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

To someone who is good at eyeballing frame sizes - does this look more like a 56cm than a 58cm?

magicbastarder wrote: »

from my understanding, two things have changed to influence this; having say six or seven gears with a cassette sizing of 11-28 would have resulted in massive gaps between the gears, but the increasing number of indexed gears at the back has certainly facilitated a usable jump in the size of the cassette sprockets.
the second was a move to the 'spin to win' ethos where it's less taxing to keep cadence high, than it is to grind up hills.

And cassettes arrived because a freewheel with more than 6 sprockets and a standard hub, leads to axles snapping at the drive-side cone (most bikes shops do a few 7-speed axle-replacements a week).

You're right about the gaps though - I'm used to my good bike having an 11-speed cassette, and now I'm also riding a 9-speed cassette bike, and the bigger gaps are pretty annoying...

No, you're right about it not being possible to take it apart - you can dribble some heavy oil onto it (3-in-1 style, rather than thin WD-40 stuff), but if there's a lot of play or some crunching that the oil doesn't fix, then it's done...

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 can't remember what my handlebars are, but I just had to get some longer bolts for this fairly standard bell to fit. I wrapped a bit of electrical tape around so the fitting wouldn't abrade the tape.

I included the nuts that came with the new bolts. The inside of the hole of the bell fitting is threaded anyway, but I thought no harm reinforcing it with extra nuts.

Today my left crank arm fell off. It's Shimano Deore FC-M591-L. On inspection I could see the security tab had popped up at both sides so when I got home I loosened the pinch bolts, the only thing holding the security tab was the grease. This should be easy to fix, the spline seems to be ok. Does anyone know any local bike shops in Dublin that stock said part (Y1FU98120)?

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.

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 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 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

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

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

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