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

cdaly_ · 09-08-2019 9:34am

Probably but two teeth on the front ring won't gain you much. What cassette have you? Something with a wider range would make a difference.

Type 17 · 09-08-2019 12:30pm

DaveyDave wrote: »

Dropped the back wheel to get trued earlier. Your man asked has anyone else touched them as they were very tight and there may not be much they could do. This was the first I've heard of this being an issue with a wheel, is this true?

They've only been trued once. I've had other wheels trued a few times in the past. Campag Zonda wheel.

Overall wheel tension can be an issue - many people truing a wheel only think to tighten spokes, when you often need to loosen others to keep the overall tension within range.

Did yer man mention spoke tension, or was he perhaps talking about tight (partially-siezed) nipples?

DaveyDave · 09-08-2019 12:47pm

Type 17 wrote: »

Overall wheel tension can be an issue - many people truing a wheel only think to tighten spokes, when you often need to loosen others to keep the overall tension within range.

Did yer man mention spoke tension, or was he perhaps talking about tight (partially-siezed) nipples?

He was taking about the spoke tension, he gave them a squeeze and said they're tight. They're Zonda wheels so hopefully there's no issue.

Reisers · 09-08-2019 3:20pm

Hi, there's a continuous rattle just started on my road bike.

I don't see anything obvious on the drivetrain and im thinking its the BB as it's there years.

How would i be certain? I can't replicate the rattle off the bike

smacl · 09-08-2019 3:28pm

Reisers wrote: »

Hi, there's a continuous rattle just started on my road bike.

I don't see anything obvious on the drivetrain and im thinking its the BB as it's there years.

How would i be certain? I can't replicate the rattle off the bike

Trick I used to use was put it up on the turbo and start pedalling with someone else isolating the source of the noise. If it is the BB there may also be some play on the cranks if you've a damaged bearing, so worth checking. I usually blame the BB for all sorts of random noises and am usually wrong

Reisers · 09-08-2019 3:51pm

smacl wrote: »

Trick I used to use was put it up on the turbo and start pedalling with someone else isolating the source of the noise. If it is the BB there may also be some play on the cranks if you've a damaged bearing, so worth checking. I usually blame the BB for all sorts of random noises and am usually wrong

There isn't an awful lot of play but I've suspected the BB needs replacing for a while now

Unfortunately I've no turbo

CantGetNoSleep · 09-08-2019 10:37pm

CantGetNoSleep wrote: »

Put a new set of wheels on my disc bike today. There is a little bit of break rub and the levers feel very spongy. The rear lever almost touches the handlebar when you brake hard. Bike has relatively low mileage (few hundred km) but was sitting unused for a year before I started using it.

Would a bleed solve these issues? Anyone recommend a YouTube tutorial on how to do so? I have a Shimano bleed kit but never used it

As a few of you helpfully suggested - I think I have solved the brake rub issue on this by loosening the calipers and repositioning them so the pads were more symmetrical. Very easy job actually.

The rear brake in particular is still not right as I have to pull the lever fully to get any sort of strong braking force. In the past on a rim brake bike I'd have the pads quite close to the rim so a small pull on the brake would already engage the braking. Is there anything similar you can do with discs? Someone suggested a grub screw but I haven't found anything - shifters are Shimano RS505. Any ideas before I go messing with fluids etc?

smacl · 10-08-2019 5:37pm

CantGetNoSleep wrote: »

As a few of you helpfully suggested - I think I have solved the brake rub issue on this by loosening the calipers and repositioning them so the pads were more symmetrical. Very easy job actually.

The rear brake in particular is still not right as I have to pull the lever fully to get any sort of strong braking force. In the past on a rim brake bike I'd have the pads quite close to the rim so a small pull on the brake would already engage the braking. Is there anything similar you can do with discs? Someone suggested a grub screw but I haven't found anything - shifters are Shimano RS505. Any ideas before I go messing with fluids etc?

