Folding Bikes - Help selecting a gear system for my NWT

Hi All,

I have my entry level NWT for 2.5 weeks now and am not happy with the gear system (every thing else is very good). I a consider to upgrade it and will appreciate any advice.

Current configuration:

Cranks Alloy 170mm 30/42/52 130/74 bcd 119mm
Derailleurs Fr. Shimano R443 Braze triple Ft
Derailleurs R. SRAM 3.0 ESP Long Cage (34t)
Shifters SRAM 3.0 8x3 micro front ESP/pair
Cassette 11-32 8sp SRAM PG-830 Cassette Chains 3841
Hub R. BF Select 32o 130mm REAR-Silver/black

My main goals are:
1. Get rid of the front derailleur (difficult to fold, need to micro adjust).
2. Get better quality components and improve shifting and reliability
3. Nice to have but not required: get rid of rear derailleur
4. Maintain gear ratio of at least 350%, nice to have >= 450% (currently I have 504%)
5. I am happy with twist shifters but other kinds may also be ok
6. Upgrade cost lower than let’s say $500 (not a hard limit but I am trying to find a sub Rohloff solution)

The bikes are still in the 30 days refund period so it is OK to have solutions that are not compatible with the existing frame (I discussed it with BF).

My typical usage pattern: the bike lays folded in the back of my car. Each time I ride them I unfold, ride 5-20 miles, fold, and put back in the car.

Here is the list of the options I identified so far

1. SRAM DualDrive. Qualms: noisy? Reliability? RD can be damaged easily when folding?

2. Alfine + tensioner + 2 chain rings (manual range switch by moving the chain between the chain wheels by hand). Qualms: inconvenience of moving the chain between chain rings, Alfine's iregular shifting ratios.

3. Alfine + Crank gear (don’t remember the name of this two shift gear that is part of the crank where you shift by moving a button with your feet) Qualms: too complex? Option 2 seems to be simpler since I don’t need the entire range all the time.

4. I-Motion 9: Qualms: noisy? 350% range is marginal.

5. Get a 8x3 RR/FD configuration similar to the existing one but with better quality components. Qualms: will it make the folding and shifting better?

6. Anything else?

Which option would you recomand?

Any advice will be greatly appreciated.

Thanks,

Kam

The DualDrive is no more vulnerable than your existing derailleur (which will probably work with it just fine). However, you would have to mind the clickbox, which sticks out a bit. Very reliable, only noise pleasant whirrings.

My opinion are to get a IGH with one sprocket rear and one chainring in the front. Are you sure you need more gears than you get from a Nexus 7? (said to be better than the Nexus 8). If so go for the Rohloff. It is better to spend the money than doing this 2-3 times without being happy with it.

I like the Nexus for many reasons, but most of all for the clean cable line with no clickbox.

Hi Kam,
I have owned 3 bike Fridays 2 with Dual Drive and one with conventional front and rear derailleurs. From your post I really can't tell what your issues are but hear are my observations:

1. The Dual Drive is a good setup and very reliable. However, I found the following issues.

a. It is heavy.
b. Can be costly and catastrophic if you have a breakdown, especially on long tours.
c. Not as efficient as a traditional front derailleur.
d. Does not allow the use of a quick release.

2. The traditional derailleur setup does not have the above issues and I found no additional packing hassles on my current AirGlide. For me I have found that the better the quality of the derailleur setup the less hassles, the more efficient the ride and the better the packing and folding. Because of this, I use Shimano Ultegra.

Hi All,


My main goals are:
1. Get rid of the front derailleur (difficult to fold, need to micro adjust).
2. Get better quality components and improve shifting and reliability
3. Nice to have but not required: get rid of rear derailleur
4. Maintain gear ratio of at least 350%, nice to have >= 450% (currently I have 504%)
5. I am happy with twist shifters but other kinds may also be ok
6. Upgrade cost lower than let’s say $500 (not a hard limit but I am trying to find a sub Rohloff solution)

Any advice will be greatly appreciated.

