First Fumblings in Bike Maintenance

Makhaira · 10 May 2015 at 19:56

Few things are as dangerous as the curiosity of a naive but enthusiastic tinkerer, especially when access to the internet makes them feel like they have all the knowledge they need at their fingertips...

So I've got some questions about stuff I found that I think is wrong, but I also thought I'd jot down my ramblings as I know there are a few other people on here just discovering these self-powered half-cars...

Questions:
1) My front shifter cable is fraying, can I replace with any old gear cable, or does it need to be something specific to my bike?
2) I think my front sprockets are warped or bent. When I rotate the pedals, there's approx 2mm of lateral change in the position of the chain relative to the derailleur. Made adjusting it a right challenge as I don't have much clearance to the pedals! I'm assuming that level of wobble is not deemed acceptable? There is no play in the BB.

Findings...
1) A 5mm allen key, torx driver, and a pair of pliers is pretty much all you need for doing this stuff. Rubber gloves, kitchen roll, GT85 and IPA/degreaser are handy too.
2) Rear-wheel-only bike stands may be cheap, but they're really not ideal for maintenance. I'm going to build/buy my own proper stand ASAP
3) Having a laptop with all the various sites already open in different tabs is a massive help. (pro tip - put clingfilm over the keyboard)

What I ended up doing...
- Realigned brakes and adjusted tension with the clamping bolt and then barrel adjusters. Dead simple.
- Checked rear derailleur for clean and crisp shifts - no issues
- Front derailleur. Boy did I open a can of worms here. Shifting up to the larger cog wasn't always that clean, so I thought I'd have a go at tweaking the FD. Height, rotation, limits, tension. I ended up playing with this for an hour, and came to a few conclusions.
1) The logic of this is actually very simple
2) If you put too much cable tension in then it won't shift down again. Really frustrating when you think you've got it sorted and then find that out!
3) I have hardly any clearance between the FD being in place to allow big sprocket and smallest rear gear and then pedal hitting the FD. Not sure if it's a problem from the components I have, but it's bloody annoying
4) My front sprocket wobbles (see question bit above)
5) Pedalling on a rear-wheel-only stand is a fiddly endeavour

Got to say though, enjoyed myself! Thanks to the guys who pointed me at various resources online.

mattyfez · 10 May 2015 at 20:29

I'm still learning too, my gears are not spot on yet but getting there, it's much more rewarding and fun (not to mention cheaper) to learn how to do it than simply taking it to a shop and paying to get it done.

Roady · 12 May 2015 at 11:21

Makhaira said:
Questions:
1) My front shifter cable is fraying, can I replace with any old gear cable, or does it need to be something specific to my bike?
2) I think my front sprockets are warped or bent. When I rotate the pedals, there's approx 2mm of lateral change in the position of the chain relative to the derailleur. Made adjusting it a right challenge as I don't have much clearance to the pedals! I'm assuming that level of wobble is not deemed acceptable? There is no play in the BB.

(1) Fairly sure you can change it for 'any old gear cable' but bear in mind that new cable isn't exactly expensive! The crimp ends are inexpensive and a cutting tool is a worthy investment.

(2) It does sound like they are bent, although it could be the bearings in the BB which are out of alignment, rather than 'play' in them.

Makhaira said:
Findings...
1) A 5mm allen key, torx driver, and a pair of pliers is pretty much all you need for doing this stuff. Rubber gloves, kitchen roll, GT85 and IPA/degreaser are handy too.
2) Rear-wheel-only bike stands may be cheap, but they're really not ideal for maintenance. I'm going to build/buy my own proper stand ASAP
3) Having a laptop with all the various sites already open in different tabs is a massive help. (pro tip - put clingfilm over the keyboard)

(1) I've also found electrical tape very useful for holding things, like a 3rd hand! Latex gloves are great, I use 'craft' ones rather than anything special (£3.60 for a box of 100). Only slight problem with latex ones is degreaser/GT85 causing them to stretch/tear, but get them cheap so not an issue. Get some grease and lube too and you'll be set!
(2) A proper stand makes life much easier, I picked up the 'Jobsworth' one from PX when they had it on sale. £30 is a good price, if the only option was £60+ I would probably look at making my own. A quick & simple (cheap) solution (depending on your setup) can be a couple of pulleys/supports screwed into the ceiling and rope loops to hold the bike in the air.
(3) Laptop/tablet, I tend to find my Phone good/big enough (S5).

