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-   -   Looking for a high-speed folding bike (https://www.bikeforums.net/folding-bikes/475511-looking-high-speed-folding-bike.html)

invisiblehand 10-12-08 07:07 PM


Originally Posted by veggie_lover (Post 7648684)
I might be missing something really obvious, but if you are pedaling hard and only going 12 mph then there is something seriously wrong with your fitness and technique. Changing the equipment ain't going to fix the problem. Are you sure your speedometer is calibrated?

Yep ... no doubt about that. Ya got ta spin man!

Tommy C 10-12-08 07:58 PM


Originally Posted by Bacciagalupe (Post 7651573)
I used folding bikes exclusively for about a year, and did several tours, numerous "metric centuries" (60+ miles) and an "imperial" century (100 miles) on folders.

In general, I do not recommend most folders for century rides, but it can definitely be done, and it's OK if you meet a few critical requirements:

• You find the folder to be very comfortable on longer rides.
• The century you're going to do is flat, OR the folder has very wide gearing.
• You're sure your folder is in excellent mechanical shape.
• You don't make any major changes to the bike (or change bikes altogether) shortly before the century.

There are only a few high-end folders/separatables I'd recommend for 100 miles. A well-fitted and properly geared Bike Friday; just about any Moulton; maybe a Pacific Reach. Others can be used but only if you really, really, really aren't bothered by road buzz and don't need a wide gearing range.

I would point out that I do a lot of distance riding and vastly prefer 700c bikes, but that might not fly 'round here... :D

You might be right there, since I had to return my Mu P8 and I am between folders, last night I took the Trek 4300 for a ride, WOW it was so much fun to have a front suspension even a pretty simple one, I don't mind riding on small wheels and more upright riding position but the huge advantage was not thinking about all the creaks and clicks coming from the hinge nor seatpost/ frame but overall I like the idea having a folder but I guess after all they are not reliable and not almost comfortable like standard bikes.

jur 10-12-08 08:11 PM


Originally Posted by Bacciagalupe (Post 7651573)
In general, I do not recommend most folders for century rides, but it can definitely be done, and it's OK if you meet a few critical requirements:

• You find the folder to be very comfortable on longer rides.
• The century you're going to do is flat, OR the folder has very wide gearing.
• You're sure your folder is in excellent mechanical shape.
• You don't make any major changes to the bike (or change bikes altogether) shortly before the century.

These 4 points are not folder-specific at all.

veggie_lover 10-12-08 08:14 PM


Originally Posted by Urbanis (Post 7650193)
I'm not using a GPS system; I'm just calculating average mph based on distance and time.

12 mph door to door probably means you are cruising at 18-20 mph on the flats. Get this:

http://www.amazon.com/Schwinn-SW654-...3864030&sr=8-1

This will be a big eye-opener and teach you the importance of high cadence.

Urbanis 10-28-08 04:50 PM

Update: I've gone ahead and ordered some upgrades for my Downtube Mini and 8H.

On the Mini, I'm planning to replace the tires with Big Apples and the 25T rear sprocket with a 23T. I'm not planning on any other mods; while I'd like to improve performance, it's going to remain my main multi-modal commuting bike and I don't want to compromise the compactness, speed, and ease of folding.

On the 8H, I'm planning a greater makeover with an eye towards touring (e.g., 50-100 mile rides). The changes will be:
1. Rear tire: Big Apple; Front tire: Marathon Racer
2. Pedals: MKS AR-2 Quick Release with Powergrips
3. Handlebars: Trekking/Butterfly

Question: Any advice on how to position the butterfly bars? I've seen two configurations:
(a) With ends facing towards the rider
(b) With ends facing away from the rider

It seems the facing away option (b) would offer a more stretched out, aerodynamic riding position on the 8H, but I have no experience here.

Thanks for your thoughts.

Bacciagalupe 10-28-08 09:36 PM


Originally Posted by jur (Post 7652696)
These 4 points are not folder-specific at all.

