Some Brompton Mods (56K Warning)
 

Hi all, over the past months I have been making some mods to my Brompton. I love tinkering with my bikes and the Brompton is certainly a unique 'canvas' to work on. Here are the mods that I have made so far:

Upgraded Roller Wheels. The original rollers don't really roll. With this upgrade I can push the folded Brompton and it will easily glide 50 feet across a subway platform. The rear wheels are 72mm inline skate wheels that I got from my nephew's skates which he outgrew (I slipped him $5 for it). The front are 100mm in diameter I think, and they came from some kid's broken Razor scooter that he left in front of my house here in NYC. I had to buy longer bolts for the front and back and it cost around $1.50 for the hardware. A must for all Brompton owners methinks.
http://piofort.zenfolio.com/img/v4/p917080601-4.jpg


When folded they give much clearance and can easily travel over sidewalk cracks that would bog down the original rollers.
http://piofort.zenfolio.com/img/v4/p890085686-4.jpg


Improved Braking. I changed the pads to the Salmon Kool Stops. They brake so much better. I also inserted V-brake noodles into the brake line. This allows better cable pull in the tightly curved area. Works great.
http://piofort.zenfolio.com/img/v4/p764769575-4.jpg


Comfy Seat. I ditched the original Brompton seat and put in a green Brooks B17 with copper rails. I love it! The green color became darker with each ride. It is attached to the post with a generic seat adapter that I got for around $2. I can't bring myself to get the $30 Pentaclip which does the same thing. Note that I have a 'seat backward' position so I can stretch out.
http://piofort.zenfolio.com/img/v4/p709416494-4.jpg


The Cockpit. I replaced the M handlebar with an Azonic MTB handlebar with a 2.5 inch rise. This lowers the handlebar a bit which I like, and it is probably the same height as the S type handlebar now. Even though I cut around 1 1/2 inches off each end of the bar it is still around 2.5 inches wider than the M bar. I like this wider grip as it allows me to breath a bit easier and in a way maneuver the bike better. When folded there is a lot of clearance from the sidewalk, always a good thing.
http://piofort.zenfolio.com/img/v4/p546189460-4.jpg


I changed the brake levers to Shimano R550's. The original ones felt mushy to me, and I found out why when I took them out, they didn't have a return spring! These Shimano levers have a strong one in each lever, and they make for a snappy positive return. I put black tape over the Shimano logo to keep it stealthy. The bar ends are from Singletrack Solutions. I like them as they are lightweight and comfortable, but one must resist the urge to over-torque them because they break when done so. I found out the hard way. They do not interfere with the fold. The bar end plugs are wine corks that I whittled down to fit. They came from a Cabernet but I guess any wine will do ;)
http://piofort.zenfolio.com/img/v4/p952599454-4.jpg


Though I got used to the original shifters, I really didn't like them as they felt and looked clunky to me. I was able to get this SRAM Spectro T3 Twist Shifter for 99 cents at Ebay, though shipping was a whopping (relatively) $5.99. I was pleasantly surprised as they worked well with the SRAM 3 speed rear hub. There is a bit of a learning curve as I used this shifter, and now I am used to it. I like the cleaner look. For the left twist shifter. I could not find a 2 speed one so I opted to get the SRAM MRX shifter, micro adjust version, for $15 shipped, and it just arrived yesterday. I am thinking that I can rely on the limiting screws for controlling the shifting, with the micro adjust feature as some sort of friction mode. I will report as soon as I have set it up and tested it when I have free time.
http://piofort.zenfolio.com/img/v4/p247489626-4.jpg

A view of the whole cockpit.
http://piofort.zenfolio.com/img/v6/p25405394-4.jpg

Continued on next post.....

All in all I am satisfied with the changes that I have made. Now I am wondering that with the lower handlebar, what Brompton front bags can I fit into this bike. I never did understand why only the S bags fit the S Bromptons. I plan to get the Folding Grocery Bag and see if it fits.
http://piofort.zenfolio.com/img/v4/p708227088-4.jpg

http://piofort.zenfolio.com/img/v4/p280225450-4.jpg

Thanks for looking! :thumb:

Wow, I like it, especially the cockpit !
:thumb:

Yeah, that is a pity. Let us know how it turns out. It is because the S-Stem bends forward to create a longer "toptube" and the frame of M-Bags gets in the way (and it is lower of course, with a full laden Travelbag would interfere with brake levers)

You have no clearance probs with the rolers and ankles?

nice, i like how you've kept its inherent brompton-ness intact. i'll be plundering your ideas when my warranty runs out.

