Technical > Transmission

refresh the lot

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JimK:
I haven't been riding so much this year, mostly just running various errands around town. No good excuse, just too many distractions and diversions! But somehow, probably when I changed the oil in my hub, I put on a new chain. It was pretty grumbly, a new chain on an old sprocket, but I figured it would settle down before long - that's been my experience in the past. But this time things actually got worse. For sure the chain got pretty loose, and it started skipping when I pushed the torque. I tend to do that in traffic, e.g. making a left at a stop light when the light turns green. Skipping becomes a safety concern in those situations! So I decided I needed to act. Today was the day.

At 21,440 miles on the odometer, it was time for a new sprocket. I don't remember when I flipped the first sprocket, but anyway  I remember that sometime along the way I did. Fortunately I'd already bought a new sprocket - I think when I heard about the new splined sprockets, I figured I'd better get an old style one when I could. The old sprocket came off easily enough - I have a chain whip and a mighty big crescent wrench so I don't expect much resistance!

I also flipped my chain ring. I'd installed a Surly ring when I got the chain glider, quite a few miles into my ownership, so it hadn't been flipped yet. I don't know if it was really necessary, but I'm thinking I'll start changing chains more frequently so nice fresh tooth surfaces will get me started on the right foot! I notice the Surly is not exactly symmetrical, but that didn't seem to get in my way.

Putting on a new chain means adjusting the eccentric bottom bracket. Somehow it seems when I put the new chain on early this year, I had the eccentric at maximum extension, so to tighten it would have meant removing a link. I don't remember why it didn't seem to work to just remove that link at the beginning. Anyway, now with a new new chain etc., the eccentric seemed perfectly happy pretty close to minimum extension, where I could reuse a dent. The eccentric was moving a bit stiffly, so I worked some grease in between it and the frame. Not easy to get in there, but I just slide it from side to side, exposing a bit which I grease and then keep going back and forth and around, and eventually the grease spreads inside reasonably well.

I also cleaned up my chainglider - it was pretty filthy! I also put a touch of chain lube inside it... I've never tried that before, but I figure it can't really hurt!

I must say, it was like getting my bike back after a long absence. The crunchy noise and the skipping meant that riding was just not so fun. Now, with my new drivetrain, the bike is very quiet and I can stand up and jam on the pedals and the bike is just happy to respond!

It's looking like September may not be so filled with distractions and diversions... maybe I will be able to get out and ride more! Having the bike running properly is sure an inspiration!

The old sprocket:

Andre Jute:
I dunno, Jim, it seems like your sprocket could do another 21440 miles. Compare, for instance, this sprocket from one of the trans-Africa tourers:

Only joking! That's a fascinating report, admirable in its instructional level of detail, and I agree with you wholeheartedly: you don't want to save a few bucks if it risks your life in traffic.

I've saved your sprocket pic to compare my sprocket at 10720m/17250km to check if needs turning yet. There's a difference in our riding milieu -- I have no dirt roads at all -- and transmission management -- I run my chains for their entire life solely on factory lube inside a Chainglider, zero extra lube -- but your approx 10K per side seems like a reasonable aspiration.

Thanks a lot, Jim.

JimK:
Wow, Andre, that's a sprocket that got used!

PH:
Thanks for the interesting info Jim. Maybe we ought to have a thread where such things are detailed,  owners experience on wear is all on the forum, but it's spread out in lots of different threads.
I've just replaced the chain and flipped sprocket and chain ring for the first time on my Mercury, 6,800 miles, no chain guard, no fancy cleaning routine, but it's always well oiled.  I could have tried the new chain without flipping the chain ring and/or sprocket, but I'm basically lazy so as your title - refresh the lot - is the easiest way to know it's all going to work well for many miles.

John Saxby:
Hi there Jim, 

Nice to hear about your two-wheeled doings & plans, and thanks for all that well-presented info on chains, rings and sprockets. Look forward to more photos from high in the Wasatch Front.

A note which may be of interest, now or in the future:  This past summer, I've moved away from using Surly stainless rings (36T) on my Raven.  Had an irritating ripply-clickety creak at the front of my drive train, and couldn't trace/banish the wretched thing.  I thought that irregularities in the ring might have been partly at fault, even though it was new in July 2018, with only about 1,000 kms on it in mid-2019.

So, I ordered a very spiffy 36T alloy item from Rivendell Bike Works in your neighbourhood (California).  This is made for RBW by Originate, and it's very well made indeed -- no tight spot in my chain.  The ring is quite thin, 3mm below the teeth, which is the max recommended for using a Hebie Chainglider.  When I installed the new ring, I upped the torque settings slightly for all five chainring bolts, and did the same for the two grubscrews which fix the Raven's EBB.  (So, I changed several variables at once -- not so good for fault tracing, I know.) The outcome is that the irritatin' ripply-clickety creak has surrendered and gone away.  (I haven't yet re-installed the Surly ring, just to check.)

I'm assuming that the Rivendell ring won't last anywhere near as long as my Surly rings have done in the past (around 10,000 kms), so ordered a 2nd Rivendell item for future use.

Cheers,  John

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