The Folding Society

The SP - the first 120 miles with a new Brompton-based folder

To keep the size of this page down, and reduce the transfer time, the photographs are on a separate page. For illustrations, see our SP photo report.


I have deliberately refrained from rushing to report on my new SP, as some pictures and reports on the prototype have already appeared in FSN and on the web pages; I wanted to wait until I had more to report, rather than merely repeat information that was already available. Although 120 miles is not really enough for an in-depth review of a bike, it does give a much better impression than a quick test ride of a mile or so, and during the two weeks that I have had the bike it has been used in a variety of different conditions.

For those of you who don’t already know, or have forgotten, I had better start by explaining that the SP is a folder based on the Brompton, with quite extensive modifications carried out by Steve Parry. The first 3 or 4 of these bikes were produced by Steve from modified complete Bromptons, and thus were referred to as Brompton –SPs. In future Steve will be building the bikes from scratch using major frame components supplied direct by Brompton, and they will therefore be known as SPs. My bike is actually a modified Brompton rather than a true SP. It seems that at present there are quite a lot of differences between each of the SP/Brompton-SPs being built, partly as a result of on-going development but also because the bikes are tailored to the requirements of individual owners; mine seems to be fairly typical of the planned future production models in most major respects.

A standard Brompton is an excellent bike for getting from A to B, especially when used in conjunction with other means of transport such as trains, but despite its ability to successfully undertake longer rides, it does lack something for those who ride for the pleasure of cycling. It is an important feature of the modifications incorporated in the SP that the resultant bike should retain the many virtues of the standard Brompton, but that the improvements should make the bike more appealing to the enthusiastic owner who wants something that is perhaps more suited to longer rides, and which is more exciting to ride.

In summarising the features of the bike here, and commenting on its performance, it’s important to recognise that the basic Brompton design does what it was intended for brilliantly; it is the fact that the Brompton performs so well at what it was intended for that owners are tempted to extend its use, and thus start wanting things such as more gears and more powerful brakes. These of course come at a price, and although standard Bromptons are not cheap, the standard specification is influenced by the need to keep the price down. One of the main reasons why Brompton and other cycle manufacturers do not fit as standard items which enthusiastic and knowledgeable owners would like added is that this would increase the price, and unfortunately the majority of prospective buyers are obsessed by price and ignore value and cost of ownership. We should also say that in commenting on the SP, some of the minor criticisms we may mention are imposed by building the bike from the standard Brompton frame parts and retaining all the good points of the Brompton, while minimising the use anything that is not a standard cycle component.

Steve's modifications are intended to make the Brompton perform better overall, and to make it even more suitable for enthusiastic use under a wide variety of conditions. The bikes are produced individually by hand, and Steve is deliberately using some of the higher end specification components to ensure good performance - there is little point in having a customised hand-built machine fitted with low price, low specification components. This inevitably means that the SP is not cheap if you simply look at the price, but if you look at quality, performance, life etc, it still represents good value. As the bikes which have been produced so far are all modified Bromptons rather than SPs built from scratch, we don't have a price for the final bike at present - the fact that they are built to owner's requirements means that prices are likely to vary anyway.

We’ll start with a brief summary of the main features of the SP which differ from the standard Brompton.


The first prototype SP, and one Brompton modified for an owner (Peter King), were fitted with the Shimano Nexus 7-speed hub, but this is relatively heavy and needed careful adjustment for reliable gear selection - something which folding the bike, and thus moving and bending the cables, tended to upset. Steve therefore changed course and switched to a 7-speed derailleur, which he managed with some difficulty to shoehorn into the existing rear triangle. The sprocket set used is an 11-28, which gives a good range, with a very smooth progression in the ratios. The range is a little wider than on a 5-speed Sturmey-Archer hub as fitted to standard Bromptons, roughly equivalent to one extra gear, but with none of the uncomfortable large steps (notably from the middle gear to the next one up) which the hub suffers. With a reasonably clean transmission, efficiency should also be higher than with the hub, which at least on my elderly T5 (with an old two-cable Sturmey-Archer 5-speed) feels exceptionally inefficient in the lowest gear in particular.

