Sunday, 30 December 2012

frankenfenders two - a five minute fix

Before I get into describing how I built up the rear fender of my commuter mountain bike, I would like to complain about something. If you don't want to read that bit, skip to the pictures.

Ok, I admit it. I am a klutz.

No, really, I am.

I have a positive talent for messing up mechanical projects. I am not scared to try adjusting or making things, but more often than not, I mess things up. Some people can, when handed a device or machine, figure them out and seemingly like magic, make them work properly. I figure out how to foul them up beyond belief. My favourite mechanic at the LBS sees me coming and often greets me with a "What did you do this time?!?" and a look of fear and trepidation on his face. Sigh.

With that in mind, consider what happened tonight. I rejigged my rear fender to create more clearance for snow, and managed to mess up the rear brake caliper to the point where I think it may need replacing. While putting the rear wheel back on the bike after working on the rear fender, I nudged the tab on the dead brake pad (the non-moving one) with the brake disk and pushed the pad out of alignment. It was stuck inside the caliper. The only way I could see to get it out was to remove the back plate adjuster part of the caliper and reseat the brake pad. I have seen this done before and it works. But. You knew there had to be a but, didn't you. But, I forgot to clean the threads of the adjuster plate and it jammed. Seeing as I have been riding in the snow and salt and grit of winter this was predictable but I failed to clue into this until it was well and truly too late. I tried, very carefully, to remove it, but the wrench slipped and I stripped out the Allen key hole in the middle of the adjuster leaving it stuck in the wrong position. So now I have a rear brake which works, but is wildly out of adjustment. If the mechanic at my favourite LBS can get it out, and if that part is replaceable, I might be looking at a cheap fix. I suspect though that I am looking at a new rear caliper.

Grrrrr.

I had taken some pictures for tonight's blog entry on my Fuji X-10. This camera uses an SD card (I hate those things and much prefer CF cards - this was true even before tonight's story). I caught the edge of the card on the edge of the card reader and managed to foul up the plastic dividers between the broad flat pins on the card. I no longer trust the card, and should get a new one. It took nail clippers to trim off the plastic bits to get it into the reader so that I could retrieve the pictures.

Grrrrr again.

I am not touching anything breakable again tonight. Like chairs.

Anyway, on with the frankenfender.

The rear frankenfender on my bicycle is made up of three parts. The lowest part is a scrap of skinny mountain bike whip fender that I had left over from another bizarre fender build from a few years ago. It is not really needed except that I like to keep as much crud out of the front derailleur as possible. 

This is the top of the small fender bit I use as a shield to protect, at least somewhat, the front derailleur. It is mounted by a screw in the threaded hole in the cross brace between the chain stays.
This shows how the fender bit is attached to the frame. It also gives some idea of the (limited) protection the fender offers the front derailleur.
Next up is a standard cheap sks fender. It is one of those ones which clamps onto the seat tube with a cheap flexy "claw" (see the above picture) and mounts to the brace between the seat stays with a bolt and a bracket on the fender. What I did was remove the bracket entirely and use zip ties to mount the fender to the brace and bike rack.

Close up of the criss-crossed zip ties holding the fender in place. There is an indent in the fender which is lined up with the seat stay brace which gives almost 1cm more clearance between the fender and tire once the normal mounting bracket is removed.
Underside of the criss-crossed zip ties. This looks like it will catch some snow, and it will, but it won't catch much snow and the added clearance is worth it.
This zip tie keeps the fender from flopping all over the place. The thing is very securely mounted, and the fender is well protected, so the likelihood of the zip ties breaking is very low.
The final part of the frankenfender is a rear deflector shield which I use to both end off the fender and to make a deck on my rack.

As you can see, there is huge clearance here for the wheel. This part was unchanged in tonight's rejig of the fender. I can testify that it does a great job of keeping crud off of me. I am not sure about people behind me, but I don't get anything on my clothes. I had to trim it a bit as the length, while good for blocking wheel spray, was such that heavy bumps bounced it into the tire where it would jam and pick. To fix that, I trimmed off a chunk and refixed the trimmed bit with zip ties (I love zip ties) to the bike which ended up both stiffening and shortening the fender part.
Here is what the whole thing looks like "live" on the trail. This picture is the older version of the set up, but shows how it looks when all covered in snow. The only difference between this and the current version is the amount of clearance for the forward two bits of fender.

The snowy front part - it looks the same now but for the added clearance. This does show why the refit was needed though - powder snow like this is fine, but the wheel would almost jam up with continued riding through slush which freezes to ice on the bike.
The rear part of the fender. It is clear to see how I added the hacked off bit back to the bike, and how much clearance there is for snow. Buildup is a non issue for the rear of the fender.
And lastly, the whole thing with both frankenfenders in the snow.
That's it for tonight.

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