The Folding Society

The Dahon Helios SL

By Jacob Kite


For the last 2 years I have been commuting daily by intercity train from the Midlands to London and have been using a 2002 Brompton L3 for this purpose until recently. I have found that the bike can be squeezed into some very tight spaces on the train and the speed and neatness of the fold is absolutely unmatched by any other folding cycles.

I have however, always been slightly unhappy with a couple of features of the Brompton; I find the brakes poor and they need a lot of maintenance in order to keep them usable (i.e. stripping and cleaning of callipers and periodically, cable replacement). What I most dislike about the Brompton is the design of the handlebars. As I understand it, for Brompton it is part of the image to have handlebars this shape but I think they are impractical, and more importantly dangerous. The degree of flex is very high also there is a tendency for the handlebars to rotate forwards in the clamp under pressure (this has happened a couple of times when cycling in the rain and accidentally dropping the front wheel in a pot hole – unavoidable on London’s roads). I can’t help but feel that a conventional straight handlebar would be a lot more rigid and would not suffer from the rotational problem. I have seen, but not tried the handlebar brace that Brompton supplies I assume that this will make the bars stiffer, but adds a mass to the handlebar which I think might increase the risk of rotation. I have also seen photos of Bromptons which have been modified by Steve Parry. He has addressed both issues of the handlebars and the brakes and I am told this makes a substantial improvement.

Another problem that I have found is that I have developed sore knees from riding the Brompton. I think that this is a combination of bad riding posture – mine and the bike’s - and riding in too higher gear, as there is a large gap between the middle and top gear (perhaps an L6 would have been a better choice). I often ride the Brompton for long distances (15 miles or more), which I appreciate is not really what the bike was designed for. The new Bromptons have been improved since I bought my 2002 model, they have made the bike longer and also have added rubber gaiters to the brake cables in order to help prevent water and grit entering them. But as the problem with the handlebars still exists I decided to disregard the L6 in my search for a worthy replacement.

Looking at the options

Here are some of my views on some of the options available:


My next stop was to look at the Birdy by Reise and Muller. My opinion of these bikes is that they offer a better quality, full suspension ride and are reasonably light. In terms of folding this was second only to Brompton, the folded package is not as small or quite as tidy but it’s still one of the most compact folders available. However the fact that these bikes are so obscure (having an 18” wheels), and there are very few UK dealers left me worried about availability of spare parts. The bikes themselves are very expensive which I don’t think is justifiable given their components.


My next step was to look at the Specialized Globe Mity. For those of you that don’t know (I didn’t at the time!!!) this is a reworked Dahon Roo – a model not available in this country. A brief summary of this bike as follows:

I visited Cycle Surgery in London where the staff were very helpful and allowed me to take one of these for a test ride. I found this bike to be very comfortable and rode exceptionally well; the handling was very sure footed, predictable and unlike most small wheeled bikes not at all twitchy. The seat post suspension worked well, the riding position is also very adjustable (the handlebars can be raised or lowered on a quick release system) and the seat post is very long to allow for tall and short riders alike. It has a conventional seat allowing for the usual adjustments and could be replaced with one of your choice.

Folding the bike is quite easy: The handlebars fold down in the same way as a Brompton or Birdy, the seat post slides down, the frame folds in half and there are two magnets which secure the folded package. In terms of portability this bike is a bit lighter than my Brompton but more bulky and has more protrusions, it is also quite large. The carry bag is very good quality, it’s very strong and has a padded insert to protect you from the bike while wearing it over the shoulder. The down side is that it is a bit awkward to get the bike in the bag with the zip being at the bottom, so you have to drop it over the bike and then lie the bike on its side to close the bag – not ideal on a busy train platform but does offer superior protection to a drop over slip cover. Another small inconvenience is that the telescopic handlebars need to be raised to the upper position in order to be folded. The quick release clamp means that the handlebars can rotate left to right whilst being adjusted so attention must be paid that they are set straight on unfolding. I would also add that the bike is not quite as stable as a Brompton in its folded state and tended to fall over when the train swerved violently, a small point but worthy of note as the derailleur is on the outside of the folded bike and could get hit.

Overall I like this bike, it was well set up and if space was not such a premium would rate it highly for daily use; but unfortunately the folded bike will not fit in the luggage racks on some trains as the seat post is a little too long. This makes the folded size just a little too tall – the post cannot be removed as it acts as a prop to keep the folded bike upright and it cannot but cut down because of the suspension mechanism. Also I found myself missing the fast, responsive handling and acceleration of the Brompton; this is probably due to the Globe’s quite wide 65psi tires. Value for money is good considering a Birdy with Shimano 105 gears will cost nearly double this price. Also, if commuting, a Dahon slip cover will fit this bike - available for £15.


My next stop was Dahon. Dahon make a vast range of different models and after my positive experience with the Specialized, I began to give them serious consideration.