Of course with a derailleur you cannot change gear when the bike is stationary, which is a drawback which derailleur users get used to. Squeezing the 7-speed derailleur into the standard rear triangle also leaves the rear mechanism extremely close to the tyre in bottom gear – there is no way of avoiding this, so one just notes that this is the case. To avoid the chain coming adrift when folding the bike, Steve recommends putting the bike into one of the three lowest gears before folding. While this is a slight inconvenience, the fact that with a derailleur you need to engage a lower gear when stopping to be able to start off again comfortably (as you cannot change gear when stationary), means that this is not much of a hardship, and the fact that any one of the 3 lowest gears will do makes it easier. It is also a good deal more convenient than some other derailleur geared folders which have to be put into top gear when folding – only one gear, and the least suitable when it comes to riding off after unfolding.

With such small wheels, even the standard Brompton 50 tooth chainring gives gears ranging from about 27 inches to 76 inches – quite low. This favours a fast twirling style of pedalling, rather than slogging along in high gear at a low cadence. I favour a higher cadence pedalling style, and it is probably better for the knees too, but if you want to pull much higher gears you will have a problem with this gearing system, even with quite large chainwheels. Dave Holladay and others will not like this!

Gears are changed using a standard twist grip, which works very smoothly and positively, and also leaves the handlebars uncluttered. In carrying out his modifications Steve favours using good quality components, and the rear mechanism is a Shimano XT, which as one would expect is smooth and trouble free.


Bosses for V-brakes are brazed on to the front and rear forks, and Steve again opts for high quality components, fitting Shimano XT V-brakes, with a ‘booster’ to stiffen the rear forks. In my case a carbon fibre booster was used, and I believe this will be the standard equipment, though Peter Henshaw opted for a metal booster on his SP. The levers on the bars are also Shimano XT. The brakes are extremely powerful and quite progressive, though I do find it rather easy to lock the rear wheel when conditions demand a sudden stop.

Tyres, wheels and hubs

Primo tyres are fitted instead of the standard Raleigh Records, and as has been explained many times in the past, these are the single biggest performance improvement for a Brompton. They give much reduced rolling resistance and a more responsive ride. The ride seems, subjectively, a little harsher due to the higher pressures, and the relatively smooth tyres are not as suited to muddy off-road riding - but then few Brompton/SP owners would use this bike extensively in such conditions anyway. The Primos seem no more prone to punctures than the Records in normal conditions, but can get rather badly cut by glass, and the very thin side walls, which contribute to the good riding characteristics, are rather fragile. Life of the Primos, while adequate, is not as good as the records, but individual users get very different mileages out of tyres.

A split hub is being used to fit into the narrow space available, although mine does not have this. There is some choice on the number of spokes used, but although I am light (under 9 stone) I opted for the full 36-spokes in the rear wheel - at least one owner has chosen 24 spokes instead. Steve fits grease nipples to the hubs, so that an occasional injection of grease can be applied easily. I certainly prefer this approach to the current construction of hubs which means that to lubricate hubs it is necessary to dismantle them - this saves money in manufacture, and thus keeps the price down, but causes more work for owners later.

Handlebars and suspension stem

The normal riser is cut off just before the point at which there is a forward bend, and a shim is inserted so that a suspension seatpost (Post Moderne) can be fitted. The post is set up with light springing, as it is going to take much less weight than would be the case when it is used for its intended purpose. The post is mounted so that what on the seatpost would be a small rearward extension becomes a small forward extension, which means that there is no interference with folding. Conventional good quality straight bars are fitted, with short bar end extensions. The bars and bar ends are normally taped, but I opted for hard foam rubber instead, which I find more comfortable, and this also leaves the end of the normal bars accessible for mounting one of the mirrors which plug into the handlebar end.

Although the post can be raised and lowered, its length means that at its lowest height the bars are only very slightly lower than standard Brompton bars, which is a disappointment for shorter riders, though still better than the standard system.

The modified stem is much more rigid than the standard Brompton system, and the suspension gives a more comfortable ride.

Rear suspension and seat post

Steve has used a stainless steel jubilee clip around the rubber suspension block to stiffen it. Many riders seem to prefer the results, but at under 9 stone I find it makes the ride noticeably harsher, and the standard block performs well under my weight. I have therefore removed the jubilee clip.

