Australian Cycling Forums - Bicycles Network Australia

blizzard wrote: ↑

Sat Aug 31, 2024 6:59 am

Also for Shimano it's possible to burst the bladder in the lever pushing the piston back in, so to be safe you can crack the bleed port on the lever. I've never done it and haven't had an issue, I think it's more a shop mechanic thing that incase the system has extra fluid in it because it was bled incorrectly previously.

Incorrect, it's more likely - but still very rare - with brakes that use DOT fluid (SRAM, Hayes & others); the fluid absorbs moisture and expands, increasing the volume of fluid in the system. Mineral oil systems such as Shimano, Tektro and Magura do not absorb moisture, so the fluid volume doesn't increase.

Duck! wrote: ↑

Sat Aug 31, 2024 11:41 am

blizzard wrote: ↑

Sat Aug 31, 2024 6:59 am

Also for Shimano it's possible to burst the bladder in the lever pushing the piston back in, so to be safe you can crack the bleed port on the lever. I've never done it and haven't had an issue, I think it's more a shop mechanic thing that incase the system has extra fluid in it because it was bled incorrectly previously.

Incorrect, it's more likely - but still very rare - with brakes that use DOT fluid (SRAM, Hayes & others); the fluid absorbs moisture and expands, increasing the volume of fluid in the system. Mineral oil systems such as Shimano, Tektro and Magura do not absorb moisture, so the fluid volume doesn't increase.

Thanks Duck for the correction. I've heard Dave Rome talk about cracking the bleed port, when pushing pistons as a precaution, not sure what his context was.

jasonc wrote: ↑

Fri Aug 30, 2024 9:28 pm

g-boaf wrote: ↑

Fri Aug 30, 2024 9:04 pm

I damn well hate changing pads on disc brake bikes and all the damn maintenance on them.

Take the wheel off
Remove the old pads
Push pistons back
Install new pads
Reinstall wheel
Bed in pads

It needed bleeding, that's done now and it's happy again. I was admittedly tired and short of patience yesterday.

The morning ride I took the Canyon Ultimate CF Evo out instead - which worked out well because it was so gusty. The S5 would have been blown about terribly.

Bled brakes for the first time a week or so ago, on a bike where I volunteer. Have to say it was easier than I thought it would be, although I have done it on cars before (a lot of years ago). It was messy so if I do it on my new bike I will be making sure I have syringes at both ends and avoid spreading the fluid everywhere.

Must remember to clean the pistons next time I replace pads, forgot last time. Plenty of isopropyl here, I use it to clean records.

DS

after my tubeless tyre failed to stay inflated, even after plugging it, I put a tube in it. So I bought a new tyre, and new valve. After about 10 different efforts I have finally got the tyre to stay inflated. The soapy water on the bead, and the right rubber bits on the valve finally did it. what a pain. I used a floor pump without the valve installed to pump it up. Before the soapy water I just don't think it was sealing in the bead properly. Now I just need to insert the sealant

Took the pulleys off my commuter yesterday to give them a good clean in preparation for giving waxing a try. Of course, I didn't take note of which was which (two different size pulleys - GRX800), or which side was what. So a simple job took me an extra 30 minutes of Googling contradictory information and working out which pulley goes in which direction.

With jockey wheels I only ever do one at a time

Shimano jockey wheels are usually marked "G-pulley" for the top, guide pulley, and "T-pulley" for the bottom, tension pulley, and are marked with rotation direction arrows. In some generations of derailleurs, the t-pulley is asymmetrical, so even if it's in the right place, if it's the wrong way around it can foul on the derailleur cage.

jasonc wrote: ↑

Sun Sep 15, 2024 8:56 am

after my tubeless tyre failed to stay inflated, even after plugging it, I put a tube in it. So I bought a new tyre, and new valve. After about 10 different efforts I have finally got the tyre to stay inflated. The soapy water on the bead, and the right rubber bits on the valve finally did it. what a pain. I used a floor pump without the valve installed to pump it up. Before the soapy water I just don't think it was sealing in the bead properly. Now I just need to insert the sealant

I have a 240v compressor with a storage tank that will run a paint spray gun. I whip the valve out and blast air in through the stem to seat the tyre with that. Sometimes it takes significant pressure to get the tyre to "pop" over the bead.
Once seated I put sealant in througn the rim with a Stans syringe designed for the purpose. Reinflate and put the wheel on its' side and wobble it around to coat the tyre and the bead on both sides. Usually all good after that.
A comparitive pita to install a new tyre compared to tube but the reduction in punctures has more than offset it for me.

