Saturday, 28 March 2020

Pedal washers

I've fitted or helped to fit two SRAM crank sets and they come with washers that go between the pedal and the crank.


My bike did not have those washers.


I bought some stainless steel shim washers of the right size, 14mm (ID) x 20mm (OD), I had to guess on the thickness but 0.5mm looked about right.


I fitted those today.

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Hand wash shelf

Just a bit of tidying up round the stables.



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Saturday, 14 March 2020

Continuation of my bide rack for a Discovery 4

Following on from my first attempt, I have completed a solution that holds two bikes securely on the back of a Land Rover Discovery 4.


This version has the bikes with their tyres facing the back of the car.


A single strap is sufficient to hold the bikes securely on the rack although I will use a couple of others to stop them bouncing about.








This version has a few features:

  • The lights and the number plate are not obscured
  • Easy to fit
  • It comes apart easily so it fits in the back of the car




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Sunday, 8 March 2020

Insoles for skates

I did a late night skate, a month ago. I was skating for about 4 hours and my feet were a wreck afterwards!

For some time, I've thought I could do with trying some other insoles in my skates to make them a better fit. It was the long session that made me get round to it.

Don't get me wrong. The insoles that came with my K2 skates, are pretty good, I've skated on them for years but my feet are getting older and now need a little extra help.

* Sorbothane Double Strike - No good for my skating

In all my shoes I fit Sorbothane Double Strike insoles. They are great in my shoes adding the extra bounce underfoot that I need. I tried those in my skates, for one evening, and it was clear that the very soft arch support was not sufficient for the sideways motion from skating.


I bought a couple of choices of sports insoles, with moulded arch support. One gel and one of a soft plastic, more like the Sorbothane. Both available at a reasonable price from Amazon.

* CosyInSofa Orthotic Sport Gel Insoles - Good for my skating
CosyInSofa


* FootActive Orthotic Sports Insoles - have not tried yet

FootActive


Both have a harder moulded plastic heel and arch section that supports the foot with a covering of something soft. At their thinnest, near the toes, they are both about a millimetre thinner than the original.

One is gel and one is a more foam like plastic both with a woven fabric style upper surface.
The only significant difference is that the gel insoles do not have quite as rigid arch support. I would describe them both as having a firm arch support but one is marginally less firm than the other.

I cut them all to size, using the original insoles as a pattern and fitted the gel insoles for the evening.

I skated for about 3 hours and I was very happy with the result. They were comfy and held my foot well for skating. Being slightly thinner, there was a little bit more room for my toes, which, for my big feet, makes them more comfortable.

I thought, being thinner, that I might feel the rivets inside but, so far, no sign of that being an issue.

I liked them enough that I have not tried the other pair yet.

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Saturday, 7 March 2020

Replacing a SRAM press fit bottom bracket

As mentioned in an earlier article about fitting a dropper post, I had to put back the bottom bracket (BB) on my bike. That is not recommended because removing press fit BB's is very likely to damage them. I now know for sure, that is the case.


What's in a Name

As an aside, why is it called a bottom bracket?

Nowhere on the bike, that I know, is called a top bracket, so the word 'bottom' is superfluous. It is not the sort of thing that I think of when referring to a bracket, so the word 'bracket' is inaccurate!
It should be called the 'crank axle bearing housing,' or something to that affect.

The derivation is probably lost in the mists of time.
I'm not suggesting that it should be renamed, it just struck me as odd.





During the 30 mile ride, last weekend, my bike sounded like a bucket of nails. Some of that was to do with the pedals but I suspect most was due to the bottom bracket bearings falling apart inside.

Fitting a new BB is fairly easy. In this case it is a SRAM dub pressfit.

The chain has to be out of the way. Pulling back the derailleur gives enough slack to easily remove the chain from the chain ring.


It is not necessary to remove the pedals but I was replacing those as well, so they came off. The right pedal has a normal thread but the left hand pedal has a reverse thread. Even though I knew that, I still accidentally tried to turn it the wrong way for a moment before correcting myself.


Stopping the cranks turning is always awkward, so I spent some time making a wooden stand, of the right height, to rest the end of the crank on to get enough leverage to release the bolts. For this, the bike needs to be on the ground not in a stand.


It makes removing the crank axle bolt on a SRAM set, very easy. At least, very easy, with a long breaker bar. I lean over and on the saddle to keep the bike, and therefore the crank, from moving towards me.