A grease nipple is fitted to the rear suspension bearing. Not only does this mean that it can be lubricated properly, avoiding possible problems, but if the pivot needs replacing in the future it can be done much more easily - at present this is a factory job, or can only be done by dealers who have the necessary special tools. When the nipple is fitted, the job can be done by removing the nipple and locking the shaft, so that the allen bolts at either end can then be released.

There is also a small catch bolted to the end of the block which latches onto the seat post bolt, which means that when the bike is lifted in unfolded form, the rear wheel does not flop down. This makes carrying the bike up and down steps, or over a kerb, far more convenient, and also makes it easier to manoeuvre the bike in a confined space - when bringing it into a building, for example. The catch is released by simply bending the rubber suspension block up slightly, so the effect on speed and ease of folding is minimal. The one awkward feature I have found is that when the bike is unfolded, the catch needs to be manually engaged, otherwise it rests against the seat pillar bolt, and when the rider mounts the bike it is forced up with a loud click, and in the process is bent so that it will not longer engage properly. After this had happened twice, and I had bent the clip back to shape, I filed it down slightly so that, although it does not usually engage of its own accord, when it clicks into place it no longer gets bent. One should of course remember to engage it manually rather than let it get forced into place, but it is very easy to forget.

A carbon fibre seat post is fitted as standard, this being cut down at the time of delivery to suit the rider, and a rivet being fitted to make the height setting simpler - just pull the post up as high as it will go when unfolding (of course if the bike is used by more than one person, and they have different leg lengths, only the taller can be accommodated by this trick). Steve is normally inserting an alloy tube inside the carbon fibre seat post to reduce flexing, but for short, light rides such as myself this is unnecessary.

Other features

In building up the bikes, Steve makes many relatively minor modifications which all serve to improve the bike. Examples include the replacement of bolts with stainless steel socket headed bolts, rounding off of rough edges on dropouts etc to improve paint adhesion (and reduce weight!) and painting of rear mudguard stays to reduce corrosion. The headset bearing on my bike was also replaced with a lighter and better quality item.

Regular readers will know that Steve has produced a small bracket to fit onto the Brompton luggage mounting block, which can be used to mount a small bar bag in place of the standard Brompton bag, which is larger than is sometimes necessary. Steve has also turned his attention to the back of the bike, and has produced a neat, small rack, onto which a quick release bracket attaches. This bracket carries another Brompton front mounting block, so that another Brompton front bag can be fitted at the rear - or of course a smaller bag using Steve's bracket. The quick release bracket of course needs to be removed when folding the bike, or parking on the rear rack, but this is easily achieved, and makes carrying luggage on the back a more practical proposition than with the standard Brompton rear carrier. The bike still stands reasonably securely on the new rear rack, though it is not quite as stable as the Brompton version. The new rear rack also lacks the front and rear wheels of the Brompton equivalent - I have never found these very useful, since they are too small to roll the bike on, and the front ones are too easily knocked, very painfully, with the ankles when riding. Since the Brompton folds so easily and quickly, it is best to roll it on its road wheels, and fold it at the last moment, then picking it up when necessary.

On the road

The first impression of riding the bike is that it is light, responsive and comfortable. The Primo tyres obviously contribute to this, but the overall weight of the bike is around two pounds lighter than an equivalent standard Brompton - exact weight depends very much on how the owner sets the bike up, but the figure of 2 pounds relates to my SP and my old T5, the latter already having Primos, carbon fibre seat post and a light saddle. The bike feels very free running, which must be in part due to the hubs and not just the Primos tyres, as my other Brompton already has Primos.

The new handlebar stem feels far more rigid than the standard Brompton one, where the unusual curved handlebar design is the way it is in order to provide some insulation from the road. The SP system, with the suspension seatpost to provide protection from vibration, can be much stiffer. The net result is that there is a significant improvement in comfort as a result of the springing, while the bars do not flex noticeably in normal riding, which I find they do on a standard Brompton, particularly if bar end extensions are used.

The ride is good under all road conditions, and bumps, potholes etc are handled well, and with less discomfort than on the standard Brompton. The only road surface which the suspension stem did not handle particularly well was a damaged coarse top dressing - but it was no worse on this than any other bike I have tried, including full suspension models.

The brakes are very powerful and inspire confidence, though if braking in an emergency one needs to take account of the fact that the rear wheel can now be locked relatively easily.