Warthog1-i was investigating compressors but my pump is sufficient, thankfully

After switching forks on my pub/shop bike a while back I hopped on to ride to the shop. After locking the doors and rolling out the drive I noticed the bars weren't straight off by about 5degrees. Tried to pull them straight without success. Obviously tightened the bolts to a decent torque while the bars were properly crooked. Rode it anyway. It's less critical when you've got shopping bags swinging from the bars.

Duck! wrote: ↑

Sun Sep 15, 2024 11:13 am

Shimano jockey wheels are usually marked "G-pulley" for the top, guide pulley, and "T-pulley" for the bottom, tension pulley, and are marked with rotation direction arrows. In some generations of derailleurs, the t-pulley is asymmetrical, so even if it's in the right place, if it's the wrong way around it can foul on the derailleur cage.

Thanks Duck, I did work all that out eventually. With the chain off the bike my first challenge was working out the rotation direction for each pulley, trying to visualise it with no chain there. And the Googling I did initially was confusing in some descriptions of which pulley is guide and tension - I couldn't work out which one was "top" at first because the cage was horizontal so both neither pulley was "closest to the cassette". Something so simple in theory but several things to work out before I got it right

jasonc wrote: ↑

Sun Sep 15, 2024 8:56 am

after my tubeless tyre failed to stay inflated, even after plugging it, I put a tube in it. So I bought a new tyre, and new valve. After about 10 different efforts I have finally got the tyre to stay inflated. The soapy water on the bead, and the right rubber bits on the valve finally did it. what a pain. I used a floor pump without the valve installed to pump it up. Before the soapy water I just don't think it was sealing in the bead properly. Now I just need to insert the sealant

the tubeless tyre survived the journey in. looks like it was a success.

An airshot or 240V compressor is an essential for a tubeless install in my book.

It's about the only way you can guarantee it'll bead up, and neither is a huge investment.

It also depends on the tyres (even with tubes). I fitted some Schwalbe Almotion 700c x 50 (with tubes) last year and tried 4 times using my large pump. I even tried soapy water on bead and rim, tried "manipulating" the tyres when partially inflated, nothing worked. The tyres were not concentric to the rims, not far off, but not right.

So I fired up the compressor and blasted it up to around 65psi, and the tyres made 2 or 3 loud "pops" and job done.

Mr Purple wrote: ↑

Mon Sep 16, 2024 8:23 am

An airshot or 240V compressor is an essential for a tubeless install in my book.

It's about the only way you can guarantee it'll bead up, and neither is a huge investment.

well I don't have an air compressor. I was tempted to buy one half way through saturday, but I got there

jasonc wrote: ↑

Mon Sep 16, 2024 8:43 am

Mr Purple wrote: ↑

Mon Sep 16, 2024 8:23 am

An airshot or 240V compressor is an essential for a tubeless install in my book.

It's about the only way you can guarantee it'll bead up, and neither is a huge investment.

well I don't have an air compressor. I was tempted to buy one half way through saturday, but I got there

Even one of these makes life a lot easier.

https://www.pushys.com.au/airshot-tyre- ... 6AODvjyZWV

I get the job done — as I have done successfully for decades now, with a Silca floor pump, progressive inflation, massaging the tyre into place, then full inflation.

240V compressors should be left to the purpose for which they were designed — low pressure, high volume inflation of car tyres and more sturdy objects than pricey bike tyres.