Have a look at the following document, notably the section on free stroke adjustment; https://si.shimano.com/pdfs/dm/DM-BR0008-10-ENG.pdf

CantGetNoSleep · 10-08-2019 10:31pm

That is very helpful thank you

magicbastarder · 11-08-2019 7:25pm

i bought pannier bags reduced in lidl yesterday on a whim, so had to buy panniers in halfords today to go with them. the quandary became which bike to put them on; they're non-disc compatible panniers, but i thought they might fit on the disc bike, but they foul against the brakes. so fine, i'll put them on the rim brake bike. except...

the caliper brake is in front of the mount points higher up on the seatstay, so i can't mount it. anyone come across this issue before?

Type 17 · 11-08-2019 7:29pm

Show us the rack/carrier. You often have to re-shape the struts that go to those seat-stay bolts to clear the brakes. If things are really tricky, you can use a centre (brake-mount) stay for the left one, and use the bolt on the seat stay as normal for the right side.

magicbastarder · 11-08-2019 7:36pm

it's one of these - it does expllicity say in the instructions that you can bend the mounting struts, but i think i would need to bend them where they're already bent 90 degrees (where they swing from being horizontal to vertical). will have a faff around again.

https://www.chainreactioncycles.com/ie/en/topeak-super-tourist-dx-rack/rp-prod32817

Type 17 · 11-08-2019 7:41pm

Those stays are pretty flexible in a bench-vice and with the help of a slip-joint pliers

You might need a longer one* for the left side, to take account of the roundabout route it will have to take over the brakes.

*Many LBSs have them for smaller bike frames, where the seat stays are much further "down" the rear wheel.

cdaly_ · 12-08-2019 10:36am

I would say that before adjusting free stroke that you make sure the brakes are properly bled. You can test this by pumping the lever a couple of times. If there is air in the system they'll likely get harder with a couple of pumps, if there is no air in the system they'll be hard on the first stroke and won't get any harder on subsequent strokes.

If there's air in the system, you have to bleed first.

CantGetNoSleep wrote: »

As a few of you helpfully suggested - I think I have solved the brake rub issue on this by loosening the calipers and repositioning them so the pads were more symmetrical. Very easy job actually.

The rear brake in particular is still not right as I have to pull the lever fully to get any sort of strong braking force. In the past on a rim brake bike I'd have the pads quite close to the rim so a small pull on the brake would already engage the braking. Is there anything similar you can do with discs? Someone suggested a grub screw but I haven't found anything - shifters are Shimano RS505. Any ideas before I go messing with fluids etc?

smacl wrote: »

Have a look at the following document, notably the section on free stroke adjustment; https://si.shimano.com/pdfs/dm/DM-BR0008-10-ENG.pdf

MojoMaker · 13-08-2019 4:00pm

MojoMaker wrote: »

So I have 36/52 rings on one of my bikes. It's a nice DA 9000 chainset but I want to go lower, without having to replace the big ring (not cheap). Can my standard 5800 FD work with a 34/52 setup?

I have heard mixed opinions but nothing definitive one way or the other.

Might have gotten buried in a busy month, but any ideas anyone?

Type 17 · 13-08-2019 8:00pm

Should be ok, but to be sure, you need to confirm that your FD cage will come low enough to accommodate the chain when you are in the small ring/smallest sprocket gear*.

To confirm before you buy a new ring, find a bike with a 34, put it in the small/small gear and measure vertically from the centre axis of the chainset to the bottom of the chain where it passes through the bottom of the FD cage (let's say the distance is 45mm). Then, on your bike, confirm that your cage comes down to less than 45mm from the chainset axis, ie: low enough to clear the bottom of the chain if it had a 34t small ring.

*Yes, I know that you will never use this gear because you hate cross-chaining, but the drivetrain may get put into this gear accidentally, and if the chain drags/catches the FD cage, it will bend/destroy the FD, so it needs to clear the FD cage properly.

magicbastarder · 14-08-2019 8:33pm

magicbastarder wrote: »

they're non-disc compatible panniers, but i thought they might fit on the disc bike, but they foul against the brakes.

had a 'duuuuh' moment while out on the bike last night; four washers between the rack and the frame and it clears the brakes by mm or two.

magicbastarder · 14-08-2019 10:51pm

fairly straightfoward question i assume; my four or five year old 105 5800 shifters don't feel quite as crisp as they used to. nothing wrong with them, but i guess in the probably 15k on them, they've gummed up a tiny bit; is there any standard spot to drop/spray in a little light oil to keep them performing, or any other maintenance i could try on them?
should note, this is after a reecnt cable and housing change.

mirrormatrix · 15-08-2019 10:48am

I normally spray a bit in occasionally. I'm a bit imprecise, but I find that if you pull the shifter across the full extent and then spray some lubricant into the mechanism then that normally frees things up a bit.

