Wednesday, 28 August 2013

Rathlin Island

Rathlin Island is a place that I often saw, when on a cycle run as a teenager, from the north coast. It lies 6 miles off the County Antrim coast at Ballycastle. A ferry service runs from town harbour to Church Bay on Rathlin Island. In my younger years the 'ferry' was on open boat on which you were just as likely to encounter livestock, as people. The six mile journey over Rathlin Sound, in an open boat, was not for the faint hearted, through the North Atlantic swell and strong tidal current running through the Sound. I heard enough stories of rough, wet crossings and sea sickness to put me off visiting the island in an open boat. However, a recent visit has shown me how much things have changed. There are now two vessels that operate the ferry service, a fast catamaran for foot passengers and bicycles, with a more conventional vessel for motor vehicles. 

Rathlin Island is relatively unspoilt, and it is only in recent years that the islanders have had electricity. Rathlin Island is around 16 miles from the Mull of Kintyre in Scotland. The island has 3 lighthouses, which reflect the often dangerous sea conditions around the island. The coast is littered with ship wrecks. Strong currents and often deep water make diving a challenging proposition. The wreck of WW1 cruiser HMS Drake lies in Church Bay and the site is marked by a buoy. Marconi transmitted some of his first commercial radio signals from Rathlin's East lighthouse to Ballycastle on 6th July 1898. The RSPB  now has a nature reserve for sea birds on the cliffs at Rue Point, the location of the west lighthouse.

On my recent visit I used the fast ferry and there were a number of bicycles on the vessel. Most were modern aluminium or carbon bikes, but I did see a 1960s five speed French lady's Motoconfort 650B bicycle equipped with a Huret Svelto rear mech on the ferry. 

The island is quite hilly and the roads quite narrow. The route to the west lighthouse at Rue Point is a challenge by bicycle. The traffic is usually light and a short walk or cycle south from Church Bay along the coast road will bring you to the remains of the Kelp House.

The gathering of Kelp was a local industry in the first half of the 20th century, the seaweed being used in the production of iodine. Only the shell of the Kelp house remains as, a visible reminder of this once important industry to the Rathlin islanders. Further along the beach from the Kelp House, the visitor can usually get close to seals resting on the rocks of the foreshore. 

They are unperturbed by the visitor and seem to embody the calmer pace of life on the island on a long summer's day.  The island is well worth a visit and can be reached by National Cycle Network route 93.

Wednesday, 21 August 2013

On Cycle Threads

One of the things about working on bicycles are the different threads that you can encounter. Why is it important to know the type and size of thread? Firstly, if you know the type and size of thread, then you know what replacement part you need. Secondly, if you are fortunate enough to be able to afford the tools, then you can often repair damaged threads or clean (chasing) the thread prior to refitting the part. In Britain there used to be different thread standards, B.S.W., B.S.F., B.A., and B.S.C. British Standard Cycle (B.S.C.) replaced the earlier C.E.I - Cycle Engineers Institute who set the standard in Britain for cycle threads up to 1938. The cycle thread angle was 60 degrees, as compared to 55 degrees for B.S.W and the depth of cycle threads were shallower than either B.S.W or B.A.

Grease nipple
Bottom bracket shell
2 BA
Mudguard eyes on dropouts
26 TPI
Retaining bolt for bars
Headclip headset
Retaining bolt for top race
26 TPI
Seat bolt

26 TPI
Front hub axle
British Standard Cycle
26 TPI
Pedal cone thread
British Standard Cycle
Pedal axle
British Standard Cycle L & R I.S.O.
30 TPI
Fork steerer tube
B.S.A. headset
24 TPI
Fork steerer tube
British Standard Cycle I.S.O.
26 TPI
Fork steerer tube
1 3/8”
24 TPI
Bottom bracket
British Standard left & right I.S.O.
1 3/8”
24 TPI
Fixed Sprocket
Thread on rear track hub
1 3/8”
26 TPI
Bottom bracket
Raleigh left & right

The table above gives some of the threads found on older British made steel bikes and the list is not exhaustive. I have marked the ones that are commonly encountered  with the highlighted I.S.O.  Modern bikes tend to use metric thread – M3, M5, M6, M8, M10 along with some of the above. If you are working on French made bikes manufactured before 1980, you are likely to encounter French metric cycle threads. Italian bicycles also use a different metric thread. Tandems often use larger cycle threads than a solo bicycle. Worn tandem headsets on old tandems can be problematic especially if you have a French made tandem.

