CityCyclingEdinburgh Forum » Stuff

Today's most unsatisfactory and wholly rubbish bicycle maintenance

(216 posts)
  • Started 5 years ago by Arellcat
  • Latest reply from urchaidh

No tags yet.


  1. chdot
    Admin

    “what are the advantages of horizontal dropouts?“

    “You don't need any other chain tensioning device?”

    Essentially yes.

    In the olden days horizontal dropouts were because most bikes were single speed or had hub gears (mostly 3 speed).

    They also allowed for a certain amount of shoogling if the frame or wheel weren’t entirely straight (not that that is a good reason of course!)

    With derailleur gears it enables some choice of where the axle/gears are in relation to the mech, but this shouldn’t be necessary...

    Posted 3 years ago #
  2. dessert rat
    Member

    not sure if this fits in here, but no real obvious thread.

    yesterday, a bike shop mechanic told me when I queried something "I have an Engineering degree!".

    wasnt really sure how to take it, as its usually the other way around ie mechanics mocking customers who say "I'm an Engineer".

    Posted 3 years ago #
  3. gembo
    Member

    @IainMcR - I wouldn’t use a mechanic whom I queriied. I would never dream of querying Hannah or Chris.

    Posted 3 years ago #
  4. I were right about that saddle
    Member

    yesterday, a bike shop mechanic told me when I queried something "I have an Engineering degree!"

    Had you queried the price?

    Posted 3 years ago #
  5. gembo
    Member

    Why buy a dog if you can bark yourself?

    Posted 3 years ago #
  6. Arellcat
    Moderator

    wasn't really sure how to take it, as its usually the other way around ie mechanics mocking customers who say "I'm an Engineer".

    Yes.

    Exhibit A.

    Posted 3 years ago #
  7. dessert rat
    Member

    is there a right way and a wrong way for mech pulley wheels ?

    They don't have the identical markings, but no indication if one is upper or lower, only direction of travel.

    Does it matter ?

    Posted 3 years ago #
  8. Murun Buchstansangur
    Member

    Looks like one is a ceramic bearing and the other is ball bearing? I have no idea which should be the tension pulley wheel.

    EDIT: the link below says the sealed bearing is the ‘jockey’ (tension?) and the ceramic is the idler

    https://www.bike-components.de/en/Shimano/Derailleur-Pulleys-for-Ultegra-XT-Saint-9-10-speed-1-Pair-p47983/

    Posted 3 years ago #
  9. urchaidh
    Member

    Since they turn in opposite directions the arrows should be enough to tell which is which. Also, the top/guidw wheel may be a little narrower with sideways float in the bearing.

    Posted 3 years ago #
  10. acsimpson
    Member

    "Since they turn in opposite directions the arrows should be enough to tell which is which"

    do they not also turn in opposite directions depending on whether you dismount to the left or right though?

    Posted 3 years ago #
  11. dessert rat
    Member

    UPDATE: indeed the top one is the ceramic & the bottom the sealed. I looked at the old ones when I took them off.

    Miles of increased, lower friction efficiency ahead of me now. I can sense I will be shaving literally nanoseconds off my 5 hour trips to Moffat. Ups will feel like downs and downs will more even more downerer.

    Posted 3 years ago #
  12. I were right about that saddle
    Member

    All men have secrets and here is mine. So let it be known that I just did possibly the worst bit of spannering I have ever done.

    Was asked by a pal to show her how to take square taper cranks off. On my suggestion she'd got herself a scrapper bike off the council's stairwell clearing team to learn on. So I nipped round to her garden with a bag of tools. Rats, bike is really old and has ordinary bolts on the cranks. Back home to get sockets, bit of a rush.

    Drive side crank not keen to come off after thirty years. Tommy bar, blowlamp. Crack. Off she drops.

    Non-drive side seems absolutely welded. Steel crank though so I persist, feeling my way. CRACK. Has the crank moved? What has happened? Ah, my brand new Park Tools crank extractor has snapped, leaving the stub in the crank which is firmly attached. By the bolt I forgot to remove.