Thanks,

Kam

On my Jetstream XP, I installed a Schlumpf Speed Drive 2spd bottom bracket and Shimano RedBand 8spd hub.. always a straight chainline and no derailleurs .. gear range is right about 506% .. cost at the time was less than half of a Rohloff .. the drivetrain has been ultra reliable as there isn't anything to get knocked out of whack..

http://farm2.static.flickr.com/1304/726768307_b340b9739c_o.jpg

Any front derailer system you get will require you to trim the front derailer for certain combinations of chainrings and cogs. However, this should only occur with extreme combinations that most people don't use in the first place.

The SRAM Dual Drive has a pretty good track record over at Green Gear. By removing the front derailer, you do get an easier fold since you don't have to worry about the chain tugging against the derailer. My understanding is that the Dual Drive adds about 1.5 - 2 pounds relative to a derailer drivetrain. The three speed internal hub is very robust; but as is the case with many internal hubs, if it does brake you have a much more complicated repair relative to a derailer-based drivetrain.

With the NWT, the distance from the cog to the chainring changes during the fold. So you probably want a rear derailer or something similar to keep tension on the chain helping prevent the chain from dropping.

As long as you lay your bike on the non-drive side, you should have little problem with derailer damage while traveling in a car.

(^^ Hey Bruce)

I've got the Dual Drive on my NWT now, I think it's a good system, but I'm not a big fan. I tend to over-shift with the hub gears, bacause those gears are more fun to shift, and then I use the RD for fine tuning. However, doing this i often get caught with bad chain lines, which annoys me. So I'm about to swap out the DD for an Alfine + FD once the new brifter is available. I've never had a FD on the NWT, I hope it won't make folding more difficult (I think I would have heard about that if it did) I really don't want to pony up for another Rohloff.

Let us know what you decide

Are you sure you need more gears than you get from a Nexus 7?

I tried last weekend to limit myself to a 300% range (gears 2.2 to 3.8). I was missing gears on the low side and used the full high range. 350% should probably be work good enough for me.

Kam

I've never had a FD on the NWT, I hope it won't make folding more difficult (I think I would have heard about that if it did)

It does for the reason I mentioned. That is, if you are a little careless, the chain tends to fall off during the fold. The chain falls onto the front derailer and sometimes gets stuck on a brake mount. Consequently, as you drop the rear triangle, it puts a lot of leverage onto the front derailer potentially bending it, the front derailer mount, or both.

Ask the Bike Friday techs, search the YAK archives, or some of the folding videos by Walter.

Solution ... be careful when you fold the bike or use a setup without a front derailer.

EDIT: Similarly, you can get a similar effect if the chain falls off and you roll the rear wheel while folded/folding.

It does for the reason I mentioned.

thanks, I hadn't seen your post before I started typing mine. My wallet is starting to get nervous.

I got two BF, one a NWT with a Capreo 9sp with a 44 t. chainring and a Llama with a 36/46 front chainring and Capreo hub cassette. Carry a latex glove if the chain falling off is a bother. I don't see the need for a wider gear range or mondo 27gear set-ups if a double gets me a tightly spaced 25"-93" gear range. First short tour in 25yrs was with the 9spd setup and about 16lbs of gear on the bike. My excess body weight is more of a limit getting up 6% grades than the gearing. The issue of the tiny 9tooth cog wearing is less of an issue given that most of the time I was in the 10,11,13 tooth cog

Thank you everybody for the great feedback. Based on the feedback here and other sources I decided to go with option 1 SRAM DualDrive. It seems to fit my needs the best.

Kam

I think you won't regret the DD - I have one on my NWT and couldn't be happier. I have done a few tours (3-4 days) and have had no issues with the clickbox, but when touring I do carry a spare clickbox (they are about $14) and a spare pin (they are $2), just in case.

For folding, I appreciate the lack of a FD, and for riding in the city, I like to be able to shift gears while stopped. I also have the H-bar/twist shift combo, btw.

