for the Maguras, which drives up the cost a bit and has me leaning Formula.

Quote:

---

Originally Posted by bagtagley

I'm on the fence between MT Trail Sports and Curas and could use a shove.

Formula rotors are normal (1.8mm) thickness, correct? I know I'd need to get the thicker rotors for the Maguras, which drives up the cost a bit and has me leaning Formula.

---

Im running MT5s with standard rotors... it works.. I’ll get some Magura specific rotors at some point, difference I imagine is just a slightly tighter bite point....


Sent from my iPhone using Tapatalk

Quote:

---

Originally Posted by Toddball

Now for my own issues, concerning suspension on my Canfield Riot:

1. My 2018 Fox 36 FIT4 Factory whatever fork has generally not been great since I got it. I can choose between massive fork dive when I touch the brakes or push into a berm, or having all trail chatter transmitted directly to my hands (I have chosen the latter). It has had a tiny amount of bushing play* for a while, but on my ride yesterday I noticed a pretty significant clunking-around when I was climbing up a moderately rough trail, i.e. while loading and unloading the fork with hardly any force. I think this is excessive bushing play*, but I guess it could be something else.

What amount of service is worth doing on this fork? A Grip2 damper is just over $300, whereas pretty decent new or lightly-used forks can be had for around $500. I am having a hard time getting in touch with my very busy bike shop, but I guess a bushing and seal replacement will be around $150 (and a significant wait time).

*i.e. I can hold the damper side fork leg, lock the front brake, and rock the bike back and forth; and I feel some clunking or knocking inside the fork leg.

2. I have a little play in my suspension linkage, which can be felt by holding the seat tube and rocking the bike side-to-side; I can see the rear triangle moving side-to-side relative to the front triangle. The movement is maybe 1mm. I replaced the bearings at the end of last season, all the links and axles seemed fine. Should I care about this?

---

1) A Grip2 damper is clearly superior to the fit4, but a new damper isn't gonna fix bushing slop. That said, sounds like something is fucky with your damper - the fit4's weren't great, but they weren't as terrible as you're describing. I'd probably start with a rebuild, then if you still don't like it, sell it. Of course, if that rebuild was going to take more than a week or so, that might change things.

2) side to side play in your rear linkage is bad. Not sure what it'd be - a missing washer / spacer somewhere is the most likely culprit. Left unchecked, that play will lead to bigger issues down the road.

Quote:

---

Originally Posted by toast2266

1) A Grip2 damper is clearly superior to the fit4, but a new damper isn't gonna fix bushing slop. That said, sounds like something is fucky with your damper - the fit4's weren't great, but they weren't as terrible as you're describing. I'd probably start with a rebuild, then if you still don't like it, sell it. Of course, if that rebuild was going to take more than a week or so, that might change things.

2) side to side play in your rear linkage is bad. Not sure what it'd be - a missing washer / spacer somewhere is the most likely culprit. Left unchecked, that play will lead to bigger issues down the road.

---

Agreed with all of that. Only thing I'd add is, make sure you're not just feeling the brake pads rocking in the caliper as the play before you start replacing bushings. From the way you described it sounds like that's probably not it, but it'd be worth double checking.

Thanks for all the advice everyone, replaced my fork without incident. I ended up getting a steerer tube saw guide in addition to the star nut setter thing, the combination of which made it quite idiot proof. Took me like 6 tries to get the stem lined up with the front wheel, that was probably the hardest part.

Quote:

---

Originally Posted by toast2266

1) A Grip2 damper is clearly superior to the fit4, but a new damper isn't gonna fix bushing slop. That said, sounds like something is fucky with your damper - the fit4's weren't great, but they weren't as terrible as you're describing. I'd probably start with a rebuild, then if you still don't like it, sell it. Of course, if that rebuild was going to take more than a week or so, that might change things.

2) side to side play in your rear linkage is bad. Not sure what it'd be - a missing washer / spacer somewhere is the most likely culprit. Left unchecked, that play will lead to bigger issues down the road.

---

Okay, if I can get the fork rebuilt in a reasonable time frame I'll do that. I am loathe to tear down the linkage again, because getting the captive bottom link back in the frame together with the requisite washers is such a pain, but I guess it's worth doing.