How do you identify a thread? You can use a Vernier calliper to measure the outside diameter to give you the nominal size and then a thread gauge to measure the threads. The other thing to note is that C.E.I./B.S.C. threaded bolt heads on older bikes usually require a B.S.W. spanner to remove. It is worth arming yourself with a set of Whitworth spanners or wrenches in the smaller sizes for working on old bicycles. A set of metric spanners or wrenches are useful for bicycles made after 1980 and a set of metric allen keys would also be useful. (British bikes from the 1970s tended to use a mixture of imperial and metric hex allen keys bolts just to cause more confusion). Most sets don't include a 7mm hex allen key, but this size was used for the expander bolt on some French made bicycles pre 1980.

Cutting taps and dies in the correct sizes are the tools you will need to repair damaged threads. Metric taps and dies in M3 – M10 are easily available. Buy the best quality you can, use oil or cutting compound and go carefully. A taper tap is best, as it will tend to find the existing threads. Be careful that the tap is square to the hole, so you don't cross thread and end up doing more damage than you set out to repair. If you are not sure, take it to a bike shop that can repair it. British Standard Cycle taps and dies tend to be more expensive as they are less common. Steerer dies, bottom bracket taps, and pedal taps, are specialist cycle workshop or framebuilder tools and are not cheap. They are sold through the cycle trade by specialist cycle tool manufacturers and usually come with the die holder or tap handles. 

British Standard Cycle bottom bracket threads are handed left and right, so you need to know what you are doing. Manufacturers usually sell bottom bracket taps in Italian thread sizes to fit the same handles.On the subject of Italian threads, Campagnolo Gran Sport or Nuovo Record hub thread is a mixture, 9mm or 10mm by 26 TPI as compared to metric 9 x 1 or 10 x 1.  Zeus was another anomaly as the axles and cones were initially Campagnolo copies but the thread was subtly different to Campagnolo. Campagnolo cones would fit the hubs but not on the Zeus axles, so you had to replace this too, if you didn't have the correct Zeus spares!

Where you will struggle, is to get taps and dies in the older steerer and bottom bracket sizes. It is worth visiting auto jumbles, to see if you can pick up some of the tools in the sizes you need, as early motorcycles tended to use cycle thread. Make sure that you know the sizes you need and check the taps or dies you find are sharp. If they are loose in a box, covered in rust and filth, be careful as they more than likely have had the cutting edge knocked off. Taps and dies should be stored in such a way, so as they don't rub together, to preserve the cutting edge. 

The same is true for tapered and parallel reamers. Older taps and dies, if still sharp are good for chasing and repairing damaged threads. Do not try and use them to cut threads where none previously existed. This is a job for a new cutting tap or die which has to be very sharp along with cutting compound.

Wednesday, 14 August 2013

The end of the road

A person I know brought his old bicycle to me rather than throw it in the skip. The bike was in 1970s trim and had been repainted black at some stage. 27” x 1 1/4” wheels, short mudguards, dynamo and a mechanical odometer driven off the front wheel which also gave an indication of the speed of the rider. 

The chrome steel rims had reached the end of their useful life, but a cursory glance at the frame seemed to indicate it didn't look too bad, but there was a question about the fork...

The bike was stripped down with patience to the bare frame with all the parts put to one side in a parts bin. It was my intention to have the frame powder coated once it had been checked for track. However, during the stripping down, it became obvious the bike had been hit at the front end. Close examinaton revealed the down tube was bent a not far from the head lug. 

It was also obvious once the headset was removed that the front fork steerer tube was bent above the fork crown and the fork blades had also bent as the wheel twisted in the fork (see above). As the frame is steel, it didn't break and in theory, the frame is repairable. However, the frame tubing is Hi-ten and the residual value of the bike makes it uneconomic to repair. I had to break the news to the owner this afternoon. It should be possible to source a replacement of similar vintage, in good condition for him and at less cost if he wants. It is a straightforward job to clean and refit the dynamo, mudguards and speedometer. So what to do with the damaged frame? It has been moved to the 'donor' pile. It can now have a further life as a source of parts to repair other frames.

