Thursday, 2 January 2020
Disk Brake Pads
I'm pretty happy with them - good performance, consistent behaviour in the wet, no need to adjust for example. On the downside they make a horrible squealing noise in the wet.
By chance I had the bike in the stand to change the chain and in an idle moment pulled the front pads out of the callipers. There was no reason to do this - it was just interest and a dry run prior to needing to change them at some point in the future
Rather surprisingly the pads were completely worn - one completely down to the back plate. This was clearly why there was some noise when braking! ON close inspection of the disk there was with hindsight some slight scoring to the disk itself This was after only 3100 miles (2 winters and a lot of commuting to work). I took a photo of the pads so as to help with ordering the correct spares/replacements
The next issue was - organic or sintered? There appears to be no definitive answer, with each having benefits and disadvantages. I took a gamble on sintered pads. Fortunately BR RS505 pads seem to be very available (and are compatible with BR RS805) and are quite cheap. The model I bought was Clarks, £5.79 from Wiggle (Jan 2020)
When I came to fit the new pads I put them against the existing pads for comparison:
The most worn pad (2nd on the right) this is the one with no material left at all.
Needless to say I needed to get the pistons completely back into the calliper before I could even attempt to fit the new pads. The rear pads by comparison were only about half worn
Sunday, 17 November 2019
Di2 Fit File Decoder V1.1.0
See the latest version here: V1.1.0.4
My application (Di2 Fit File Decoder) has had a minor update. In this release (V1.1.0) it now uses a MS SQL database to store the data. This uses more disk space but is easier to store the data and also extract it in other ways that are better and easier than using file based methods
Updates
Data Stored in SQL data base (Fit_File_data.mdb)
Additional data tab now added for displaying the Fit File contents in a tabular format
The Time/distance graph of the shift date is now a tab in its own right
The Time/distance graph now correctly updates
Export of the shift summary data (time/count) enabled
Some coding improvements (tidier code, some compiler information issues addressed)
Still to do
Improved error handling
Investigate why 3 text files containing the shift data totalling ~12KByte results in a SQL database of ~73MByte
I'll continue to tweak the code but the next steps are to incorporate this code as part of my Strava data application - I have learnt more and implemented some code in this application that will improve the Strava data application and make some steps to improve the readability - I have developed the code for the application on the fly and its becoming a bit of a monster to maintain and develop to be honest and I can see some improvements to apply that will improve this
As before there are 2 links - 1 for the standalone exe file and one for the .Net (C#) project:
Exe file Link
.Net project Link - I am more than grateful to recieve any feedback on the code
The code is provided completely "as-is" with no warranty
I have developed it to meet a personal interest in the data and to develop my software skills - I am a mechanical engineer NOT a software engineer
Updated Screenshots:
Sunday, 3 November 2019
Di2 Fit File Decoder V1.0.1
I also added the option to plot the gear shift data against distance as well as time:
However the graph does not seem to display the distance based data - it looks like it just plots it against time for bot Radio Button options - more work to do here!
As before here are the links to both a standalone .exe file and the Visual Studio project:
Link to .exe file: Link
Link to VS .Net project file: Link
Saturday, 26 October 2019
Modifying my Giant Propel
Here its is after the 1st or 2nd ride:
Here it is about 9 months later - still no changes
Here it is when I added a 4iiii left hand crank power meter
Here I an riding it at Mallory Park race circuit - still no major changes
In 2018 I bough the "official" Giant rubber bungs to plug the holes in the frame for the Giant Cadence sensor - these bungs fit in the non-drive side chainstay. I got these from www.giantbikespares.com. The postage cost as much as the parts. I got this because I was now sometimes riding the bike when it was damp and did not want to get water in the frame
This year (so about 3.5 years after I bought the bike) I finally gave up and downsized the chain rings from 52-36 to a more normal Compact (50-34). I bought Ultegra rings even though the cheaper 105 rings are completely compatible to keep the specification correct
The main difference between the Ultegra rings (above) and the 105 (not shown) is that the Ultegra big ring is a metal/nylon composite whilst the 105 is all metal (with integral strengthening "ribs"). You can see the nylon quite clearly above. I also needed to change the chain at the same time as it had done over 4000 miles, although the chain wear checker did not suggest that it was over the recommended 0.75%. Obviously changing the front rings (a 2 tooth reduction on both rings) meant I needed to also look at the chain length and the position of the front dérailleur. I took some photos before for all the gear extremes (52-28, 52-11, 36-28 and 36-11) to look at the original chain relationship and to compare to what it was going to be like with the new extremes (50-28, 50-11, 34-28 and 34-11).