Quote:

---

Originally Posted by HAB

Agreed with all of that. Only thing I'd add is, make sure you're not just feeling the brake pads rocking in the caliper as the play before you start replacing bushings. From the way you described it sounds like that's probably not it, but it'd be worth double checking.

---

I know the rocking brake pad noise and feel very well (and so does anyone who rides within earshot of me), and this is not it. I can really clamp down hard on the brakes, so the pads don't move in the calipers, and still feel the fork clunk.

Quote:

---

Originally Posted by mall walker

Took me like 6 tries to get the stem lined up with the front wheel, that was probably the hardest part.

---

I worked in a shop as a mechanic for years, and it still feels like I fuck that up on the first try at least half the time.

Quote:

---

Originally Posted by bagtagley

The advantage to the Ardent, over something like a Nevegal, is that it makes it very clear very early that it's not going to grip in a corner. No trickery or false sense of security, it's very open about the fact that it sucks at cornering. Kind of admirable if you think about it.

---

Ardents and Nevegals.

This thread has jumped the shark. :nonono2:

Quote:

---

Originally Posted by toast2266

<snip> if you still don't like it, sell it.

---

This has been my solution to every Fox fork I've ever had.

Disclaimer: I ain't had many, but they both had to go because they sucked. :D

Quote:

---

Originally Posted by grskier

They make noise. Notice a decline in performance?

---

No, but it's brand new, so I'm not sure I'd even know because I've been playing with pressure/rebound with both front and rear.

I'm going to check pressure tonight as I set it last night then rode today. Going to see if I've lost any.

I don't know, maybe this is normal for a Fox shock?

https://vimeo.com/431449772

Quote:

---

Originally Posted by cmor

I want to lower the gearing on my cross bike. Currently at 46/36t with a 11-26t 10spd cassette. Looking to go to a 11-36t cassette. It's a 2013 with Sram Re, that derailleur only takes 28t. Was looking at picking up a Sram GX 10spd derailleur with medium cage and to accommodate the new cassette. Can I shift a 2020 GX derailleur with Sram Red from 2013?

---

I’d get an 11-30 or an 11-32 and you’ll be fine with a little bit of B-tension screw adjustment on that derailleur. You might need to find a longer b-tension screw, or you can reverse the bolt direction fir some added length.
If you really need 11-36 you can use a MTB XX, XO, X9 or X7 10 speed derailleur driven by your 10sp Red shifters.

When SRAM launched their road technology from scratch they re-applied the MTB SRAM 1:1 actuation ratio (shifter cable travel : derailleur movement) for 10 speed rear shifting.
This is a redesign from the 9 speed SRAM stuff.
So SRAM’s 10-speed mountain bike derailleurs XX, X0, X9 & X7 are compatible with their 10-speed road shifters Red, Force, Rival & Apex.

Quote:

---

Originally Posted by HAB

Agreed with all of that. Only thing I'd add is, make sure you're not just feeling the brake pads rocking in the caliper as the play before you start replacing bushings. From the way you described it sounds like that's probably not it, but it'd be worth double checking.

---

That was my first thought. I've had people swear they can't get their headset play out when it was actually that.

the fork I just got came set at 110psi (with a mfr's stated max of 145), and can hand flex it by leaning on the handlebars somewhat readily. the manual says at my weight (150lbs) it should be 65-75psi. this seems insane, but is it stupid to just let it be and ride it 30+psi over recommended?

Quote:

---

Originally Posted by mall walker

the fork I just got came set at 110psi (with a mfr's stated max of 145), and can hand flex it by leaning on the handlebars somewhat readily. the manual says at my weight (150lbs) it should be 65-75psi. this seems insane, but is it stupid to just let it be and ride it 30+psi over recommended?

---

Do you know how to measure sag? If so, what is your sag at now?

Quote:

---

Originally Posted by Toddball

Do you know how to measure sag? If so, what is your sag at now?

---

hm, I do in theory and I have some zip ties. I'll take a look later

Quote:

---

Originally Posted by mall walker

hm, I do in theory and I have some zip ties. I'll take a look later

---

You'll want a shock pump too, won't be able to adjust it accurately with a regular pump.

Quote:

---

Originally Posted by snowaddict91

You'll want a shock pump too, won't be able to adjust it accurately with a regular pump.

