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

CantGetNoSleep

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

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

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

Thank you both, will order a new chain

Tony04

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Seth Brundle

Like this driver...?
NSFW

Type 17

68 lost souls wrote: »

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.

When looking at a derailleur to see if it is bent, check whether there is good parallel alignment between the surface that faces the hanger, and the surface at the bottom of the parallelogram section of the derailleur that interfaces with the plate of the swing-cage (red lines in the pic). If these two surfaces are not fully aligned across every potential gear position (observe whilst operating it with your hands), then the parallelogram section is twisted, and the derailleur is toast. If the parallelogram is ok, but the swing-cage is not fully aligned (the one in the pic is a bit crooked), it can usually be realigned by clamping the hanger-bolt tightly in a bench-vice (align the derailleur carefully with the vice's jaws, so you can use the vice as a reference point) and using a water-pump pliers to gently align the cage in stages, working in one direction/plane at a time. To align the jockey wheels themselves, if required (they can still be crooked even when the cage they're in is straight), grab the two ends of the jockey wheel bolts tightly (while the derailleur is still in the bench-vice) with the water-pump pliers, and twist them into alignment.

cletus wrote: »

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

You'd be surprised - a few times a year, people come into the bike shop with their rims or discs covered in oil, saying that the brakes had been squealing, and that they had added oil but that it hadn't helped...

cletus

Type 17 wrote: »

You'd be surprised - a few times a year, people come into the bike shop with their rims or discs covered in oil, saying that the brakes had been squealing, and that they had added oil but that it hadn't helped...

I'm a teacher. I'm rarely surprised by stupidity

8valve

cletus wrote: »

I'm a teacher. I'm rarely surprised by stupidity

You, sir, have just won the internet.

fixXxer

How difficult is it to change a back tyre? Went across something last night and the tyre is completely flat. Was going to do it myself but looking at the gears and all the rest as a n00b, I might just wheel it down to the local bike shop tomorrow and give them the business.

cletus

fixXxer wrote: »

How difficult is it to change a back tyre? Went across something last night and the tyre is completely flat. Was going to do it myself but looking at the gears and all the rest as a n00b, I might just wheel it down to the local bike shop tomorrow and give them the business.

Its very easy, although as you note, slightly more difficult on the back. Once you open the quick release (assuming thats what you have) the wheel should just pop out (well, depending on your brakes, I suppose). Once you've changed the tube, just make sure the chain is on the top of the cassette (back gears) when you put the wheel back on. Have a look at the video below

magicbastarder

as above, but worth noting it's more fiddly getting the wheel back on the bike if you've disc brakes as you've to be more precise lining it up.