Cycling UK Forum

actually the chain may not want to come off if it is too snug on the sprockets or chainrings. 'As near as dammit' means 0.2mm different in some cases, and yes, that is enough. As I have mentioned previously, the chain will run on the chainrings and generally will look as if it is going to be OK until you encounter mysterious shifting issues....and these are generally much worse on a triple than a double. If you have a mismatched set-up on your troublesome triple, it would explain a lot.

cheers

yes, I think so. But if you are converting then you may or may not get away with using various other bits of the transmission. A suprise item here is the chainset; the 10-speed chain may run on 8-speed chainwheels, but it won't necessarily shift.

cheers

26.4 normal? -well, kind of... some frames were built with 'odd' DB seat tubes with 1.0/0/7/1.0 tube walls and these were even 'standard' in some tubesets for a while; even when reamed these won't take any larger than 26.6mm pins. 'As built' a 26.4 may seem like a good idea. If the seat pin 'rattles' slightly in the bore when everything is clean and the clamp isn't nipped up, that would explain it. Or you could have a plain gauge seat tube. Or- you may have a few French spec tubes in there just for fun...

I have a Peugeot Super Competition frame of mid-70's vintage, built in 531DB; it still has the remains of the 'slant' style sticker (all in French) to prove it. This frame has various gallic eccentricities including a 22.0mm stem insertion diameter, a 25.0mm headset thread and steerer , and a 35x1mm bottom bracket thread IIRC for while French bikes either came with a Double right BB thread or a Right/left pair. all in metric, of course, and obviously it would be too simple to have the same thread as the Italians... so when taking out the fixed cup from some frames, it is more of a guessing game than normal, because the parts are not necessarily marked. All you know is that the adjusting cup is French thread if you take that out first and measure it. After that you are on your own... It also has odd tube sizes, and the seat pin is 26.6mm diameter, presumably for the similar reasons as above.

Eventually even Peugeot couldn't stand it any more and went to BS threads sometime in the early eighties. But maybe they just did that for export...

cheers

provided the fork blade is reasonably wide, I think brazing a small tube through the fork gives a good low-rider mounting point without causing a really bad stress-raiser. The true 'braze-on' mounts are fine, but as noted can break off. I guess this is preferable to a hole in the tube where a single sided fitting might tear out if that is the alternative...

cheers

A chum of mine has just bought one; with a 2:1 chain drive (As Shimano suggest) you get gears of twenty-something to well over 100" with 27" wheels. A 23T rear (the largest shimano list) and a 40T front goes lower... How low do you want to go? And what top gear is acceptable?

Actual ratios are:

Gear Ratio Total Difference 409%
Gear Ratio 1 0.527
Gear Ratio 2 0.681
Gear Ratio 3 0.770
Gear Ratio 4 0.878
Gear Ratio 5 0.995
Gear Ratio 6 1.134
Gear Ratio 7 1.292
Gear Ratio 8 1.462
Gear Ratio 9 1.667
Gear Ratio 10 1.888
Gear Ratio 11 2.153

The hub is smooth to ride and gear ratios seem nicely spaced (unlike the Alfine 8 ) but it is early days re. long-term reliability as yet. Although there are already reports of units that have broken, or required attention, it is clear that at least some of these have seen, erm, unfortunate treatment. One for example, was apparently filled with brake fluid when the wrong stuff was supplied. Incorrigible mudpluggers have reported 'a few crunching sounds early on' which made me wince; they didn't say so but were probably shifting under load.

If the experience with other hub gears is anything to go by, sensible use and regular maintenance (oil changes a bit like the Rohloff) count plenty; neglect, maladjustment, shifting under load (except perhaps in a few shifts where it can be OK) etc will turn a box of cogs into a box of shrapnel. Alfine indexing is in the lever, not the hub, and the correct alignment is via coloured splodges on the hub ring, which will not always be easy to see; on some frames at all, and once covered in dirt, or the paint is washed off... Also note; hub bearings are adjustable cup-and-cone which is good if you can be bothered to do it and do it well, but bad if you do not adjust when required.