Well, they are and they aren't. ;) They do apply to any bike, but the first two have some folder-specific aspects, and the 3rd has a Downtube-specific element:

1a) 20" and smaller-wheeled folders tend to be less comfortable, especially for longer rides. Cushy tires can help but will usually slow you down.
1b) Most folders, including the ones the OP is talking about, are "one size fits all" and that can result in major fit issues. Not a problem for short rides, but definitely an issue for centuries.

2) The overwhelming majority of folders have insufficient gearing for anything other than a flat century. Single chainrings just don't have a good range.

3) Downtube bikes tend to have a lot of no-name parts (hence the reasonable prices). They're standard and therefore fairly easy to upgrade, but after having a couple of mechanicals impact my rides, I like to go with reliable gear for touring and centuries.

jur 10-29-08 04:18 AM


Originally Posted by Bacciagalupe (Post 7752004)
2) The overwhelming majority of folders have insufficient gearing for anything other than a flat century. Single chainrings just don't have a good range.

Just for interest: A typical roadie with 53/39T rings and 12-25T cogs has a smaller range of gears than my Swift with 60T and 11-32T cogs. Granted the highest gear is geared higher but OTOH the lowest gear is much higher too, so with those really steep hills begin to become a serious liability. I have many times observed the roadie bunch I occasionally ride with, grind very hard on the steep hills and I easily overtake. On the downhills I do have some disadvantage, having to either pedal faster, or aero tuck and freewheel, but I still keep up.

With a 50-34T set and 11-23T, the roadie range is the same as the Swift.

So the bolded statement is not true at all - it is a case of 'it depends'.

8bit 10-29-08 10:04 AM

My mother just got a Tikit and I've been riding it for the last week while she's out of town. She got the base model and commuter'ed it up with a rack and fenders, but that thing can MOVE! Bike Friday didn't design that bike for speed, either, so I can imagine that when they do design for speed you get something incredible. I'm thinking about an express Tikit, myself, to replace my Downtube Mini. I don't know if there's a way to upgrade the mini to make it faster when I feel like all my effort is going into the bouncy rear suspension.

I'm actually sort of curious about how to make a Tikit suitable for century rides or ultralight touring. The range of gears on the express Tikit with the 9-speed Capreo (33-95 gear inches) doesn't have all of the low end I've spoiled myself with but I think that it still will get me up most anything. The bigger issues are the fit and feel of the bike and I won't know that unless I get one and set it up.

PolishGuy 10-29-08 10:23 AM

Unless I overlooked it somewhere, the Airnimal (spelling?) Company makes a line of bikes that partially fold and separate for travel purposes. Haven't ridden one but the reviews seem to be quite good. PG.

rhm 10-29-08 11:41 AM


Originally Posted by Urbanis (Post 7644850)
Thanks for everyone's feedback. I really like the idea proposed by 14R to mod my Downtube Mini (thus sticking with a bike I already have and enjoy and saving lots of money). I also have an 8H--would you suggest the same modifications (54T chainring, faster tires, and multi-position handlebar) to it? If so, I may mod the 8H instead--it's got the integrated rear rack, larger wheels, and may be better for touring anyway.

Questions:
1) I have no knowledge of tires--is there a particular brand you'd recommend for the Mini and the 8H?

2) For the multi-position handlebar, are you recommending a butterfly bar or some other type (e.g., drop or moustache)? I found an article about them here: http://sheldonbrown.com/deakins/handlebars.html (again I'm no expert on this topic).

3) Would installing a multi-position handlebar compromise the fold? My Mini folds with the stem and handlebar between the wheels. On the 8H, the stem and handlebar fold on the outside, so I suspect it would be less of a problem to do the mod on that bike.

Speaking only of the mini....

I normally cruise around 15-20 mph on mine, often get up to 25 mph, occasionally over 30, and once I even got over 35. So if you can't get yours up to 15, there is something wrong.

Better tires will make a difference. I like having a Schwalbe Big Apple (2.0") on the front and a Schwalbe Marathon (1.5") on the rear. Keep them pumped up.

