A.R.S.E.

Yeah I had to jam a screw driver in to push back the pistons. It seems the fluid used in the system doesn't like heat so it seems to expand and the piston wont go back unless forced. I went for a ride and it seemed fine until I had to use the front brake. It screamed and howled but hopefully it burnt the pads some.

Dr. Pain wrote:Yeah I had to jam a screw driver in to push back the pistons. It seems the fluid used in the system doesn't like heat so it seems to expand and the piston wont go back unless forced.

Dot fluid or mineral oil brakes?

Ive used both on my MTB's and never had this issue happen and ive ridden on some stinkin hot days. Worts ive had happen is brake fade down some of the downhill trails at Fox.

I'm not sure Knappo. The fluid is whatever the system came with but I think it's mineral oil. I have urban bike and I've never reset the pistons in the 3 or 4 years I've owned it but got it on the front anyway. I might have to bleed the back.

Dr. Pain wrote:I'm not sure Knappo. The fluid is whatever the system came with but I think it's mineral oil. I have urban bike and I've never reset the pistons in the 3 or 4 years I've owned it but got it on the front anyway. I might have to bleed the back.

What brand are they?

From my experience Shimano use mineral oil and everyone else pretty much uses Dot fluid which can be a pain in the arse in having to de gas it when bleeding. More manufactures might use mineral oil these days but Dot fluid was the go for years.

The pistons (or just one) could be jamming from being dirty. My old Avids have one side of the calliper with a jammy piston, they are a nightmare to get the gapping correct of the pad and rotor but they still work and you can get it to spin freely. They were free from a mate and its my backup bike so reluctant to spend coin on them, they need a service...

http://bennosblogandmore.blogspot.com.a ... s-and.html

My Avid's suffer from step 4. Step 6 onwards shows how to clean em up if this is what you might be experiencing. Popping the pads out and having a look if the pistons positions in the caliper are asymmetric is a pretty good sign one of them is needing a clean.

I have promax deciphers and its DOT fluid not mineral oil. Anyway I've got really nice clearance in the front now but need to ride it and use the brakes, but it's pissing down rain.

So back to chain waxing...
post CX national series rounds I've taken the chain off the bike, through the ultrasonic cleaner and dipped into the wax bath.. all up, i'm pretty impressed with how clean the chain comes up, and particularly how easily it cleans up. Not really sure how many kilometers this chain has done, but from memory it's been through a bunch of slushy races so i'd say it's had a bit of a hard life.
If you have the patience to set things up initially, i'd fully recommend it.

had one of those days today on the bike maintenance front..

The other day i was hearing a fairly unpleasant sound coming from my drive train, including an occasional vibration being transmitted through the pedals. Pulled the rear wheel out and discover that the bearings in my freehub are shot. No problem; for some reason i have some spares that i don't recall purchasing. After some effort i pop one of the bearings out and the spacer that sits inside the freehub. The second bearing is retained with a circlip, for which i have no tool. So i call it a night.

fast forward to today, and I rush out and buy a cheap set of circlip pliers. i get them out of the package at home and realise i bought the wrong ones (i could have sworn i picked up the interior version. through a bit of stubbornness i manage to get the circlip out anyway.

i start trying to hammer out the second bearing, when i realise that it's turned slightly jamming it into the freehub tight. so i apply more hammer.. which results in the centre of the bearing disintegrating, and leaving the outer race still inside, but now loose. I have zero idea how i'm going to get that out of there

fortunately i do have a second freehub body, so i think i might try to reassemble that one with the new bearings..

so the lesson from today.... more hammer isn't always the answer :/

So for those curious.....

Garmin Edge 800s don't seem to like being filled up with water :/

i charged up my old Garmin 800 last week (probably the first time in quite a while) and realised that it was having difficulty picking up the satellites. No problem, leave it outside for a while and it'll sort that out....

Of course, i forgot about it and it's been out there for about a week though some of the decent rain that we're had recently here :P
Having been well used, the rubber seal covering the power button is split, and just for good measure i hadn't closed the rubber seal on the USB port. :/

have currently disassembled it and hopefully a good drying out will allow it to spring back to life

Submerge the Garmin in a bowl of rice overnight mate. Cover the bowl with cling wrap to seal it good.

