By Piers Mahon
Ever wanted a lower gear on a hill with luggage? Or found that the jumps between gears prevent you from peddling at just the rate you want? Or just an upgrade junkie that has run out of go-faster stripes to add to your pride & joy? Or perhaps, like me, all of the above?
Since moving to London I have given up my car and tried to use public transport and my Birdy bike for all my transport. Since this decision, I’ve taken my Birdy on tour in Scotland, Switzerland and Africa. Climbing the Grosse Scheidegg in Switzerland fully loaded made me realise that I needed more gears or better lungs.
Back on my commute apathy go the better of my plans. But in November I was invited to a wedding in South Africa. I thought it would be fun to cycle there. Looking at the map, I could see that the route was going to take me through some serious hills. The wedding was two months off. New gears became a priority.
The simplest and cheapest solution would have been to change my seven speed 11-28 cassette for a seven speed megarange 11-34. However, on my commute in London, I only used the smallest three gears (11-13-15). Often, I wanted a 12 or 14. A Shimano LX nine speed cassette gives more even steps of 11-12-14-16-18-21-24-28-32.
I also needed a nine speed shifter, a new nine speed chain, a new cable and some new grips. I dislike Grip-shifts as they are too big for my hand. Instead I brought a top of the range XT trigger shifter, available “right hand only”. Lesser shifters come only in front & rear pairs. Thus XT luxury was only six pounds dearer and more environmental.
The biggest expense was buying a rear wheel compatible with a nine-speed cassette. This would have been £60 or so new, depending on hub choice. Replacing the hub on a 7 speed wheel would be cheaper but fiddly. I brought a pair of second hand Birdy 8/9 speed wheels advertised in A to B just before Christmas.
Such are the plans of mice and men! The wheels were caught in the Christmas post and arrived three days before I left. I could not find an 11-32 LX cassette and was forced to chose XT. So on the morning of my departure I removed the old wheel & chain in my living room and cleaned the parts that would not be upgraded. On a Birdy disassembling the rear derailleur (undo the two bolts holding the jockey wheels) and removing the chain guard (undo the screws and slide the outside guard off) allows one to remove the chain unsplit and helps with the cleaning. Using an old toothbrush and plastic off-cut I scrapped the worst of the dirt off before using kitchen roll & rape seed oil (genuinely bio-degradable) to dissolve the remaining stains.
I now had to assemble the cassette onto the wheel – unexplored territory. 8-9 speed hubs are splined asymmetrically, so if the spider, sprockets and rings are put on in the right order and orientation, Shimano engineers will align everything up. On with the lock nut, and the rear wheel was ready. First cup of tea earned.
The next task was to fit the chain, supplied split. The cunning will make the chain off the bike, and then slip it on with the derailleur still disassembled. I forgot and had to fight against the derailleur spring to align the two ends – a trick here is to use a small Allen key to pin the derailleur forward. When assembling the Birdy chain catcher – the wire guide bolted to the bottom of the derailleur cage – set it at a right angle to the cage.
I disengage the gear cable from the derailleur and remove the end-cap. The old grips were removed with brute force and twisting. Loosen the small Allen bolt on the Gripshift to slide it off, withdrawing its cable from its outer. The Birdy uses two gear cable outers, one running from the handlebars to the top of the rear triangle, and one from the derailleur that runs up the inside of the rear triangle to meet its mate. This latter is exposed to grim from the wheel, so it is worth replacing and lubricating well. I lubricated mine by sucking oil up it with a syringe.
My shifters came with the cable pre-installed, but if yours don’t install the cable as instructed. Slide the shifter onto the bars, and slide its cable down the first outer to the rear triangle, stopping once an inch appears. With the lower outer removed push the inner through the hole in the rear triangle, and carry on feeding inner cable through until it pops out of the bottom of the rear triangle. Feed the inner through the lower outer and push the lower outer up the rear triangle using the inner to guide. Trying to thread the lower outer in situ is near impossible! Make sure both outers are properly seated.
Attach the cable to the derailleur, with little or no slack. Cut and cap the cable. Adjust the limit screw on the derailleur for 9th gear. Change gear to 8th & adjust the cable tensioner to give a crisp change from 8th to 7th and back down. Check the other limiter is correctly set for 1st. Tighten all bolts, adjust the rear brakes and happy riding!
Time: 4 hours
Experience: If you can adjust gears & brakes with ease you can do this
Cost: Typically, £90-130 + rear wheel with 8/9 speed hub (£30-60), though I spent £228 including a new front wheel
Need: RHS nine-speed shifter, nine speed cassette, new handlebar grips, HG 72 chain, rear wheel with 8/9speed hub.
Tools: Chain tool, pliers / cable cutters, 2, 5, 6 mm Allen keys, light bike oil, kitchen oil, 8mm spanner, old toothbrush, electrical tape, large adjustable spanner, small Phillips screwdriver
Links: www.edinburgh-bicycle.co.uk - where I typically buy my parts. www.sheldonbrown.com - great site for making an informed parts choice
In issue 19 of Folding Society News I described briefly how I converted my 7-speed Birdy Red to a 9-speed. The process involved was very similar, though I chose the 11-34 megarange, since I was particularly keen to lower the gearing, and I considered the bike over geared anyway. Performance of the gear change was excellent, and the gear range was much more to my taste (though still too high in top of course). The only snag was that the more distorted chain line, with a rather short chain, was quite noticeable in bottom gear, with more contact being made between the chain and the plastic chain retention plates on the chainring. The 9-speed is still in use by Dick Hanson, and he confirms my view that it has one of the smoothest gear changes we have used.
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Copyright (C)2002 Piers Mahon
Last updated: 15 May 2002