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| 52-11 |
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| 52-28 |
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| 36-28 |
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| 36-11 |
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| 50-11 |
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| 50-28 |
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| 34-28 |
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| 34-28 |
I also noticed that although the original chain was not over 0.75% wear, the new chain actually ran more quietly and smoothly and shifted better, so clearly the wear indicator method does not always show a true real world level of wear.
Some careful photos also meant that I could reset the front dérailleur into the new lower position:
There was one real benefit here with Di2 - this was that I didn't need to do anything to reset the cable length like I wild have had to with a traditional mechanical set up
This photo is with the original 52 ring so I set the same height gap for the 50 tooth ring
The change to the smaller front chain rings is by far the biggest change to the bike - and the outcome is that it is easier for me to ride and I can use more of the cassette, so it was money well spent. For info I got the rings from Rose Bikes (ignore the .uk domain - they are a German company). Its clear that although the 6800 series Ultegra is only one generation old it's already seen as obsolete as I could not get these rings in the UK
I have also needed to swap the rear tyre out - it was still just about OK at 4600 miles but the wear indicator was long since gone and the tread area no longer round:
The tyres are Giant P-SL1 700 x 23c. These are around £30 each and are starting to be replaced by P-SL2. However by compete chance I looked on EBay and saw a pair of almost new P-SL1 tyres. I bid and got the pair for only £22. They really had done only a few 100 miles at most - what a bargain
The final changes I have done are to fit a Shimano SM-EWW01 unit so I could read the gear position and other Di2 data into my Garmin. This is documented here: di2-monitoring
So - my bike is still almost as built but has some small changes, some more visible than others. It's a great bike but as I will freely admit - a better bike that I am rider
Painting a Bike
I wanted a bit of as project so offered to completely strip the bike, strip the paint from the frame, repaint and rebuild, which is what I did.
Here's some pictures of the state of the frame at the start (these were taken to record the location of the Boardman transfers):
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| You can see here the state of the top tube |
These pictures were taken after I had stripped pretty well everything off the frame. It was in a very bad way. I could only get one of the Bottom Bracket bearings out myself - the other I gave up on and took it to a bike shop. There was a lot of banging for 5-10 minutes to remove it. I only had the plastic tool and a "half" round spanner for it for these smaller Shimano Bottom brackets as follows:
I just could not get the cup to move.I have since bought some more and hopefully better tools as the visit to the LBS cost £10:
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| This is a Park Tools BBT-69.2 Tool 3/8" drive |
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| This is the Park Tools BBT-9 tool - identical size to the BB62 but also fits centre lock disk lock rings |
BBT-69.2 - Link
BBT-9 - Link
I could not remove the bottle cage bolts with the cage in place so I cut the cages off (they were nylon) and ended up having to drill the bolts out (carefully). I needed to re-tap the threads after this. The screw that held the bottom bracket cable guide did come out with an impact driver after a soak with penetrating oil.
The rear brake retention nut had rounded off the internal hex.
Once the brake cable was removed I could remove the brake calliper itself. I then screwed in a standard bolt into the nut. Plan A was to hammer the nut out using the bolt but this was not shifting it. Plan B was to place a thick metal plate on the rear of the seat stays behind the nut and then apply a G Clamp to the head of the bolt and the metal plate. In this way I could get a lot of static pressure onto the bolt. Once this was as tight as I could get it I then tapped the clamp to shock the nut through the bolt. This broke the corrosion holding it in place and I could then tighten the clamp a little more and push the nut out pretty easily. I needed to use an 8mm drill (carefully) from the rear to clean the corrosion out from the frame locating hole and I greased it thoroughly before reassembly. This close up (after priming) shows that there is a sufficient gap between where the nut sits flush and the seat stays
The BB, bottle cage and cable guide bolts were really hard to remove and took most of a morning, a lot of swearing and sweat. Although the rear brake nut was also tight it did come out relatively easily using the Plan B approach
Having got all the fittings removed from the frame I spent a long tine stripping the paint off back to the bare metal. I used a combination of a delta sander, standard paint stripper, a fine grit emery sponge pad (by hand) and a Dremel with a small wire brush attachment and sanding band:
The use of the Dremel and the attachments was surprisingly effective and durable. The sanding band was quite course but scored the paint well so that the paint stripper could get right into it and remove it with only a couple of applications. The wire brush lasted for the whole frame and whilst looked tired by the end was still effective. It was really useful to get into all the frame joints and remove paint where emery paper just could not get to. Whilst it removed the paint it did not scratch the frame itself.
