Cycling UK Forum

I would caution against an old Dahon Speed TR unless you’ve got a good idea about the condition of what you’re buying. The SRAM Dual Drive hub is out of production and parts are increasingly hard to find. You could always replace the hub with the Sturmey Archer equivalent which removes the sensitive shifter pin protruding from the axle, but it’s still more to go wrong. If you’re willing to sacrifice some of the higher gears, a wide-range MTB cassette with a compatible medium or short arm derailleur is a simple solution that can be easily installed to your average 8-speed folder.

Exhibit A below started life as a flat bar Tern Link D8 with an 8 speed 11-32T block. These days it’s running Microshift Advent with a 9 speed 11-46T block and bar end shifters on dropped bars. The back rack by Blackburn has enough heel clearance for Carradice Super C rear panniers and the luggage truss is happy with a bar bag. It’s happy enough on the hills and I can’t say I’ve had a problem with flex when out of the saddle. I need to be careful packing panniers to avoid too much weight to the rear wagging about, but since that photo ive adjusted the rack mounts to the seat stays to stiffen things up more. And it stop folds down small enough to be taken on the bus…

Carlton green wrote: ↑22 Aug 2023, 6:54pm I’m gathering that trail (plenty of) on the front forks is important.

Thinking about the effect of seat stay length on the saddle’s horizontal position relative to the rear axle suggests the longer the better. I guess that relative seat stay length (long or short) can be estimated by the gap between the seat post and the rear mudguard.

I think it's important to realise the difference between bugs and features. Plenty of trail or none to speak of, or long short/long stay length are differences, one is not necessarily better than the other in an absolute sense, and what's "good" or "bad" on paper can turn out to be irrelevant in the flesh.

Most folders, certainly generic Dahon rebadges and similar, are used by a great many people with no problems at all. I think for most people, most of the time, you just get on and ride. I doubt it's worth sweating the details as long as it'll do the basics of what you want in terms of gearing, luggage space, folded size etc. (Having said that, a pal who tried a couple of things before settling on a Brom found an early Strida "squirmed" when ridden, and that a Creswell Micro was twitchier than anything else he's ever ridden by a country mile.)

Pete.

Winders wrote: ↑24 Aug 2023, 11:46am I would caution against an old Dahon Speed TR unless you’ve got a good idea about the condition of what you’re buying. The SRAM Dual Drive hub is out of production and parts are increasingly hard to find. You could always replace the hub with the Sturmey Archer equivalent which removes the sensitive shifter pin protruding from the axle, but it’s still more to go wrong. If you’re willing to sacrifice some of the higher gears, a wide-range MTB cassette with a compatible medium or short arm derailleur is a simple solution that can be easily installed to your average 8-speed folder.

Exhibit A below started life as a flat bar Tern Link D8 with an 8 speed 11-32T block. These days it’s running Microshift Advent with a 9 speed 11-46T block and bar end shifters on dropped bars. The back rack by Blackburn has enough heel clearance for Carradice Super C rear panniers and the luggage truss is happy with a bar bag. It’s happy enough on the hills and I can’t say I’ve had a problem with flex when out of the saddle. I need to be careful packing panniers to avoid too much weight to the rear wagging about, but since that photo ive adjusted the rack mounts to the seat stays to stiffen things up more. And it stop folds down small enough to be taken on the bus…

The Sachs/Sram Duo drive has indeed been out of production for a number of years but if you look at folding bikes for sale on ebay for example, how many of them have been bought and hardly ridden? I'm in my fourth year of riding a Linear recumbent which has an ancient Sachs 3 X 7 rear hub and it's been used a lot with no issues. That is arguably a better design than the Sram version as it has a toggle chain rather than using a fragile plastic carbuncle of a click box which is just waiting to get bashed. The Sram version is fitted to my HP Velo Spirit which at least is a 21st century machine. I'm reconciled to trying to find the Sturmey version built into a wheel if one of them breaks internally, but for now at least most external spares are still available for the Sram.