---

I have a $25 “fox racing shox suspension pump” ... but it’s a bit janky

e: https://www.backcountry.com/fox-raci...uspension-pump

it worked fine for adjusting the dropper seat's suspension, but it did not seem to affect my actual fork suspension much. maybe I am doing it wrong idk

Quote:

---

Originally Posted by mall walker

the fork I just got came set at 110psi (with a mfr's stated max of 145), and can hand flex it by leaning on the handlebars somewhat readily. the manual says at my weight (150lbs) it should be 65-75psi. this seems insane, but is it stupid to just let it be and ride it 30+psi over recommended?

---

Quote:

---

Originally Posted by Toddball

Do you know how to measure sag? If so, what is your sag at now?

---

Ditto what he said. Ignore the charts for a moment and make sure you have a way of measuring the fork sag. Ideally you have a stable bike stand or a partner to help, but I’ve done this just by leaning against the wall.

This article was the first one that came up on google, start at the “Adjust your controls” section halfway down and go from there.

https://www.mbr.co.uk/how-to-2/hardtail-set-up-376850

Here are some tips:
-if the fork doesn’t have a rubber o ring travel indicator, use a zip tie around one stanchion
-ideally when measuring sag you would rock the bike back and forth, then slowly get into a standing “descent”
position, have someone set the o ring to the bottom of the stanchion (or ever so delicately do it with one hand while supporting your body with the other), then slowly get off the bike so you can measure the amount of travel you used.
-figure that 20-25% only as a starting point ... one school of thought is that you should have your suspension set up so that when riding hard, you are bottoming out at least once per ride, meaning you are using all the travel available from your fork ... which is why you may need to add or remove air after some test rides
-write down your suspension settings (air pressure, rebound clicks CCW from full closed, compression clicks CCW from full closed), like in a note file on your cell phone. This way you can keep track of where you are at and see how specific changes are reflected in the riding feel.

Special notes:
-Whenever changing air pressure remember to really cycle the fork before measuring air pressure and testing the resulting sag, this is because most air spring forks need to equalize the pressure in the positive and negative spring chambers
-some forks do *not* bottom out where the stanchion tops out at the crown! This will affect your perceived sag and “am I using full travel available” observations!

^ interesting. I will measure the sag tomorrow morning before I ride then. what does "really cycle the fork" mean - fully compress it? e: also, is "full closed" rebound all the way to the minus sign or all the way to the plus sign? lol

A recent video with Jordie from Fox had him saying, just do a dozen very short pumps of fork (5mm or so), until you hear/feel the equalize of chambers.

Yeah, there's not really any reason to get deep in the stroke. Basically there's a little dimple on the inside of the stanchion near the topout point, and when the seal on the air piston passes over it, it lets air past the seal between the positive and negative chambers. You're just trying to go back and forth over that a few times to get the two chambers equalized properly.

Useless bottle cage mount solution?

I am running a size small Knolly Warden Carbon with a Push coil shock, so the cage mounts are useless unless I had some weird 2" diameter water bottle.

I would like to use those mounts to strap a small custom water bottle or my CO2/tube or thin can of bear spray to.

Salsa makes the "Anything Cage" but that looks pretty huge for mounting feed bags or full size Nalgene bottles too. Is there a similar product I am not seeing. Basically a metal bar that attaches to frame using cage mounts and then has 2 or 3 velcro straps. If it doesn't exist I am just gonna make it with home depot alu flat stock.

EDIT:

Nevermind. Think I found exactly what I needed.

https://www.wolftoothcomponents.com/...d-mount#loaded

^ what those guys said on the pressure equalization thing.

On the fully closed thing, fully closed means all the way “righty tightey” and I also say “clamp to damp” as a moniker. This next bit is just “what I’ve heard” because despite being a semi-engineer guy I’ve never torn down a fork to validate what is happening in the damper assembly myself ... but what I’ve heard is that the reason to count number of clicks CCW from fully closed is that on some forks, the first 1 or 2 clicks CW from fully open may have no or little effect (on compression or rebound dampening) compared to subsequent dial movements.

Quote:

---

Originally Posted by Whiteroom_Guardian

Useless bottle cage mount solution?

I am running a size small Knolly Warden Carbon with a Push coil shock, so the cage mounts are useless unless I had some weird 2" diameter water bottle.

