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

Internet Friend

Answered my own question in the end :rolleyes:

Thanks for the help folks!

doozerie

Macy0161 wrote: »

I did think the manufacturer's had discounted cross chaining as having any real impact though?

I thought I'd read something with a recent date where various manufacturers gave varied responses to the question. Now that I search though, I can't find anything more recent than this article dating from May 2017.

A summary of the responses in that article:
* Shimano: cross-chaining accelerates wear and degrades shifting performance, recommend to avoid it.
* Campagnolo: cross-chaining is less efficient and accelerates wear, recommend to avoid it.
* SRAM: DO IT!
* FSA: cross-chaining means higher stress on the chain, "we decided to invest in the development of much stronger chains", now we're all, like, whatever.

It's a mixed bag there. FSA are the only ones to venture close to the question of whether cross-chaining might increase the risk of the chain snapping, they don't address the question directly but arguably their aim of producing "much stronger" chains could be interpreted as them considering it a concern worth addressing.

Whatever about manufacturers though, it's entirely a personal choice as to whether to cross-chain or not. I'm not aware of any real evidence, as such, that cross-chaining increases the risk of a chain breaking, but my personal sense of it is that it does add an extra element of risk. Besides, I see no benefit for me whatsoever in cross-chaining, despite what SRAM say in the article above (SRAM seem to like being the controversial/provisional wing of the cycling industry), so avoiding cross-chaining is an easy choice for me.

mirrormatrix

Internet Friend wrote: »

Ok so turns out the problem is being caused by a missing cap for the bottom bracket. Must have come loose (maybe previous owner had been working on it) at some point and fallen off without me noticing. BB is a FSA MegaExo so will check with the LBS and see if they have the spares. Shaka Co don't have the parts to fix it, but they tightened screws etc on the derailleur to keep it in place for now, free of charge so that was pretty sound of them.

May just bite the bullet and switch to 105 BB and crank, both chainsets are looking a little worn at this stage. Not sure about the 26km spin home now...

Do you mean a missing preload cap for the crank? Are they telling you that your chainset is loose and has moved out from the frame?

Otherwise, i am not sure how a missing cap has anything to do with your deraileur being out of alignment?

Internet Friend

Crank bolt had fallen out, seemingly the FSA ones are prone to doing so, so chainset moved out from the frame.

Either way, 105 chainset in the post so will be replaced shortly.

CramCycle

doozerie wrote: »

Whatever about manufacturers though, it's entirely a personal choice as to whether to cross-chain or not. I'm not aware of any real evidence, as such, that cross-chaining increases the risk of a chain breaking, but my personal sense of it is that it does add an extra element of risk. Besides, I see no benefit for me whatsoever in cross-chaining, despite what SRAM say in the article above (SRAM seem to like being the controversial/provisional wing of the cycling industry), so avoiding cross-chaining is an easy choice for me.

I used to be against it but in recent times, I really don't see the issue if you keep an eye on your chain and are OK with a slight increase in wear. I have stuck solidly to the big ring and cross chained all year without issue. The slight increase in friction when crossing is minimal and considering it is only on decent climbs that happens, I can live with it. Using a SRAM chain, 1130 I think, previous anecdotal experience tells me it lasts longer than Shimano but this could be BS. It is definetly wearing quicker than in previous years though. At this point I'd be happy enough with a 1X set up for the road.

mirrormatrix

Internet Friend wrote: »

Crank bolt had fallen out, seemingly the FSA ones are prone to doing so, so chainset moved out from the frame.

Either way, 105 chainset in the post so will be replaced shortly.

By the sounds of it you are lucky the crank didn't come off while you were cycling!

magicbastarder

mirrormatrix wrote: »

Do you mean a missing preload cap for the crank? Are they telling you that your chainset is loose and has moved out from the frame?

looks the crank bolt on FSA cranks is where the preload cap would be on shimano cranks?
https://www.youtube.com/watch?v=vCxf98hXqus

Internet Friend

mirrormatrix wrote: »

By the sounds of it you are lucky the crank didn't come off while you were cycling!

