Cycling UK Forum

Mudguards?

If you try to unstick the stem by holding it in a vice and twisting the forks (or vice versa) it might work but you're just as likely to finish up with bent/out of track forks and still have a stuck stem. If Plusgas/WD40 doesn't work then the best way is to ask your LBS to apply a blowtorch (GENTLY!) which should result in freeing the parts. Unfortunately the frame will then require a respray Only other way I can think of is to butcher the stem so you can get inside it to cut through the vertical metal, then cold-chisel it out. Very fiddly and messy and still not guaranteed to work.

As for the gears - the reason the new chain is jumping on your old 6-block is because the sprockets are worn and the chain isn't. Ditto possibly the same with your 7-block. How many miles do you consider 'not many'? Anything more than about 3,000 with the same chain, even less if ridden in wet/dirty conditions and not cleaned regularly, and at least one of the sprockets will be worn enough to jump with a new chain. Of course there's always the possibility that the chainwheels are also well worn and are causing the skipping, but that should be obvious by just looking at how the chain sits on the teeth. If the chainring teeth are hooked and you can pull the chain away from the teeth so that you can see the tips of the teeth - you need new rings as well.

Sorry, not good news, but it does give you somewhere to start looking for causes and solutions.

rogerzilla wrote:Velox 10mm is way better than the stupid factory blue stuff, which just doesn't fit the rim at all. If I were in charge at Brompton it would be on my list of about 10 things that really need to be fixed with the product to make it truly excellent:

1. The paint is appalling - mine looks as if it's been in the sea after a year despite never being ridden in the rain;
2. The wheelbuild is very poor, with slack spokes (although according to the local dealer they do get the odd good one, so it's variable). I pulled them apart and rebuilt them the day after buying the bike;
3. The rim tape doesn't fit the rim;
4. The rear rollers catch your heels or calves (I have the scars) if your feet are big enough and/or you have the saddle set back a bit;
5. The head tube has no reinforcing rings top and bottom, which any lugless frame should have. Our older L3 has a very loose lower cup as a result;
6. The swaged crankset is nasty and can shear if you "give it some" away from the lights - I have seen the photos;
7. The folding pedal bearing lasts about 500 miles and it can't be replaced* although a new SKF 62032 bearing is only three quid;
8. The grips are absolutely horrid;
9. The rear hinge is a bizarre piece of steampunk engineering (plain bronze bushings reamed in situ with an Imperial tool costing over £100) and costs £45 or so to get sorted out when it goes sloppy. Why not use replaceable needle bearing cartridges?
10. How hard would it be to put two bottle bosses on the back of the stem?

On the other hand, I do love the little thing because it's fun to ride, goes anywhere, has brilliant brakes and makes women swoon. Almost.

*unless you do a bit of metalwork, like I did.

FWIW, I know someone who works for Brompton. He has asked me to post the following response to the above comments on the Company's behalf, which I happily do so with no further comment or intention to create or get involved with any ongoing argument. Brompton do seem to be addressing most of the issues raised already, and the last sentence says it all :

If you would be so kind please assure the contributors to this thread that whilst the comment about non-lugged frames requiring reinforcing rings is completely incorrect, everything else that has been mentioned is in hand, or being looked at in detail already.

Incidentally, we will not be using cartridge roller bearings in the rear hinge, because they are absolutely not the right solution for the task and they are also much heavier. Dave Turner of Turner mountain bikes has a thing or two to say about using cartridge bearings in oscillating pivot locations. A change in this area is coming however and in the mean time, we do loan the special reamer to shops if they request it.

If the poster thinks they have a legitimate warranty claim regarding loose headset cups, they should contact their dealer, since our service policy is second to none.

Are you sure it's Milano and not Milremo? Ron Kitching use the latter as a house brand name for several components in the 60's, the hubs looked very similar to Campag but I think were made by Atom.

As thirdcrank says, Mafac were the Bees Knees in their day, the best stoppers around. Genuine blocks are definitely OK with alloy rims - at least when new, I don't know how old yours are but the material could be very hard by now. Still probably no problem with the rims, but the stopping distance might increase. In any case, even Mafac's bear no comparison with modern dual pivots and braking materials, it was as much a revelation when I changed over to modern calipers as when I went from old Weinmann sidepulls to Mafacs. Beware of Fibrax replacements, IMHO they either wore away very quickly or carved the rim up in not much longer time!

Try making it up a bit weaker, see if that helps.

Titan used to put a globe on their bars - but from memory the name 'M.Kint' (Marcel Kint) was usually engraved on the equator line. In the 50's they made steel and alloy bars badged with the names of several Belgian/Dutch Pro riders such as Maes, Schotte and Van Steenbergen.

531colin wrote:With the saddle at a proper riding height I can get a toe down well enough to hold myself up, but tandems are more of a challenge. Its not just the extra weight, its the fact your foot can go in a dip due to the huge wheelbase!
The mountain bike is noticeably higher than the other bikes, and can catch me out if I havnt ridden it for a bit. Not ended up in a heap yet !

