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Old 01-25-18, 02:39 AM   #1
avole
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Brompton upgrades

I bought my Brompton S model in 2013, and have generally been happy with it. The bike has been half way around the world, is used for daily commutes, and does the link in my yearly France/UK trips. However, I've always recognised it isn't the most comfortable for longer trips, but have always put that down to being what it is, a small-wheeled folding bike. Then came the Neo, a Brompton copy, which, as I completed a 120km trip with ease, made me wonder. The differences between the two are higher seat post, higher and adjustable handlebars, brakes in normal VTT position. So, having scanned the web and found this useful
, I ordered the riser from China, and took advantage of a UK trip to buy all the other parts.

My Brompton is the 6 gear model and has the dynamo lighting. Brompton advise being very careful the cable routing is correct, otherwise there may be problems with the fold. You can download the documents covering cable changes from their site, which I did, but would also advise taking photos before you start.

Step 1: raising the seat
Brompton make an extended stem, so I bought one. Fitting was, as you'd expect, a piece of cake: drop the old one out, put the new one in. Also wondered about that pentaclip as I swapped things over - do you really need that level of adjustment? I'll leave it for the time being, but have experienced re-assembling one after I changed a saddle, and wonder if the complexity is worth the gain.

I did my return trip across London then Paris with the extended stem. Far better in terms of leg length and power, but, as you'd expect handlebar height was definitely too low.

Downside: The Brompton no longer fits in the bicycle bag unless the saddle is removed. Not a deal breaker, but bagging it at St Pancras just as the train is being called adds very much to the fumbles!

For steps 2 and 3, I attached the brake levers to the handlebars, but you must route the inner cable through them, there's no way you can do it after.

Step 2: Changing the brake cables
You need to replace front and rear with H type pre 2017 cables.

The front is easy, as the outer cable comes in two parts, the top of which is the only one you really need to use if your existing cable is in good condition. I opted to leave the bottom part as is, mostly because the dynamo wires are attached with ties to it.

The rear is a little more complex as it must be routed with the rear light cable, the derailleur cable and the hub gear cable, but essentially, if you've replaced a brake cable before, it is no different. The bent to insert the cable outer into the bottom part of the brake is steep, but there's not much you can do about it. Any other routing takes the cable far too close to the rear wheel.

Step 2: Changing the gear cables
Again, you need H type pre 2017 cables. You also need to remove the rear wheel, so I refreshed my memory by looking at the
.

The Derailleur gear cable is the tricky one. Although it is covered by the Technical docs, it wasn't immediately clear to me what was holding the cable in place

TBC...
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Old 01-25-18, 09:36 AM   #2
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Well, it had to happen. Took the wheel off, which was quick as I've had to do it a couple of times. Started with the hub gear cable, to discover I ddn't have a spanner small enough to remove the nut and free the inner cable. There's a spanner at work, so no problem.

Started on the derailleur to find, as I thought, the only way to get the inner cable out is from the back of the cable assembly where it joins the dog leg. At that point, I had to stop, as someone gently reminded me that I had to pick up the dog food from the vet, buy groceries, and cook tea.

On the plus side, it should be finished at some point tomorrow. Not that I'll be taking the bike out tomorrow anyway, since another day has been added to the month long spell of rain we've been having.
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Old 01-25-18, 10:36 AM   #3
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Interesting that you bought, and waited so long to correct, what seems to be an ill fitting bike. I can understand that it takes time to realize that a particular handlebar config is comfortable/uncomfortable, but proper seat position/leg extension should be known day one.

FWIW, I do some touring on the Brompton, and other bikes, and personally don't find one handlebar position - whether S-bar low, or M-bar upright - to be particularly comfortable, but rather simply the ability to vary between the two, back and forth while riding to be more comfortable (with multi-position drop bars most comfortable). My Dahon has an adjustable height handlebar, but it just doesn't do the trick since you cannot vary position while riding, and frankly I find it an annoyance as another point of looseness/slop and another step in the folding process.

I personally got tired of my M-bars upright position and aerodynamic drag and so rigged a drop bar grip position in the bottom my M-bar's 'U' that has resolved both issues for me. This upgrade has made me virtually indifferent to riding my B, or 700c gravel bike, on regular rides (no folding involved).

As much as I love my M-bars now with 2 riding positions, and 3 grip positions (GP2 bar ends), if I where do it again, I would seriously consider the P-bars. Don't care how ugly they look, we ride 'circus' bikes after all.

Good luck on your upgrades!
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Old 01-25-18, 11:23 AM   #4
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Quote:
Originally Posted by reppans View Post
Interesting that you bought, and waited so long to correct, what seems to be an ill fitting bike. I can understand that it takes time to realize that a particular handlebar config is comfortable/uncomfortable, but proper seat position/leg extension should be known day one.
Oh, I knew straight away, but thought it a compromise one had to make for the convenience. Except for the SE Asia/Australia trip I don't usually use it for touring , so decided to live with it. You can't beat the convenience when it comes to trains, planes and automobiles, always free.

Last edited by avole; 01-25-18 at 02:25 PM.
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Old 01-25-18, 01:39 PM   #5
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Looking at the often reposted chart, the Brompton H mast puts the center bar clamp at a height similar to the S mast,
but by moving the hinge upwards when folded the M riser bar wont hit the ground..

so replacing a straight bar or a modest rise bar with more sweep angle , will be accommodated.. in the fold planning..
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Old 01-25-18, 02:25 PM   #6
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I'll add some photos of the components tomorrow, but they're mostly the ones talked about in the video.
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Old 01-26-18, 12:04 PM   #7
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The best intentions ...

Solved the mystery of the derailleur cable, all for one small but critical detail. The Brompton instructions clearly state it, and I thought I had one, but if you don't have a 1,5mm hex key you can't release the cable from the lever, and without that, you can't remove the cable at all.

In my case that involved a 50km hike to the nearest DIY store to buy one, after which restaurant duties called, so will have to finish the job tomorrow. Ah well.
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Old 01-27-18, 02:02 PM   #8
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Job nearly done. Only problem was some of the cable routing, which will be corrected tomorrow, and lack of tension on the derailleur cable caused by a slack connection at the lever end.

If anyone wants to try this, I'd heartily recommend getting a bike stand. Some of the cable replacement is fiddly, and scrabbling around on a cold concrete floor routing, adjusting and connecting cables is a pain where you can be standing with the bike at a sensible level. Shame I had no access to mine. Because of the rain, it was impossible to open the door of the shed, the wood had swollen so much.

Other than that, if you've got a full set of Allen keys plus a decent spanner kit the job is straightforward.
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Old 01-27-18, 02:12 PM   #9
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Forgot the hacksaw and file. You have to cut the handlebar to 610mm length.
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Old 01-29-18, 09:31 AM   #10
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The combination of bolt-on grips/bar ends such as Ergons and a QR in lieu of the stem bolt at the the handlebars is very nice for easily switching out bars. BTW, a pipe cutter for copper pipes does a very nice job on handlebars, getting the cut exactly square to the bars.
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Old 01-29-18, 01:52 PM   #11
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same saw guide at the LBS, for fork steerers works fine on 7/8" handlebar tubing..
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