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Tuesday, April 02, 2019

Dahon Upgrade

Sometimes when a couple of us are  reconnoitering a club tour we use the train  to ferry us and the bikes to our route start, but with the newer trains and the policy of the rail companies to limit the number of bikes, its getting harder and harder to take bikes on trains.  Very often its down to the good nature of the train staff that so many bikes are on board.  The train companies policy is counter productive to the Government policy to get more people commuting by bike, so unlike the continental trains, but that's another rant.

However you can take folding bikes on trains as they just count as hand luggage and this led to me thinking of using the Dahon for these rides.  Whilst its a great bike with a SRAM Dual Drive hub,  24 gears,  but it had a fairly high gearing,  for me, on hills, with its 53 tooth front chainring.  This gave a top gear of 123 inches and a  low of 23.   Fantastic for the flat as you can keep up with ordinary bikes but a bit hard on the hills and especially when I have panniers on. 

Sheldon Browns gear calculator site is very handy for working these out.


So, I changed the front ring to a 46 tooth and the rear cassette for a 34 - 11, 8 speed, plus a new chain.










 As I often ride this bike in ordinary clothes I like a chain guard, and this one with the chain ring came from Spa Cycles, who are very helpful, especially as I needed 3mm spacers and longer chainring bolts to keep the guard away from the chain.





All finished and running smoothly.  

There's always a trade off with changing the components and the gearing is now top 106 inches with a 19 inch low.  However if I want / need to up the gearing its relatively quick to just change the front sprocket.


I did think of putting a double chainring on the front which would be a bit much, as in theory I would then have 48 gears, although some would be the same.  

It can be done and who knows what will happen over a few rainy days in winter???


15 comments:

  1. Good work there Dave, and part of the pleasure of bike ownership is modifying them to suit your particular needs.
    Oh but the trains... don't get me started on the state of the trains these days! They seem to be run for the benefit of the train companies, not the passengers!
    I was 'in to' railways back in the 70s, and back then BR took a lot of stick, but the service offered was so much better. No problem taking a dozen bikes on a train, just roll up and put them in the huge guard's van. No standing on trains back then either (outside of commuter chicken chasers) as at busy times, they just put more coaches on.
    A year or two ago they had a big press do after modifying the guard's space on the 125s to make a little more room, so unaccompanied goods could be carried, such as Broccoli and Daffodils. Space is still very limited, and needs booking but hey, a few boxes of flowers can now go to London on their own. Well back in the day, whole vans were added to passenger trains to take truck loads of Broccoli and flowers up to London, several times a day.
    I've seen coffins carried on passenger trains (empty I assume) motorbikes and all sorts of big stuff, all carried without hassle. Grrr...

    Oh sorry, I've got myself started, but the railways really do get me going these days - they're a disgrace compared to other countries.

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  2. Thanks Mick. You probably have seen this,
    https://www.youtube.com/watch?v=QPkT0paGEnQ
    if only it was still like this.

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    Replies
    1. That film is a cracker isn't it! Far simpler times, and the main thing was there was so little traffic to contend with compared to today. Not everything was better back then of course, but the same can be said for now too.

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  3. Annoying if trains will not have you.
    Better weather will have you out and about soon.

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  4. Yes it is Mr A as its a great way to travel, bring back the goods van!

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  5. I immediately thought of that wonderful film which you mention in the Youtube clip when you complained about current cycle space (or lack of it.) on trains.

    The good old days of '50s cycling. I started club cycling with the CTC in 1955 (New Claud Butler Avant Coureur Special), toured and time trialled on fixed in the '60s (1947 Raleigh Record Ace) which I converted to Benelux 5 speed Touring gear in the '70s and rode it until quite recently (with a major recondition about 10 years ago). Now back to a Raleigh once more, but, following a stroke, it's a Motus Tour ebike!

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    1. I dont suppose we'll ever see the return of the goods van as the cost of supervising whats inside would be too much for the rail companies. You certainly have a long history of cycling, whilst my cycling goes back 60 plus years its has been for transport and pleasure. The joy and memories of cycling with friends in the late 50's is the same as the pleasure and fun I get from cycling with friends now. Lets just keep pedaling.

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  6. Hi Dave. Were you able to reuse the chainguard or did you buy a new one?

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    Replies
    1. Annie,I had to buy a new one as the old chain guard had a larger diameter than the new chain ring.

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    2. Annie and it also had a different fitting.

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  7. Oh my, coming to your blog is such an education. I love your bike life!!!

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  8. Thanks Wanda, its keeps me out of mischief.

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  9. A nice modification ...just right for your requirements... As you say it would be easy enough to swap back if required....

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    Replies
    1. ...and I'm almost tempted to fit some panniers and go touring on it.

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  10. This comment has been removed by a blog administrator.

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As you have taken the time to read my blog and comment then whenever possible I will always reply. Thank you. Dave