Duke wrote:Submerge the Garmin in a bowl of rice overnight mate. Cover the bowl with cling wrap to seal it good.

think i have it working. disassembled it all, left it with paper towels to soak up the moisture. seems to be charging and powering on. Though it doesn't seem to have found satellites yet. maybe i should leave it outside for a bit....

Anyone dabbled with tyre pressures recently given the trend of wider rims/tyres = less rolling resistance?
I have been using this calculator & am even running closer to wet weather pressures in the dry as it feels so good even if not the fastest...

https://axs.sram.com/tirepressureguide

Road bike 25mm GP5000's I weigh 83 kg I usually run 90 psi seems to work for me!

being relatively old school, i 've really struggled to move away from the "pump it up to the Max Pressure rating" philosophy. Though i have been experimenting a little bit more recently.

On my Pinarello, i have 23mm tyres on 25mm width rim. so i'd typically put them at 90 PSI (rear)/80 PSI (front). On my Giant roadie, i have 25mm tyres on a narrower rim, but i inflate to about the same. Based on that calculator, i could drop to ~75 PSI (rear)/ 70 PSI (front). I reckon i have run at those pressures before, and while it generally felt okay, I was constantly looking down at my tyres to see if the squishyness was a flat tyre or not :/

The settings for Cyclocross are interesting.
I'd normally run ~40PSI rear, 30ish PSI front. If i'm feeling aggressive, then that might drop to 35 Rear, 25 front. The calculator suggests 30.6/28.8PSI rear/front. I *could* run that, but I think i'd risk rolling the tyre off the rim and burping the tyre :/ In fact, i reckon i did that in a National Series round

23mm on a 25mm rim... Is that the inner or outer rim width CLP?

This is the inspiration for my experimentation: https://blog.silca.cc/tire-size-pressur ... got-to-now

Although I am doing it for the comfort benefits more then for the so called "marginal gains" around aero & rolling resistance.

Blame it on getting old.

Duke wrote:23mm on a 25mm rim... Is that the inner or outer rim width CLP?

Outer. (actually.. just checked the specs.. it's 26.2mm outer at the brake track, 20.2 inner.)

Ooo! i've played this game before!

Damn Darren, that's a well used CR.

There is still some meat on it yet Darren.

Next photo is how match the old chain has stretched compared to the new one?

The chain didn't seem terrible when measuring which confuses me a bit. It's 1/16" longer over 12 links. 38.3mm for 15 links. As far as I can find that's due for replacement but the rest of the drivetrain is still supposed to be fine? It was a fair bit longer when lining them up to get the new one to length but I didn't take a pic of that. It did about 4500km, regularly cleaned and lubed. Not sure how long these bits are supposed to last.

I replaced the cassette and big ring as well to play it safe, but it was hard to pick out wear when comparing those. Only issue I was getting was when shifting from the small to the big ring. Probably something to do with them being 1/4 link out of alignment from the wear :o

It had sram chainrings, shimano 105 cassette and KMC chain. Made it all shimano 57xx this time with a 6701 chain. Switched to wax as well, with Squirt. Hopefully that makes things cleaner and easier.

Had the rear derailleur cable go yesterday, shifting had been shit all morning but luckily it didn't let go until I got home trying to see what was causing the issue.
But as it had broken I had a bitch of a time trying to get the cable end out of the shifter as it had broken just a few cm from the end.
The way the cable routes & where the end inserts into the Ultegra 6800 shifter and the lack of a large opening makes fishing it out a nightmare.
It is the first time I have not been happy with a Shimano design decision.
Also the cable only last 6000k's but can't remember what sort of life-span I used to get with the older Ultegra models but I feel it used to be more than 6 months of riding.

Interesting read.

Adam K has made a nice little business with ZFC and he's really nice bloke too. Though from a science standpoint, i do take minor issue with the term "zero friction" in relation to drivetrains :P