I would like to use those mounts to strap a small custom water bottle or my CO2/tube or thin can of bear spray to.

Salsa makes the "Anything Cage" but that looks pretty huge for mounting feed bags or full size Nalgene bottles too. Is there a similar product I am not seeing. Basically a metal bar that attaches to frame using cage mounts and then has 2 or 3 velcro straps. If it doesn't exist I am just gonna make it with home depot alu flat stock.

EDIT:

Nevermind. Think I found exactly what I needed.

https://www.wolftoothcomponents.com/...d-mount#loaded

---

I was gonna say, doesn’t every cheap bike pump come with a bottle cage mount with Velcro straps that you could instead use for a can of bear spray? I also haven’t tried this but it seems the money move is to replace the Velcro straps with short voile straps ... of course if a mama brown bear is charging at you, is much rather have that shit on my hip belt ...

Quote:

---

Originally Posted by SchralphMacchio

I was gonna say, doesn’t every cheap bike pump come with a bottle cage mount with Velcro straps that you could instead use for a can of bear spray? I also haven’t tried this but it seems the money move is to replace the Velcro straps with short voile straps ... of course if a mama brown bear is charging at you, is much rather have that shit on my hip belt ...

---

Yeah, I am one of those kooks who has slowly evolved to try to ride with the least amount of stuff on my person. I honestly can't believe I used to ride with an actual backpack. Now the 2L hip pack feels bulky at times. If it's a 2.5 hour ride or less I will have nothing on my back and it's amazing.

Bear spray strapped to the cage mount probably wouldn't be all that useful to grab in .0004 seconds.

Either mounting one of these or just wearing the damn hip belt makes sense. Although I have heard of people crashing their bike and puncturing the bear spray. Talk about Type 2 OTB with extra spice!

https://www.atkenco.com/counter-assa...oaAkMOEALw_wcB

Quote:

---

Originally Posted by Whiteroom_Guardian

Yeah, I am one of those kooks who has slowly evolved to try to ride with the least amount of stuff on my person. I honestly can't believe I used to ride with an actual backpack. Now the 2L hip pack feels bulky at times. If it's a 2.5 hour ride or less I will have nothing on my back and it's amazing.

---

Hilarious.

25 years ago: "I honestly can't believe I used to ride shit strapped all over my bike. Now when I ride I will have everything on my back in a hydration pack and it's amazing."

:D

ya this ^^

Quote:

---

Originally Posted by XXX-er

ya this ^^

---

Fuckin' n00Bs, amirite?? :D

Quote:

---

Originally Posted by skaredshtles

Hilarious.

25 years ago: "I honestly can't believe I used to ride shit strapped all over my bike. Now when I ride I will have everything on my back in a hydration pack and it's amazing."

:D

---

Full circle. Dayglow and hair bands coming next

I ignored a creak that I thought was new pedals, it was mildly annoying for a while. I meant to look at it but kept forgetting to. Went on a really long solstice ride. It got really bad, I was just trying not to bonk but took a quick break to tighten everything up and couldn't find anything loose. The next day I was looking over the bike and I realized it was my drive side crank that was really, really loose. I tightened it up but it quickly came loose again on yesterdays ride. They are SRAM XO Dub cranks. Am I looking at new cranks?

Quote:

---

Originally Posted by dfinn

I ignored a creak that I thought was new pedals, it was mildly annoying for a while. I meant to look at it but kept forgetting to. Went on a really long solstice ride. It got really bad, I was just trying not to bonk but took a quick break to tighten everything up and couldn't find anything loose. The next day I was looking over the bike and I realized it was my drive side crank that was really, really loose. I tightened it up but it quickly came loose again on yesterdays ride. They are SRAM XO Dub cranks. Am I looking at new cranks?

---

Most of the problems are people not being able to loosens he bolt on DUB cranks.
Do you have the correct spacer(s) on the DUB bottom bracket?
The torque setting for the driveside 8mm hex bolt is really high. Like 50+ N.m. After tightening you need to hammer the crank fully towards the non-driveside and then adjust the preload adjuster.

I will give that a try. These had been on the bike and been fine for quite a while.

What's the advantage (theoretical or real) of the DUB or Race Face cinch type crank vs GXP or Shimano 24mm type? The preload adjustment seems fiddly.