Wednesday, 7 August 2013

Frame numbering

One of the most frequent postings on web forums by people who are starting to collect bikes is 'can anyone identify my bike or frame?'  The easiest route to possible identification is find the frame number.   It sounds simple enough, but it is made a lot easier if you know where to look.   Volume bicycle manufacturers like Raleigh tended to use the seat lug, as in this 1925 Raleigh roadster.

The size and font of the numbering could also change over time as illustrated in the Raleigh Moulton frame number, although the location of the frame number was the same.  

One caveat about Raleigh frame number information on the web. Sheldon Brown is quite accurate on Raleigh frame numbering, except where he supposes about Irish Raleigh production. His information is simply incorrect. As it was posted 'on the internet', it is assumed by many, as an incontrovertible truth, when it is not. Sheldon's pages were a work in progress. Unfortunately, this all came to a halt, on his untimely passing. I will blog accurate information on Dublin Raleigh frame numbers using known examples at a future date.  Raleigh have also used the back of the seat tube, either below the seat lug, or above the bottom bracket, the underside of the bottom bracket shell and rear dropout as location of frame number.  Some of these locations were used for 'badge engineered' Raleigh production.  As mentioned above, the style of font used in the sequential frame number changed over time and the example below was found on a 1920s British roadster.  

Other British bicycle manufacturers used either the seat lug or a rear dropout. BSA sports frames tended to have the frame number on the left rear dropout. 

Hercules in the 1950s also used the left rear dropout and used a different font to BSA. 

Sunbeam during it's time of ownership by AMC used the right hand rear dropout on some models. 

Bespoke custom frame builders in Britain used various locations to install a frame number. Unusually, some builders put their frame numbers on the bottom bracket shell at the down tube lug. 

Others stamped the underside of the fork crown. It was not unknown to have the frame number on both the frame and fork. 

Often the frame number was stamped on the fork steerer tube as well. 

However, easily the most common location for a frame number was the underside of the bottom bracket shell. 

The number was usually stamped in line with the axle, or at right angles to the crank axle and parallel to one on the bottom bracket cups.  Imported Peugeot bikes from the late 1970s/early 1980s had a frame number stamped into the bottom bracket shell which was parallel to one of the bottom bracket cups. Peugeot also had a paper identifier covered in clear vinyl wich identifies the model, frame size and sequential frame number. 

The location varied between the underside of the bottom bracket, bottom of the seat tube above the bottom bracket shell, or on the left hand chainstay.

The model numbers appear to be slightly different according to the country of sale. Gitane put their frame number on the left rear dropout of their tandems. The sequential frame number is on the bottom part of the dropout and the year identifier above. 

A further complication and a bit of a red herring can be a re-finisher's number. 

Frames were often stamped by a re-finisher before being enamelled to make sure the right frame and fork were returned. These are usually 3 digit numbers and can confuse as they are on both frame and fork.

Once you have located the frame number, the process of trying to indentify  the machine that you have found can begin. Finding the frame number can be difficult if it is only lightly stamped, or been damaged on a rear droput, or covered up with paint. Some small bespoke frame builders didn't bother with a frame number. Late 1980s volume manufacturer (Londonderry built) Viking 531 frames also don't appear to have been given frame numbers. I have also found 1990s examples of Dawes 531 frames with the same problem. Finally, another recent phenomenon which can add to the confusion is post code stamping of a bike frame to try to deter theft and ensure the frame is returnable to it's owner. These are usually 7 digits, usually two letters, three numbers and two letters. They tend to be stamped where they can be easily found, so keep looking to see if there are any others!

Thursday, 1 August 2013

A Giant leap forward......?

This project came about by chance because of a bike I was asked to undertake a small repair on. It was a child's Felt bicycle which was a bit different from the normal kid's B.S.O.s (bicycle shaped objects). The bike had a nice frame and some nice components but was very, very, heavy. I wondered at the logic, which married some good kit with the very heavy mediocre, to produce a heavy kids bike with pretensions, at a hefty price tag. As chance would have it, I came across a Giant 24” wheel aluminium frame MTB that was heading for the scrap bin. 

