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

John Hutton

El Tarangu wrote: »

Very clever! thanks

You were right; in the end the size was right, but now having bought it I've decided that it's a bit too heavy for my needs, so I think I will sell it on again - oh well.

Where are you based and how much?

El Tarangu

John Hutton wrote: »

Where are you based and how much?

Sorry pal, I'm in Belgium

Th 2nd-hand market is indeed good here - that one cost me €120 in the end.

irishrover99

I dropped my bike into a lbs yo have the BB changed. The new BB is a bigger size so it needed the front derailleur adjusted.
When I collected it, the guy told me that I could do with a new front gear cable. I thought nothing of it as it was perfect when I dropped it in.
So cycling home I changed gear and it went to the small ring fine but it would not go into the big ring without a lot of pressure and it kinda jumps into the big chain ring. So today I spent 2 hours fiddling about trying to the change the cable and eventually I got it through the frame but it made no difference at all. It’s still very hard to push into the big chain ring.
Can anyone give any ideas to why this happened.
I’m pissed tbh and looks like I’ll end up bringing it to another shop which will cost me more money.

CormacH94

Refurbishing an old hybrid - noticed the triple front derailleur has a sticker saying 42 tooth on it - is this the largest chainring that can be put on the bike with this derailleur or is it just telling you how many teeth are on the chainring.

Type 17

irishrover99 wrote: »

I dropped my bike into a lbs yo have the BB changed. The new BB is a bigger size so it needed the front derailleur adjusted.
When I collected it, the guy told me that I could do with a new front gear cable. I thought nothing of it as it was perfect when I dropped it in.
So cycling home I changed gear and it went to the small ring fine but it would not go into the big ring without a lot of pressure and it kinda jumps into the big chain ring. So today I spent 2 hours fiddling about trying to the change the cable and eventually I got it through the frame but it made no difference at all. It’s still very hard to push into the big chain ring.
Can anyone give any ideas to why this happened.
I’m pissed tbh and looks like I’ll end up bringing it to another shop which will cost me more money.

Possibly the LBS didn't have the correct BB axle length, and fitted one that was a bit too long - the FD has a sweet area where the movement of the arm that the cable attaches to generates the right amount of movement in the guide-cage. If the BB is too long, the FD won't work properly as the cable-pull from the shifter won't move the cage far enough. You see when this is an issue because the limit screws won't be of similar heights - when the BB is too long, the H will be out a lot and the L will be screwed right in. You should ask the shop that fitted it to change it for a shorter one.

CormacH94 wrote: »

Refurbishing an old hybrid - noticed the triple front derailleur has a sticker saying 42 tooth on it - is this the largest chainring that can be put on the bike with this derailleur or is it just telling you how many teeth are on the chainring.

The sticker indicates that the shape/radius of the FD cage only works well with 42-tooth (big ring) chainsets. If you try to use the FD with 44 or 48-tooth chainsets, you will get poor shifting, unavoidable rubbing, or other issues.

irishrover99

Type 17 wrote: »

Possibly the LBS didn't have the correct BB axle length, and fitted one that was a bit too long - the FD has a sweet area where the movement of the arm that the cable attaches to generates the right amount of movement in the guide-cage. If the BB is too long, the FD won't work properly as the cable-pull from the shifter won't move the cage far enough. You see when this is an issue because the limit screws won't be of similar heights - when the BB is too long, the H will be out a lot and the L will be screwed right in. You should ask the shop that fitted it to change it for a shorter one.

.

I supplied the BB myself though. I was converting from press fit bb30a to shimano with a C-bear BB.
They are specific for this change and stick out less from the BB shell than the hollowtech 2 bb. So the 105 derailleur should be able for that

Type 17

irishrover99 wrote: »

I supplied the BB myself though. I was converting from press fit bb30a to shimano with a C-bear BB.
They are specific for this change and stick out less from the BB shell than the hollowtech 2 bb. So the 105 derailleur should be able for that

Yes it should - the info I posted above refers more to square-taper BB's.
Is it the R7000 FD or the older 5800 with the arm on top?

irishrover99

Type 17 wrote: »

Yes it should - the info I posted above refers more to square-taper BB's.
Is it the R7000 FD or the older 5800 with the arm on top?

5800 derailleur going with new 7000 crank.

Type 17

irishrover99 wrote: »

5800 derailleur going with new 7000 crank.

