Gear problems

[cyclebum]

This is one for you technical guys, but I need answers in 'Janet and John' terms please.

Before my slight hicup in health in December I was having increasing problems changing gear up IE; coming down hill. I would change but was getting an increasing delay before it responded. Eventually it was on occasion taking so long I would try again only to have a double change resulting in a foot slip. I was able to ride home past Halfords and they happily checked it out on the spot and I had a smooth ride home. That was my last ride out until last week and I did a gentle 13 miles without a problem. My next ride was yesturday and did closer to 20 but working much harder and I have noticed that already it is starting to do it again. I am planning 2 final big rides this weekend before setting off for India and worry incase it gets worse. Should it be doing this so quickly after having been adjusted, and what can I do if it happens out in the middle of nowhere???

 

[Scoosh]

I'm no tekki but have found this happening on occasions. I checked:
- that I eased off the pedal pressure just as I change gear
- that my chain, sprockets and all the other 'oily bits' were oily, not cruddy
Then, having cleaned the crud off - it usually worked better - but not perfectly.
So now I am using friction shifters on my ancient bike

I think you will do much better in India than you can imagine.
Happy pedalling !

 

[cyclebum]

I have actually been quite good at hosing down and cleaning and all looks clean, they also oiled (or greased, whichever) when they made the adjustments and the chain looks fine, however I will make sure I add more before I go out again.
And thanks for the words of encouragement, though I am now stressing more about my packing than my fitness which despite everything seems to be back on track!

 

[fossyant]

1. Check the allen bolt is tight on the rear mech - the one going into the arms - not the one connecting it to the frame. (where the cable is tightened - it might be loose)

Next, as you are having problems shifting up, turn the adjuster screw (on the mech) anti clockwise about a half turn first - this pulls the cable tighter, and shifts the mech inwards to the bigger sprockets.

As a quick check, get down low at rear of bike, and see if the top jockey wheel is in line with the sprocket. We are talking even 1mm here. If too far towards the outside, turn anti-clock, if too far towards wheel, turn clockwise

Only move the adjuster half a turn each time - (that's the bit where the cable enters the mech).

To try, I usually put my head under the top tube or seat nose to lift rear of bike, then pedal with one hand and change with the other using the shift levers. I rest the frame/seat on the back of my neck.

 

[Gary D]

I had the same trouble on my hybrid. I found it was the shifter cable sticking.

When changing to a smaller sprocket on the rear, you effectively release the tension on the cable, and rely on the spring pressure in the rear derailleur to take up the slack in the cable and move the mechanism towards the outside of the bike which in turn moves the chain with it to a smaller sprocket.
If that cable cannot move freely because it is sticking, then the spring will not be able to pull the cable enough for the rear mech to move straight away - hence the "delay" in changing gear. Eventually though, the vibration and jiggling will help move the cable and it will change gear unexpectedly as you describe.

You need to check the cable is moving freely. On my bike, the problem lay in the very short length of outer cable that loops nearly in a half circle just before the rear derailleur. Water had obviously got inside it and had started to cause rusting. You mentioned that you hose the bike? That may well be the problem - as it will force water in to those places where it shouldn't get to.

You can check this by undoing the cable at the rear mech. It will be secured by a small bolt with, I think, a 5mm hexagon in it. Change the gears on to the smallest sprocket at the back, and also mark the cable first with a piece of tape so you can re-fit it in the same position.

If you then operate the gear shift lever on the handlebars while holding the cable between your fingers and applying very light tension, you should find that when simulating changing up a gear i.e to a smaller sprocket, the cable should move freely with the light tension. If it doesn't then it is sticking.

If this is the cause, then pull the inner cable from the outer, wipe the cable clean with an oily cloth, and then try and force some liquid through the outer to clean it. A spray can of WD40 with the small pipe on it would do. When you reassemble everything, just give the cable a smear of grease or oil.

Another place to check for sticking is where the cable passes under the bottom bracket housing (where the spindle for the crank and pedals passes through in the frame). The cable runs in a guide. Check it has not become dislodged or clagged up with mud.

I hope this helps.

Gary.

 

[cyclebum]

Thanks Fossyant and Gary, I never knew cycling would end up with me being a contortionist aswell! I think I will print off your replies though as balancing the bike on my neck while tring to read the screen to see what to do next may be 1 step too far!!
Seriously though, I appreciate the advice, I have worried about hosing down but thought leaving it caked in mud was worse. I do have a quick dry spray though I have to say I don't always use it, but I do usually try and dry off as much as possible with a cloth though not necessarily the parts in question. I think I am more in fear if knocking something.

 

[rich p]

Cyclebum, will there be a mechanic on your tour? I found them very useful for that kind of problem when I've done organised tours before. If you can't get it sorted before you go, I mean.

 

[yenrod]

Are your jockey wheels tight ?????????

 

[cyclebum]

Are your jockey wheels tight ?????????

OOh you are awful !!!

As for mechanics, yes there in India but they also provide the bikes there too. However this weekend there is just me, and my hubby who although he taught me how to change a tyre, I think that is about the extent of his mechanical expertese

 

[fossyant]

You fixed it yet.....get spraying the lube, make sure you have no sticky cables, check the jockey wheels are in line with the sprockets, then twiddle with the adjuster.

 

[Amanda P]

This sort of thing is very often cables sticking, either in the housings or in the tunnels and guides. If your cables run through some little groovy things underneath the bottom bracket, I'd be prepared to bet that that's where your problem is.

 

[cyclebum]

Yesturday was a nightmare day and was out all day. I'm off to the hairdressers now (a lady has to try her best), but this afternoon I'll release Bertha and hopefully put all this advice to good use, though Ill have to watch the hair while balancing the bike on my neck .
I'll let you know how I get on

 

[cyclebum]

You guys would wet yourselves if you could see me know, thank god I'm not on web cam. It was too cold outside so I wimped it and brought my bike into the kitchen ( yes I would have killed my hubby if it was him).
I conveniently bought a box of chardonnay at the cash and carry the other day which is now acting as a support for my rear wheel. I tried Fossy's contortionist idea but couldnt get my head through as my bottle holder was in the way, so I got my youngest to turn the pedal as required ( = my daughter!). with my lap top on 1 chair and my bike maintenance for toddlers on another I think I have been able to do it. I was amazed just how dirty it all was but I got my brushes and my newly aquired tool kit out. I've brushed, wiped, screwded and sprocketed as if I knew what I was doing, but now I know my top from my bottom jockey (always important don't you think ) and all are now lined up and changing gears smoothly, even bottom gear which is always difficult but of course I don't use that much!! All that is left is a bit of lubing.
Unfortunately I don't have time to test it out properly tonight but I'll soon find out tomorrow. Just hope i've pull that cable tight enough as I didn't have any spanners to hand. What would indicate if it is too loose?
anyway, thanks for all the advice which has hopefully saved a trip down to my LBS which just happens to be called Halfords!

 

[Amanda P]

You'll hear it called lots of other things on here!

 

[cyclebum]

I've seen them, I'm lucky that mine happens to be pretty good and very helpful, so for them I am happy to mention them. I may have got better from my 'real' LBS, but as a starter I really couldn't afford their bikes and I don't like to use them for practical support as they would probably charge me. However I do support them by buying most of my accessories from them. Infact I wanted to invest in a decent new pair of gloves to take to India and I got them from there as my old ones were so good but a bit too worn now for such distances. (my Halfords gloves are only good for about 10 miles)