The gear range is good overall, and the spacing is very good, with none of the knee breaking large gaps of the hub system. With the standard 50 tooth chainwheel the overall gearing is a little on the low side for my taste - I like the 27 inch bottom gear, but 76 inches for the top gear is a bit on the low side. A range of about 30 to 80 would suit me better, which will mean a 54 tooth chainwheel. Those who like to ride in very high gears at a low cadence might want something higher still, and of course larger chainwheels are not easy to come by. The gear change is very smooth and precise, and although I am not a great fan of twist grips, this one works well and leaves the handlebars looking very uncluttered.

During the relatively short distance covered so far, there have been no problems with the bike, and I have been very pleased with its performance. I don't do much off road riding, apart from occasional short stretches of canal towpath, and so far I have only used the SP on roads. Bromptons generally handle dry towpaths and the like surprisingly well, provided there are no really deep ruts, and I would expect the SP to behave similarly, but with better insulation via the suspension stem, but the fairly small ground clearance of the derailleur mechanism would need to be remembered. No doubt in due course I will be able to report on real experience of using the bike in these conditions.


The only effect on the folding of the bike compared with a standard Brompton is the need to be in one of the bottom 3 gears before folding. I find that this is quite easy to remember - much less trouble than having to remember to put the bike in top gear when stopping, as is the case with some other derailleur geared folders.

The (optional) catch to prevent the rear triangle folding when the bike is lifted is a big advantage when manoeuvring the bike - lifting it over kerbstones, wheeling it in passageways etc - but the need to positively engage it when unfolding the bike is a slight nuisance.


The optional extra rear carrier, with its quick release attachment, is useful if you want to carry more than is easily handled by the Brompton front bag alone, and further enhances the excellent luggage carrying facilities of the Brompton.


In making comparisons with a standard Brompton, I feel I must reiterate what I wrote earlier, namely that the standard Brompton does the job it was designed for brilliantly, and at a reasonable price. The SP, with improved components and specification, and a substantially higher price, certainly should out perform the Brompton in not just its basic use, but also the range of applications for which the bike can be used. In handling, ride, gearing, brakes etc the SP certainly does perform better than a standard Brompton - in fact it is really only in folding, where one of the bottom 3 gears needs to be engaged before folding, where there is a tiny loss of performance in the SP. For those who only do short utility rides, or who use the bike simply to get from A to B, these improvements may well not be important, but for those with an interest in longer rides, and riding for the pleasure of cycling, the improvements are quite significant. Perhaps more important though is whether the changes make the Brompton more suitable for the type of use for which it is not so good in standard form. The freer running, better gearing and brakes, and improved riding position and comfort would certainly make me much more willing to use an SP in situations where in the past I would have preferred not to use a standard Brompton. We all have different capabilities and opinions on what mileage we or others can do in a day, or on a particular bike, so I don't think it is useful to try to put a specific figure on this, but I would say that with an SP I would be happy (not just able) to do around 50% more miles than I would on a standard Brompton. This makes it quite suitable for short to medium day rides, and even perhaps some gentle touring, when the need to fold is also important.

Comparing an SP with a standard Brompton is far less relevant and interesting than comparing it with other folders, such as the Birdy in particular. I have a Birdy, two Bike Fridays and several Moultons, so comparisons are easiest with these. The SP retains the advantages of the Brompton over most over folders - simple, quick folding, which results in a package which is easily carried, and very convenient and extensive luggage capacity. The ride quality and ability to enjoy riding longer distances is greatly enhanced. Compared with a Birdy, the SP folds more conveniently and produces a smaller package which is easier to carry. The weight is very similar too if we include mudguards and carriers. The luggage carrying capabilities of the SP are vastly superior to the Birdy. Gearing is very similar to a Birdy Red, and the brakes are at least as good. Ride quality and riding position are not quite as good as on the fully suspended Birdy, but the difference is quite small. I would expect the Birdy to handle off-road riding better than the SP, based on my experience of the Birdy and a standard Brompton. As I don't have a price for an SP, as opposed to a modified Brompton SP, it is difficult to compare the bikes in this respect, but it seems likely that the SP will be more expensive than a Birdy red, and probably near the price of the Birdy Blue. Based on 1500 miles on a Birdy Red, several thousand on a standard Brompton, and this fairly short experience of the SP, I would choose the SP over the Birdy every time for my purposes. The few areas in which the Birdy does perform better represent either only quite small improvements, or are situations in which neither bike is the best for the job.

