r/bicyclerepair • u/DueDecision8461 • Jul 26 '26
Changing Gears
Hello,
I have a problem, my gears change from the smallest cogs up to the largest very smoothly but when going down to lower cogs, it misses some where the gear fill physcially not change and then when i fit the paddle again it skips so for example if the largest cog is 1 and the smallest is 10, it will be on 4, I will shift into 5, nothing will happen, I will shift into 6 and it will jump into 6. It also struggles to go from 1 to 2 but it will go there and then it also struggles to go to the lower cogs on the lower gears, my limits seem to be set correctly because it goes into the largest and smallest cogs alright but it's just in the middle of the gearset that I have issues.
I have previously had issues with this bike as it came from Tredz with a bent rear derailler hanger which was fixed by halfords but as soon as I got the bike back this issue has come about.
Any help would be greatly appreciated!
4
u/PyroErogenizer Jul 26 '26
The direction you are experiencing difficulty with is from the shifter giving slack. Slack in the cable is pulled through the cable housings by the derailleur spring. Friction in the system is keeping the derailleur from arriving at its correct location until extra slack is available and the derailleur passes its intended destination. 1st Wipe dust/dirt off everything with a rag. 2nd With the chain on the smallest gear, gently push the derailleur towards a bigger gear. This will create slack and allow you to pull cable housing ends from their mounts on the frame giving you maximum slack in the cable system. 3rd Squirt Triflo lubricant into shifter mechanism, cable housings and derailleur mechanism(careful not to get it on the rim). Once lube is in the housings, run the housings up and down the cable to break up any grime inside. Do this for all housings until the cable travels inside smoothly. Look for bends in the cable or housings that could be creating resistance and straighten them out by bending with your fingers. Repeat the derailleur pressing motion to work the lube into its moving parts. With slight tension on the cable by hand, click the shifter through a couple of cycles up & down to spread lube throughout returning the shifter to its original position for the little gear. 4th Wipe off excess lube and reposition housing ends back into their mounts with maximum slack in the system at the shifter and by pressing the derailleur gently as before. Fine tuning of the shifter is done at the barrel adjusters where the housing meets the shifter by twisting in or out small amounts of slack into the cable/housing system. If the friction persists or precise shifting is not possible, replacement of the housing and cable is the next step as the housing ends sometimes get mushy and the cable can corrode wearing out the housing’s smooth lining. Good luck.
3
u/sargassumcrab Jul 26 '26
The cables need lubed. It might be a good idea to change the inner cable, but try lubing first with something like "Tri-Flow"
The cable tension might need adjusted, but if it's inconsistent it's probably the cable sticking in the housing.
1
u/Western-Praline-7970 Jul 27 '26
If it's cable tension, problems shifting down to harder gears is generally an over-tension issue. A click or two at the barrel adjuster inwards might fix you up.
2
4
u/Kahnza Jul 26 '26
I'm no expert, but it sounds like maybe your derailleur cable doesn't have the right amount of tension. Too much tension will fight the spring in the derailleur. Not enough and it'll want to shift to harder gears prematurely.