I don't know which shifts can safely be made under moderate load; it is moot anyway if the Shimano drop bar STi type lever is used as there is no gear indicator; the ratios are so well spaced and silent (even when the hub is brand new) that there would be no clue otherwise, it would be easy to lose track... Also I was surprised to see there is no 1:1 gear which gives comfort since it gives you some hope that it will 'get you home' if things go bad, without causing much further damage if there is some kind of internal breakage or problem.

I note with interest that whilst Shimano don't presently offer individual internal gear spare parts (just the gear unit in a big lump, which apparently comes out fairly easily) they do sell the special tools to disassemble the main gear unit. I'm not sure how many bike shops (let alone owners...) will wish to wrestle with its fiendish complexity but its nice to know that you could 'have a go' if you wanted to I suppose...

The gear cable is mounted on a spool and bracket -which shimano call a 'cassette', confusingly- and this lot come off the hub with a QR ring by hand when the wheel has to come out of the frame. Its not bad, (its the same arrangment as the Alfine 8 I think) and there is only one loose piece (the ring) to lose, but there are more coloured splodges to line up on reassembly and I found it a little bit fiddly when I tried, for the first time, anyway.

Overall, I guess its a question of whether you can live with the shortcomings, perceived or otherwise. A Rohloff at 2/3 off? No, not quite, but a good effort for sure, and worth a go I reckon.

I read another old motoring book which went into great detail about the best method of reversing sideways into a hedge, backwards, should your brakes fail on a hill, which was clearly a likely occurrence at the time...

BTW if anyone want details of my FW four to five speed conversion -which retains nearly all the original FW parts,and is reversible- do let me know. I've also done it on FG units, and I have an FM in the works too.

cheers

Re 631; oh, good to repost, I had overlooked that, apologies... and thanks for your kind words...

I confess, I kind of lost interest in frame tubing for a while a few years back and 631 etc didn't come high up on my radar.....

but my understanding -which may be incorrect or at least incomplete- is that 853 and 631 are a CrMo steel, not a million miles removed chemically from 4130CrMo, but variously worked and heat treated differently. If so, Reynolds' statement that it is 'a development of 531' is a little disingenuous.

CrMo frames can be very lightweight and ride very well. My criticism of it, as a material type, is that it can harden too much if built with a high cooling rate; coincidence or otherwise, I have seen more cracked CrMo frames than MnMo (think 531, 753 etc) steel.

For those with an interest in older Reynolds tubes, as used in Gazelle frames;

http://fivenineclimber.com/bikes/gazelle/misc/reynolds_80.htm

is interesting

cheers

When I consider a future filled with electronic shifting systems and the like, I cannot help but think of this quote;

".....says of the ........ Corporation products that 'it is very easy to be blinded to the essential uselessness of them by the sense of achievement you get from getting them to work at all.'
'In other words - and this is the rock solid principle on which the whole of the ........... Corporation's ...... success is founded - their fundamental design flaws are completely hidden by their superficial design flaws... "

-from 'So Long, And Thanks For All The Fish' by Douglas Adams

Does this make me a grumpy old man?

cheers

pherron wrote:To answer the last poster, on the wife's bike the brake simply locks on until you stop and take the forward momentum off the front wheel, then you can release the brake.

I had one which (when the weather was right) would require a small backwards roll to release the brake sometimes. After some apparently minor -and, I thought, most likely inconsequential- fiddling of the sort indicated, the problem went away.

cheers

smart algorithms on cameras?

Did you see?

http://jmblogger-latestgadgets.blogspot.com/2010/01/racist-camera.html

I'd hate to have that kind of system deciding when I wanted to change gear for me, ta...

cheers

MikewsMITH2 wrote:Brucey I don't know whether you are an electronics engineer or not but a speed transducer under water on a yacht or a masthead wind speed and direction unit has a very hard life and will typically last 10 years. I have designed electronics systems for vehicles and aircraft and it ain't that hard to weatherproof it.