Makhaira said:
3) I have hardly any clearance between the FD being in place to allow big sprocket and smallest rear gear and then pedal hitting the FD. Not sure if it's a problem from the components I have, but it's bloody annoying
4) My front sprocket wobbles (see question bit above)

People will say you shouldn't be using Big/Small but in reality you should physically be able to, with your pedal/crank arm hitting the FD it hints at quite a major misalignment! On the rear of some crank arms there is a 'spacer' (like a metal noodle) which spaces the arm out away from the chainrings, if your crank arm has one it may show you where the 'warping' is coming from. Usually chainrings will fix to the crank so them being bent should have no bearing on the crank arm and the FD. You may have a bent crank arm/spider.

Home maintenance is very rewarding, I currently have a 'click' I'm trying to resolve! I will fix it eventually!

touch · 12 May 2015 at 12:10

Makhaira said:
Questions:
1) My front shifter cable is fraying, can I replace with any old gear cable, or does it need to be something specific to my bike?
2) I think my front sprockets are warped or bent. When I rotate the pedals, there's approx 2mm of lateral change in the position of the chain relative to the derailleur. Made adjusting it a right challenge as I don't have much clearance to the pedals! I'm assuming that level of wobble is not deemed acceptable? There is no play in the BB.

1- Any gear cable will do. You fit it then cut it to size (and put an end cap on too)

2- Check if it does this in both chainrings. If both rings seem to have the same wobble, it's likely to be a problem with the alignment of the whole crank. If not, it might just be one ring bent. It's easy to replace, just make sure you get the right BCD (bolt circle diameter - distance between bolt holes)

Roady said:
People will say you shouldn't be using Big/Small but in reality you should physically be able to

Big/Small should be fine. It's big/big where you get cross-chaining problems.

Have you got the front derailleur on straight?
Put it into the position where it comes close to the pedal and look down on it from above. The outside plate of the derailleur should be parallel with the chainring. (Unless your chainring isnt straight

)

Makhaira · 12 May 2015 at 12:31

Thanks guys. Last night I stripped the rings off and had a check with some calipers, and there doesn't seem to be variation in the bb rotation (fsa power drive cartridge) but the spider is definitely warped. I've got everything set up now, albeit with tight clearances, so I think I'll run this until I have issues and then just replace the bb and cranked - there doesn't seem to be much love for the fsa vero pro that I have. On the plus side I've learnt lots reading up about all this!

Roady · 12 May 2015 at 16:50

Glad to hear you've had a good look at it, with the spider bent be sure to check for any cracks. If it's aluminium it may eventually fail/break if steel it'll probably be ok. Do you know the history of the bike? If it's been involved in an accident (with enough force to bend the crank spider) I'd be suspect of the frame in general. If it just got 'squashed' in someones shed by their lawn mower, maybe less so...!

topgun06 · 12 May 2015 at 16:56

I was surprised to find a hairline crack in one of my old chain rings last night :eek:

Makhaira · 12 May 2015 at 22:37

Had it since new. No sign of cracks. Apparently there have been other instances of warped spiders on these from new, I just didn't know enough at the time to check.

OspreyO · 16 May 2015 at 17:29

Any time I've adjusted my derailleur I tend to make the problem worse. I think its because I always end up rushing it. I must spend a bit of time really messing with them to really get the nuance of it all. Brakes I have no problem with.