Wanting something performance orientated and not having too tight a budget I began to look at the more premium models in their range. Although the folded dimensions of the 20”wheeled models were the same as the Specialized, some of them do not have a suspension seat post which would allow me to saw the bottom off the post provided that I move the minimum insertion accordingly – I’m 6' tall and there is still a couple of spare inches in the post at my ride height, I have discussed this with Mark Bickerton at Cyclemotion (UK distributor of Dahon) who confirmed that this is possible.

The models I test rode were the Speed Pro £750 and the Helios P8 at £499.99. The shop I visited was part of a large chain of cycle shops in London. Two points I feel it is important to make are: I suspect that the bikes had been unpacked and put straight out on the showroom floor without being set up properly. Also the staff while having a very positive attitude and endeavouring to help had very little knowledge of the products.

Helios P8

At 10.7 kilos this alloy framed bike is about the same weight as the Specialized and offers the same folded dimensions, but with a non suspended seat post.


My impression of this bike is that it is a middle of the range model. The frame is rigid but is marred by the fact that the seat post seemed to be a little too flexible, and the gears were not the smoothest I have encountered but had a good range. The brakes were good and the Schwalbe Marathons are good hard wearing tires - I have them fitted on my Brompton, so no complaints there. Folding follows exactly the same procedure as the specialized. Overall I’d say this bike has a nice frame that outclasses its components, which is no doubt due to keeping the price down. Handling was similar to the Specialized and the frame is more ridged being triangulated, but given the choice I’d find the extra £150 and get the Specialized because of better componentry. Please bear in mind the fact that my opinion may be coloured by the test bike not being set up properly by the shop.

Speed Pro

This is more of a premium bike and at 10.9 Kilos is marginally heavier than the Helios P8. Here’s the list:

Dahon markets this bike as more of a sports bike, which appealed to me more than the Helios P8 commuter. The steel frame was quite rigid but with a little spring in it as you’d expect, the aluminium seat post is ultra ridged and fitted with a racing seat. A point to note is that there is a special system for fitting the seat to the post so changing the saddle is not an option. Handling is good and the tires give a livelier faster ride. The SRAM Dual Drive system comprises of a three speed hub gear combined with a 7 speed derailleur which means you can change gear while stationary. The hub gear is operated by a lever and the derailleur by a grip shifter, both are on the right hand of the handlebars I found these gears to operate well and have a very broad range of 28” to 118”. I did not think that the suspension hub in the front wheel did a great deal but I’d obviously need to test it a lot more to get a true idea. However something which does concern me about the hub is that when the suspension is at maximum compression the brake blocks are no longer on the rim braking surface – this was pointed out to me by Mark Bickerton at Cyclemotion. There is a handlebar extension on this bike in order to give it a more forwards reaching riding position. I didn’t feel this was necessary for me and it would have added a substantial amount of time to the folding as it requires the use of an Allen key in order to rotate it. The bar ends are comfortable but I wouldn’t use them as I don’t like to get too far from my brake levers on London’s roads.

Overall this bike is fast and looks the part thanks to the front wheel’s paired spokes and the fetching “Mango” paint job however the compromises on foldability, safety concerns regarding the suspension hub and the fact that I felt that I wouldn’t have a use for all those gears to justify the extra weight and maintenance. In all fairness I think this bike is not really designed for the type of commuting I do and would be better suited to taking on holiday for long rides.

What next?

What if you could cross the best elements from these bikes…

Featured on the Dahon website there is a model called the Helios SL which has the Helios triangulated frame combined with premium light weight components, but trying to find one of these I these in the UK proved rather difficult. I ended up ringing Cyclemotion the UK distributor for Dahon and speaking to Mark Bickerton with whom I had an in depth conversation with about the various models. I felt that he was very knowledgeable about his products, he listened to my concerns and was honest with me (after all it was he who first drew my attention to the potential problems of the Pantour hub). The first shipments of this model were due in early June and they would be available to purchase mail order from Cyclemotion directly. He did stress that it would be preferable for me to order this bike through a shop rather than directly from his company as warranty servicing and initial set up could be carried out by the shop. However Fisher Outdoor Leisure who supply the shops do not supply this model and after a couple of failed attempts at trying to get cycle shops to order this bike for me I gave up. So I had a good hard think about whether or not I really wanted this bike as I would not have the opportunity to try before purchase.

While looking at eBay one day I noticed a German shop called Radel Max who were offering some of Dahon’s more modest models substantially cheaper than UK prices. Being curious I followed a link on one of their adverts to their website. Although the whole site was in German I saw the Helios SL advertised in their range, I decided to email them and enquire about price and availability of the bike. I received a very prompt reply saying that they would look in to the matter for me and would get back to me. Within 2 hours I received an email saying that the bike was available and would cost me €909 (£607).