Quick update, got the new NWT this week and took them yesterday and today to test drives (total of 20 flat and hilly miles). So far so good. The shifting is flawless (both derailleur and internal hub), being able to shift down at stop is very useful and I made usage and need the entire gear range. Also, it is simpler and cleaner then my old NWT (with front derailleur), the folding is easier, and it is nice to have the chainring guard (did not have it with the front derailleur).

Notes:
1. Weight - the NWT are not light anyway so I did not feel any significant difference.
2. Noise - all three IH gears make a continious click-click sound. The third gear is louder than the first two. It sounds like a clock and it does not bother me.
3. Ergonimic - I like the twist shifter. The Thumb shifter of the IH is also not bad. Few times I shifted unintentionally from 2 to 1 so this is something I should work on. Also, the marking of the IH shifter is counter intuitive. When you think that you are at second gear, you acutally at first, but I got used to it.
4. The dualdrive hub does not have quick release (can I install after market QR?). This is its main drawback IMO. I plan to take with me a patch kit and fix the rear inner tube without removing the wheel. Never tried it. I hope it is feasible.
5 Chain line - when the deraulure is at higher gear (9th), the deviation of the chain line from the chainring line is very high and every new link makes a slight click before it settles down. Also, without the chainring guard, shifting form 8th oto 9th tend to drop the chain, but not a problem though when the chainring guard is on. I noticed the chainline problem when the bike was hanging on a repair stand. When actually riding it, it seems to be ok though I am trying to avoid using the 9th gear for long time periods (I switch the IH gear instead).
6. The chain fall off each time I unfold the bike. I am aware that there is a folding procedure that avoid it but I don't bother since puting the chain back is easier than with the front derailur. I wonder if I can add an inner chainring to avoid the chain drop when folding.

Overall the DD was a good choice for me and I am glad that I found bike that work for me without having to resort to a Rolhof hub.

Thanks everybody for helping me making a good decision.

Kam

Good that you like it!

* Try to avoid using the extremes of the cassette to limit the amount of cross chaining.
* You can't fit a QR on an internal geared hub - the axle is solid or levers run through it. You will have to carry a 15mm spanner with you. Learn how to take the wheel off beforehand.
* It is a simple procedure to fit a chain guard on the inside - see if you can get a suitable size from Greenspeed
* a chainguard is necessary to avoid chain drops during shifting. Alternatively, a small U-shaped guard that sits over the chain will do the same.

* You can't fit a QR on an internal geared hub - the axle is solid or levers run through it. You will have to carry a 15mm spanner with you. Learn how to take the wheel off beforehand.


Except for the Rohloff 14 sp internal hub.

Good that you like it!

* Try to avoid using the extremes of the cassette to limit the amount of cross chaining.
* You can't fit a QR on an internal geared hub - the axle is solid or levers run through it. You will have to carry a 15mm spanner with you. Learn how to take the wheel off beforehand.
* It is a simple procedure to fit a chain guard on the inside - see if you can get a suitable size from Greenspeed
* a chainguard is necessary to avoid chain drops during shifting. Alternatively, a small U-shaped guard that sits over the chain will do the same.

Jur:

1. How feasible is it to fix a flat tube on the road (as opposed to replacing it) without taking out the wheel? This way I don't need to cary a 15mm wrench (or do I need two?).

2. I searched for chainrings guards. What does "110 mm BCD 52-tooth 5-bolt chainring" mean, that the guard is intended to protect 52-tooth chainrings or that the size of the guard is identical to a 52 tooth chainring? What guard size do I need for a 46 tooth chainring? (BTW, my crank is Shimano Sora 50-34t 9-Spd 170mm 2-piece if it matters).

3. Do I need to have spacers between the chainring and the inner guard? The outer guard is spaced out by the spider but I am not sure how the inner guard should be spaced.

Thanks,

Kam

Except for the Rohloff 14 sp internal hub.

Hmm, we always come back to Rolhoff ;-)

I should try one day a Moulton + Rolhof combination.