I'm a materials scientist by training and I've worked for well, several hundred companies providing consultancy support mostly in relation to materials selection and joining technology. In addition I've owned, repaired, designed and built electronic devices that make vehicles go and stop, so I have a fair idea of what is required. I didn't say that proper weatherproofing couldn't be done, I said that even where it could mostly be avoided it wasn't being done well enough in a more consumer-oriented market. Electronics for aircraft is not exactly noted for being inexpensive and in marine environments it is generally neither inexpensive nor lightweight.

The problem with electronics on cheaper cars is the price point demanded by manufacturers and the fact that the vast majority if garages understand nothing about electrics let alone electronics. The deign life of cars is now 8 years when I was in the industry it was 10 years and 100k miles. No cycle manufacturer wants you to keep your bike more than a few years anyway. Mechanical parts wear out in a few thousand miles. Well designed electronic systems will outlast them.

I think we agree then, if we say that cycle electronics also have been -and will be- built to a price. And that the design life of cars isn't as long as it was, or should be. Garages shouldn't have to know too much about reliable electronic systems... it happens sometimes...ask yourself if you have ever seen any repair info on a MKI Bosch ABS ECU. Nope, me neither, the faults lie elswhere with this system... If we look at one of the few car electrical parts that must see a bicycle-like environment, an ABS sensor, however, then these little blighters fail often and they are not noticably inexpensive either. When you think that they are little more than a coil of wire, some soft iron and a magnet potted up, made in their millions, you start to wonder how more complex cycle electronics will be done if it is to be both reliable and affordable. The only car I have owned that was properly electrically reliable -although not fault free by any means- was a 1980's Honda; pretty much all the wiring harness had properly waterproof connectors on it, and just to make sure, each plug was packed with waterproof grease before assembly. But even they (unlike MB) were not daft enough to believe that electronic brakes might be a good idea. And early SMG gearboxes bear comparison with the likely performance in early electronic cycle shifting in that they were ludicrously expensive and didn't actually work that well. Current car gearboxes (DSG say) are mechanically more complex and arguably less electrically sophisticated than their antecedents which gives you an idea of where the biggest problems lay...

As to hub gears £1000 plus for 14 speeds is a non starter for most people. Apart from Rohloff the experience with more than 3 speed hub gears has been mixed.

The Alfine 11 may show the way ahead here but its early days yet. One with the seals, half the gears and half the price would suit most utility riding. Myself I've used a SA FW hub (modified to 5 speed) for, oh, about 40000 miles so far and it hasn't even begun to wear out noticably yet. This is fifty-year old technology, and its not as if it was a branny-spanking-new when I started with it.... Yes, mechanical things on bicycles do wear out, but with few exceptions you can, if you can be bothered to look, see them wearing out which is why a bicycle is such a beautifully elegant machine. Spontaneous and catastrophic mechanical failures on bicycles are comparatively rare, and those parts that are shown to be suscpetible to them are swiftly consigned to the dustbin of history. Yet it is exactly this kind of failure (along with the exceptionally irritating 'intermittent connection'... ) that characterises electronic components and systems which are built to a cost.

Methinks said dustbin awaits....

-but we'll see...
cheers

a tiny smear of moly grease on the backplate bushing (if you can get at it) and a tiny smear of copper ease on both the cam and fixed pivot may help.

Sometimes filing a new 'lead' (chamfer) at the leading and trailing edge of each shoe will help too.

cheers

MikewsMITH2 wrote:Contrary to the comments above, cycling is not a severe environment compared with auto electronics where the temperature spec is -40 to +120 deg C and has to be resistant to all kinds of fluids and lubricants. If that is severe just think about the marine environment where electronics is ubiquitous. So environment isn't a barrier.

I don't agree; it is quite easy to design a car so that the electronic parts are not routinely sprayed with salty water and virtually impossible to design cycle electronics in the same way. Despite this one of the most common reasons that a car of 5-10 years goes off to the scrappies or incurs high repair costs is because there is an unresolvable electronic problem (cost or capability). I own a car which is known from surveys to be the most reliable in its class but a trawl through the owner's forum shows it to be susceptible to numerous electrical faults. Gawd knows what a bad one is like then... The poor reliability of present cycle electronics is only tolerated because -with the exception of lights, where hardened users carry duplicates...- the systems are not essential to basic operation and can be (and are, often) simply junked when they clap out. To be reliant on this kind of stuff for basic operation is the stuff of nightmares. A plague on it, I say.