With the cranks removed it is a case of bashing out the bearing cups on each side. This is what damages the bearings.



First remove the spacer if fitted. On my bike it is a 4.5mm thick plastic ring, that fits in a groove round the bearing on the drive side.

To remove the bearing cups, I think it is best to use a tool designed for the job. This pushes out the bearing cups evenly to avoid damaging the frame. It could be done carefully with a straight punch, a little at a time, but I prefer the specialist tool.

It needs a lot of force to remove the cups. You can bash them with the bike upright and against your body but I find that unsatisfactory. I much prefer to lay the bike on it's side, put a block of wood against the frame, as close top the bottom bracket as I can, so I can get a solid base to bash against.


In that position one or two good swings, usually gets each cup out, one side at a time.

After that the bike can be put in to a stand for the rest of the work.


Looking at the bearings, once they were out, it was obvious that they did need replacing. The shield was clearly badly deformed.


Anything going back on, I cleaned. The cranks, chain ring, bottom bracket and the SRAM spacer.

Now to fit the new bottom bracket



Last time I did this I did not have the correct tool to hand and made a bearing press out of large washers. That worked but took care to keep everything central and inline. I now have the correct size bearing press for the SRAM dub bearing cups. I also have a larger size set of bearing presses.


Some people fit both bearing cups at once but I prefer the strategy of fitting one at a time. SRAM recommend fitting the LEFT hand cup FIRST. That is the one that does not have the sleeve attached.

I greased the frame where the bearing cups will sit.


I have a bearing press that fits neatly in the frame, without any stress and one that fits in to the dub bearing. The pressure is applied a little at a time using a long threaded bolt. The correct tool, keeps everything alighted square with the frame to avoid damage.

Once one cup is in, I removed the frame size bearing press, put the right hand cup with the attached sleeve up against the bottom bracket and added the dub size press. I had already made sure that I had not attached the spacer. Accidentally pressing against the spacer, will damage the bearing!

Using the correct tools, the bearing cups went in easily.

Fitting the cranks is easy.  First I pushed on the 4.5mm spacer.


I wound back the adjustment collar on the non-drive side and added grease to the axle and the threads, as suggested by SRAM.


The torque setting is shown on the bolt cap, 54 Nm.


Once the axle was tight, I adjusted the collar to remove any side to side motion and tightened up the screw to hold it in place.


I added my new pedals, torqued up to 35Nm, as per the instructions that came with the pedals. It helps to have a torque wrench that torques in both directions. Many torque wrenches do not, they only work clockwise. I expected to do this often enough that it was worth the little extra trouble of finding and buying one that has a push through connector, specifically so it could be used in both directions. I did not want to over tighten one of the pedals!


I put the chain back and went for a very short test ride. All nice and quiet from the drive train.

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Sunday, 1 March 2020

Mudhugger mudguard

I fitted the rear Mudhugger in preparation for a ride starting and ending at RSPB Minsmere in Suffolk organised by The Pedal Revolution.



I went for the largest size mudguard because I have 29" tyres. I wanted it to cover the radius of the tyre, which it does, however, it was also exclusively long.




I cut off 75mm (3") and it still easily stops all the mud, I could probably lose at least another two inches and it would still be effective.


I like the idea that the Mudhugger travels with the rear suspension. Other mudguards have to be fitted high up to avoid the tyre hitting them when the suspension compresses. That gap does give plenty of space to avoid mud getting stuck between the tyre and the guard but then I end up knocking it out of the way when mounting the bike or almost sitting on it when going down steep sections.


To protect the frame from the movement of the cable ties, the Mudhugger comes with some sheets of heli (helicopter) tape. This is thick strong clear tape, sticky on one side. At 0.3mm it's a lot thicker than other types of sticky tape.


It does not bend in multiple directions very well. I ended up with bubbles in the tape where it wrapped round the curved seat stays. I used a hot air gun to soften it and was able to shrink or move most of the bubbles to the inside surface, where they cannot easily be seen.



Fitting the cable ties is easy. I pulled the guard in line with the rear tyre before cinching the cable ties tight.


The mudguard was put to the test on the RSPB ride because there were plenty of path spanning puddles and even a flooded section. The water was deep enough, in a couple of places, to get my feet wet while pedalling but none of it went up my back.





We had an enjoyable 30 mile ride with nice weather for the time of year.

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