Very well done! :)

nice

Nice mods! Will certainly be pondering switching to a grip shifter for my rear hub on my brompton too! And keeping an eye out for old MTB bars..... XD

One thing i'm a little skeptical about, is the use of skate wheels to replace the rollers. Is there a tendency for your heels to clash against those? I had a friend who did the same mod on his P-type brompton but often found his heels knocking into them....

Out of interest, about your handlebar choice: what's your height and is the steering twitchy like that? The standard brompton bars would effectively increase 'stem' length.

My back heels clash against the stock roller wheels anyway so I've developed an inside out pedal stroke to compensate. There is a part that a Japanese bike site sells that will push the wheels further back so that won't be a problem. No one seems to carry here in the U.S., though.

http://www.loro.co.jp/index2-lcw.html

Thanks to the OP for letting us know that the 100mm wheels will work. That will be my next Brommie mod. Great job!

Forgive my perplexity, I have a 1996 Brompton with a 3-speed Sturmey-Archer hub, so I'm not up-to-speed (no pun intended) with what's current. What drivetrain does your Brompton have so that you need 2 different shifter controls on your handlebars?

I see the brakes have been improved from cheesy, flimsy sidepulls to ones of Brompton's own manufacture.

For the record, I replaced my stock bars with $1 straight MTB bars I found at a bike sale plus cheap MTB grips, the stock saddle with a WaveFlo FlowLite gel racing saddle (also a cheap deal from somewhere), and the S-A shifter with a 3-speed SRAM GripShift on sale at Nashbar (mounted on the left, as it was intended for an MTB front derailleur). Being a roadie, I found the stock seating position too upright and the stock padded plastic saddle too wide and mushy.

That would be a 6 speed brompton. 2 sprockets mounted on a 3 speed hub to give a total of 6 speeds. One shifter for the hub, another for the sprocket derailleur.

Hey thanks for looking and for the comments all! I must say that I have been inspired by the mods presented in this forum and that it is only fair that I share my experience with my Brommie. Now to answer a few questions.

Somna, I see what you mean about the bent S-stem assembly and how it would interfere with taller bags. With that in mind, I think my present setup will allow the use of the grocery basket. I am pretty excited about getting it as I plan to mod a few bags and baskets so that they can be secured to the frame that comes with the folding grocery basket. I think a small black plastic milk crate will look good on the bike. Thanks for the clamshell tip on another thread, by the way.

About the rollers and heels - I did have some problems with heel strike at first, but I adjusted my pedal stroke to clear the rollers. This was a long time ago, it has been months since I had my last heel strike. For people that can't seem to get rid of heel strike, there are pedal extenders available that increase the Q factor of the pedals. I have several inline skate wheels of varying diameters and I experimented with different sizes and combinations. I found that I prefer the larger wheels as they can negotiate sidewalk cracks and uneven pavements better. They really make subway forays easier as all the bike needs is a little nudge. Once in the train though you have to wedge the bike between your legs or a wall so that it doesn't roll around. An interesting fact about the 100mm Razor scooter wheels is that they are actually around 2mm thinner than a regular inline skate wheel, so that helps a bit. On a related topic, all of my relatives know that I am on the hunt for inline skate wheels so they save their old skates for me instead of throwing them out :)

I am very happy with my handlebar choice. It allows me to get into a slightly more aerodynamic position that I am used to. At the same time, it gives me a wider grip that gives me better steering control and breathing. I searched the internet for the tallest mountain bike riser bar that I could get and I wound up with this Azonic WF Riser. It is available at 1.5", 2", and 2.5" heights and I opted to get the tallest one. The stock M handlebar is 5 inches tall and gave me an upright ride that was Ok with me but I felt that I would be better off with lower handlebars. I am 5'10" by the way and my preferred road bike size is 56 c to c.

Shiny, thanks for the link on that gadget, that looks very interesting. Another future mod that I plan to do is to install swiveling casters so that I can maneuver my folded bike like a shopping cart. Now that would be interesting :)

By the way, I have noticed that my folded Brompton when pushed travels in a slight arc rather than in a straight line. Do your bikes do the same?

Stormclad is right, thanks! My bike is a 6 speed Brompton. Dorky, how does that SRAM shifter mesh with the S-A hub? I think there is a 3 speed Torpedo S-A twist shifter that would work better with that hub.