C02 cartridges are also a quick and efficient way of speedy inflation without such pricey toys as the device at Pushys.

Mr Purple wrote: ↑

Mon Sep 16, 2024 9:10 am

jasonc wrote: ↑

Mon Sep 16, 2024 8:43 am

well I don't have an air compressor. I was tempted to buy one half way through saturday, but I got there

Even one of these makes life a lot easier.

https://www.pushys.com.au/airshot-tyre- ... 6AODvjyZWV

At $90 for 1.15 litres, I'd look at using a 2 litre soft drink bottle (burst pressure should be 150-170 psi, so 100 psi should be fine) empty fire extinguisher, or even a 5 litre pressure sprayer from Bunnings

i hadn't thought of using a pressure sprayer. that's a cheap solution. just need to be able let it rip

That does sound like a good solution.
Interested in how well it works.
I had the compressor already so just decided to use it to seat tubeless too. Pretty hard to beat for dumping a large volume of pressurised air quickly imo.

jasonc wrote: ↑

Mon Sep 16, 2024 8:43 am

Mr Purple wrote: ↑

Mon Sep 16, 2024 8:23 am

An airshot or 240V compressor is an essential for a tubeless install in my book.

It's about the only way you can guarantee it'll bead up, and neither is a huge investment.

well I don't have an air compressor. I was tempted to buy one half way through saturday, but I got there

I'd go to a servo and use the air there, the auto stop ones have a flat tyre mode which pumps at full bore.

Getting ready for the JM15 National Criterium Championship. (My son, not me, just in case you thought I was 14)

Before I pumped the rear tyre I noticed that the threaded spike of the valve core was at a funny angle. Tugged at it after inflation and it broke off. Bugger. Never mind, still plenty of time. Pull the latex tube out, replaced it with a TPU tube, pumped it up, good to go? 10min later it was nagging at me that the valve wasn't protruding as far as I thought it should. Deflated the tube, physically pulled the valve about 10mm further out, re-inflated ... Psssss. Turns out to be a hole at the edge of the reinforcement at the base of the valve.

In the meantime I had remembered that I had a couple of spare valve cores and had put another one in the latex tube, so I replaced the core and reinstalled the latex tube.

I have had a few TPU tubes fail at the edge of the reinforcement and it is impossible to patch there successfully. I suspect that the failure is actually as a consequence of being inflated without the valve being physically pulled down prior to inflation, because these tubes don't seem to just push the valve out by themselves like I'm used to. I'm not in the habit of actively pulling on the valves before inflation, and I think I should be... Even though in this instance, the tube was holding air just fine until I fiddled with it, I suspect it was a failure waiting to happen.

In the end the tyre inflated fine and remains in good order.

Cheers,

Cameron

^^^ Hmmm. I've put in a dozen or so of those TPU tubes. The valves can definitely be sketchy, but haven't busted one like that before, just make sure the valve base is kindof where it should be. I don't bother preinflating them either, just make sure the tubes go in straight , and inflate with care.

Does anyone know where i can buy one of these pole clamps ?
https://youtu.be/TLg0NNjDBMQ?t=856

My rear shifting started to be less crisp than normal and once I confirmed it was not my imagination I went and bought a new cable as I am a champion mechanic and can fit them myself.
Sure enough, when I peeled back the hood there were a few bits of wire in there. Disconnected the cable at the back and tied some cotton on, with a bit of heatshrink over the top just to be sure, pulled the old cable out ( it was a mess ), pulled the new cable in - pro level so far.
And as I pulled a bit of tension on the cable to do up the clamp, the cable outer disappeared into the frame up near the steerer tube. Knuckle head had dropped a bit and not noticed. Frustration.
Repeat the process, cotton, heatshrink, pull the cable out - and the cotton fell off inside the chain stay. Breath, it is not end of the world.
Luckily the cable is outside the frame as it goes under the bottom bracket and with the aid of some magic incantations I was able to jiggle the cable back out the hole and tie the cotton on better.
Second ( third ? ) attempt was successful - Champions always prevail.