In that case, have a look at the adjustment section here, and if it doesn't look right on your bike, ask the shop to re-adjust it.

(PS: Have a look at the H & L screws - the bit above about vastly differing heights applies with this FD, as a general indication as to whether the setup can be adjusted satisfactorily)

https://si.shimano.com/pdfs/dm/DM-FD0002-05-ENG.pdf

irishrover99

Type 17 wrote: »

In that case, have a look at the adjustment section here, and if it doesn't look right on your bike, ask the shop to re-adjust it.

(PS: Have a look at the H & L screws - the bit above about vastly differing heights applies with this FD, as a general indication as to whether the setup can be adjusted satisfactorily)

https://si.shimano.com/pdfs/dm/DM-FD0002-05-ENG.pdf

Will do, thanks. TBH I can imagine if I brought it back now I would have much of a leg to stand on since I have changed the cable today. I should of turned straight around and went back to the shop when i noticed it.

Type 17

Fair enough. In that case, maybe take a look at the doc and do the alignment/limits/cable tension setup again.

velo.2010

I think Shimano indicate that older FD's aren't compatible with R series cranks. I'm sure it could be worked around but you might struggle to adjust the cable tension if you don't have a working barrell adjuster on that cable — pulling it tight by hand might not be enough.

I upgraded the FD's on both bikes to eliminate such problems. They're tricky to fit but cable adjusyment is taken care of without use of barrell adjusters. Just to note, I run 5800 cranks with a R7000 FD on one bike with no compatibility issues.

irishrover99

velo.2010 wrote: »

I think Shimano indicate that older FD's aren't compatible with R series cranks. I'm sure it could be worked around but you might struggle to adjust the cable tension if you don't have a working barrell adjuster on that cable — pulling it tight by hand might not be enough.

I upgraded the FD's on both bikes to eliminate such problems. They're tricky to fit but cable adjusyment is taken care of without use of barrell adjusters. Just to note, I run 5800 cranks with a R7000 FD on one bike with no compatibility issues.

Would that be more of a chain rub issue?
This just won’t shift without using force

brownian

An option is to fit an inline barrel adjuster to the FD cable. This is, I think, a nice longer-term solution, because it's in the nature of derailleurs to need tweaking. The adjuster costs a fiver or so, and fitting is easy enough (fiddlier if internal cable routing, of course).

JMcL

caviardreams wrote: »

So I finally got a bell but it seems to be too small for teh handlebars of my road bike (30mm or so). Most bells I have seen online are 22-25mm - is it hard to find one that fits 30mm that doesn't cost a fortune (I saw a nice knog one) or is there some way to make the smaller ones fit?

Or are my road bars very chunky and in need of a diet?

I got a trigger bell and it works very well. Mounts behind the hood on the left and can be rung from the hoods or the drops

CormacH94

Question on gearing/swapping gearing - If I have a 53/39 crank with an 11/27 cassette is it possible to switch to a 50/34 and an 11 -28 with little hassle?

My understanding is all I need are new chainrings, cassette and new chain? Will the front derailleur accept a low gearing? Or what size cages on FD and RD are needed for this combination?

magicbastarder

I don't think there are any RDs which can take 27 tooth but not 28; and FDs are not compact or semi compact specific. You might even be able to reuse the chain if it's got little wear, but that would be the cheapest component you'd be replacing anyway.

CramCycle

CormacH94 wrote: »

Question on gearing/swapping gearing - If I have a 53/39 crank with an 11/27 cassette is it possible to switch to a 50/34 and an 11 -28 with little hassle?

My understanding is all I need are new chainrings, cassette and new chain? Will the front derailleur accept a low gearing? Or what size cages on FD and RD are needed for this combination?

magicbastarder wrote: »

I don't think there are any RDs which can take 27 tooth but not 28; and FDs are not compact or semi compact specific. You might even be able to reuse the chain if it's got little wear, but that would be the cheapest component you'd be replacing anyway.

All you technically need are the new chainrings. The chain will be slightly too long but I have gotten away with it, it's not by much. Possibly have to move the FD down a smidgen, but again, I got away with doing nothing on my commuter.

07Lapierre

CormacH94 wrote: »

Question on gearing/swapping gearing - If I have a 53/39 crank with an 11/27 cassette is it possible to switch to a 50/34 and an 11 -28 with little hassle?

My understanding is all I need are new chainrings, cassette and new chain? Will the front derailleur accept a low gearing? Or what size cages on FD and RD are needed for this combination?