I note that the steel Speed tr came with different options for gearing, too, single speed and simple derailleur if an obsolete hub gear introduces too many risks for the second hand purchaser. The tr was just put forward as a suggestion. I have no skin in the game regarding that model, though if I came across one at a reasonable price I might go for it as an experiment. I just like offbeat bikes such as recumbents and folders.

I'm totally in accord with adapting bikes to suit individual needs, though for longer trips I tend to use a recumbent these days unless I need to 100% be certain of getting a bike on a train.

My continued thanks to those who have supported the thread.

Getting a good fit on a folder is important - as it is on any bike - and part of that involves handlebar height. The folding pillar on which the handlebars are mounted is seemingly usually supplied as one size fits all. What’s the commonly recognised name for that pillar, are there replacement compatibility issues and who carries adjustable/alternate length ones in stock?

Winders wrote: ↑24 Aug 2023, 11:46am I would caution against an old Dahon Speed TR unless you’ve got a good idea about the condition of what you’re buying.

Personally speaking, so would I in the end I had to return mine, due to flex in the hinge whilst riding. Whilst bikes like the Cresswell fold it, and brompton stuck with a simple clamp and hinge arrange, the dahon hinge was over complicated and developed enough force to bend the hinge pin.

Carlton green wrote: ↑21 Aug 2023, 7:03am What do people think makes a good 20” wheel folder? Wheel base, tyre width, brakes, saddle, weight and folding style come to mind as likely factors. What models have they experience of, what would they change if buying again and what would they avoid?

My thanks in anticipation of your responses.

I would recommend looking at folding & transporting it folded and baggage carrying, as well as other factors.

First, transporting it folded. My (older) Dahon is ok to move around folded. I leave the handlebars up, and use them as a handle to roll it around on one wheel. It's not the easiest thing to do, but it works. It's heavy enough that I'd rather not bag & carry it, though I have been tempted to work out a Bike Friday type arrangement, either by building it up from a carry-y type trailer or modifying a suitcase. I have bumped the derailleur hanger once (hard enough to require adjustment), so I'm careful about that. The higher end folding bikes are *much* easier to wheel around folded. I wheeled a folded Brompton a few days ago & it was piece of cake compared to my Dahon, and the derailleur was protected in the folded position. If I were looking for a used or low-end folding bike, I think I might go around some shops and evaluate how different bikes wheeled folded.

One advantage with some of the lower end bikes is that because they basically just fold in half, you can fold it with some luggage on. I've worked out a system with my Dahon, where I put a pannier on the side where it doesn't fold, and leave the handlebars up, with a bar bag on. That's enough for an overnight trip, but not more than a couple of days or carrying a computer, or something else extra. With more baggage on, I cannot fold it.

Another area where Brompton seems to me to be quite a bit better than other folding bikes is providing easy luggage attachments that don't interfere with folding. My Dahon has a rack, but it's smaller than standard. I don't know if replacements are available. Some clips are a bit big on it, and larger bags hang a bit too low. Something like Ortleib front rollers might work. My back rollers are too long. I use some older Karrimor ones, but the clips are a bit loose, so I have to be careful that any panniers are well secured with weight &/or the bungie. So that's something else I'd take a look at.

Edit: regarding handlebar height, my Dahon can be adjusted quite a bit. I can't fold them from all positions, but I could just mark the tube with a bit of paint or marker, and put them back each time. I almost never fold them, though. Dahon calls the tube the 'handlepost' and they've had a couple of different systems. Mine has a mounting tube with the handlepost sliding inside it. Newer ones, the handlepost comes in a few different lengths, and further adjustment is done with a longish adjustable stem. If you google for instructions for something like a Dahon 7, you can see an example of this.

