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

Flaccus · 20-09-2022 10:11am

Is sit worth going from 28mm to 32mm tyres if riding normal tarmac roads (80% in good condition) ?

Running GP5000 clincher 28mm on Hollowgram Knot Rims (21mm ID). They size up to just over 29mm and as I am 100KG I run close to max pressure for the rim which is 95psi on 28mm tire. If I went 32mm I would be gaining an extra 3mm+ and could likely ride at around 80psi or lower. I happen to have 32mm tires (came on bike but have sold the stock wheels) so won't be any expense swapping around.

Thanks

CramCycle · 20-09-2022 10:45am

https://www.boards.ie/discussion/comment/119640591#Comment_119640591

Which wheels are they, as 70psi sounds like hookless rims, which adds in other things to think about.

Large bottle small glass · 20-09-2022 10:53am

As the Elizabethan era is over perhaps we could use SI units... Or at least stick to one system..

loyatemu · 20-09-2022 11:26am

it's one area where the imperial units are clinging on here, the other being using feet&inches for height. KGs seem to be overhauling stones/pounds for weight though.

back on topic - the figures given by that calculator are too high IMO. Your tyres only really need to be hard enough to avoid pinch flats. I run my 25mm tyres at 80 on the back and 70 on the front (sorry about the mixed units there...). Anything more and you get a very rough ride on our crappy road surfaces which also impacts on the energy you're expending, or at least cancels out any rolling benefit from the harder tyres.

Fian · 20-09-2022 11:30am

I have bled my rear hydraullic disc brakes a few times.

Each time they work great, for a while, but quickly become spongy again. When I bleed them i don't drain the whole system, just squirt up some extra mineral oil and push out some. It does get the air out though.

Do I need to drain the whole system? Or is it more likely i have a leak somewhere and perhaps need a new hose? Or is there another explanation likely?

Or should I maybe just drop it into a shop to have them try it? I am a few minutes walk from Jow Daly's in dundrum or i can drop it to harry's bikes in clonskeagh.

I doubt it matters but just in case - this is on my hybrid commuter not a road bike. Shimano brakes.

Oh and one other thing - how important is it to have a "spacer" between teh pads when doing this? I think i may not have used one.

Any suggestions/advice welcome.

Large bottle small glass · 20-09-2022 11:33am

There are a few things to keep in mind, marked tyre widths are at best a guide.

I fitted 30mm WTB tyres last night which are narrower than the 28mm I've been using for years.

I've put 28mm Vittoria tyres on my wife's bike which were narrower than 25mm GP4000.

So first off I'd measure.

Pressure gauges aren't very accurate.

If you are riding poor or very poor surfaces run as wide and as low as avoids pinch flats or go tubeless.

If you ride mainly good surfaces you are beyond assistance! 😀

Squidgy Black · 20-09-2022 12:11pm

https://www.boards.ie/discussion/comment/119640780#Comment_119640780

Was looking at the 4 season or the aero wides alloy, so hooked for both I believe, but all their wheel sets seem to have 70psi max for 32mm regardless

JMcL · 20-09-2022 12:12pm

https://www.boards.ie/discussion/comment/119639573#Comment_119639573

I'm running Rubino Pro 28mm, which again have a recommended pressure of 85psi, tubeless at around 70psi with no issue. I've run them lower but 70ish seems to work for me. Running tubeless tyres at that sort of (recommended) pressure loses most of the benefits of tubeless in the first place. I usually ran my (tubed) 25mm GP 4 Seasons at 85-90psi with no issues and I'm tipping the scales around the 90kg mark give or take. Somebody else mentioned the Hunts are hookless, so not sure how that affects tyre compatibility.

JMcL · 20-09-2022 12:13pm

it's one area where the imperial units are clinging on here, the other being using feet&inches for height. KGs seem to be overhauling stones/pounds for weight though.

Though "568ml Guinness please" doesn't really have the right ring to it either 😁

CramCycle · 20-09-2022 12:17pm

https://www.boards.ie/discussion/comment/119640806#Comment_119640806

PSI is the only non metric units as the bar is too difficult to get precise on my track pump, and its not an SI unit either but shorthand for one.

rmactier · 22-09-2022 10:07am

is it possible to get a replacment adjuster grub screw for a drop bar brake/shifter lever?

i have a pair of Sunrace R80 Ergo shifters and the stupid plastic grub screw that adjusted the reach of the lever broke the head when i tried to adjust it, now there is no slot to use a screwdriver anymore. its only plastic so i could prob get it out but would like to replace it to i could shorten the reach of the lever.

or am i stuck with it unless i replace the lever altogether?

similar question for a pair of Shimano sora flight deck levers (1990's) where the cable wheel inside the unit isnt holding the cable end anymore and cant change gear.

phelixoflaherty · 22-09-2022 10:12am

Looking to get mudguards for my Cube Editor.