    I am beetroot. Pal gets on street whatsapp group and five minutes later a hacksaw and a brand-new angle-grinder are delivered by children. I saw into the crank and drift out the remains of the tool. Nip home for my spare crank extractor. The crank is too weak to hold it with the sawn section missing. I steel myself and begin sawing, letting the blade follow the square taper. Fifteen minutes later I bang in a screwdriver and split the crank.

    We continue to strip down the frame. Pal has learned that old bikes need some rough treatment. She hammers the seized stem out of the steerer and notes the missing quill. The non-cartridge bottom bracket only finger-tight by contrast.

    Pal tells me not to worry and feeds me ale from the keg and we lose track of time and I get stern looks when I arrive home.

    Posted 3 years ago #
  13. urchaidh
    Member

    Brilliant. There, but for the grace of the cycle gods, go I.

    Posted 3 years ago #
  14. Roibeard
    Member

    IwratS - I am convinced that all our brains are shrinking due to the lockdown. I have strongly advised colleagues to accept more extensive peer review and to be very cautious in making decisions as a consequence.

    The number and variety of "Doh!" moments are quite extraordinary - hopefully the embarrassment will fade with the hangover!

    Robert

    Posted 3 years ago #
  15. gembo
    Member

    IWRATS I think 10 Hail Marys - 5 for bad repair 5 for showing off to girls (Pere Gembeaux)

    My eyes are also going, need to go down poundland for new specs

    Posted 3 years ago #
  16. Arellcat
    Moderator

    firmly attached. By the bolt I forgot to remove.

    I did the opposite, once. I forgot I was dealing with a square taper and not ISIS, and promptly torqued the thing to about 80 lbs-ft, whereupon the taper end of my lovely old DX crank went CRACK.

    Posted 3 years ago #
  17. I were right about that saddle
    Member

    @Roibeard

    Wise words as ever. Like many people I suspect my brain is not what it used to be. I shall take your advice to heart.

    @urchaidh

    At the lowest point of the operation I was improvising a crank extractor extractor. The cycle gods are like the Viking ones. They really don't care about us except as pawns in their games.

    @Père Gembeau

    My sins are written clearly enough even for your defective eyesight. I accept my penance as graciously as I can.

    @Arellcat

    Most generous. Thank you.

    Posted 3 years ago #
  18. Colin
    Member

    IWRATS, thist scenario has a sadly familiar ring to it. I seem to remember that a long time ago, crank bolts had a washer which also had to be removed before use of the crank extractor......

    Well done for helping a fellow cyclist though.

    Cheers
    Colin

    Posted 3 years ago #
  19. mcairney
    Member

    My rear derailleur been bugging me for weeks (3 clicks to get from the highest/smallest cog to the next highest and not being able to reach the 2 lowest cogs).

    Watched the Parktools video and the answer seemed to be lots of turning of the barrel adjuster (Like literally 5 or 6 complete turns- I was worried that the adjuster was knackered), slightly hampered by my ability to tell the difference between clockwise and counter-clockwise.

    The result is that shifting up the cassette is silky smooth but shifting back down is pretty jumpy.

    I suspect I've simply over-tightened the barrel adjuster but I might just get someone who actually knows what they're doing look at it!

    Posted 3 years ago #
  20. mcairney
    Member

    Phoned up my LBS- they're fully-booked for repairs until 21st July!!
    Gave the barrel adjuster a half-turn clockwise to loosen it off slightly and that appears to have done the trick.

    Posted 3 years ago #
  21. mcairney
    Member

    Thanks, it's internally-routed so probably best left in-situ for now.
    My eventual plan is replace the entire drivetrain (including brakes) once the current set is run into the ground as I'd like to upgrade from the TRP Spyre mechanical disc brakes to either 105 or Ultegra hydraulic (depending on finances).

    Posted 3 years ago #
  22. chdot
    Admin

    “it's internally-routed so probably best left“

    So, continuous outer cable?

    Should be straightforward to remove.

    Getting end out of lever may or may not be easy (mostly depending on lever/hood design).

    Posted 3 years ago #
  23. chdot
    Admin

    Decided my ‘new’ bike would be better with a triple chainset.

    So that meant a new bb.

    Bought a Park tool to remove Campag one.

