New answers tagged

2

Are all of your inner tubes from the same batch, by the same manufacturer, manufactured at about the same time? There has been occasionally failures of inner tube valve stems due to manufacturing defects. It may be possible the defects are not a thing of the past but have returned again.


21

Check that the rim tape (tape or liner that sits in rim bed) is not loose or spinning. I had an identical issue where a brand new tube would be ruined after a 10 minute ride. The rim tape spins on braking and drags the tube with it effectively tearing the tube away from the valve. If this the culprit, throw the current rim tape away, it can’t be fixed. ...


21

There is a mark in the middle of the valve stem as if something has pressed against it: Given that it was a fresh new tube, it likely means that it had been installed with the valve protruding at a sharp angle from the rim hole. Externally, it will look like this: This is bad because the air pressure creates additional uneven stress to the rubber around ...


9

It appears to me that the valve is torn or cut. Check your rim for sharp edges at your valve hole. you could try to cover them with a tape. Make sure the valve sits straight when the tyre is pumped up. I suggest to insert the tyre slightly filled with air before pumping the tyre. Also check the offending place o the rim for any other offending debris. ...


11

Carbon fiber composites are made up of sheets of carbon fiber filaments. These are usually impregnated with resin. To make CF structures, manufacturers will cut up the sheets, then lay them up onto a mandrel or other structure. They will then bake them at high pressure and temperature to cure the resin. The image below is from a Youtube video showing how Mad ...


2

The M590's are awesome shifters. Like all trigger shifters, the factory grease can become hardened and contaminated over time leading to frozen pawls--little levers that move the internal cog by fitting in the tooth grooves of the cog and act to either move the cog which winds both the inner cable and a spring. Another pawl, engages a groove holding the cog ...


3

You are describing brake squeal caused by the brake pads resonating on the rim during braking. Wet rims often squeal worse than dry ones and the flour use reduced the friction somewhat which reduced the ability to resonate as well as diminishing brake effectiveness. There is a way to alleviate much of the braking noise with the technique of "toeing"...


3

The derailleur you are using has an integrated adapter claw. A rear derailleur hangar claw. The bolt you have circled is used with a special washer to properly orient and secure the claw, which puts the derailleur in necessary position and alignment to the cogs for good shifting. This bolt has little to do with the axle alignment of the wheel and once it is ...


-4

The reason is simple, it's due to the properties of the chain drive system. A worn driving sprocket engages to both worn and new chains. A new driving sprocket engages to only new chains. So, by having a worn driving sprocket, your bicycle is superior to one that has a new driving sprocket. You aren't limited to using only new chains, you can use worn ...


4

In my experience, a chain or cassette cost half what a chainring costs, and an integrated chainset costs much more. A bike shop's charges vary, but labour is a significant part of the cost. If they spend an hour on a task, that time is charged, and its well above the hourly wage of the mechanic doing the task. A complex time consuming task plus the part ...


10

The chainrings last a long time but are expensive, and a lot of cyclists are surprisingly tight when it comes to servicing. Worn rings should be replaced when necessary though, otherwise the shop is throwing away good reputation and good income. The teeth on many modern rings are often quite pointy and shaped, making identifying wear that much less ...


2

I kept having this problem after I changed to a new crank set. The new crank had a larger gap between the smallest chainring and the bottom bracket. I fixed the problem using a plastic wheelbarrow bushing that I cut to fit between the crank and the frame. It works great to keep the chain out of that little space.


5

The symptoms you are describing seems to be a "Ghost Leak" - Rides of Japan terms it this way. It might actually just be a kink in the hydraulic hose. His symptoms are similar. Squeezing the brake feels powerful, but holding on to it will eventually cause the hydraulic pressure to release. Once he lets go of the brake lever, and squeeze it again, ...


2

Sadly serial numbers are useless - they're not a VIN like cars have and only mean something to the manufacturer, who may have encoded info in the number, or may not even have kept track of the numbers. If you have a sample of the paint you want, take it to an automotive paint specialist and ask for a colour match. Not your local big-box store, somewhere ...


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