As far as I can tell, changing to a different handlebar will either make no difference or will badly compromise your fold. The only workable handlebar modification that I've found is to change the mounting of the one you already have; either turn it forward, or take it out and put it back in upside down. I've tried both. Either way, you have to do a lot of trial and error to get the best position and least interference in the fold. I currently have it back the way it came from the factory.

You don't need a bigger chainring until you hit 35 mph. When you get to the point where you're regularly running out of resistance in 8th gear. I've been trying for months to beat SesameCrunch's record, and can assure you, my failure is not the bike's fault (it's the hills: he has better hills than I, that's all).

Karlgw 11-27-08 07:38 AM


Originally Posted by Bacciagalupe (Post 7651573)
There are only a few high-end folders/separatables I'd recommend for 100 miles. A well-fitted and properly geared Bike Friday; just about any Moulton; maybe a Pacific Reach. Others can be used but only if you really, really, really aren't bothered by road buzz and don't need a wide gearing range.D

I can confirm that the Pacific Reach would be fine for longer journeys - the ride is very similar to any good road bike as the dual suspension compensates for the small wheels/high pressure tyres combination that can make for an uncomfortable ride on some folders. I did 60 miles on mine without problems and I am 43 and out of condition! You might also consider one of the Airnimal Chameleons - another high end folder range designed primarily as good fast road bikes, with folding a secondary priority. With both the Pacific Reach and the Chameleons the fold is not that great - you have to remove the front wheel to fold - but Pacific have recently brought out a new version of the Reach with IF (integrated folding) technology that gives a much better fold. Not sure about the prices of these though.

noteon 11-27-08 07:56 AM

Will the Downtube Mini accept an IGH? Putting one on my Swift cost about $350. The bike now has 24 speeds and a gear-inch range of 21.5-120.

Urbanis, we could meet up and you could check it out if you're interested.

EvilV 11-27-08 08:24 AM


Originally Posted by veggie_lover (Post 7648684)
I might be missing something really obvious, but if you are pedaling hard and only going 12 mph then there is something seriously wrong with your fitness and technique. Changing the equipment ain't going to fix the problem. Are you sure your speedometer is calibrated?

EDIT:

Post removed - went on about calibrating speedos and then found out he was guessing his speed.

timo888 11-27-08 09:14 AM


Originally Posted by noteon (Post 7925949)
Will the Downtube Mini accept an IGH?

DT Mini's narrow rear spacing (116mm) limits options to SA.

Regards
T

noteon 11-27-08 09:15 AM


Originally Posted by timo888 (Post 7926223)
DT Mini's narrow rear spacing limits options to SA.

Which I know you're not a fan of, but I don't know why.

timo888 11-27-08 10:17 AM

The currently available SA8 (a new model solving this problem is ready but not yet on the shelves) is very finicky -- the common wisdom is that cable tension adjustment must be perfect or it can slip, while you're pedaling, into neutral. Dangerous, possible rider-over-the-bars scenario. Of course, if you're folding the bike all the time, it's almost impossible to keep the cable tension in adjustment.

http://www.bikeforums.net/showthread...eeling+forward

For another view which holds that the SA line of hubs has a design flaw which causes this problem of slipping into neutral when the rider is pedaling with force in top gear:


Originally Posted by Jobst Brandt, industry luminary
Sturmey-Archer hubs have been in service for many years (1887) ... Yet they have had a design flaw from the beginning that escaped scrutiny through most of the popular life of the common 3-speed AW hub. This flaw has consistently been "swept under the rug" or laid at the feet of the mechanic so completely that few have questioned why it jumps into free wheeling when ridden forcefully in top gear. I think the symptom and cause should be explained to prevent injuries. ... The result is that the rider, if standing, dives over the bars, with the bicycle following. ... SA has always maintained that the shift cable was misadjusted, something that is easily disproven by disengaging the shift chain entirely. [emphasis added]
http://www.sheldonbrown.com/brandt/sturmey-archer.html

Regards
T

EvilV 11-27-08 10:34 AM


Originally Posted by timo888 (Post 7926411)

http://www.bikeforums.net/showthread...eeling+forward

For another view which holds that the SA line of hubs has a design flaw which causes this problem of slipping into neutral when the rider is pedaling with force in top gear:



Regards
T

Rubbish!