I think you've made the point clearly, in line with the OP's query. In theory MTB's should have higher ground clearance than road bikes, hence the necessity (rather than preference) to get off the saddle when stopping. In turn, touring bikes might have (though not always) a lower BB than racing bikes, as cornering speed/lean angle is not so important. With mass produced frames these differences may well be not as great as they can be with handbuilt frames and, as I said earlier, using smaller frames and sloping top tubes disguise or eliminate the old problem of standover height. Also modern pedals have platforms closer to the axle, so that changing pedals may require an increase or decrease of saddle height to maintain pedal axle-saddle-top measurement but affecting 'foot down' options. Finally as reohn2 said, some riders may prefer to have the entire foot flat on the ground whereas others may be happy with just a toe.

So I guess we're all correct in our habits, either by preference or by mechanical dictates!

Well, sorry folks, I have to disagree entirely. On all of my bikes I have no problems getting my foot (actually toe) down on the floor whilst still perching on the saddle, and no problem getting my knee down on the corners - even whilst pedalling at times. After several decades of racing and touring on bikes, trikes, tandems and tandem trikes, I'm pretty damn sure my position is spot on, in fact others ask my advice on their position. Yes I prefer to put my foot down on a kerb or verge, and if none is available I have been known to get off the saddle so I can put my entire foot flat on the floor, but if it's a short stop at the lights, or an emergency foot/toe down in traffic, I can still stay on the saddle - it's one action less to contend with, I prefer it that way, and so do most of the folk I ride with.

EdinburghFixed wrote:This came up recently on another topic, and I was mystified to discover that there are any keen cyclists who try to stay in the saddle at all (none of my or my better half's bikes allow it).

If your bikes won't allow it then you obviously have either too great a BB height, too great a saddle height, or too big a frame! Setting foot down whilst remaining on the saddle enables you to get off to a quick start with minimal wobble.

For a given crank length, a higher BB means greater ground clearance but further to reach floor when stopping at traffic lights etc - with distinct possibility of toppling over if staying in the saddle and kerb not in reach!Racing frames also tended to have higher BB's than touring frames so as to avoid hitting pedals on ground when cornering. Maybe with modern sloping top tubes and generally smaller frame sizes it's easier to get off the saddle when you stop, without coming into contact with the top tube (ouch!)

Luddite, what's the frame number? The last two digits are normally the year of manufacture, the digits before that represent the number of the frame built in that year. If you need any more info then Grant at merciancycles@gmail.com should be able to help you.

aek wrote:So probably 3 bikes for me would be justified.

Welcome to the slippery slope

sarahm wrote:Thank you Thirdcrank, I will stick with what I've got at the moment, as I said before I think I'm just being a tad impatient.

All the best things take time to achieve! You'll always find someone who's fitter/stronger/faster than you, but in no time at all you'll be riding more efficiently (and faster) yourself and wondering what all the fuss was about

Chainrings and cassette cogs interact to define the distance you will travel for each turn of the pedals. The chain connects the two ends to generate a gearing effect. The larger (more teeth) the chainring and the smaller (less teeth) the cassette sprocket, the further you will travel for each turn - and the harder it will be to get the gear going.

The English define a 'gear' as the equivalent diameter of an old Ordinary bicycle wheel which had a direct drive through the cranks (no chain), whereas the French multiply the gear (diameter) by Pi to give the 'development' or distance travelled by the wheel for each pedal revolution.

Thus for a nominal 27" diameter wheel, a 'gear ratio' e.g. 52x13 gives a 'gear' of 52x27/13 = 108" = 'development' of 339.3", whereas 36x30 gives a 'low gear' of 32.4" = 'development' of 101.8" ; in other words, you will pedal over 3x more in bottom gear to travel the same distance you would go in top gear.

Apologies if this sounds complicated, but you did ask for an explanation - so, what does it all mean?

If you change the cassette and chainrings you will change your gearing but will not affect the basic issue, which is that to go faster you have to either pedal faster in the same gear or have the strength to push a bigger gear. Of course if you were racing you would have to push a big gear fast

My advice would be not to change anything just yet, as you already have a wide range of gears with your existing setup. You should try to increase your pedalling speed (cadence) rather than push a big gear slowly, and try to maintain cadence by changing gear up or down according to the terrain. Most experienced cyclists find their optimum cadence is in the range 85-95 rpm for efficient progress. You should also ensure that all your bearings (hubs, pedals, bracket) run freely, the brakes do not rub on the rims, and the chain and sprockets are not worn because otherwise you will lose efficiency of your pedalling efforts. At the end of the day, your speed depends on the weight and mechanical efficiency of your bike, and the efforts you put in. Changing gears is 'tweak' rather than a solution.

Hope the above helps