the 'there's no such thing as a stupid question' bike maintenance thread

07Lapierre · 13-11-2020 11:26PM

Sounds like the chain is catching the frame or possibly "chain suck". This usually happens when the chain is on the largest sprocket and small chainring. As you pedal, the chain catches something and is dragged upwards (which would explain why the RD is dragged forward).

cletus · 13-11-2020 11:33PM

I was about to reply, but both responses above cover what I would have said. Basically, I think the BB change and your issue might be correlation, rather than causation

CramCycle · 13-11-2020 11:47PM

It sounds like an issue with the chain slipping off the top wheel of the rear derailleur which causes it to jam slightly. I have had similar issues in the past. Rear derailleur is the issue IMO, Might be fixable with an adjustment to the rear derailleur

a148pro · 13-11-2020 11:48PM

Thanks for quick responses lads

Type 17 wrote: »

I presume the chain and ring are the same speed (width)?

I don't think the ring, chain or cassette have been changed since purchase of the bike so should be yes, one of the cranks just broke so LBS changed the cranks

cletus wrote: »

I was about to reply, but both responses above cover what I would have said. Basically, I think the BB change and your issue might be correlation, rather than causation

As in its just a coincidence?

cletus · 13-11-2020 11:51PM

a148pro wrote: »

As in its just a coincidence?

I think so

running_away · 14-11-2020 01:57PM

I bust the 11-51t cassette on my mtb. Can I replace it with an 11-40 without having to change chain or derailleur etc..? Thanks!

grogi · 14-11-2020 03:21PM

running_away wrote: »

I bust the 11-51t cassette on my mtb. Can I replace it with an 11-40 without having to change chain or derailleur etc..? Thanks!

Yes, no issues at all. As long as you keep the same number of sprockets

CantGetNoSleep · 14-11-2020 06:32PM

CantGetNoSleep wrote: »

I'm looking at a bike to put permanently on the turbo but it's currently set up 105 5800 11-28 so I'm imagining it is a short cage derailleur. I have an 11-32 on the turbo and another bike so ideally I'd leave the 11-32 on the turbo.

Will the 105 SS derailleur work with an 11-32 on the turbo (assuming I avoid big ring / largest cog)? And will I need to change chain or are there any other complexities to consider?

I've set this up today and without changing any limit screws, indexing or changing the chain, it works with the exception of the 50-32 gear which I would tend to avoid anyway. See first photo below - the derailleur is not touching the cassette but it sounds like the derailleur would snap off if you pedaled in this gear.

Is there any risk of riding this as is if I take care to stay out of big-big? Also adding a photo of the second largest cog on the rear which is a gear I could find myself in, which works ok. It will be used on the turbo so not the same risk of being stranded with a snapped chain, but don't want to do any damage to the derailleur or hanger. Is the issue in the first photo caused by chain being too short or can I mess with B-screw etc to get it better?

https://imgur.com/a/qI5xj5c

https://imgur.com/a/TDrNs1F

cletus · 14-11-2020 06:38PM

CantGetNoSleep wrote: »

I've set this up today and without changing any limit screws, indexing or changing the chain, it works with the exception of the 50-32 gear which I would tend to avoid anyway. See first photo below - the derailleur is not touching the cassette but it sounds like the derailleur would snap off if you pedaled in this gear.

Is there any risk of riding this as is if I take care to stay out of big-big? Also adding a photo of the second largest cog on the rear which is a gear I could find myself in, which works ok. It will be used on the turbo so not the same risk of being stranded with a snapped chain, but don't want to do any damage to the derailleur or hanger. Is the issue in the first photo caused by chain being too short or can I mess with B-screw etc to get it better?

https://imgur.com/a/qI5xj5c

https://imgur.com/a/TDrNs1F

Regarding chain length, have a look at the article below to see how to measure for a chain. You may need a longer one than you have

https://www.parktool.com/blog/repair-help/chain-length-sizing

Type 17 · 14-11-2020 06:52PM

Chain is really a few links too short - the spring in the derailleur that controls the jockey cage can get stretched by doing this, with the result that the derailleur always sits too low afterwards and the shifting is poor, even with the B-screw fully opened.

The Park Tool article/video that cletus linked to will help you check it - with a big cassette (32+ teeth biggest), the measurement method is different than for smaller stuff.

CantGetNoSleep · 14-11-2020 07:12PM

Thank you both, will order a new chain

Tony04 · 14-11-2020 08:37PM

running_away wrote: »

I bust the 11-51t cassette on my mtb. Can I replace it with an 11-40 without having to change chain or derailleur etc..? Thanks!

Back out the b screw and shorten the chain

grogi · 14-11-2020 08:48PM

Tony04 wrote: »

Back out the b screw and shorten the chain

What for? He already had a ~40T sprocket working fine on the previous casette.

68 lost souls · 15-11-2020 01:24PM

Had a fall and need to replace the derailleur hanger, may also need to replace the derailleur and not sure which length I have. It’s a 5701RD off a trek madone 2.1 2013 running a compact chainset and 12-30 cassette. I suspect since there’s a 30 in the back it’s long cage?