Take off your anti-foreign blinkers and get with the up to date information. The SRF3 and the new AW as made in Taiwan do not have this old 'western technology' fault. It is impossible to find a non drive state in these hubs. They have been re-designed to prevent the fault since the Taiwanese took over the company name and the rights over the old designs.

Historical issues are irrelevant to this thread. The old hubs have not been available since about 2001.

timo888 11-27-08 10:51 AM


Originally Posted by EvilV
Take off your anti-foreign blinkers and get with the up to date information ... Historical issues are irrelevant to this thread...

EvilV,
There's nothing anti-Taiwanese or anti-foreign about this view. If I had a problem with a Shimano product would you accuse me of being anti-Japanese? Cease and desist with these ad hominem attacks.

I don't know about the shipping status of the corrected AW. But the new version of the SA8, the one that according to the Sheldon Brown website solves the forward freewheeling problem, is being withheld from circulation until the stocks of older hubs have been sold off. That is not a historical fact but a current one.


Originally Posted by Sunrace Sturmey-Archer on its blog
March 29, 2008 6:07 PM
1. Since the new 325% hub is labeled 'XRK8', can we assume the old, current version to eventually be discontinued?

Yes. Once any remaining 8 speed hubs that are in the US are sold, our distributors will be supplied with the new version.
[emphasis added]
http://sunrace-sturmeyarcher.blogspo...bike-show.html

Regards
T

EvilV 11-27-08 10:59 AM

Cease and desist yourself.

You have pedalled your anti Chinese crap here for long enough without being called for what you are, an obsessive anti chinese obsessive. Get lost. I'm sick of reading it. And stick your regards where the sun don't shine as well.

noteon 11-27-08 11:05 AM


Originally Posted by EvilV (Post 7926592)
Cease and desist yourself.

You have pedalled your anti Chinese crap here for long enough without being called for what you are, an obsessive anti chinese obsessive. Get lost. I'm sick of reading it. And stick your regards where the sun don't shine as well.

Well reasoned.

timo888 11-27-08 11:48 AM


Originally Posted by EvilV (Post 7926592)
Cease and desist yourself.

You have pedalled your anti Chinese crap here for long enough without being called for what you are, an obsessive anti chinese obsessive. Get lost. I'm sick of reading it. And stick your regards where the sun don't shine as well.

EvilV,

An obsessive obsessive?

I don't understand why you're so averse to discussing issues of quality that you're willing to go on frothing-at-the-mouth tirades against another forum member who simply has an opinion different from your own (and who happens to back those opinions up with references to acknowledged authorities) and has demanded that you stop calling him names.

We're not a cheering section for the manufacturers. At least I'm no cheerleader, but a consumer and an enthusiast interested in design.

Regards
T
P.S. These are fresh regards, btw, that did not come from the place where the sun don't shine, though I was sorely tempted to give you the ones you asked me to stick there.

jur 11-27-08 04:17 PM


Originally Posted by timo888 (Post 7926411)
The currently available SA8 (a new model solving this problem is ready but not yet on the shelves) is very finicky -- the common wisdom is that cable tension adjustment must be perfect or it can slip, while you're pedaling, into neutral. Dangerous, possible rider-over-the-bars scenario. Of course, if you're folding the bike all the time, it's almost impossible to keep the cable tension in adjustment.

http://www.bikeforums.net/showthread...eeling+forward

For another view which holds that the SA line of hubs has a design flaw which causes this problem of slipping into neutral when the rider is pedaling with force in top gear:



Regards
T

Just to put things straight:

The older SA 3sp hubs had 2 problems:

1. A "neutral" between 2nd and 3rd gear, only found if the cable is mis adjusted, and easily rectified.
2. Under very hard cranking in 3rd only, the gear engagement would slip out of 3rd into that "neutral". Only happens when cranking very hard like sprinting out of the saddle.

