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clubman

Member since Jun 2008 • Last active Sep 2020

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  • in Bikes & Bits
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    46t with 16 cog = 2.88.
    46t with 17 cog = 2.71.

    https://www.bikecalc.com/gear_ratios

    I don't think I've ever seen a gear chart like that - it's information is woefully incomplete because it doesn't take account of the wheel size.

    Personally, I like the English system of stating a gear in inches because that's how I've always thought of gearing, and because it gives an easy to remember set of numbers. For example 46 x 18 (the traditional British utility bike gear) is 66 with 26" wheels, but 69 with 27's - a significant difference (n.b. 700's are in between and vary according to the tyre size, but can be taken as about 26.5).

    In these days of calculators gear charts are unnecessary - all you do is to divide the no. of teeth on the front by those on the back and multiply by the wheel size, preferably in inches ! I can remember people laboriously working out these sums with pencil and paper using long division.

    I know the continental system of 'development' is more rational, but it doesn't give a memorable set of numbers. I think it's quite possible to be able to feel the difference between 66 and 69, especially into a head wind.

    I've another comment to make, but it's now stopped raining so I'm going out on my bike - more later.

  • in Bikes & Bits
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    needs to fit a 35mm dia hole.

    If you had asked Mr. Chater-Lea (there was such a person) he would have said 'I think you mean an inch and three eighths'. That is the size of Chater BB cups, so you need the complete set - two cups, lock ring and spindle plus some 5/16th balls.

    I can't tell you the part no. you'll need for the spindle, but I know that '1007' is standard width for use with a single chain ring, so that won't do for the tandem.

    You might try The Tandem Club - I think they have some special tandem parts.

  • in Bikes & Bits
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    Thanks for that comment. It is a pleasure for me to find an outlet for my obscure knowledge !

  • in Current Projects
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    An excellent and informative post, Veloham !

    A couple of points:

    The Radsport ad - I don't know the date, but the reference to 'this year's Tour of Britain' suggests it's pre 1958, which was the first year it was called The Milk Race. Even this isn't conclusive since there have always been some people who prefer the Tour of Britain name (they include me). The ad certainly looks mid fifties.

    The founding fathers of the Veteran-Cycle Club strongly believed that old bikes should not be 'museumised', but taken out and ridden whenever possible, so I'm sure they would have agreed with your comments on tyres.

    Veloflex - I've got some of these and I'd say they are the best wired on tyre I've ever come across. Mine say they are 'hand glued' which was always considered to be a sign of quality with tubulars.
    I would be interested to learn why this method makes a better tyre than vulcanising, which is the normal practice.

    Your rims without the'longhi' ferrules. Those ferrules must add a significant amount of weight, especially when you've got 40 of them - perhaps your rims were intended for track use.
    BTW, I've never seen any of those trapezoidal rims in the flesh - I guess most purchasers would want to be able to use their track wheels for the occasional TT.

  • in Current Projects
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    Those track rims:

    I'm fairly sure you could use them with brakes, but they may be made of lighter material than the standard version and so would be more fragile.

    A clubmate once used a pair of Super Champion 'Medaille d'Or' rims for road racing. These were intended for track use, but could be used for TT's as long as the rider kept a very good look out for anything resembling a pot hole; they seemed to be made of material not all that much heavier than kitchen foil.

    It's not possible to watch out for imperfections in the road surface when you're in a bunch,and my chum soon found himself sitting on the road watching the peloton disappear into the distance - he had hit a modest bump which caused both wheels to collapse.

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    I've only just seen that fascinating ad and description of the Dunlop range of tubs.

    It may not be immediately obvious, but I'm pretty certain it is pre-war.

    I say this for two reasons:

    1. Some of the tread patterns shown are different from the post war versions - the no. 2 is shown as having a plain tread, whereas the no 2's shown in the thread above are ribbed, which is how I remember them ( even I don't remember seeing the pre-war version). There are some other differences, for example the no. 3 I remember was more like a smaller version of the no. 5.

    2. The prices: I'm sure these are pre-war prices.

    There was something like a 300% inflation between the 1930's and the '50's.

    So, pre-war, Cycling (the magazine) cost 2d. (i.e. £1 would buy you 120 copies!, in the '50's it was 6d), a reasonably good wage would have been £5 per week, a gallon of petrol (4.5 litres) about 7p. and a suburban three bed house (London) about £500. You can make your own estimates of the rate between the 1930's and the 2020's, but it's got to be at least 100 fold*, and more like 200 - excluding real property, obvs.

    I think this will give some idea of just how expensive Dunlop tubs were, and why people would ride out to races carrying their racing wheels on sprint carriers - the tyres were far too precious to use for anything except actual racing.

    • I mean you need to multiply by 100 (or 200) - I don't mean 100% which is only multiplying by 2.
  • in Bikes & Bits
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    28 mm is not that much narrower than 1.25" (1 inch = 25.4mm).

    For me the standard tyre size is 23mm, I do have a bike with 28mm and to my eye they look huge!

  • in Bikes & Bits
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    I have a few bikes with 26 x one and a quarter rims, and I can confirm that the Schwalbe tyres mentioned above are the best you are likely to find.

    Unfortunately they are essentially roadster tyres in terms of weight and tread pattern and I doubt that the bike you are going to use them on is a heavyweight clunker, but at least these tyres do take an adequate pressure (85psi). Those tan wall things on Ebay only take 55psi, and they would probably go out of shape with as little as 60 psi.

    I've actually managed to wear out one Schwalbe, and it did give quite good service and was ok to ride on, but I don't think anyone would describe these tyres as 'lively'.

    It's possible you could find something old which might still be ok - I have a couple of Michelins (not World Tour btw) which are perfectly useable, but most 40 plus year old tyres are too perished to be worth fitting.

    So get some Schwalbes, unless you intend to do ambitious riding of any kind (speed or long distance touring), in which case I suggest converting the bike to 700's which usually fit these old frames better than the 26's for which they were intended .

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  • in Current Projects
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    They look superb, I'm jealous, it's incredible how light these old wheel sets are.

    No, I think it's incredible that modern riders are prepared to accept heavy rims and tyres.

    My contemporaries were obsessed with light wheels, and not without reason. Revolving weight is more significant than static weight (eg: the frame) when accelerating, and how do you win at track and road racing? With rapid acceleration - it's even helpful in TT's.

    Wired on rims have to withstand the 100+ psi pressure needed for speed work, sprint rims don't need the same strength (and hence weight) because the pressure is retained within the tyre.

    But sprints and tubs need a lot of skill and hand work, which is not compatible with making money, so we've been persuaded to put up with kit which is basically inferior to that which was used in the past.

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