Kam

Quick update, got the new NWT this week and took them yesterday and today to test drives (total of 20 flat and hilly miles). So far so good. The shifting is flawless (both derailleur and internal hub), being able to shift down at stop is very useful and I made usage and need the entire gear range. Also, it is simpler and cleaner then my old NWT (with front derailleur), the folding is easier, and it is nice to have the chainring guard (did not have it with the front derailleur).

Notes:
1. Weight - the NWT are not light anyway so I did not feel any significant difference.
2. Noise - all three IH gears make a continious click-click sound. The third gear is louder than the first two. It sounds like a clock and it does not bother me.
3. Ergonimic - I like the twist shifter. The Thumb shifter of the IH is also not bad. Few times I shifted unintentionally from 2 to 1 so this is something I should work on. Also, the marking of the IH shifter is counter intuitive. When you think that you are at second gear, you acutally at first, but I got used to it.
4. The dualdrive hub does not have quick release (can I install after market QR?). This is its main drawback IMO. I plan to take with me a patch kit and fix the rear inner tube without removing the wheel. Never tried it. I hope it is feasible.
5 Chain line - when the deraulure is at higher gear (9th), the deviation of the chain line from the chainring line is very high and every new link makes a slight click before it settles down. Also, without the chainring guard, shifting form 8th oto 9th tend to drop the chain, but not a problem though when the chainring guard is on. I noticed the chainline problem when the bike was hanging on a repair stand. When actually riding it, it seems to be ok though I am trying to avoid using the 9th gear for long time periods (I switch the IH gear instead).
6. The chain fall off each time I unfold the bike. I am aware that there is a folding procedure that avoid it but I don't bother since puting the chain back is easier than with the front derailur. I wonder if I can add an inner chainring to avoid the chain drop when folding.

Overall the DD was a good choice for me and I am glad that I found bike that work for me without having to resort to a Rolhof hub.

Thanks everybody for helping me making a good decision.

Kam

Bike Friday sells a chain keeper for folding.

http://store.bikefriday.com/popup_image.php?pID=10204&image=0&osCsid=27a043d64529f1a6e53731a6

I'm surprised that the salesperson failed to mention it.

You should also look at the videos on this page (http://www.bikefriday.com/foldingpacking) for tutorials on folding the bike.


Jur:

1. How feasible is it to fix a flat tube on the road (as opposed to replacing it) without taking out the wheel? This way I don't need to cary a 15mm wrench (or do I need two?).

2. I searched for chainrings guards. What does "110 mm BCD 52-tooth 5-bolt chainring" mean, that the guard is intended to protect 52-tooth chainrings or that the size of the guard is identical to a 52 tooth chainring? What guard size do I need for a 46 tooth chainring? (BTW, my crank is Shimano Sora 50-34t 9-Spd 170mm 2-piece if it matters).

3. Do I need to have spacers between the chainring and the inner guard? The outer guard is spaced out by the spider but I am not sure how the inner guard should be spaced.

Thanks,

Kam

For certain types of punctures, fixing flats without removing the wheel is straightforward.

Thank you everybody for the great feedback. Based on the feedback here and other sources I decided to go with option 1 SRAM DualDrive. It seems to fit my needs the best.

Kam

I have a bike with a dual drive (non-folder) and here's how I use it. First, I set the derailluer on a gear that is slightly lower than I'm comfortable. This is just a "start-up" gear designed to get me up to speed when I'm leaving a stop light. Once I'm up to speed, I shift up the dual drive to high gear (3rd). If this high gear is too high for your taste, your start up gear should be lower.

When you come to a hill, just shift down the dual drive to the middle gear (2nd) and that should get you over. If you still need to go lower, shift the dual drive to the lowest gear (1st) and that should get you over unless you're climbing a mountain!

I like this shifting technique since you're basically only using the Dual drive the entire time. The derailluer is almost never used and you're really treating your bike like a three speed! It makes you wonder if the derailluer fell off, you would hardly miss it.

Bike Friday sells a chain keeper for folding.

http://store.bikefriday.com/popup_image.php?pID=10204&image=0&osCsid=27a043d64529f1a6e53731a6

I'm surprised that the salesperson failed to mention it.