A 53/39 crankset will have BCD of 130mm, whereas a compact crankset has a BCD of 110, so you need to confirm the BCD before purchasing chainrings. AFAIK, you will need a new chainset if you want a 50/34 chainrings

Weepsie

07Lapierre wrote: »

A 53/39 crankset will have BCD of 130mm, whereas a compact crankset has a BCD of 110, so you need to confirm the BCD before purchasing chainrings. AFAIK, you will need a new chainset if you want a 50/34 chainrings

Not necessarily. The 4 armed newer shimano ones are all just 110 bcd. I've swapped 53/39 for compact on a 5800 chainset.

That said, it's often cheaper to just get a new crankset

Question for others when you replace cables do you replace the outers too? I always have and never really thought about it until tonight as I've run out and won't have enough to do the job. So I'll have to reuse some of the ones already on the bike.

I should at least clean them out with some degreaser or something and leave to dry right? or should I be a lazy bastard and just feed the new cables through?

I think I know the answer :pac:

swarlb

07Lapierre wrote: »

A 53/39 crankset will have BCD of 130mm, whereas a compact crankset has a BCD of 110, so you need to confirm the BCD before purchasing chainrings. AFAIK, you will need a new chainset if you want a 50/34 chainrings

Do you mean PCD ? Pitch Circle Diameter What does BCD mean ?

CormacH94

Weepsie wrote: »

Not necessarily. The 4 armed newer shimano ones are all just 110 bcd. I've swapped 53/39 for compact on a 5800 chainset.

That said, it's often cheaper to just get a new crankset

For reference it's the older 5 arm Shimano - does this affect the BCD?

irishrover99

brownian wrote: »

An option is to fit an inline barrel adjuster to the FD cable. This is, I think, a nice longer-term solution, because it's in the nature of derailleurs to need tweaking. The adjuster costs a fiver or so, and fitting is easy enough (fiddlier if internal cable routing, of course).

I’ll look into this, thanks, but as an update, dropped the bike to joe Daly’s this morning and they could not find any issues with the set up of the front derailleur. They said maybe to try the new r7000 derailleur to see if that helps. Not sure what to do now as I’m lost to see how this issues could be due to it been the 5800 derailleur.

CormacH94

Looks like the older 5 arm Shimano crank has different BCD (I'm guessing this is bolt circle diameter for crank bolts?) it's 130 for the double crank and 110 for the compact

Easier to just buy a whole compact crankset?

Edit: Looking for 105 compact cranksets (5750) with 170mm arms - seems to be like hens teeth

07Lapierre

swarlb wrote: »

Do you mean PCD ? Pitch Circle Diameter What does BCD mean ?

Yep...Bolt Circle Diameter.

grogi

swarlb wrote: »

Do you mean PCD ? Pitch Circle Diameter What does BCD mean ?

Bolt Circle Diameter. https://thecyclemechanic.co.uk/bolt-circle-diameter

swarlb

grogi wrote: »

Bolt Circle Diameter. https://thecyclemechanic.co.uk/bolt-circle-diameter

Same thing, different terminology......
I suppose coming from a motoring background I'm used to PCD

https://en.wikipedia.org/wiki/Pitch_Circle_Diameter

JMcL

Deleted User wrote: »

Question for others when you replace cables do you replace the outers too? I always have and never really thought about it until tonight as I've run out and won't have enough to do the job. So I'll have to reuse some of the ones already on the bike.

I should at least clean them out with some degreaser or something and leave to dry right? or should I be a lazy bastard and just feed the new cables through?

I think I know the answer :pac:

You should, but in practice you should be grand unless you've been picking up lots of crud over the winter that'll have worked it's way in. The last couple of changes I've done, I haven't bothered with the outers as a) I was in a rush and b) wasn't in the humour for unwrapping/rewrapping the bar tape. I sprayed them with a bit of PTFE lube and they've been grand. Gear cables are a bit more pernicity than brakes I'd imagine, though that's based on no sound knowledge other than mere supposition!

CormacH94

Anyone explain in laymans terms what I'd be able to do to swap out a 105 5700 53/39 170.2mm crank for a 50/34 170mm crank?

Head is melted trying to figure out compatibility between generations

Can I use a newer 105 crankset (R7000) on a 10 speed 105 system with no issues?

Or can I use Tiagra 4700 cranks?