phtomita

In general, how many miles before having to replace your drivetrain?
I have a 105-5800 with about 5K miles - chain was replaced with around 3K miles (but I kept the old one, so I can compared them later).

On another bike I got a used Ultegra 6700 and have put some 2K miles (don't know the previous owner mileage) - I had a new chain when I built it.

Since I am cheap, I will probably use it for more many miles.
What are the criteria BFs use to replace a well used drivetrain?

Also notice my rear wheel rim on my commuter shows some usage where brake pads touch it - I have a long half mile descend where I use the brake,
Any recommendation when should be replaced, signs to watch out/keep eyes on?

dsbrantjr

I repair drivetrain parts by condition,not mileage; chains at 1/16" stretch in 12 inches, cassettes and chainrings when they skip with a new chain. I use an Iwanson dental gauge to measure brake track thickness and replace rim at <1mm. https://www.amazon.com/Stainless-Iwa.../dp/B0087HKWCO Rear rims tend to wear more since grit gets thrown onto them especially in the wet.

sweeks

AKA "crown thickness gauge" used for measuring the thickness of finished dental crowns (before cementation) and wax-ups of crowns (before casting). Good ones are accurate to 0.1mm and ar handy to have around for a variety of non-dental applications.

dedhed

I have about 20K miles on an Ultegra 6600 drive train. on 2nd cassette, new chain & cables every year, original chainrings, BB, Freehub, shifters, derailleurs, hub bearings serviced or replaced every year. Mavic open pro 36h wheels. I've replaced brake pads at least once.

phtomita

Cool, that's nice. I think will try to get a new cassette this year - current I have a 11sp 11-32 on it. I am looking for probably a 11-34 since I have a steep hill and getting a 1-1 ratio should be good
My commuter is 32h on both front and rear, so I could swap the rims and rebuild the wheels since the front one is in much better shape currently.

dsbrantjr

It would be less work to just rebuild the rear with a new rim and leave the front as-is.

alcjphil

+1
Putting a badly worn rear rim on the front involves completely unbuilding both wheels and then rebuilding them with possibly poor results. If a front wheel fails due to a worn rim or a poor build the results could be very painful

phtomita

Yeah, makes sense - let me keep eyes open for some sale on H+Son Archetype

AnkleWork

+1
And if you learn to use the front brake predominantly then you may never need to replace the rear rim.

sweeks

This puzzles me (though it makes complete sense!). I have worn out the rear rims on my commuter bikes several times. 20" wheels (406), always the rear. I commute in all sorts of weather in Chicago. My "winter" bike was the worst until I replaced the rear V-brake with a roller brake. My "good weather" bike is on its third rear rim at about 7,500 miles. I use the front brake predominantly. My hypothesis is that the front wheel kicks up dust and road debris which then lands on the rear wheel. I have no other explanation.

base2 

Or you just use your rear brake predominantly for stopping & under utilize the front. Exactly the opposite of what is most effective. Combine that with rarely removing grit/road grime/abrasives from the pads & brake surface...Well, It's hard to believe any wheel would last "only" 7500 miles, let alone a rear. Something is amiss with your habits. Does the left brake go to the front & right go to the rear? American standard isn't necessarily the way your bike may be cabled. Brit's do it opposite.

A better balance between front & rear brake application & an occassional bath would save you a bunch of $$$.

Some people keep a bucket of water by their back door/garage to rinse off the bike before puting it away.

Drew Eckhardt 

Replace the chain when it measures 11 1/16" between pins which should be 11" apart, or flexibility from side clearance increase has degraded shift speed onto the big ring. I get 4,500 miles out of chains.

You can't see the few thousandths of an inch difference between measuring at 11 and 12 inches, but having the fractional inch marks will be more accurate. You don't want to use a chain checker that also measures roller wear which doesn't effect pitch and therefore does not matter.