Thanks. No, the sales person did not mention it, nor an internal chairing guard. I naively assumed that because I have only one chainring, the chain will not drop (better chainline, less chain slack, etc).

Is it intended to avoid the chain drop when folding/unfolding? The chain does not drop while riding, just when folding and after I replace the chain, the drive train performs very well.

Kam

Is it intended to avoid the chain drop when folding/unfolding?

Yep. The chain falls off from the bottom while folding. The chain keeper prevents it from coming off that side.

Your salesperson dropped the ball by failing to mention it, IMO.

Yep. The chain falls off from the bottom while folding.

Thanks invisiblehand.

Kam

Thanks invisiblehand.

Kam

Anytime. Hope that you enjoy the bike.

I should try one day a Moulton + Rolhof combination.


I've just finished fitting a Rohloff to my wife's Moulton, formerly a TSR30.

I've just finished fitting a Rohloff to my wife's Moulton, formerly a TSR30.


Heaven on earth.

:)

I've just finished fitting a Rohloff to my wife's Moulton, formerly a TSR30.

One more advantage of Moulton is that separable bikes are easier to lift in/out of deep car trunks.

(I am speculating, never tried it).

Kam

Thanks. No, the sales person did not mention it, nor an internal chairing guard. I naively assumed that because I have only one chainring, the chain will not drop (better chainline, less chain slack, etc).

Is it intended to avoid the chain drop when folding/unfolding? The chain does not drop while riding, just when folding and after I replace the chain, the drive train performs very well.

Kam

Kam,

I have an NWT and the wife has a Crusoe. I had the chain fall off several times on each as I was "learning" to fold them when they were new. Now I never have the problem. The secret - it's buried in one of the BF videos on the subject - is NOT let the pedals rotate backwards as you unfold (or after you have unfolded) the rear tri-angle. The best way to insure this is to rotate the pedals forward a revolution after unfolding.

I have found that where I would normally get into trouble was when I had to partially re-fold the rear tri-angle because I had not made sure the cables were properly routed under the BB on the initial unfolding move. Lifting up the rear by grabbing the seat stays and then revolving the pedals forward that one turn will solve that problem. I do have the aforementioned BF chain guides on both bikes.

With regard to the outside Chain Guard - actually a large chain ring with the teeth machined off, if you get it from Bike Friday. We have 46 tooth chain rings on both bikes. The '50 tooth protector ring' on mine just coveres the chain. The '53 tooth protector ring' on the wife's more than covers the chain. Conclusion, a protector ring made from a 52 tooth chain ring would work very well.

BF can supply them and even powder coat them to match or contrast with your bike.

With regard to that 15 mm wrench to remove your rear wheel, I carry a Craftsman "stubby" version in my small, under seat bag. It only takes one wrench to remove the wheel. I can tighten/loosen the wheel nut easily with that wrench. You can purchase individual wrenches at most Sears stores.

http://www.sears.com/shc/s/p_10153_12605_00944117000P?vName=Tools&cName=HandTools,GeneralPurpose&sName=Wrenches&psid=FROOGLE01&sid=IDx20070921x00003a

Hope this helps.

Lou

I have an NWT and the wife has a Crusoe...

Hi Lou, thanks for the info.

I tried today to unfold the NWT without letting the chain drop and I managed to make it to work at the second attempt. I need to keep practice since there a bunch of things that are going on while unfolding the bike and I have only one pair of hands (I also use one feet to rest the dropouts so they don't get into the sand).

As for the wrench, I am using the Park Tools DCW-2 (15/16mm). It is short, light and is even thin enough to be useful for the MKS EZ pedals.

http://www.parktool.com/products/detail.asp?cat=18&item=DCW-2

Probably it is not as strong and the Craftsman one but so far it does the job.

It is interesting that you said that BF can "match or contrast" the color of the chainring guard. My NWT is yellow and the matching chainring guard looks kind of childish. I think that a contrasting color (black, silver, etc) will look better. At the time I ordered it I was not thinking about this aspect and the BF salesman did not ask me either.