Vorpal wrote: ↑25 Aug 2023, 8:53am

Carlton green wrote: ↑21 Aug 2023, 7:03am What do people think makes a good 20” wheel folder? Wheel base, tyre width, brakes, saddle, weight and folding style come to mind as likely factors. What models have they experience of, what would they change if buying again and what would they avoid?

My thanks in anticipation of your responses.

I would recommend …

Thanks for that, some really useful stuff in there. The thread is, thankfully, getting long so I liked that you returned to the original post; thread drift can be good but sometimes responses - however good they are - become barely, if at all, relevant to the original post. Oh course I’m grateful to all that respond to any of my threads but relevance and pulling remarks back toward the original post is particularly appreciated.

Vorpal wrote: ↑25 Aug 2023, 8:53amI would recommend looking at folding & transporting it folded and baggage carrying, as well as other factors.

Medium-distance carrying is the one issue I have with my Bike Friday (New World Tourist).

It's fine for folding up and putting on a train. It goes in a suitcase for long-distance travel too.

But I haven't yet found a comfortable way of carrying it a long way where I can't unfold it - basically, along the platform and around the station at either end of a Eurostar journey. I do have a shoulder bag with straps that's meant for folding bikes (originally made by Dahon, I think) but it's awfully uncomfortable. I'm sure there's a knack with velcro and bits of padding that I'm missing...

Carlton green wrote: ↑25 Aug 2023, 7:55am
Getting a good fit on a folder is important - as it is on any bike - and part of that involves handlebar height. The folding pillar on which the handlebars are mounted is seemingly usually supplied as one size fits all. What’s the commonly recognised name for that pillar, are there replacement compatibility issues and who carries adjustable/alternate length ones in stock?

Up to a point...
Fit is increasingly important the more you get away from a simple upright stance, and your typical folder tends to go for a more upright stance rather than a sporty crouch, and this helps a great deal with the "one size its most" ethos. One of the reasons an oma/opafiets is so popular in NL is that the bolt-upright stance means that as long as you can actually reach the bars to use the controls there aren't really many issues of fit, and IME that's how it goes with fairly upright designs like your typical folder.

Changing the bars themselves is probably going to be easier than changing the mount. For example, to change a Brompton S in to a Brompton P or M it's simply a case of changing the bar style, everything else is the same, including the bit the bars bolt on to.

I've seen some Dahons with a telescoping bar stem, but on the whole the one-size-fits-most geometries work better than I would have guessed before I tried it. There will obviously be designs that suit some better than others, but if you don't need a high spec and are buying second hand you're generally looking for good enough, rather than as perfect as possible.

Pete.

pjclinch wrote: ↑25 Aug 2023, 12:54pm

Carlton green wrote: ↑25 Aug 2023, 7:55am
Getting a good fit on a folder is important - as it is on any bike - and part of that involves handlebar height. The folding pillar on which the handlebars are mounted is seemingly usually supplied as one size fits all. What’s the commonly recognised name for that pillar, are there replacement compatibility issues and who carries adjustable/alternate length ones in stock?

Up to a point...
Fit is increasingly important the more you get away from a simple upright stance, and your typical folder tends to go for a more upright stance rather than a sporty crouch, and this helps a great deal with the "one size its most" ethos. One of the reasons an oma/opafiets is so popular in NL is that the bolt-upright stance means that as long as you can actually reach the bars to use the controls there aren't really many issues of fit, and IME that's how it goes with fairly upright designs like your typical folder.

Changing the bars themselves is probably going to be easier than changing the mount. For example, to change a Brompton S in to a Brompton P or M it's simply a case of changing the bar style, everything else is the same, including the bit the bars bolt on to.

I've seen some Dahons with a telescoping bar stem, but on the whole the one-size-fits-most geometries work better than I would have guessed before I tried it. There will obviously be designs that suit some better than others, but if you don't need a high spec and are buying second hand you're generally looking for good enough, rather than as perfect as possible.

Pete.