Could I turn this ugly duckling into a swan that might fly? The frame was sound, but all the cheap, heavy components were badly rusted and the bottom bracket and headset were shot. The bike was put to one side of the workshop. The occasional glance while working on other things started the the ideas train rolling. The first task was to strip the bike down to the bare frame. The challenge was to see if the bike could be rebuilt, firstly, to make it a lot lighter and secondly, to produce a good quality child's bike on a budget. I am aware of Islabikes as being the only bicycle manufacturer in this part of the world who produces good quality children's bikes and is not committed to the 'heavy kids clunker' concept.

The penetrating oil was reached for and liberally applied. With patience the bike began to come to bits and the scrap pile grew exponentially on the workshop floor. Once the frame was stripped down and the heavy, rusty suspension fork and headset removed, it was checked for visible signs of damage. Some minor scrapes to the paint finish but no obvious sharp impact damage. The bike was originally fitted with a six speed freewheel. The cost for rebuild had to be kept under control, as the bike would be sold on, once the project had been completed and must produce a return for the work carried out and parts fitted. The original wheels were steel hubs laced with rustless spokes into an alloy rim. The wheels were heavy and out of true. The spokes were corroded, so even attempting to true them was a complete waste of time. Replacement alloy wheels would be fitted. 

I gave some thought to building wheels using a cassette rear hub, but rejected this on the grounds of cost. I used stock 24” replacement wheels, alloy threaded hubs, stainless spokes and alloy rims. I also fitted a 7 speed freewheel. The bike needed new suspension forks and after doing a bit on online searching identified the SR Suntour XCR as the best model available for 24” wheels. More online searching produced a heavily discounted purchase.  The replacement headset was a stock item and the fork steerer column was measured and cut to size before fitting the star nut inside the steerer tube. The forks were then fitted and the headset adjusted. 

Turning my attention to the handlebars, I saved the original alloy stem, but dumped the rusted steel handlebar. I managed to source some narrower  alloy downhill bars which were remaindered stock. 

The bike originally had a cheap bottom bracket set comprised of separate cups, ball bearings and axle. I chose to replace this with a sealed square taper bottom bracket unit and a new alloy Sunrace triple chainset. 

The original derailleur mechs were heavily corroded and I chose to replace these with a rear Shimano Altus mech and a Shimano LX front. A new chain was also fitted, along with Sunrace twist grip shifters. I had considered using rapid fire levers, but after talking to my youngest daughter, went with her preferred choice, for ease of use – twistgrip. The drive train was then cabled and adjusted.

The steel seatpost was scrapped and a branded 'Giant' alloy one bought on ebay. The original saddle was saved and refitted along with the Cateye reflector. 

The alloy V brakes were cleaned, refitted, recabled and adjusted. The new wheels had been given, new rim tapes, but the original inner tubes were reused as they were sound. Tyres were then fitted. The bike is much lighter than the original spec and the drive train works well. My youngest daughter has road rested the bike and declared it good to ride.  

The bike is a one off, but has proved it is possible to produce a reasonable quality, relatively light, child's bicycle, which is durable without breaking the bank. Is there a market for this sort of bike? I believe, yes, however, it has to come with the caveat that the market is a small niche, in the overall scale of children's bicycle buying. Why do I say this? Firstly , on the evidence from Islabikes, who sell directly to customers via the internet, servicing a global market and secondly, I don't know too many families yet, that use bicycles solely for transportation. The majority attitude towards children's bicycles in this part of the world seems to be, that they are toys and are bought through toy shops or supermarkets. A £60 BSO (bicycle shaped object) is considered a good buy. The fact it is incredibly heavy and therefore tiring to pedal, over anything other than a short distance and has to be assembled from the carton, is not an impediment to sales. The number of children's bikes bought through cycle shops here, has dropped dramatically and the once annual Christmas bonanza for the LBS of children's bikes has long since gone. Children's bikes are considered as a 'throw away consumer item'. This may change as more adults start to ride bicycles again, but I believe attitudes will only change significantly, when the bicycle is being used for transport, not just recreation.