Kam

...With regard to the outside Chain Guard - actually a large chain ring with the teeth machined off, if you get it from Bike Friday. We have 46 tooth chain rings on both bikes. The '50 tooth protector ring' on mine just coveres the chain. The '53 tooth protector ring' on the wife's more than covers the chain. Conclusion, a protector ring made from a 52 tooth chain ring would work very well.

A quick update about the BWT chainring guard. I got the Sugino 110mm 44-46T guard from here http://www.velo-orange.com/suchgu.html and it fits perfectly.

BTW, the image may give the impression that the edge of the guard is raised. The one I got is completely flat and it fits very well.

Kam

Bike Friday sells a chain keeper for folding.

http://store.bikefriday.com/popup_image.php?pID=10204&image=0&osCsid=27a043d64529f1a6e53731a6

I'm surprised that the salesperson failed to mention it.



A quick update.

I got the chain keeper, installed it on my NWT and indeed it prevents the fold/unfold chain drop but I decided to take it off.

The main reason is that when the bike is folded, the chain keeper causes the chain to pull the rear derailleur sideways at a very aggressive angle and I am concerned that it will get bent.

Maybe this is the reason that the BF salesman did not recommended it ;-)

Kam

Kam,

1) Put the the bike into the highest rear rear derailleur gear (9th, I would assume). This will keep the drive train pretty much aligned.

2) the position of the "chain keeper" also influences the tension on the chain system when the bike is folded. Keeping it more toward the 11 o'clock position (when viewed from the left side).

3) Agree, using a foot - or two - helps when folding and unfolding. Also, once rear wheel is "unfolded", hold pedal in left hand, lift rear of bike off the ground slightly with right hand and rotate that pedal forward one revolution. this will fully mount the chain onto the chain ring and eliminate the possibility it will come off. (If you let that rear wheel spin backwards before doing the above, the chain WILL come off.)

Sounds like you are working through things. It's pretty simple once you get some practice.

Lou

A quick update,

I installed recently the N Gear Jump Stop http://www.gvtc.com/~ngear/whatis.html on my single chainring (DualDrive) NWT and it works just great.

1. It stops the occasional chain drops that I had wile riding.
2. It prevents the reverse derailment when unfolding the NWT.
3. It does not create an aggressive chain side bent as Bike Fridays's chain keeper does.
4. It is small and not as visible as BF chain keeper.
5. It cost half the price of the BF chain keeper.

Highly recommended.

Kam

As the NWT has changing chain length during fold it will need a chain tensioner. So one main advantage of an internal gear hub will be lost. I would recommend to just use a 11-34 cassette (e.g., Shimano XT). Gives you a good 300%. Dual Drive is just too heavy and slightly inefficient.

Edit: Or get a custom 9-32 Capreo cassete, offers 355%
See: http://www.bikeforums.net/showthread.php?t=521409

Chain tensioner? The rear derailleur of the DualDrive takes care of the chain tensioning.

I have the DualDrive for several months now and making a good usage its 550% range.

As for the efficiency, I don't have a good enough reference to evaluate it (nor do I notice efficency difference between the 1:1 and overdrive modes). When I select a gear combination, I just optimize for the chain line.

Kam

Kam

Chain has a 1% loss, derailleur another 1%, the internal hub adds ~4% sums up to 6% energy loss, roughly. Dual drive weight is 1067 g, compared to a front derailleur setup adds ~600g weight difference (BTW, there are people paying $500 to shave off 300g of their wheelset).

And regarding shifting: its a myth that you can shift a geared hub while standing. You always need some travel to make it shift. With a geared hub you'll need this travel to be unloaded. A loaded start is not possible, i.e., you cannot stand on the pedals and crank away but first need to give it a quarter rotation to get the gear in. This is especially problematic on steep hills. In contrast, some good derailleurs can shift while fully loaded.

My conclusion: A geared hub adds inefficiency, weight, and less pleasant shifting performance. It can on the other hand provide a clean chain line - but that is not possible for the NWT.