I don't know about the new hubs and these 2 problems. I think they are very minor problems, even if they still existed.

The current 8sp hub does not have "neutral" points between gears. At least not the same as the old AW. The 8sp also does not have that problem of skipping out of gear when cranking very hard. Rather, its problem is lack of tolerance to slightly mis-adjusted gear cable. It can happen in any gear except 1st, and the hub defaults back to 1st gear on such a case. If you're in 6th, it may feel like a neutral because you'll be spinning fast in 1st, it will feel like no pressure on the pedals.

So it is not correct to ascribe the AW's (minor) problems to the SA line of hubs. Different issues altogether.

EvilV 11-27-08 04:57 PM


Originally Posted by jur (Post 7927490)
So it is not correct to ascribe the AW's (minor) problems to the SA line of hubs. Different issues altogether.


TCS
October 16, 2007 at 7:24 pm
Mick,

The old Sturmey AW did have a neutral between the 2nd and 3rd ratios. The Sturmey AW-NIG does not. The AW-NIG began production in 1984 and is the basis of all their three speed hubs (SRF3, etc.) that have been produced since 1999.

You can compare the exploded diagrams at

old AW3:

http://www.hadland.me.uk/sa/saaw.pdf

new SRF3:

http://www.sturmey-archer.com/pdfs/S…2005-05-25.pdf

and see for yourself that the internal mechanism is different.

I’m sorry that Jobst Brandt was hurt on a ride in 1960 using an AW hub, but to still be claiming in 2007 that SunRace Sturmey-Archer hubs have a dangerous neutral is in error and one must wonder about the motivation of such a claim.

TCS
http://hubstripping.wordpress.com/in...ar-hub-review/

jur 11-27-08 05:19 PM

I take that to mean, "jur, :beer: !

EvilV 11-27-08 06:01 PM


Originally Posted by jur (Post 7927652)
I take that to mean, "jur, :beer: !

Yes - sorry. I pasted the entirety of a post on hub stripping by TCs. I think he posts here as well.

I was trying to illustrate the point you made with further evidence.

In fact the post now contains a broken link. The diagrams for the hub internals of the srf3 are here ->

http://www.sturmey-archer.com/pdfs/S...2005-05-25.pdf

Those for the new version of the AW are here ->

http://www.sturmey-archer.com/pdfs/A..._Speed_Hub.pdf


And the internals of the old AW which had a possible fault condition as you mentioned are on the Tony Hadland site here ->

http://www.hadland.me.uk/sa/saaw.pdf

As I understand it, Sunrace SA have included and extra set of pawls on the driver assembly. If you look at the Hadland site diagram at the driver unit(K452) it has no pawls, but on the new AW (part labelled 16) it has a set of pawls. The other differences I have noticed are in the shape of the centre pins of the planetary gears. These hardened pins serve two purposes: a) they provide an axle for each gear to rotate on, and b) the ends of them protrude to engage in the clutch providing a top gear by driving the planet carrier inside the ring gear. It is said that small amounts of wear on these pin ends in the old AW design, could cause disengagement under heavy pressure that would take riders by surprise. The pins are shaped differently on the new hubs being parallel throughout their length rather than of smaller diameter at the engaging ends on the old model AW.

To be quite honest, I am not certain whether it is the additional set of pawls, or the differently shaped planet gear pins that stops the disengagement, or both together, but it certainly doesn't happen any more. The gear is either in second or it is in third. It has no disengaged position. I have had experience when the cable was out of adjustment of the gear changing out of third and into second, but there is no neutral position. Maladjustment will also occasionally produce a fault state in which the hub makes a noise in second as it is on the point of engaging third. This I believe is caused by the planet gear pins contacting the clutch while the pawls on the driver are still driving the ring gear in second. The point of transfer between the driven ring gear and the driven planet cage is so close (to avoid a neutral) that misadjustment can create a noise condition. The smallest twitch on the twistgrip solves this and it only rarely happens in any case.


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