Curb Your Enthusiasm · 16-08-2019 12:45pm

Hey,

I seem to have a grinding issue seems to be coming from the back chain mechanism where the pedals are.

Any idea how to get rid of it? Sounds like sand or grit trapped somewhere. It's a new bike. Thanks!

magicbastarder · 16-08-2019 1:13pm

first thought would be if it's a new bike, bring it back to where you bought it for them to have a look - a mechanic with physical access to the bike will obviously be waay better placed to diagnose than people on the internet.

Interested Observer · 17-08-2019 1:50pm

I have a monumentally stupid question, going to change a tyre and tube for the first time. Use my bike for commuting the rear tyre has gone flat 3 times in the last few months so I'm putting a new tyre and tube in, and I'm going to do it myself so I don't need to go back to a shop for a simple job.

The tyre on there at the moment is 700x38c. Can I put a 700x35c tyre on instead?

Type 17 · 17-08-2019 2:03pm

Yes, no problem.

17-08-2019 2:19pm

I'm curious about the different widths front and back. Passed a bike recently that was locked up and did a double take as I spotted it had what looked to be a 30 on the front and maybe a 26 on the rear.

smacl · 18-08-2019 8:25am

Deleted User wrote: »

I'm curious about the different widths front and back. Passed a bike recently that was locked up and did a double take as I spotted it had what looked to be a 30 on the front and maybe a 26 on the rear.

At a guess, if you've a wider tyre up front it will be running at a lower pressure and absorb that bit more road buzz, akin to a bit of additional front suspension. Given the bike hits things front tyre first, this is where you need the extra give.
Might also be the back has less clearance so the owner was going for max width on both. Then again, could just be whatever tyres were available as they needed replacing.

tuxy · 20-08-2019 10:46pm

On Road bikes with deep section wheels the opposite is actually common and Canyon sell some models with mismatched tyres. 23 up front for aerodynamics and 25 on the back for less vibration sent to the saddle. The front wheel hits the air first so it's more important to have a good transition from tyre to wheel at that point.

CramCycle · 21-08-2019 7:35am

smacl wrote: »

Then again, could just be whatever tyres were available as they needed replacing.

This is where my money is, asked shop for tyre, shop handed them what was there. Won't really affect a commuter bike in any noticeable way.

CantGetNoSleep · 25-08-2019 3:41pm

I'm doing a bike build that I had intended finishing today but got stuck.

It is an older model (2016) but new CAAD12 frame. It has a strange standard in that it still uses the older post-mount fork and flat mount rear caliper. I have both calipers but the wheels won't fit - looks like this is because I have 160mm rotors but I don't have any of the plastic adapters (picked up all of the parts on adverts type sites so not everything came in boxes).

I'm wondering if it is easier to get adapters or new rotors? Adapters should be cheaper (the rear flat mount 160mm should be easy to find, the front post mount maybe more difficult), but I worry that I'd run into space issues at the rear in particular as it looks very tight around the triangle. Anywhere I see that particular years' model reviewed it takes 140mm rotors. Any thoughts?

Zen0 · 25-08-2019 5:40pm

I didn’t think 140mm was recommended for a front disc unless you are very light. I may be wrong. My CAADX has 140mm on the back and 160mm on the front, both post mount. If I’m right, you may have a choice in terms of what you do at the back, assuming you can get flat mount adapters. On the front you would need a 160mm adaptor. Whether it is plastic is another matter. Mine looks and feels like alloy, and I’d be very wary of trusting plastic for that purpose. There can be huge strains on a front caliper, and it’s not something that you want to fail.

CantGetNoSleep · 25-08-2019 5:59pm

Yeah reading up it looks like this adapter will do the job

https://www.bike24.com/p23452.html

Going to give it a try rather than changing rotors.

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

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