Type 17 · 15-11-2020 01:33PM

Probably is a long cage, but Google 'Shimano RD-5701 GS' and look at the images to compare the SS (short cage version) and the GS (long cage) against what you have.

68 lost souls · 16-11-2020 01:39PM

Finding it hard to tell from the pictures. Also can’t seem to find anywhere a measurement I’m sure there must be a way to compare the distance between pulleys or something? Mine is approx 59mm

cletus · 16-11-2020 01:46PM

Some information here, although the video is no longer available

https://forum.bikeradar.com/discussion/13073081/ss-or-gs-derailleur

Here's a methoud for measuring cage length.

https://bicycles.stackexchange.com/questions/32729/how-to-find-the-cage-length-of-a-rear-derailleur

I suppose you could find the spec sheets for both and compare

magicbastarder · 16-11-2020 01:47PM

looks like a short cage to me - the gap between the jockey wheels is probably half the diameter of one of the wheels. compare that with a long cage:

https://bicyclebuysell.com/item/455237/shimano-105-r7000-long-cage-rd

grogi · 16-11-2020 01:53PM

68 lost souls wrote: »

Finding it hard to tell from the pictures. Also can’t seem to find anywhere a measurement I’m sure there must be a way to compare the distance between pulleys or something? Mine is approx 59mm

If it was the long one, there is hardly any room to make it shorter. Must be the short one.
I would get a long cage anyway (which would open you up for wider cassettes), but I don't really pay that much attention to weight.

68 lost souls · 16-11-2020 01:57PM

cletus wrote: »

Some information here, although the video is no longer available

https://forum.bikeradar.com/discussion/13073081/ss-or-gs-derailleur

Thanks looks like SS alright from that. Found a replacement online for €36 so might as well swap it out just in case. Been on there for coming up on 9000km anyway.

grogi · 16-11-2020 02:01PM

68 lost souls wrote: »

Thanks looks like SS alright from that. Found a replacement online for €36 so might as well swap it out just in case. Been on there for coming up on 9000km anyway.

Are you really sure it's cooked? Derailleurs don't wear that much and should be fine after an incident, as it is the hanger that is designed to absorb the hit.

magicbastarder · 16-11-2020 02:04PM

68 lost souls wrote: »

Been on there for coming up on 9000km anyway.

as grogi mentioned, it's probably fine. i've probably double that on mine and would consider it in good health.

clio_16v · 16-11-2020 02:10PM

I have a slightly wobbly / loose front wheel. I assume it is thr wheel bearing? How do I know for sure what it is and how do I replace the bearings? Any simple diy vids out there?

magicbastarder · 16-11-2020 02:12PM

what make/model of bike is it? bearings come in two types - cup and cone, and cartridge bearings.

it may be as simple as tightening up the nuts on the axle - though if they've come loose, it might suggest excessive wear.

https://www.youtube.com/watch?v=opommURFB4o

Seth Brundle · 16-11-2020 03:31PM

Going to start replacing my cassettes. Watching & reading online, some suggest adding some grease to the freehub whereas other sites don't seem to do this.
Should I and if so is there a specific type of grease I should use?

cletus · 16-11-2020 03:34PM

I would have thought greasing the threads of the lockring would be enough.

Regarding the type of grease, everything gets lithium grease, specifically Holt's Blue Grease, because thats what I have in the shed

*Edited to add* every except the drive train, obviously

8valve · 16-11-2020 03:36PM

Seth Brundle wrote: »

Going to start replacing my cassettes. Watching & reading online, some suggest adding some grease to the freehub whereas other sites don't seem to do this.
Should I and if so is there a specific type of grease I should use?

A very fine skim of any lithium grease will be fine on the outside surface of the freehub body, although some people don't bother.

I've only ever come across a couple of cassettes/sprockets that I've had to lever off carefully with a flat large screwdriver but they were purely down to excessive dirt and gunk buildup (or individual sprockets biting into the raised ridges of the softer metal freehub body), rather than any corrosion issue.

68 lost souls · 16-11-2020 03:52PM

magicbastarder wrote: »

as grogi mentioned, it's probably fine. i've probably double that on mine and would consider it in good health.

There's definitely some road rash on it, I can see where it took a hit and the chain was wedged in and twisted in it so I had to wrangle the chain free.

Hanger snapped and needs replacing for sure but not 100% sure about the derailleur, I guess I'm just worried that if its bent in anyway it might cause another failure. Theres scratches and marks where I can see it took the brunt of the fall

I might wait until the hanger is replaced and test it on the bike stand and then the turbo before heading out on the road.

Seth Brundle · 16-11-2020 04:44PM

cletus wrote: »

I would have thought greasing the threads of the lockring would be enough.

Regarding the type of grease, everything gets lithium grease, specifically Holt's Blue Grease, because thats what I have in the shed

*Edited to add* every except the drive train, obviously

...so the brake blocks do get some? :pac:

cletus · 16-11-2020 04:45PM

Seth Brundle wrote: »

...so the brake blocks do get some? :pac:

Disc brakes on my bike, but I make sure to give the disc a liberal application

the 'there's no such thing as a stupid question' bike maintenance thread

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