Hi,
I have a 4 month old Team Boardman road bike with Shimano 105 gearset.
I am learning and understanding the mechanics of road bikes and have read a lot of info online and watched videos and am attempting to set up the indexing correctly on the rear derailleur.
The H & L limits are set correctly but the indexing is not set correctly. Basically I have 2 problems:
1. When downshifting (moving to the larger cogs, lowest gear) the shifting is moving the chain 2 cogs at a time. My understanding is that downshifting is caused by increasing the cable tension which pulls the derailleur inwards thus shifting the chain. Therefore this suggests that the cable tension is too tight. Again my understanding is that this is tweeked by turning the barrel adjuster clockwise to reduce the tension.
However, I have done this and turned the BA, 4 times (1/4 turn each time and it makes no difference). The BA is now turned all the way in so I am unable to loosen the tension any further using the BA.
2. I also tested upshifting (moving to the smallest cogs, highest gear) and from the downshifting problem indicating a too tight cable, I would expect when upshifting that the derailleur would likely require 2 shifts (as my understanding is that upshifting is caused by loosening the cable, and the spring in the derailleur pulls the derailleur outwards, shifting the chain outwards towards the smallest cogs). However, strangely on the first two shifts from the largest cog, it also jumps 2 cogs although the remainder of the shifting on the final cogs is fine.
I therefore don't understand how the cable can be shown to be too tight when downshifting and too loose when upshifting as it would therefore be impossible to adjust the cable tension correctly for both downshifting & upshifting.
I would also note that the chain has been cleaned (it's a relatively new bike so wasn't really dirty anyway) and I have checked the derailleur hanger and it does not appear bent in any way to me.
I would be grateful of any help as this is becoming quite frustrating.
I have a 4 month old Team Boardman road bike with Shimano 105 gearset.
I am learning and understanding the mechanics of road bikes and have read a lot of info online and watched videos and am attempting to set up the indexing correctly on the rear derailleur.
The H & L limits are set correctly but the indexing is not set correctly. Basically I have 2 problems:
1. When downshifting (moving to the larger cogs, lowest gear) the shifting is moving the chain 2 cogs at a time. My understanding is that downshifting is caused by increasing the cable tension which pulls the derailleur inwards thus shifting the chain. Therefore this suggests that the cable tension is too tight. Again my understanding is that this is tweeked by turning the barrel adjuster clockwise to reduce the tension.
However, I have done this and turned the BA, 4 times (1/4 turn each time and it makes no difference). The BA is now turned all the way in so I am unable to loosen the tension any further using the BA.
2. I also tested upshifting (moving to the smallest cogs, highest gear) and from the downshifting problem indicating a too tight cable, I would expect when upshifting that the derailleur would likely require 2 shifts (as my understanding is that upshifting is caused by loosening the cable, and the spring in the derailleur pulls the derailleur outwards, shifting the chain outwards towards the smallest cogs). However, strangely on the first two shifts from the largest cog, it also jumps 2 cogs although the remainder of the shifting on the final cogs is fine.
I therefore don't understand how the cable can be shown to be too tight when downshifting and too loose when upshifting as it would therefore be impossible to adjust the cable tension correctly for both downshifting & upshifting.
I would also note that the chain has been cleaned (it's a relatively new bike so wasn't really dirty anyway) and I have checked the derailleur hanger and it does not appear bent in any way to me.
I would be grateful of any help as this is becoming quite frustrating.