In the latest Audax UK magazine ‘Arrivée’ there is an article by Neil Goldsmith about his experiences as principal mechanic at the remote Eskdalemuir control assisting the 1500 riders on the 2017 London-Edinburgh-London ride. Here is an excerpt from it.
“We had one rider who had broken his gear hanger. Unfortunately there was nothing we could do for him. All carbon, aluminium and many titanium frames have replaceable gear hangers. A gear hanger is a sacrificial part designed to break to save the frame. There are around 200 variations of gear hanger and bike shops buy them in to order. It is a roadside repair to change a gear hanger if you have one with you, and impossible without a hanger which fits. Gear hangers are easily sourced online. I regard them as an essential spare to carry along with spare tubes.”
They are very small and light and can get you home.
Is it possible to shorten the chain and ride home on a single speed set-up?
Easy enough with horizontal drop-outs, but vertical drop-outs are much more problematical. The answer is ‘yes’ if you can find a chainring and sprocket which are fairly closely in line, which give a usable chain tension (never too tight and not loose enough to permit derailing), and which (if you’re lucky) give a usable gear ratio. If the ‘perfect/theoretical’ length of chain required is a minute amount less than a multiple of 1″ then the extra inch of chain required is more than enough to allow the chain to come off a sprocket or to skip teeth.
Is it possible to shorten the chain and ride home on a single speed set-up?
One of these “Emergency Rear Mech Hanger £5” is always in my tool kit regardless of which bike I ride.
https://www.ebay.co.uk/itm/Emergency-Universal-Rear-Mech-Gear-Derailleur-Dropout-Threaded-Hanger-spare/222746066211?epid=902824616&hash=item33dcb33d23:g:1e4AAOSw6dNWSx01
Ice took me down on the way up, yes up, Staple lane. Hip took a hit, but so did derailleur and hanger.
With nothing to lose andtwo plastic bags to protect hands, derailleur twisted back to re align the jockey wheels and cassette. It worked, did another 17 miles away from ice, then another 30 yesterday.
However, my saddle bag has 2 supermarket veg stand bags, a spare hanger sourced from http://www.betd.co.uk, AND an essential screwdriver that fits the hanger mount screws – do not rely on a multi tool. Also, I found universal hangers are not, a quick look at betd will explain why.
As Chris said, all very light and next to puncture repair kit.
From first hand experience… I agree!
A recent slow speed tumble, left me with a bent hanger; nothing significant at first glance, but enough that my rear mech would touch the spokes in the lower two gears. Which could have been a very costly problem with a Di2 setup.
As it happens I managed to get home, safely, with some care on the gear selection.
A new hanger cost £12, took minutes to replace, and yes I bought two! The spare is now in my saddle bag.