The tyre size is 622-40.

Should I get ones with 40 or get a bit bigger to avoid slapping and banging?

Thanks

cletus · 22-09-2022 10:20am

https://www.boards.ie/discussion/comment/119649464#Comment_119649464

Grub screws aren’t specific to bikes. If you can get them out and measure the size/thread, I have a variety of them here, and I’m happy to send you on a few

magicbastarder · 22-09-2022 10:37am

https://www.boards.ie/discussion/comment/119649486#Comment_119649486

first order of business would be to measure the clearance on the frame; generally the mudguards would be a little wider than the tyres.

rmactier · 22-09-2022 8:27pm

https://www.boards.ie/discussion/comment/119649522#Comment_119649522

Brilliant. Thanks. I'll try to extract them this weekend. 👍

Mundo7976 · 25-09-2022 10:48am

So I rooted out the old bike, a Trek Fx2 (5 or so years old). Cleaned it up to use on the trainer but also planning to use it for messing about over the winter..

The cap for the oil reservoir is cracked, can I get a replacement or would I be better getting a new unit, it's tektro m285. Unable to locate cap on its own so might even consider a set of cable actuated brakes instead, reasonably priced

Cookie_Monster · 27-09-2022 10:30am

I've got a 2019 Canyon Ultimate with 11 speed ultegra Di2 on it. I need a smaller gear tbh because the hills around here are big.

Am I better to swap the front ring for a smaller one or get a single piece for the cassette and remove the smallest ring from it, given I never use the 11th cog, even at 50kph+ downhills ,lol. Years ago I did this on a previous bike, just getting a single larger cog on the rear and biffing the smallest, but honestly I've no real idea. Or is it a case or replace the entire cassette? I need to go and count the teeth on the rings as I cant find the manual to figure out current combinations.

Also my edge 500 is about to die, whats the current equivalent of simple no frills garmin, there really doesn't seem to be one from initial looking, the 130 seems too basic and the 530 too flash.

Paul Kiernan · 27-09-2022 10:37am

The 2018 model came with 52/36 front and 11-28 rear. Not sure about 2019!. If that's the case you've got huge potential to upgrade by changing cranks or cassette or both. Going to 11-32 or even 11-34 cassette would have a huge effect but you'd have to buy a new cassette. You could change the front to a 50/34 perhaps by finding someone to swap with you. There are often ads on here looking to do such swaps.

magicbastarder · 27-09-2022 10:43am

almost certainly would need a new RD too, i suspect the one on it maxes out at 30T.

Cookie_Monster · 27-09-2022 10:48am

https://www.boards.ie/discussion/comment/119670128#Comment_119670128

Is there an easy way to tell this?

Paul Kiernan · 27-09-2022 10:49am

https://www.boards.ie/discussion/comment/119670153#Comment_119670153

Stick up a photo!

You might need a longer chain too but they're not too expensive.

Paul Kiernan · 27-09-2022 10:51am

The 2018 has the long rear mech so 2019 surely does too!

magicbastarder · 27-09-2022 10:56am

ah, if it's already got a long cage rear mech then that's not a worry.

loyatemu · 27-09-2022 10:59am

I have the 130 and it's fine in terms of functionality but the battery life isn't great.

hesker · 27-09-2022 1:50pm

@Paul Kiernan

Off the top of my head not necessarily.

OP needs to check model number of RD. Should be written on it

CramCycle · 27-09-2022 2:23pm

You should get away with the rear mech if it's medium or GS, Shimano is very conservative. If it's a 4 arm Shimano, I have a few barely used 105 chainrings to bring it down in size.

hesker · 27-09-2022 2:33pm

Yeah. Shimano is conservative to allow for shorter chainstay bikes apparently. Could go to a 32T on rear and 50/34 front which would be a decent enough move.

Would not necessarily need a full new cassette. Can possibly change just the biggest 3. Chain might be ok provided you don’t use small small which is not advisable anyway.

magicbastarder · 27-09-2022 2:37pm

can you buy just the 3 ring cluster on its own?

CramCycle · 27-09-2022 2:54pm

There was a crowd in the UK you could buy spare sprockets but they weren't Shimano made. Never done it, and can't find them now so it was possible, no comment on the quality.

hesker · 27-09-2022 4:51pm

https://www.boards.ie/discussion/comment/119671322#Comment_119671322

Need to check my records. I think I did it a couple of years ago. Miche cassettes can be bought a little more cheaply I think. Campy and Shimano 11s cassettes are close enough that it might work. At least it has for some people.

Edit: It’s possible to buy individual Miche sprockets. Miche have a catalogue that shows what’s possible.

They can be bought online but it’s likely better value to buy a full cassette.

see here for example.

https://www.smi-radsport.de/index.php

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

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