Cycling UK Forum

You should aim at the correct grade and hardness, and that will roughly determine the material. Corrosion can ruin bearings long before they wear, and you'd be tempted to use stainless, but stainless steel is too soft. 55 to 65 is the ideal hardness and it will be carbon steel most likely. Harder bearings than this are also to be avoided because they will wear the cones and races and you'd rather replace bearings regularly than cones and races.

When it comes to grade, Shimano don't publish the specs of their bearings, but I remember Brucey (we all continue to miss you Brucey) saying that they are believed to be around 25.
I bought loose bearings from Simple Bearings and, out of their vast range of products, there were not many that met the criteria. They have grade 100 and grade 10, nothing in between that I can remember, so you have to get 10 and that really narrows down your search.
I can have a look in my shed and tell you which ones I chose if you're interested.

Yes, the Joules/Dahon hub I mention, is a "rebranded SP hub", SP being Shutter Precision.

The Capreo was quite affordable but, after a quick search, I see that it may be difficult to source these days:

https://winstanleysbikes.co.uk/shimano- ... -front-hub

You should be able to use 74 mm OLD dyno hubs, commonly seen on 20" folders, with 16" rims.

Dahon offer a variety of bikes with dynamo hubs, mostly 20" but they may have some with 16" wheels. They now use a rebranded SP hub (Joules III, they call it) while older models used a rebranded Sanyo hub, both 74 mm, which AFAIK is the smallest OLD you can get.

There is a Shimano 74 mm OLD dyno hub also made for folders, the model denomination is Capreo and it is designed for 20 and 16" wheels, according to the Shimano link below.
Apart from these three, I don't think there are any other 74 mm dyno hub options.

https://bike.shimano.com/en-US/product/ ... -F703.html

On our last long cycle tour, before the pandemic, across Europe (3,000 km, 7 countries), travelling as a couple we managed to get hosted only twice. In some areas, like Northern Italy, there would be many dozens of registered hosts on our route, and we would get no answers at all after contacting as many as twenty daily. After that, we stopped bothering and wasting time looking for potential hosts. Clearly, there were loads of hosts that had registered at some point because they thought it was cool and then forgot about it or ignored all requests.

Back at home, we hosted a couple of cyclists. We couldn't host a few others for several reasons, but I always replied to explain and apologize.

Have a look at Tektro CR720 cantis. They allow a lot of vertical adjustment and are a popular cheap option when converting to a larger rim size.

viewtopic.php?t=96386

I love Birdy , but one of its flaws IMHO is the unusual rim size, 18". You better try German online shops.


Here you have 24, 32 and 36 spoke Birdy rims for 35 euros. Look at "Birdy Felgen":

https://pedalkraft.de/birdy-ersatzteile

As you can see, this retailer stocks many Birdy spares, including 18" Schwalbe tyres that you may consider.
I checked and they do ship worldwide and will take 19% off the price (German VAT ) when shipping outside the EU. Open "impressum" at the top menu bar and you can see the contact details. You can write an email in English and they should sort you out.

Great mirror, excellent position and visibility, BUT, be warned, it breaks very easily at the bottom of the stem (happened to me twice). It'd be possibly the best mirror in the market for flat bars if the stem was made of metal rather than plastic.

The quirky bike in the previous post is a Danish-made Pedersen. The design is certainly more than classic, dating back to the late 1800's, but it is still made to this day, so you could theoretically have a freshly manufactured, brand new classic bike.

I would use vice grips or any tool that you can apply around the head rather than cutting a slot and use a screwdriver. Cutting a slot, depending on the quality of the material, may weaken and the bolt head resulting in bits braking off and an even more difficult extraction.

This bolt is far too mangled for that, but one trick that works for me with stubborn bolts like these is applying torque with the allen or torx key and, at the same time, tapping the key repeatedly with a light hammer. The vibrations help to undo the bolt without having to overdo with the key and possibly damage the head.

Union Fröndenberg was a German manufacturer of bicycle parts dating back to the beginning of the 20th century, totally unrelated to the homonymous Union bicycle brand in the Netherlands.

Around 1990, manufacturing was relocated to the Czech Republic and in 1995, the company was finally sold to the Taiwanese Marwi Group. They own the brand to this day and you can still buy inexpensive Union branded hubs from online retailers in Germany. No idea whether these are German-made old new stock or freshly made in Taiwan.
During a few years before selling to Taiwan, Union had their own professional racing team named after the company. Does Erik Zabel ring a bell? He raced for Union Fröndenberg a couple of years before moving on to join Telekom.