Shipping would cost another £19, with a surcharge on the whole transaction of £15 as I wanted to pay by credit card so the shop had arranged for me to pay using PayPal (eBay’s online payments system). The total price delivered to my door would be £641 versus £800 in the UK - I put this to Cycle Motion but they stuck to their guns and would not budge on their price. I was soon sat at my PC, credit card in hand, this was Thursday and on the following Wednesday I was unpacking my new bike. I cannot fault the level of service and communication received from the Radel Max and the speed of their email responses is fantastic.

Dahon Helios SL - first impressions

These are my first impressions of the bike after owning it for only two days.

First of all SL stands for super light – 8.4 Kilos to be precise. This bike really looks the part thanks to the black frame and Rolf paired spoke wheels.

Here are the specs:

I believe that the frame on this bike is the same as The Helios P8 model, but with alloy forks instead of steel. Folding wise this bike is the usual Dahon affair – the fame folds in half and the handlebars fold down, the chain and the derailleur are on the outside of the folded package. The bike is kept folded by means of a Velcro strap, rather than the magnets featured on some of Dahon’s other models. One thing that sets this bike apart from others in the Dahon range in terms of folding is that rather than having plastic folding pedals, this bike has metal quick release detachable versions made by MKS. These work very simply are of high quality, and when removed result in a slimmer folded bike than those with the folding versions. They also come with a small drawstring carry bag. I have fitted toe clips to mine so unfortunately I can’t use their little bag any more.

Riding the bike is about as close to a racer as I can imagine a 20” wheeled folding bike with straight bars could feel. This bike is very rigid and offers a fast ride with responsive handling, climbing hills is effortless and the aerodynamic wheels just glide along on the flat. Riding over bumps is unforgiving and I definitely would not attempt to ride this bike off road. The SDG saddle is a small narrow racer type affair – it’s hard but not uncomfortable. Gearing is in the form of an Sram 8 speed derailleur with a range of 32.5” to 94.5”. There’s a grip shift to operate the gears, which works very smoothly but produces a loud click when changing.

The grips are made from a snazzy looking stripy foam which are comfortable but I would question their durability – time will tell. The carbon fibre handle bar reduces some of the road vibration in the wrists, but for long distance I’d recommend some padded cycling gloves. There is a lot of room for adjustment in the riding position as the height of the seat and handlebars has a large range of movement. There is also a lot of scope for seat adjustment, though it is not possible to change the saddle as the SDG ‘I-Flex’ does not have a conventional fitting. Dahon employs this system on several other bikes, including the Presto Light, Speed Pro and forthcoming Jetstream XP models. The fitted tires are Schwalbe Stelvios, they handle nicely and have minimal rolling resistance, however they are slicks and I have yet to find out how grippy they are in the wet. The brakes are Dahon’s own V brakes – these work very well and are progressive, they have good stopping ability but it is also possible to apply them lightly without any ‘snatching’ on the wheel rim. The frame does have the mounts for fitting mud guards, a rear rack and even a kick stand if wanted.

A comparison to the Brompton would not be strictly fair as I’m sure the two bikes will appeal to different types of rider. Unfolded one could only expect the larger wheeled bike to perform better and I would say it is, in every respect. Brompton has its strength in folding (it takes me less than 15 seconds) and the resultant package is neater and smaller. The Dahon is easier to carry as it is more than 3 kilos lighter than my L3, and with practice I hope to get folding time down to 20-25 seconds. The UK list price of this bike is £800 which I think is reasonable for a machine of this sophistication when compared to other folding bikes.

Editor's Footnote

Folder enthusiasts take the choice of a new machine very seriously, as this detailed report shows. 

A couple of comments on Jacob's observations on the Brompton. Personally I have not had the problem with the handlebar twisting in the way described above, except once after I had adjusted the position a little and had not tightened the clamp bolt enough - it seems to need to VERY tight. I don't think the shape of the Brompton bars has anything to do with style - it is done so that there is some resilience to compensate for the small wheels and lack of front suspension. An early (1990) Brompton I have does have some flex in the bars and stem, but the later model I had for some time (about the same vintage as Jacob's) seemed to me pretty rigid. While the riding position is not quite to my taste, I have never found it uncomfortable, and I doubt that it was the cause of the knee problems mentioned. A far more likely culprit in that respect is the gearing, as described. I avoid 3-speed hubs for this reason - the 6 -speed Bromptons overcome the problem with intermediate gears achieved by using the rear double sprockets, though at the expense of less convenient gear change operation using two levers.

The comments on the Pantour hub used on a few of the Dahon models were interesting. I was a bit dubious about the effectiveness of the system, and potential problems with mudguards had already occurred to me, but the potential problem with brakes seems a more issue, and I guess, thinking about it more, it will also make it difficult to use a computer at the front too. I'm still hoping to get the opportunity to test the Jetstream XP, which has one of these hubs, at some point, so I may be able to add further comments then.

Many thanks to Jacob for his report.

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Copyright (C)2004 Jacob Kite
Last updated: 20 June 2004