Compared with something like a Bike Friday, the Fridays do not fold anything like as conveniently as a Brompton or SP, and the resultant package is difficult to carry and store. I would still prefer them for long fast rides where no folding is required, but whereas I would definitely prefer not to undertake such rides on a Brompton, I would not mind having to do so on the SP.


For the owner who uses a bicycle not just for getting from A to B, but also for the pleasure of riding, the changes incorporated in the SP make it even more attractive than the standard Brompton. In the past some potential or actual Brompton owners have bought other machines, such as the Birdy, to meet their needs for more enjoyment on longer rides, but now the SP allows them to retain the many advantages of the Brompton while giving more riding pleasure.

I have sometimes been asked in the past which bike I would keep if I could only have one (I currently have 12 bikes, 9 of which fold or separate). The answer has been in the past that for my use the most suitable single folder/separable would be the Bike Friday New World Tourist, as I enjoy riding, and on average I do not have to fold the bike more than 2 or 3 times a month. Much as I like the SP, the Newt is probably the bike I would retain if I could only have one. However, whereas in the past I would really have felt that the Brompton was ruled out in this role, the SP is a very strong contender, and if I were assigned an SP as an only bike, rather than being given a choice, I would be very happy with it. And if my cycle usage required folding 2 or 3 times a week on a regular basis, then the SP would become the bike I would choose if only one were permitted.

I hope to do some more tests in the near future on the folders using different tyres and some other modifications, so you may care to look again at this report in a few days or weeks time.

Second opinion - by John Pinkerton

At the July Origami Phoenix Ride, the rare, and well used, AM ATB I had been planning to use stripped a thread in the handle-bar stem wedge. The combined knowledge of half a dozen experienced cyclists come engineers was unable to think of a simple roadside repair. Out of the blue the rider of a new Brompton SP insisted that, as leader of the ride, I should borrow it, and he would walk and train it home (involving a 4 mile walk). There was no point in refusing - he had made his mind up, and l did not want to miss the opportunity. I had heard about the various mods. that Steve Parry had applied to Bromptons and other portables. This particular one had :- 7 speed deraillieur gears with twistgrip gear change, a suspension seat post converted to form the handlebar stem, flat handlebars with bar-ends, V-brakes that would stop you on the proverbial sixpence, if you had the guts to use them in anger, carbon fibre seat post, titanium framed saddle, Primo tyres, and a minimal rear rack for parking. As a Brompton owner and natural fan, I knew that I was in for a good ride. But the SP even suprised me. It felt even more like a conventional bicycle than ever, and was effortless to ride - well almost, but the hills did seem flatter. The seven speed gear, although a low close ratio 27 to 76 (I think), worked perfectly, and changed in both directions without the slightest hiccup. I did find that the twist grip was the slightest bit uncomfortable, but with the bar ends to change to this comment is really only nit-picking. I had expected the narrow saddle to be uncomfortable, but was wrong, although the following day there were a couple of tender spots. The brakes were quite stunning and did catch me out once when I was riding one-handed and looking round, but that was my fault, not the brakes. The simple but effective parking catch, which stopped the back wheel disappearing under the machine if you momentarily forgot you were lifting a Brompton, was easy to disengage when folding.

The Brompton has been on the market now for almost TWENTY years, and as Mike Hessey has said, unless the manufacturers introduce some improvements it will turn into a Morris Minor (if I am allowed to mention motors in these columns), which was a practical small car but outdated by the Mini and other small cars. Perhaps now that Brompton are re-housed, with room to expand, they will introduce some modifications, or at least offer them as optional extras. Having said that, Henry Ford held most of the world car market with his 'any colour providing it is black' policy. {But as with the Morris Minor when the model T did become outdated, its manufacturers had enormous difficulty producing an effective successor - MFH].

The Brompton, SP or not, is still one of the best All-Rounders I have in my collection.

{Origami}This photograph was taken before the start of the July Origami ride, and the unfortunate mishap to the AM-ATB. The SP Brompton is more or less in the centre of the picture, by the window of the tearooms. At this stage I was expecting to have more opportunities to take some better pictures of the SP!

Full Photo report

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Last updated: 15 August 1999