Derailleur Question

[stevej37]

Originally Posted by Scott Douglas

Steve, you might take a look at this video, towards the end he covers derailleur adjustments.

https://www.youtube.com/watch?v=RG3D5fmMyS8

Thanks...lots of good tips in that.
When he started ripping all the cables out, I thought...Oh no!

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[stevej37]

Originally Posted by look 171

145??? Damn, you must be a stick? That was my racing weight, between 140-145 for a long time. Now, I am 160 ish, so I have another 10 to go Ate better and smaller portions and 10 lbs just went without trying in a little a month. Weight is a big killer in bike the bike and overall health. Keep up the good work. Sounds like you really enjoy riding and being out.

I wrestled in HS at 145 and it's stayed about the same since. I think metabolism and genetics have a lot to do with it. Both parents were close to the same as I.
I pretty much eat whatever I want...which isn't really healthy for me.

I don't think I've missed over 4 or 5 days without biking since spring weather came.
I'm 72 same as my graduation year. (I think there is a name for that coincidence)

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[look 171]

Just think, if you were 180-100, it wouldn't be too good for your back and joints. You keep on riding, that's my plan anyway. I have been riding competitively since I was about 16. Took about 10 years off in my 30s. Started up again at 40 and will kept doing it. turning 60 in a couple years. Will try to keep going to the training rides with the younger faster rider to keep me young. Its even more fun now then it was when I was in great shape.

[vash]

Originally Posted by Zeke

Look at it closely in person. The black pieces are not lined up. Photo error or not, it sure looks like the chain is slightly angled left at the bottom idler wheel. Again, I can't say that is the cause of the problem. That many miles has to have had an effect. But I have straightened a few derailleurs in my time that were bent in for one reason or another.

They are very sensitive, that's all I know.

Also the chain looks dry and rusty. It might be that the chain doesn't react properly whatever that means.

in this pic, IIRC that bigger silver Phillips head screw is used to pivot the detailer back and forth. I think if you pull it tighter is swings the entire unit back adding tension.

been I minute for me. but I remember checking alignment, checking top and bottom stops, adjusting cable tension, and then making sure overall tension is good. maybe top and. bottom stops was first.

[Tobra]

Replace your chain and clean up the sprocket

[aigel]

Do you really still have a 3000 mile chain on there? I take good care of my chains, but none of them last past 2500 miles without stretching past wear limit. 1500 on the MTB. I toss them when they are over 0.75. Try a new chain and size it from scratch like you will see in those video instructions. A stretched chain will absolutely ride high and not seat all the way in the teeth and be more prone to hop off. By the way, that chain is probably less than 10 bucks.

[greglepore]

Just 2 points-most single chainring bikes with a rear derailleur run what's called a "narrow wide" chainring (alternating narrow and wide teeth) to ensure chain retention. Also, gravel and mountain bikes have a rear derailleur with a "clutch" in the cage spring to prevent the chain from bouncing and coming off. A bike set up like yours without these will have issues on rough surfaces, particularly with a worn chain.

Second, and just a personal pet peeve, chains don't "stretch". They're friggen steel. What does happen is that the rollers wear at the pin-roller interface, which effectively makes the distance between rollers get larger under load (because the hole in the roller is worn larger). This makes the chain more prone to skipping etc. Also, riding with a worn chain eventually wears the teeth on the cogs and chainring into a shape the conforms to the worn chain, making them unusable with a new chain as everything is out of tolerance.

[Zeke]

Originally Posted by greglepore

Just 2 points-most single chainring bikes with a rear derailleur run what's called a "narrow wide" chainring (alternating narrow and wide teeth) to ensure chain retention. Also, gravel and mountain bikes have a rear derailleur with a "clutch" in the cage spring to prevent the chain from bouncing and coming off. A bike set up like yours without these will have issues on rough surfaces, particularly with a worn chain.

Second, and just a personal pet peeve, chains don't "stretch". They're friggen steel. What does happen is that the rollers wear at the pin-roller interface, which effectively makes the distance between rollers get larger under load (because the hole in the roller is worn larger). This makes the chain more prone to skipping etc. Also, riding with a worn chain eventually wears the teeth on the cogs and chainring into a shape the conforms to the worn chain, making them unusable with a new chain as everything is out of tolerance.

OK, technically chains don't "stretch" but they (as you described) get longer. It's a matter of semantics. And a worn chain sure does deform sprockets. Those of us that raced karts know a lot about chains and performance. There is good reason why some cost more money.

My enduro karts used belts with teeth like a blower drive. Gilmer belt. I have seen belt driven bicycles but not very often. They don't seem to go around small diameters all that well. You'd tend to think the opposite. I believe torque overcomes the ability with too few teeth engaged.

[stevej37]

Chain keeper arrived and installed today. Took it for a ride and rode it over the chatter bumps on the gravel road that would throw the chain before....no problem.

Did it a second time, but faster and I was almost thrown off the bike...chain stayed on.

There is about an 1/8" clearance on each side of the chain links and a 1/4 on the top.
I couldn't get it mounted exactly like they pictured because I didn't have enough room to lower it any more. So, I tilted the very bottom to make it fit.

Glad that it fixed it.....Thanks for the help.

[zakthor]

I still think you should take it in and checked for chain wear and have them align the derailleur hanger. At least check that your hanger is tightly attached to the frame it looks misaligned.

I wouldnt expect that single ring to stand up to mtb so its good you got the guard.

[stevej37]

^^^ At the first sign of bad shifting, I will do that. It's never missed a shift yet..up or down.
And it's never dropped the chain on normal smooth riding.

I think the angle that I'm taking the pic at makes it look misaligned.
I don't see it and if it is..it came from the factory that way.

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[look 171]

If it shift fine, don't mess with it unless you have an alignment tool. MOst bike mechanics just eyeball that hanger on the typical bicycle. If they used a tool, its half azz done. That derailleur is not super tight like a high end racing one, so there's a bit of slop or give there no matter how straight the hanger is.

[stevej37]

Originally Posted by look 171

If it shift fine, don't mess with it unless you have an alignment tool. MOst bike mechanics just eyeball that hanger on the typical bicycle. If they used a tool, its half azz done. That derailleur is not super tight like a high end racing one, so there's a bit of slop or give there no matter how straight the hanger is.

Thanks!....I agree. I don't want to look for problems that aren't there.
The one that showed up is fixed now. I'm sure that I'll be more careful with chain maintenance now...the lubing especially.

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[Zeke]

Out of alignment just increases wear. It's not a motorcycle. If Steve can't see a problem then the thread is done.

[stevej37]

^^^ Yes...I'm very happy with the bike. The only problem was the chain dropping, and now that is solved.
I put 18 miles on it this morning...the first time since April that I had to wear long pants. Warming back up tomorrow thru Monday and then a bigger cool down. I hate to see the hot weather go.