That was my first thoughts but bike shop told me it wouldn't have happened.

doozerie

CramCycle wrote: »

I used to be against it but in recent times, I really don't see the issue if you keep an eye on your chain and are OK with a slight increase in wear. I have stuck solidly to the big ring and cross chained all year without issue. The slight increase in friction when crossing is minimal and considering it is only on decent climbs that happens, I can live with it. Using a SRAM chain, 1130 I think, previous anecdotal experience tells me it lasts longer than Shimano but this could be BS. It is definetly wearing quicker than in previous years though. At this point I'd be happy enough with a 1X set up for the road.

For me I don't see an actual need to cross chain so adding the extra wear (however marginal) and the potential extra risk (whether it even exists) that it entails aren't choices I ever have to consider. My choice of cassette ratio obviously plays a part here, as does my preferred cadence, so I don't feel the need to cross chain to avoid a significant jump in resistance when changing gear.

That's all personal preference, but there are sometimes other reasons to avoid cross chaining too. As one example, my wife's audax bike currently has 50-34 up front, a 12-34 cassette, and a medium cage rear mech. When sizing the chain for that I had two choices, make the chain short enough that small/small is just about usable but big/big isn't, or long enough that big/big works but small/small (plus 1 gear down from that) doesn't. A lot of the talk about cross chaining assumes that it's always an option, but with some bike setups it just isn't.

I read recently that by default at least one version of Di2 wouldn't allow cross chaining (that's the setting out of the box, you can change it). It's a novel aspect of electronic drivetrains that they can be programmed to either support you, or thwart you, at the whim of the person programming them. They may encourage you to keep on the good side of your mechanic I guess

LollipopJimmy

Yup the R8050 Ultegra on my bike doesn't allow cross chaining

usheeeen

Does anyone by any chance have a spare bolt for clamping the brake cable onto a cantilever arm? I seem to have lost mine when changing the pads and cable. I think its a 6mm bolt.

Dont think any shop would have a replacement and would like to avoid having to buy completely new arms as the bike is only a beater and worth nothing.

Pictures here of the other bolt on the other brake

Type 17

Any standard M6 bolt will work fine. It needs to be a few mm shorter than the hole, allowing for a washer* (cut the bolt if required), and you'll need an M6-sized washer that is thick enough not to deform.

If you can make it to the Donnybrook, Dublin area easily, PM me, and I can give you something suitable.

usheeeen

Type 17 wrote: »

Any standard M6 bolt will work fine. It needs to be a few mm shorter than the hole, allowing for a washer* (cut the bolt if required), and you'll need an M6-sized washer that is thick enough not to deform.

If you can make it to the Donnybrook, Dublin area easily, PM me, and I can give you something suitable.

Yeah I found a m6 bolt but I have no way of cutting it and cannot for the life of me find a washer in my shed. Might take you up on that if I cant find the bolt tomorrow.

Mickiemcfist

This is probably a terrifyingly dim question, I've just started commuting 10k each way into town & I've got an old 21 speed mountain bike which is quite heavy but I do like it as it's comfortable & sturdy & doesn't break my back going over the potholes, kerbs & grates in Dublin. Howweever....the gearing is quite low in that when I build up speed I'm pedalling like a maniac, is there a cost effective way of putting road bike gears on it?

Mc Love

Mickiemcfist wrote: »

This is probably a terrifyingly dim question, I've just started commuting 10k each way into town & I've got an old 21 speed mountain bike which is quite heavy but I do like it as it's comfortable & sturdy & doesn't break my back going over the potholes, kerbs & grates in Dublin. Howweever....the gearing is quite low in that when I build up speed I'm pedalling like a maniac, is there a cost effective way of putting road bike gears on it?

Sounds like the bike I have

magicbastarder

can you check to see how many teeth are on the large chainring, on the front? 44 or thereabouts would be relatively common for a mountain bike.

Mickiemcfist

magicbastarder wrote: »

can you check to see how many teeth are on the large chainring, on the front? 44 or thereabouts would be relatively common for a mountain bike.

Cheers for the reply, I'll have to check when I get home as I didn't cycle in due to the weather.

Type 17

Switch chainsets to a hybrid one (48 tooth big ring). You could look at a road chainset, but then you’ll probably be looking at a different front derailleur and other chain-line and compatibility issues.

Mickiemcfist

Type 17 wrote: »

Switch chainsets to a hybrid one (48 tooth big ring). You could look at a road chainset, but then you’ll probably be looking at a different front derailleur and other chain-line and compatibility issues.

