Beachgrad05

Last week twice on Cool Breeze I had a sudden seize up like feeling making difficult to pedal. I stopped and could see no issue and upon restart worked fine. I honestly don't recall if I had shifted right before or not. I typically stay in small ring up front and only use large ring when my speed means I will spin out .

Yesterday at ride we hit s hill and I geared down and had the sudden seize up feeling and difficult pedaling along with terrible noise that my teammates heard. I pedaled they it and eventually it went back to normal. I could see nothing wrong with chain up front as again I was never in big ring and so shift was in back to easier gear only.

Any thought on what I might look at? Rear wheel hub?

FBinNY 

If it happened when downshifting the front ring (big to small or middle) it might have been chainsuck. This happens when the chain fails to unfurl off the bottom of the ring and comes up and jams under the chainstay. Sometimes it jams such that it won't clear, but more often it clears the moment you ease up on the pedals and the RD spring and gravity pull it down and free.

One confirmation of the issue is scratches or dings under the chainstay, or between it and the chainring.

Once you confirm the issue, search chain suck for discussions about causes and cures. Be ready pleanty of reading because this issue has multiple causes and can be easy or nearly impossible to remedy.

Beachgrad05

As said no shifting of front ring only REAR cog

TrojanHorse

Weird. What is it about cool breeze - last year I thought I wrecked my shifters. They went from shifting fine to being incredibly difficult to operate after lunch.

Anyway, back to your issue - I assume your crank spins freely. Have you had any maintenance done recently?

Check your chain path through the pulleys in your RD. Stick the bike in a stand and have somebody move the pedals and shift up and down through the range in the rear and see if you see anything. Try putting a different rear wheel on and see if you can replicate the situation.

indyfabz

I experience a sudden difficulty in pedaling every time I hit a steep hill.

Beachgrad05

Thx for tips haven't had recent maintenance done as I've ridden so little since finishing ALC. I had a tune done when I got back in June. Bike only has about 300 miles since that was done.

bassjones

May be time for a tune up. Wonder if you're having cable stretch which is preventing the RD from completing shifts momentarily.

jimincalif

Can you describe the terrible noise? If you drop your chain off the small chainring, does your crank turn freely, smoothly and quietly? Same question with your rear hub if you remove the wheel from the frame.

Is your quick release skewer good and tight? Any scratches or other evidence on the chain stays or seat stays of anything getting caught between them and the tire?

Beachgrad05

All excellent things to check. Will put up on stand and do a thorough look see.

Noise I heard was hard to recall exactly how it sounded now. My teammates heard it tho and were concerned I was having a serious mechanical problem

prathmann

Once had a problem where the lockring on my cassette loosened and got partly jammed between the hub and the frame to make pedaling difficult. Mine got rapidly worse, but I could see some circumstance where a loose ring could get stuck for awhile and then vibrate out again.
Chain suck at the crank set seems more likely though.

Rowan

I wonder if you have a seized link in the chain, so that when you shift down on the rear, it catches the derailleur through the jockey wheels, pulls it forward, makes a noise and makes pedalling seem difficult. To check, rotate the cranks backwards and see if the chain "catches" on the derailleur at any stage.

If not, then... I've got nothing else at the moment.

jsigone

if you don't look for it, there is allot of gunk built up on the two pulley on the rear D. If built up enough, there is enough gunk to fill the distance from the chain to the rear D cage.

And could also be a seized link like @Rowan mentioned

ColaJacket

Sometimes I get that when I see the steep hill.

GH

Beachgrad05

I'm going to check all this out. Only thing I'm fairly certain is that it is not related to chain suck up front

Beachgrad05

Ok put in stand and can't seem to see or hear issue

TrojanHorse

no tight links in the chain & chain path is correct through RD? (I had an issue in May, ahem, which is why I keep asking). Chain engages and rolls smoothly in all 20 gears?

Beachgrad05

No issues. I ran it up and down gears and all was smooth.

FBinNY 

One possibility is the B screw adjusted so the RD is riding too high. After you shift it looks right, but before shifting the pulley may be high compared to the next larger sprocket. Then during the shift, it bumps, and the RD gets pinged back and/or the shift is delayed for a moment.

I've duplicated the effect try to show the possible cause of some otherwise unexplained broken hangers.

Otherwise the best I can advise depends on excellent reflexes. Next time it happens try to stop pedaling immediately and hold the pedals in the problem condition while you stand there and have a friend check out the chain run.

TrojanHorse

Is your rear skewer tight?

chaadster

Hmm, mysterious one!

If pedaling becomes difficult, then there needs to be serious drag, and that most likely happens at the wheel.

BB failures usually get sloppy or creaky, though I suppose if you have cage bearings, a broken off piece of that retaining cage could float loose and periodically jam the balls. That makes a pretty horrible noisez

Otherwise, I'd look to something at the wheel, again because of the amount of drag required to make pedaling hard.

I am perplexed by the transient nature and noise, though. My best guess: shot freehub bearings that allow the cassette to wobble and grind under load, but seems to spin normally when in the stand.

jimincalif

Agreed, this is your best bet. Check everything that turns in the drivetrain and the wheel and then just ride. If it happens again, stop immediately to look at it. Good luck!

Bill Kapaun

When it happens again, stop pedaling.
IF the bike slows down rapidly, the problem is in the rear.
IF not, in the BB.

FBinNY 

Bill -

I'm surprised at you. It's early out there, pour yourself another cup of coffee.

The bike has a freewheel. If the bike continues to coast freely, the problem can be anywhere between the freewheel mechanism and the BB shell, ie. chain, RD, FD, crank bearing.

Bill Kapaun

I've already drank my pot full.
I'll stick with what I said.

Rowan

Going off on a tangent, Beachgrad. But have you had the brake cables changed or adjusted recently? I know the noise doesn't gel with this, but when you said this happened while riding up a hill, moving your handlebars back and forth can "shorten" the out cable a little and engage the brake front brake. In addition, just check to see that the out cables haven't popped out of their braze-ons on the frame for some reason. That also has the effect of lengthening the cables.

Is the crankset a triple? If so, check to see if the inner chainring is rubbing on the frame... sometimes the clearances there are very tight, and any frame flex or a worn BB or a loose right-side crank bolt can induce a noise from the teeth touching the chainstay.

If this is a freewheel as opposed to a freehub, it may well be that the tiny ball bearings inside the cogset are worn. Put the bike back up on the stand, rotate the chain and see what movement there is with the freewheel as the wheel rotates.

Apart from that, I have nothing else.