S-A 3-speed hubs are notorious for shifting into idle in middle gear if the chain-tension doohickey isn't adjusted correctly; i.e. the cranks spin freely with no resistance and the hub is not engaged. The GripShift neither helps nor hinders that characteristic. It has intermediate click-stops for trim (for MTB drivetrains) but when correctly adjusted, the clicks marked for L M and H do correspond to the hub's gearing. I originally had it mounted on the right, where the S-A shifter was, but of course it made the GripShift operate "backwards" and I never got used to it. To me it makes more sense on the left, even though (US convention) left usually controls the front shifting on a derailleur bike.

Very nice mods except don't like the cork in the side of the grips myself but perhaps that's just my taste? I'll be very interested to see how you get on with the 2 speed shifter, the SRAM 3 speed one looks great and makes so much sense. The handlebar mod is very smart too.

Nice 1 - love the wheel colours !

That's the old British SA you're talking about I think. The SRF3 and new AW types don't do that. I think it is a physical impossibility on the current ones, though the early Bromptons might have that problem. The new designs came in about the year 2000 when production and design moved to Taiwan. I've riddin a fair way on my SRF3 and never had any such tendency, however out of adjustment it has been. The worst result has been a kind of grinding sound as it tries to be in two gears at once. Nobody would continue to ride it like that unless they were mad, and even out of adjustment, a slight twitch on the twistgrip solves it temporarily until you can find time to make the required adjustment.



Lovely mods by the way Biekerouac, though my eyebrows did rise at the size of those scooter wheels. I got heal strike with small ones and took them off to avoid it. That brake noodle is a great idea.

Every time Mulleady sees a cork he has to stick a cork screw in it, pull it out and get his mouth over whatever it was stuck in.... LOL

:)

How are you doing mulleady?

Nice job.

Somnatash -- she seems to be on top of everything about the Brompton -- can correct me if I am wrong, but the S-model has a longer and further forward stem. Judging from the picture below there is room for a wider and taller bar with the S-model. So if you are looking for a longer reach, you can do so with a bar with less rise.

http://www.brompton.co.uk/images/photos/models/S2L.jpg

Question: Most MTB bars I see are angled towards the rider. But using such a bar with a Brompton widens the fold. What bar did you use and did it widen the fold?

No need, test passed with honour ;-)

Yeah, how ya doing?

Mine's old enough (1996) to have a British SA, which can have the problem--even with the original SA trigger shifter. With the GripShift, there are intermediate trim click-stops that can put me into the disengaged mode, but it's easy to get out of by twisting a bit more in either direction--whereas there was no such option with the SA trigger shifter! When properly adjusted, the stops on the GripShift with the markings for L M H are spot-on.

Good to know there's been progress and the new hub gears no longer have the problem.

The rear wheels are 72mm inline skate wheels that I got from my nephew's skates which he outgrew (I slipped him $5 for it). The front are 100mm in diameter

Are the two different diameter wheels by design or chance? Would 4 x 72mm wheels or 4 x 100mm wheels work just as well? Looking at the photo, there seems to be some kind of inherent design logic to the wheel slant.


thanks

It must be pretty disconcerting to put pressure on the pedals and find no resistance. I'm amazed the original company allowed this to continue for so long. I expect it caused many accidents since they made that design for about sixty years and sold probably millions of the units.

Thanks for looking all. To answer a few queries....

Mulleady, I also think the brown corks don't jive well with the bike's color scheme either. I used it because I didn't have any end plugs lying around and to prevent the bar from exacting a core sample from my thigh in case of a spill ;) I think I will get a black marker and color the cork so that it doesn't stand out as much. I will be installing the left shifter soon, wait for the report :)

poboxnyc, I have several skate wheels ranging from 56mm to 100mm and I tried several combinations. This combo seems to work out rather well as far as rolling the folded bike goes, so I stuck with it. it looks quite nice too!

Invisiblehand, I used a hi-rise (2.5 inch) Azonic WordForce bar. It is a standard MTB bar that has a 5 degree back sweep so that the wrists are more comfortable. My setup, with the handlebar and bar ends widens the fold a bit, but for my purposes it is too minimal for concern. I believe that for those with an M-type handlebar wishing to go to the lowered stance of an S Brompton, this is the way to go instead of getting a new S-type stem assembly and a flat bar.

http://piofort.zenfolio.com/img/v4/p663567532-4.jpg

So, just for curiosity, what is the maximum folded width, bar end to pedal on the above pic?