    It wouldn’t move. (Not actually a great tool for a tight bb)

    I know the difference between left and right - right cup has LH thread.

    Turns out previous owner didn’t - even with helpful hints from Campag.

    So turning ‘wrong’ way got cups out. Frame threads damaged but less than I had expected - but enough to prevent normal cups going in straight.

    Fortunately I had a Thum sealed unit with plastic retainers that went in fine.

    Had to change front changer (had hoped I’d get away with the double...)

    Still needs some fine tuning to get bottom to middle to shift better, but extra bottom now manages steeper slopes!

    (That all might sound ‘satisfactory’ but the process certainly wasn’t.)

    Posted 3 years ago #
  24. ARobComp
    Member

    Forgot to post about this one. Snapped chain last Monday evening on a cx ride around the Pentlands. Managed to avoid coming off thank goodness as was going pretty quick. Fixed it and made a mental note to check it and most likely replace it as it was getting old.

    Riding to the office on Wednesday morning, chain snapped again on canal. I managed to avoid going in the canal but while half way over the handlebars managed to steer myself into the bushes (phew!) getting a sold knee scrape (superficial) but throwing my neck out again.

    Headed straight to bike trax after repairing it again and new chain safely installed. Thankfully looks like cassette and chainring will manage after a clean.

    Still clearly I did not fix it properly the first time and didn't take the time to run it and check when I got home. Lazy. Got my just desserts.

    Posted 3 years ago #
  25. steveo
    Member

    The curse of the ancient mtb continues. Scavenged a freehub body and repacked the hub.
    No noises now but a bit of wobble at the cassette when the wheel is in free wheel.

    I think I must have missed a spacer on the non drive side as the chain rubs on the frame in the small sprocket. The cones are maybe a fraction loose but I'm sick of the sight of this bike. Might just set the stop screw and be done with it.

    Fake edit: arrrggghhh, just taken it round the block and its slipping under power still. I'm very sick of this bike.

    Posted 3 years ago #
  26. I were right about that saddle
    Member

    Burn it, it is a witch.

    Posted 3 years ago #
  27. gembo
    Member

    I had a boiler like that once. Scottish Hydro spent a year trying to fix it and then basically replaced all of it

    I have various little fan heaters they give you to try to keep warm in the cold parts of the year.

    Also met all grades of their engineers from the you NG chap on his first solo service who broke it through to the chief.

    Posted 3 years ago #
  28. steveo
    Member

    Yeah it's turning into that.

    Had another run round the block.

    The barrel adjuster is just spinning back when I try to tighten it so I'm assuming something is missing there. That won't be helping with the indexing.

    After a deal of physical violence I managed to get it into the granny ring and no matter how much force I put in nothing slipped. So looks like the middle ring is shot.

    Does the bike station have a collection of chain rings?

    Posted 3 years ago #
  29. ejstubbs
    Member

    See my latest post on the saga of my e-bike drivetrain rebuild.

    Anyone know how to get an ISIS/Octolink type crank off when the crank puller coupler thread is stripped?

    Posted 3 years ago #
  30. ejstubbs
    Member

    Hmm, EBC say they can get the crank off, but the first available slot they have to do such work is mid-August. Harts say they'll "have a look at it" if I take it in on Monday or Tuesday next week (though if they do get it off then I'll be needing a new crank to get home, hmm...)

    If I'm going to be riding it around for a while yet with the old chainring on because I can't get the crank off, I think I'm going to put the old, worn chain & cassette back on (and accept the risk of a snapped chain). The chainring didn't actually look noticeably worn when I took it off (Bosch use these small chainrings - mine's a 16T - which I think may be made of rather tougher steel than normal chainrings) but so far I've been working on the principle that the chain was so worn that everything in the drive train needed replacing. But not the pedals or cranks...

    <rule 2>y <rule 2>ing inferno.

    EDIT: A thought: The coefficient of thermal linear expansion of aluminium is ~25% or more greater than that of steel. But I don't have a blowtorch...

    Posted 3 years ago #

RSS feed for this topic

Reply »

You must log in to post.


Video embedded using Easy Video Embed plugin