There is a problem to be solved. Many recreation cycle users do not understand their gears and have problems changing them

Hub gears solved that problem in about 1902. Since then they just got better. Simple.

On a more cynical note the cycle industry and trade have to keep us buying new stuff so planned obsolescence is also part of the agenda.

oh yes yes yes yes yes......

F1 gearboxes are effectively semi-automatic in that the driver is prohibited from downshifting too early and therefore blowing the engine. They could easily be (and have been) fully automated. Its only the rules that (sensibly) dictate that the driver has to drive the car, these days you could have a robot F1 car that would get within a fraction of the best driver on the best day. It would hardly be sport... maybe it isn't anyway... But here the goal is very simple most of the time (until they need to save fuel anyway..); best speed from an engine that 'always works the same'.

The bicycle 'engine' does not 'always work the same'. Nor does it even want to... Riders ease back in the saddle and pedal using different legs muscles, rythmn and cadence during long climbs. We also ride in and out of the saddle, and wish to speed up, slow down, and vary power output. Imagine an attack on a long climb; Rider A has chosen his gear and gone for it, temporarily pushing out x3 or x4 more power than normal and pedalling at a different speed. Rider B has an automatic gear system; he pushes harder on the pedals to counter the attack; what does the gearbox do? Shift down most likely. D'oh!

Likewise any temporary cessation of effort is likely to be interpreted as an opportunity for a higher gear, so god forbid that you should ease your effort for even a second on a climb, else when you start pedalling again you will likely be in treacle...

Whitt and Wilson wrote on this subject, oh, thirty years ago, and whilst we are better at some of the technology for implementation, I'm not sure the fundamental problems for successful control algorithms have yet been addressed.

I like the idea of hydraulic shifting a lot; I sketched up some ideas for a system myself about 15 years ago, with the attendant benefits now touted... but only one lifetime, too many mad ideas, it went on the back burner... The proof of the pudding will be in the eating though; SRAM's conception, engineering, timing and marketing will have to be spot on for it to take off.

Look at index shifting; taken for granted now, SIS was actually shimano's second or third go at producing a viable -and popular- index system (remember the 'positron' -I think- anyone?). I recently worked on an old 6-speed index system for the first time in ages. I remember it being like rocket science when I first saw it , but now it looks like barn-door engineering, and the tolerances are such that you can pretty well throw it on the bike and it will work quite well. I think Shimano could have made an eight, nine or ten speed system even then if they had wanted to, but the market wasn't ready -or educated enough- for it. I mean no-one would 'get it' if they went from ' it'll do' 5/6 speed friction shifting to modern stuff, and most folk would thus fail to set it up or maintain it properly. The same engineering -if it requires any owner involvement at all- can be a success or failure depending on the customer mindset and prior experience.

I have been surprised at -for the most part- how reliable hydraulic brakes have been on bicycles, and many cyclists are now used to the idea of hydraulics, so maybe SRAM will do OK. But then again hydraulics are not for everyone, maybe they will turn out to be 'right little bleeders'...

we'll see, no doubt...

cheers

very few cyclists maintain perfect cadence between flat and uphill for example. Racers and tourers will (intentionally or otherwise) vary this considerably even during a single climb. If you therefore have to fiddle with a control to keep yourself happy, you may as well change gear.

I own a car with an auto gearbox with intelligence and switchable modes. I am constantly using a weird throttle setting to get the thing to change gear when I want, or changing modes using the switch. Frankly the whole arrangement is a pain in the jacksie and it will be converted to a manual gearbox as soon as I can find one.

Note also that cars have had auto boxes available for about sixty years and they are; a) resolutely avoided in many markets and b) have only recently even become remotely comparable in terms of overall efficiency vs a manual gearbox. I don't imagine the development of cycle auto transmissons will be any different; it hasn't been so far....

BTW I'd love to be proved wrong on this in the coming years, but I very much doubt I will be....

cheers