Shimano 105 5700 Mechanicals

21 July 2012

Update April 2013 - see this additional post I made: Shimano 105 Shifters Revisted

On a more positive note I had been having some issues with the rear braking performance of my Focus since I upgraded the Shifters to Shimano 105 5700 series (from 5600 series) over the winter which I have almost resolved.

Basically I wanted to upgrade the Focus from the 8 speed 2300 components to 10 speed of some type and hence commonise more components between my Giant and Focus such as chains, cassettes etc. The key components that I needed were the 10 speed shifters for the Giant as the dérailleurs would be OK. After a lot of dithering, the route I took was to buy new shifters for the Focus and move the original Focus parts to the Giant. I also chose to buy the newer 105 5700 series parts rather than the previous 5600 series parts already on the Focus. The 5700 shifters are basically a newer version (11MY) of the original parts but with the key difference that all the cables are run under the handle bar tape compared to the 5600 series parts where the gear shifters exit the side of the shifters.

I had all the parts by October/November 2011 and did the swap over a series of days whilst I was on holiday over Christmas. The jobs were quite time consuming as I had to do the job twice (2 bikes) and there were a number of thing that I had not done before (swap Shimano STI shifters, re-tape handle bars etc). I did the Focus first, using the new components and was happy with the results - both seemingly in function and appearance, and then replicated on the Giant using the Focus parts. Again function and appearance were satisfactory. The thing I was most concerned about was doing a good job on the handlebar tape which would have a high aesthetic effect if not done right - fortunately there are lots of good guides on You-Tube and I was pleased with the outcome.

Given the bad and winter weather the Giant was the only bike I rode until about March. The first rides highlighted that the right shifter functions were not as good as I had hoped - poor rear braking and a stiff level to shift from the small to large front ring. The left shifter had no issues and the shifting and indexing were much improved over the previous parts. The stiff shifting I could live with as the small-big front ring shift is not a frequent operation, but the poor breaking was much more of a concern. There was some braking but it was poor and did very little to slow the bike. Initially I put it down to new pads and new wheels needing to bed in but the after more miles no improvement was seen. I also though that I had perhaps not fitted the outer brake cable properly under the bar tape so I removed the tape and checked and all seemed OK.

I had also read conflicting information that the pull ratios on the 5700 series were different the 5600 pull ratios and therefore you needed 5700 series brakes as well, whilst other people reported using the new shifters with no issues with the older brakes. What caused some confusion was that I could not really tell any difference with the front braking performance. I carried on as was but was nervous. What really made me investigate properly was that Noel had an accident before I went on holiday when a car pulled out of a drive on Fiery Hill (Barnt Green) and he hit it - luckily there seems to be nothing more than a lot of bruising/soft tissue damage but there was a lot of damage to the bike which is written off. This brought it home that the state of my bike was not suitable and I decided that I had to fix it. I decided that I would buy some 5700 105 brakes (good price and offers from Evans Cycles) and when I got them not only fit them but investigate fully to get the performance back to where it needed to be.

The brakes arrived and I fitted them, and basically rear braking was better but not by much. I then pulled out the brake cable completely and saw some trace of rust on the surface. This was a huge surprise - the cable was new when I replaced the shifters at Christmas and the bike does not get ridden in the wet very often. I pulled the cable out and replaced it with another new cable, but for the new cable I oiled it thoroughly as I pulled it through the outer. As a result of the new brakes with matching pull ratios and a smoothly operating cable the performance is now where it should be.

I am not sure how big a contribution the slightly rusty cable made but it seemed to be significantly better braking after the lubricated cable was fitted - I was personally surprised by how much. I am not sure if I then needed the new brakes as well but I have a optimised system and the bike stops much more quickly that it did and possibly a tiny bit better than before (but this may be psychosomatic rather than reality). The pads need a little more bedding in so there is more to come.

The lesson I have taken is that I need to check the cables more often and that cables at around £1.50are a cheap and simple potential performance upgrade rather than changing what they operate! I have no idea what caused the cable to rust - I have not seen it on any of the other bikes. The rear brake is internally routed so the only exposed cable is at the caliper, so it is a bit of a puzzle.

I also made a mistake in swapping the cable. I have removed the internally routed cable before and carefully taped some string to it so that I could pull the new cable back through with the string but for some reason despite fixing the string I then pulled the string fully through as well! It was then a very fiddly job to put the cable through. So the second lesson is - pay attention all the time.