Thanks, several good points there which I think could help all that read the thread. One that I particularly note is that if the handlebar pillar is shorter than idea then higher rise handlebars are available. SJS sell them but others might have better searches than me: https://www.sjscycles.co.uk/search/?ter ... 20Brompton .

As an individual I’m not after perfection but am instead seeking in-line with the thread’s tittle (20” Wheel Folders, What Makes a Good One?) and the OP.

Carlton green wrote: ↑25 Aug 2023, 2:02pm
Thanks, several good points there which I think could help all that read the thread. One that I particularly note is that if the handlebar pillar is shorter than idea then higher rise handlebars are available. SJS sell them but others might have better searches than me: https://www.sjscycles.co.uk/search/?ter ... 20Brompton .

As an individual I’m not after perfection but am instead seeking in-line with the thread’s tittle (20” Wheel Folders, What Makes a Good One?) and the OP.

One thing to remember with making changes like that, though, is how they affect foldability. If you don't plan to fold the handlebars, it might not matter, but if you do want to fold them, it will depend very much on how they fold & what handlebars you want. I could not fold my handlebars with the high rise sort, because mine fold at an angle, and go between the folded halves of the bike. Most non-flat handlebar shapes will interfere with this.

Vorpal wrote: ↑25 Aug 2023, 3:07pm

Carlton green wrote: ↑25 Aug 2023, 2:02pm
Thanks, several good points there which I think could help all that read the thread. One that I particularly note is that if the handlebar pillar is shorter than idea then higher rise handlebars are available. SJS sell them but others might have better searches than me: https://www.sjscycles.co.uk/search/?ter ... 20Brompton .

As an individual I’m not after perfection but am instead seeking in-line with the thread’s tittle (20” Wheel Folders, What Makes a Good One?) and the OP.

One thing to remember with making changes like that, though, is how they affect foldability. If you don't plan to fold the handlebars, it might not matter, but if you do want to fold them, it will depend very much on how they fold & what handlebars you want. I could not fold my handlebars with the high rise sort, because mine fold at an angle, and go between the folded halves of the bike. Most non-flat handlebar shapes will interfere with this.

My thanks again for a further excellent point. With every change this is - or rather can be - the chance to make things worse than anticipated, the law of unintended consequences, etc.

pjclinch wrote: ↑25 Aug 2023, 12:54pm to change a Brompton S in to a Brompton P or M it's simply a case of changing the bar style, everything else is the same, including the bit the bars bolt on to.

That is not correct. Each of the three Brompton sizes has a different stem. Fitting M bars on a S stem would result in bars higher than on an off-the-shelf M Brompton, would also require a new set of (longer) cables, and I believe would compromise the fold because when folded the left hand grip will be lower than the wheels. An advantage of Bromptons being so popular and well established, is that there is a lot of information available online about modifications to help people avoid such pitfalls.

CycleChat has a good sub-forum covering folding bikes, and although a lot of the threads are inevitably about Bromptons, there are threads about other folding bikes, e.g. https://www.cyclechat.net/threads/halfo ... ed.293251/.

slowster wrote: ↑25 Aug 2023, 4:04pm CycleChat has a good sub-forum covering folding bikes, and although a lot of the threads are inevitably about Bromptons, there are threads about other folding bikes, e.g. https://www.cyclechat.net/threads/halfo ... ed.293251/.

I found the folding bikes section of www.bikeforums.net a good place for threads about non-Bromptons, and not as USA-centric as much of the rest of that forum.

slowster wrote: ↑25 Aug 2023, 4:04pm

pjclinch wrote: ↑25 Aug 2023, 12:54pm to change a Brompton S in to a Brompton P or M it's simply a case of changing the bar style, everything else is the same, including the bit the bars bolt on to.

That is not correct. Each of the three Brompton sizes has a different stem...

I stand corrected! (thanks, good to know)
Though I imagine it would remain the case that a change of bars would still be easier than the stem, though cables, fold etc. would still be needed taken in to account.

Pete.