Yea I did the count, there's 44 teeth, if I change to 48 would that mean a 9% increase to top end speed? Thanks again

cletus

usheeeen wrote: »

Yeah I found a m6 bolt but I have no way of cutting it and cannot for the life of me find a washer in my shed. Might take you up on that if I cant find the bolt tomorrow.

You should be able to get a suitable washr in any hardware store. As regards cutting the bolt, a hacksaw will suffice. If you dont have one, maybe check with a friendly neighbour, somebody in work who likes diy etc.

Worst case scenario, Mr. Price sell junior hacksaws for €1.49, which should get you through one bolt

cdaly_

Mickiemcfist wrote: »

Yea I did the count, there's 44 teeth, if I change to 48 would that mean a 9% increase to top end speed? Thanks again

You can buy just the 48t chainring rather than a full crankset. You need to know the number of arms on your crank and the BCD (bolt circle diameter). You'll also probably need to raise your derailleur on the seat tube to accommodate the bigger ring.

That said, you could also learn to pedal faster. 'Spinning' is usually a better way to pedal. You do less work in each pedal stroke but you do more of them. It tends to be less wearing on the knees and more aerobic.

devonp

V brakes adjusting cable tension ..??


so put some new pads on a bike with V-brakes but the pads are rubbing off the rim now...tried adjusting the cable at the anchor bolt..no good
should i adjust the barrel screw at the lever too


is there a sequence to getting the whole system adjusted ??


cheers

Type 17

Screw in barrel adjuster on the brake lever fully.
Unhook springs from behind lugs on arms.
Screw in adjuster screws at bottom of springs all of the way (or most of the way and equally).
Adjust cable in pinch bolt so that there is about 10mm (a fingertip's width) of slack when you jiggle the top of the arms.
Re-hook the springs behind their lugs.
Check the brakes for centring on the rim (ensure wheel isn't excessively buckled).
Open the spring-tensioning screw of the arm that moves too much - work in quarter turns or less.
if you go too far, open the other spring in quarter turns to match.

CantGetNoSleep

This is maybe the definition of a stupid question. I got a new Cannondale Synapse carbon today. I had to take the seatpost out as I was putting it in my tiny car. Somehow the seatpost screw got stuck in the seat tube. I've tried turning upside down, rattling and an old coat hanger (worried about scratching the inside of the carbon) but it seems wedged in there. Any idea on how to get it out?

magicbastarder

Magnet? I'm trying to visualise how that might have happened but I'm not familiar with how the bolt works.

CantGetNoSleep

magicbastarder wrote: »

Magnet? I'm trying to visualise how that might have happened but I'm not familiar with how the bolt works.

I'm not entirely familiar with the mechanism either as it is a new bike - but the seat post clamp seems to be internal rather than the normal one that is bigger than the tube. When looking at the bike normally you can see the seat post and seat tube but not real bolt or mechanism like you usually can.

Some form of strong magnet might be the only option. I can't even get the seat post in where it is wedged so ignoring it isn't an option either

They have manuals on their site for most of the bikes , so you might find a clue there maybe

https://www.cannondale.com/en/USA/Support/OwnerManuals/Road

Is it like in the 2018 model shown there ? Page 9

CantGetNoSleep

Deleted User wrote: »

They have manuals on their site for most of the bikes , so you might find a clue there maybe

https://www.cannondale.com/en/USA/Support/OwnerManuals/Road

Is it like in the 2018 model shown there ? Page 9

Thanks - yeah it is exactly that - the whole piece in figure 1 - so a bolt and some sort of mechanism holding it in place. Whatever way it has lodged itself it just isn't moving. I'll either have to figure out a way to get a piece of string around it and the two ends back out, or else disassemble the bottom bracket and hope that i can push it from there with a coat hanger

Oh nuts so it's more like a lego brick than a simple screw and fig.A there is what should have happened but it's dropped down in the seat tube? How much movement is there in it ? like will it travel up and down the tube?

CantGetNoSleep

[Deleted User] wrote: »

Oh nuts so it's more like a lego brick than a simple screw and fig.A there is what should have happened but it's dropped down in the seat tube? How much movement is there in it ? like will it travel up and down the tube?

Seems to be wedged in - the seat tube isn't a complete circular cylinder all the way down, it changes shape around the upper bottle cage bolt and it just seems to have lodged itself there and not rattling at all