Replace the cassette when a new chain skips on it. I have over 26,000 miles on my current cassette, but expect it to be due when I change my next chain given a historic 5:1 chain to cog replacement rate.

Replace big rings and triple middle rings if you get uncommanded down shifts at high chain angles. That takes a very long time.

I've never worn out a small ring. When I wore out my first big ring I replaced the crankset because that cost less, and I changed cranks before I wore out the next one.

That's normal. If you make a depression in the brake track you should measure rim thickness with dental calipers. I've never worn out a rim before crashing a wheel and suspect I'll replace my front bottle cage first (I'm 1/3 through the aluminum at the front).

People in the wet Pacific Northwest with rim brakes can wear them out in a year, so your mileage may vary.

Watch for sluggish rear shifting which can come from broken cable strands. Changing cables is a royal PITA if they stick from too many broken strands, and regardless you don't want to ride home with just one cog. I can go through shift cables in 2000 miles, 1500 when I'm out of shape and shift more. Some people shift less and get many times that. Having brake hoods level with the bar and under tape routing added a second 90 degree bend which doubled fatigue and cut cable life in half from what we had with brake/shift levers in the 1990s.

Watch for where your brake pads touch your rims. They hit the rim higher as they wear and can go through your tire if you don't adjust them as needed.

PDKL45

A rough guide is 3-4 cassettes per set of chainrings and 3-4 chains per cassette. Check each chain at 2,500 kms for 9 speed, 2,000 kms for 10 speed and 1,500 for 11 speed. They are usually about 0.75 on a Park Tool chain checking tool at that stage, but they can be more or less worn, depending on what you've been doing on the bike. Still, you can then take the chain out to 3,000-3,500 and measure again. You can also do the same with cup and cone type hubs for longevity. I'm currently changing my Shimano XT hub bearings once every 2,000 kms, but I'm a heavy guy, I ride a heavy bike and I carry heavy loads on it.

Keeping track of the numbers is useful in terms of knowing when to check the chain and having a fairly clear picture of the state of your drivetrain. It's not meant to be limiting or a hard rule to follow, it just tells you that it's time to check your bike out and to think about changing your chain sooner rather than later to get a better lifespan out of your chainings.

sweeks

You missed this part.
I'm well-acquainted with the greater effectiveness of the front brake, and use it accordingly.
In fact, the right brake lever controls the front brake; I have all my bikes set up that way.
The bike has 7,500 miles on it, and it's on the third rim. This is the odd thing: the front rim is worn, but only slightly. Also, this problem only appears on my 20" folder; my road bike has similar mileage, yet the rims look almost unworn. A mountain bike that's 20 years old and has over 6,000 miles on it has barely noticeable wear on the rims.
I do ride the commuter bike in a fair amount of rain, so there is that. There may be something about the narrow (original) rim width with wide tires; I installed the current rim, which is wider than the original, about 3,000 miles ago... about 50% more mileage than I got on the original 2 rims, and it's not too worn.
I'm OK with washing the bike a couple times a year, but I'm not going to do it every day. Especially when it's below freezing!

02Giant 

Try using some front brake in addition to the rear.

wrk101

Well used can mean cosmetically challenged, or slap wore out. Wore out = replacement time, smart to keep ahead of the game on the chain so you don't ruin chain rings and cassette in the process. Good advice above.

Cosmetically challenged = continue on!

phtomita

Started applying more front brakes on my rides .

When we install a brake pad the recommendation I see is to have some angle on the rubber so you don't have the noise and that feeling of quick stuck and release.
I am thinking now, since the angle is there, it is a perfect way to collect the little sand/crap on the rims and kind of hold with the brake pad - because you have that little angle there.
Do you try to keep the pad as parallel as possible to the rim, so in theory you accumulate less crap between the pad and rim?

02Giant 

My thinking is the opposite, I install mine with a slight toe-in, where the leading edge would contact the rim first. It should help to clear the rim before the pad makes full contact. I could be wrong though.