G-Usain Bolt

In the last year there really has been no time for riding or for working on bikes. So apologies that everything has been very quiet. Having said that being back on the bike has shaken a few things loose. The first bolt to er.... bolt was a crank bolt on "I should Coco". I finished the section holding the crank on by force of will and foot. Now call me stupid, but I would have thought that with a simple machine like a bicycle the range of methods for attaching the crank arms to the bottom bracket were pretty standard. So stopping in Peaslake, I popped into the bike shop for a replacement bolt. Howard he say "No" - apparently no high tech enough for the bikes he sells. Fair enough.

At home I start a search on the internet for a replacement. There on the page is a veritable smorgasborg of crank bolts, all with about information on size, fitting and suitablilty missing or phrased in some sophisiticated arcane manner that makes selection impossible.

One of the beauties of the internet is its accessibility and the range of information available - this time it fails miserably. My nearest bike shop is miles away (to the extent where I think opening one up would be a good business move, if I was incilined that way). Eventually, I make a trip in the right direction and pop in with the other bolt. It takes 10 mins of rooting in the spares draw, but eventually they find one that matches (visually) to what I need. I still have no idea what size, configuation the bolt is.

The process of fitting a new crank bolt is simple - especially when you have put everything together from scratch. Everything is fantastic and I make the next ride some months later it has to be said with no bike failures. However, I don't follow the simple advice that I should clean down and check the bolts etc at the end of each ride. I forget that I have not tightened to precise torque settings and that a few things may have shaken loose from the last failure. So I am out riding solo across some trails and feeling goof about how the bike is handling in the summer sun when clank, clank, clank. Pulling up I discover the bashguard is hanging off to one side. A closer inspection reveals that 3 of 4 bolts that hold the chainring and the bashguard together have gone AWOL. Perhaps that should be LWOT (lost without tightening).

A familiar story on the internet - but here just a bewildering array of choices. A trip to a bike shop that deals in high end gear is unproductive in walking out with desired product, but helpful in learning about variations in chainring bolts and lengths. I am able to order parts and replace.

Stiff little linkers

So having installed the new chainring I thought the day is sunny and I have half an hour free time. Why don't I take the bike for a little rattle down the local treelined hill, and see what shakes out. No sooner do I leave the house and get up the road than there is a horrible clunking noise from the back. A regular little skip like a heart beat gone wrong, and a rattle and a clunk that sounds like the chain wants to move to the next gear socket. Then the chain falls off at the front.

Okay.... so perhaps I have miscounted the links on my chain and so its the wrong length. Only I could have sworn I had measured correctly. Perhaps then I have not adjusted the rear derailleur for the new front chainring? This seems like the easiest problem to start on, and so armed with my trusty screwdriver I set about the limit screws in attempt to solve the problem by the roadside.  10 minutes later and I limp the bike home clunking like the mechanical equivalent of an asthmatic who has forgotten his inhaler.

Its a week before I get a chance to sit down and review the problem. There is no way it is a the derailleur. Everything is perfectly set up from the start and the adjustments did not affect the problem one bit. Nor is it the chain length as I check again.

Perhaps it is time to revist the potential chain cross problem that I feared was a factor in losing the chain when riding with the larger 42t chainring. I get the calipers out (yes I have some, very cheap from B&Q) and start measuring. The final measurements in and I discover that actually with everything on I'm probably a few mm short of the perfect chain line. I can afford to put the chain retention device on.

So some happy time putting the taking off the bottom bracket and we are in business. Only we are not - there is still the irritating hiccup, even though the chainline looks near enough perfect by eye. So I do what I probably should have done when I put the front chainring on, I look at the chain itself. What do you know one little stiff link. Rigid and immobile and so unable to bend round the jockey wheel.

Fixing this is a cinch, if you have a chain tool, which you should by now. First I tried just wiggling it and applying some lube in case it was caused by grit or dust. Of course for me it isn't but you never know it could have been that simple. Instead I reverse the chaintool and give the central pin a little squeeze back. It works! I am up and running yet again.

Replacement of chainring

I have now received the Goldtech chainring from BETD, very prompt dispatched Tuesday and here the next day, so being free for half an hour fitted it. It is a simple job as there was no need to remove the bottom bracket and adjust the front derailleur. Simplicity does have its merits. I do need to work at getting the chainretention device to fit cleanly though. I think over the rougher downhill sections it will save me from spinning my legs in a futile attempt to provide drive when required.

A few points for future reference though - SRAM powerlinks are a life saver! I rerouted the chain after shortening the chain for the smaller chainring. This new route through the jockey chain was clearly going to do nothing for the chain or the noise levels as I cycled. Ooops! Undoing the masterlinks though was almost literally a snap. Clearly, if ever I should desire to move back to the larger chainring I am going to need a new chain. I have saved the old links, but I am not convinced despite assurances that they will do anything but act as an emergency link to get me home. Finally, summer dust is much harder to remove from the drivetrain than mud.

BSD

Today is a day of learning new things - acronyms love them or hate them they are here to stay. I was looking to replace my chainring from 42 teeth to something a little smaller. I am not small in the thigh department but I am not Chris Hoy! Riding up fire roads and hills in Surrey although short is strength sapping. Last weekend if it had not been for riding with an 11yr old who lacks the strength and technique I would have been plastered all over the hills in a state of exhaustion. Ally this with the fact that I rarely went past 7 on the rear shifter and you can see that I am wasting machinery. Perhaps one day I will have the strength and speed to peddle downhill at full tilt, but lets not run before we can walk.

So to replace the front chainring that I got with the bashguard and retention device (latter of which is currently off the bike because of chaincross). Looking on the usual suspects I find that the cost is around £30-40, which is out of my range for a good few months, even if I flex plastic. When Uncle Riotious puts me onto BETD via Howard at Pedal and Spoke. £18! Cushty! 38 teeth will take me into the realms of comfortableness a little bigger than the average middle chainring, so I should still have more oomph for the quick bits but I should be able to ride up hill on at least one back cog higher if not two.

Now to choose the Goldtech chain ring. Hang on what is this PCD in the options? Erm they have BCD in the text? Bolt something clearly. Isn't the internet a wonderful thing BCD (bolt circle diameter) right there on Wikipedia and PCD (pitch circle diameter) on the same page. Phew, all they want to know is what is the distance between the opposite bolts. But I have discovered that this is important in replacing this part and so I won't be picking up any sale items with the wrong BCD in future. Just when you think you have this bike mechanic stuff sorted it just comes back to bite yer.