I use the SRAM 3.0 Comp version, which is identical but has a 1:1 cable pull ratio. Sram calls it 1:1 actuation, whereas the MRX is 2:1 actuation and is designed to be paired with Shimano derailleurs.
They perform surprisingly well despite being the cheapest and most basic Sram grip shifters, the only issue I have encountered is that the outer rubber layer of the rotating part tends to deteriorate and peel off overtime.
You are supposed to be able to feed the new cable as you describe, but I never managed to do it. The cable has to go through a bend and it is tricky to get it right, possibly because I used standard gear cable, but it is hard to believe that 0.1 mm in diameter makes any significant difference.
I ended up dismantling the whole assembly, which is surprisingly simple and has the added benefit of allowing you to clean and lubricate the innards. It has a plastic ratchet, and the pawl is a flexible stainless steel plate that deforms as you press it over the teeth, no pivot and spring mechanism. Lots of friction and lots of plastic that will benefit from any lubrication at all.

quote="Carlton green"
"Without wishing to be negative about any product the responses about failures, problematic supply of spare parts, adjustment and lack of lubrication make me wonder how sensible using some of them really is. If a lot of your cycling needs a ready supply of generated electricity for gadgets and sometimes lights too then really good hub Dynamos are wonderful - but really good is rarely inexpensive. On the other hand if what you need is only generated electricity for a bit of night time riding (just lights) then it’s hard to beat the simplicity, economics and ease of replacement of a simple bottle Dynamo; when actually in use I find that their additional drag is trivial and the rest of the time they don’t cause any drag at all."
[/quote]

Using dynamo hubs despite adjustment, lubrication, spare availability issues etc is just as sensible as using any other ordinary hub, any cup and cone hub to be precise. All Shimano and Campagnolo hubs are cup and cone and have the same adjustment requirements.
If you don't want to deal with faffy adjustments, all dynamo hubs apart from Shimano have cartridge bearings.
You can forget about bearing adjustment, but you will have to take apart and rebuild the wheel every time you want to open or service the hub. Supply of spares is equally problematic for all hubs, I would say.

Bottle dynamos are perfectly adequate for utility, urban, commuting bikes. Hub dynamos are more durable and ideally suited for touring cycling, and many people have put 50.000 KM on SON dynamo hubs. These are certainly overkill for urban use and commuting but Shimano dyno hubs are a good, fairly reliable and inexpensive alternative provided you can adjust cup and cone bearing.
According to a German lab test that you can check out on cyclingabout.com, with the lights switched off, the most efficient hub dynamos will increase drag by 0.2% which will slow you down 17 to 30 seconds on a 100 Km flat ride. The least efficient hub increases drag by 1.3% and slows you down over 3 minutes on the same ride.
On the same site, there is an article on modern "bottle dynamos" that are very efficient and engage the rim rather than the tyre, avoiding wear on the side of the tyre. They appear to be an excellent option if it were not for the price. At several hundred, they are even pricier than SON hub dynamos.

The whole internal assembly is sold as a spare, and that includes the RHS bearing and the axel. None of the components of the internal assembly unit are available separately as spares. I struggled to get many Shimano hub spares before the pandemic, like cones and axles, and I presume that it will be even worse these days. Just before the pandemic shortages I needed to replace both bearings in a T785 XT dynamo hub after the LHS cone worked loose on tour causing extensive wear. I could have ordered an internal assembly at a cost of roughly 75% of a complete new hub, and decided to go for the brand-new hub at around 100 euros from a German online shop.
I think it makes more sense to source a new hub to use the internal assembly rather than buying one, hubs are simply easier to get than spares and are, or were, far easier to get at discount prices. Even if you only need the internal assembly, I would go for a whole hub and get some valuable spares at little extra cost.
It is an easy job, the whole assembly is threaded onto the hub shell, and then you need to adjust the bearing on the opposite side. It should take a few minutes, but, here are two little issues, first you will need a large unusual wrench to undo and replace the assembly, a 32 mm octagonal wrench, and secondly, dynamo hubs bearings are faffty and frustrating to adjust because they always run notchy and it is very difficult to ¨feel¨ when they are properly adjusted.

I would apply dry threadlock liberally on the piston threads. Spyres are notorious for loosing their adjustment as they lack any mechanism to lock the pistons at a given position, like the grub screws on the Hayes mechanical callipers for instance. They also tend to develop corrosion around the three bearings that move each piston, so they will benefit from any lubrication in that area that cannot migrate and contaminate the pads. So lubricate with care, bearing in mind that brake callipers reach hight temperatures that make even the thicker greases rather fluid.