It took a few hours over a couple of weekends but I was able to get the frame right back to shiny bare metal. I finished the job with a fine grit sanding pad.The following pictures show it hanging in the garage ready for painting. I hung it from the head tube via some studding and string and put some more studding through the rear axle so I could guide and control the frame. The light and my phone's camera is not that great but the frame is fully prepared and stripped and has been cleaned with methylated spirits. I was surprised how good the frame was under the paint - I had assumed that the worst of the visible corrosion was more than surface deep but actually it needed no more than a rub down with the emery pad to bring back to smooth metal. I did the stripping on the pation in front of the garage to avoided splashing paint stripper and dust over the inside of the garage. Here's the result:
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| The whole frame ready for painting |
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| Detail of the head tube and bottom bracket |
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| Detail of the rear dropout and studding |
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| Detail of the head tube |
I decided that despite the comment that "Spray.Bike paint will adhere to most raw metal and painted surfaces without any major pre-prep." I decided that I would use the Primer and using primer would also give me a bit of spraying practice prior to applying the more critical top coat. My son had chosen the matte black as the colour to use:
I bought 1 can of primer, 2 of of the black topcoat and 1 of the transparent Matte Finish. The instructions said that 1 400ml can would suffice for a frame, but I wanted to be sure that I had plenty of the top coat. This came to about £40 all in sop not exactly cheap. I also bought a couple of cheap face masks and used my older glasses just in case
The key message about use and application was the distance of the nozzle from the frame - and it was different for the primer and top coats.
I initially sprayed the frame with the primer. To be honest when I was in the correct spray range it covered well and evenly - I had one small run in an awkward place that I addressed following the instructions. The paint really is touch dry after a few minutes but I waited 3-4 hours before applying the top coat.
I got a similarly good result although there were a few areas where the surface was visibly "powdery" as I had not applied enough paint. It is a lot easy to spray the main tubes (top, down and seat) as these are a bigger target to aim for. The narrow seat and chain stays are where I needed a second go and this is where I needed to respray over these to improve the outcome. Here's the results after the first and second sprays:
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| Bottom bracket detail |
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| Head tube, top and down tube detail |
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| Seat post detail |
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| Head Tube detail (the white mark is a loose thread from a sheet, not a scratch) |
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| This is the top of fork |
The very nature of an aerosol spray on quite a narrow target ,means that there is quite a lot of missed spray that was on the garage floor. I had hung the frame from the garage roof and surrounded it on 3 sides with old bedsheets. This was just about OK. By the time the overspray that missed the frame had landed on the floor it was basically dry dust and could be swept up easily. However - do not try and spray without protecting everything around the area
This is the easy part - I have built a few bikes in the past years (see here) and in this case it was just a case of refitting the original (or replacement) parts. I used a lot of grease on all the threaded joints and threaded the new bottom bracket in and out a few times to ensure that both the male and female threads were well greased to make it easier to remove the next time
I was geared up to get some Boardman Transfers for the frame (loads on EBay) but my son decided he wanted it to be unmarked so its currently fully "stealth". However I don't currently have any photos of the completed bike after all this work
In overall time this was a 3-4 month project. In actual work time it was probably
2-3 weekend mornings stripping the bike and preparing the frame
2 weekend mornings painting
1 weekend morning rebuilding the bike
I'd really recommend the Spray.Bike paint - easy to use and gave a good result. The project was for me very therapeutic - I enjoy this sort of job - and my son was very pleased with the outcome





















































