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Brompton 6 speed, rear wheel problem

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Brompton 6 speed, rear wheel problem

Old 12-03-19, 08:41 PM
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candan
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Brompton 6 speed, rear wheel problem

Hi all,

I newly bought a Brompton 6 speed. However, I realized that there is a rubbing noise in the rear wheel which I guess from the hub (I checked the brake pads and fender, they are okey). And also, when I turn the wheel freely, it stops very quickly. Today I visited a bike store and checked rear wheel of another Brompton, it was turning good and I heard no noise.

Are there any one who had same problem? Can it be a production defect?
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Old 12-03-19, 09:55 PM
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Do you know its age? Has it got a rear rack? Can you have a mechanic look at it? The 'okey' statement is vague.
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Old 12-03-19, 11:00 PM
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Originally Posted by 2_i View Post
Do you know its age? Has it got a rear rack? Can you have a mechanic look at it? The 'okey' statement is vague.
Thank you for reply.

Its model year is 2018, I’m the first owner.
By “okey”, I meant the fender and brakes don’t touch the wheel or tire.

Actually, I brought it to a mechanic. He said for this type of wheel and hub, the noise and turning speed/slow down/stop is normal and made some adjustments to rear derailluer. However, when I looked closely, I realised that the small aparatus that change the gear was touching the gear and (after searching and learning the internal hub adjustment) I also understood that hub gears were not truely adjusted.

I corrected them all, but it didn’t changed the friction noise and quick slow down.

I ordered this bike online and unfortunately, the store has no branches close to me. Because, they sent me the bike unadjusted (also front wheel is not tuned well, and I can not tune it), they offered me a refund for those adjustments. I can visit another mechanic, but at this point, I don’t know who I can believe and I really need forum reviews to decide whether I will try to fix it or return.
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Old 12-03-19, 11:28 PM
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Likelihood of something being wrong with the hub in a new bike is extremely low. If the shifting for the hub interior system were off, with the gear stopping in-between, you would hear a horrible grinding noise rather than some rubbing. Problems can arise in transport in that something can get pushed against something else and get stuck or can jump out and this can cause the rubbing. A person without experience adjusting this and that can easily put the bike out of tune to such an extent that even once the original issue is resolved the bike will behave badly.

Why don't you flip the bike upside down, so that it rests on the saddle and handlebars? Put some cushion, styrofoam, rag or towel under the handlebars to protect the infrastructure there. Turn the pedals slowly, listen and observe the rear wheel and its surrounding, looking for the problem. Just that you saw the fender and brakes in the clear, does not mean that they are. The wheel is never completely even, fender is not even and flexes. The reason I asked about the rack is that the stays can bend and push the fender against the wheel. Proceed slowly with attention. By observing you learn how things are meant to work.
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Old 12-04-19, 12:13 AM
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My fear is that if there is an “extremely low” likelihood of a problem, it’s extremely likely I have that problem, unfortunately. and I really want to understand what is going on my bike

Whole evening I kept my bike in the position you suggested and tried to figure out the source. The wheel and tire is clear. It seems the source of sound and friction is in hub or there is an interaction between the hub/wheel and black plastic disc that seperates the wheel and two outside gears.

Well, given the bike I tested today, at least the friction is not normal and makes my rear wheel stop more quickly than the one in the store. I don’t think it’s because of the attachment of wheel, because it turns in balance. Am I wrong?
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Old 12-04-19, 08:09 AM
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Is the noise only when you turn the crank?
Is the noise there when the wheel turns with out the crank moving?

Last edited by Schwinnsta; 12-04-19 at 08:25 AM. Reason: Changed to the text
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Old 12-04-19, 08:47 AM
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Originally Posted by candan View Post
Well, given the bike I tested today, at least the friction is not normal and makes my rear wheel stop more quickly than the one in the store. I donít think itís because of the attachment of wheel, because it turns in balance. Am I wrong?
Was the bike in the store equipped with internal hub too? A wheel with internal hub will stop sooner than one without, but should still execute many turns once it is put in motion.

You have the option of taking the rear wheel off and testing its rotation around the axle in isolation from the rest of the bike. The process of wheel removal is cumbersome on Brompton and there is plenty of room for messing things up, particularly when putting the wheel back on. There are videos that show the process such as
. This should tell you unambigously whether the problem is inside the hub or not.

As you have a store nearby that carries Bromptons, since you went there to check another Brompton, can't you take your bike there for an examination? A mechanic with experience in Bromptons will tell you right away whether there is anything wrong there or not. Room for an error in diagnosis is only there if you go to a mechanic who mostly encounters bikes with internal gears that are complete clunkers and qualifies Brompton as such and decides that the problem is within the tolerance range expected for such bikes. My tendency would be trust the mechanic much more than yourself with the only option for reverse being of the mechanic having limited experience with internal gears.
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Old 12-04-19, 09:07 AM
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Originally Posted by Schwinnsta View Post
Is the noise only when you turn the crank?
Is the noise there when the wheel turns with out the crank moving?

When the wheel turns (with or without pedalling), I hear the friction noise.

By the way, do you work for schwinn?

Last edited by candan; 12-04-19 at 09:10 AM.
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Old 12-04-19, 10:16 AM
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Originally Posted by 2_i View Post
Was the bike in the store equipped with internal hub too? A wheel with internal hub will stop sooner than one without, but should still execute many turns once it is put in motion.

You have the option of taking the rear wheel off and testing its rotation around the axle in isolation from the rest of the bike......
Yes, the bike in the store was also 6 speed, but maybe hub model was different. I didn’t check it.

Well, I have a serious time restriction for the next 10 days and bike stores are not close to my place (yesterday’s visit was unplanned so the bike was not with me). However, the video in your post is really very informative and clear, in the following days at least I can separate the rear wheel by myself and have another look.

I will move to my home country two weeks later and that’s why I was rushing to decide whether to return it or not. But I guess, keeping the bike is the best option. If there is a production defect, Brompton will solve it; if not, the mechanic will. In both cases, I will have a well functioning Brompton, right
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Old 12-04-19, 10:25 AM
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Here's an idea. Disconnect the IGH shifter by unscrewing the adjuster mechanism that comes out of the axle on the right side. Then unscrew and remove the rod going into the hub. This effectively locks the bike into high gear. Now see if the wheel turns freely. If so the hub is either unadjusted or could have bad internals. The chain pusher should allow the wheel to spin freely on either sprocket, so if you can see something rubbing that could be your issue. I have a 3 speed hub on a 700c wheel that wouldn't work and the LBS worked on it for a while before realizing the hub is packed with 2 kinds of grease. I had read that these hubs originally used oil instead of grease so I put a few ccs down the axle and it works fine to this day. Every once in a while I replace the oil which has seeped out. Another possibility if the chain pusher does not rub and the shifter is disconnected is the cones inside the hub are too tight. There are a lot of YouTube tutorials on rebuilding an servicing SA hubs and one may address this issue for the wide range SA hub. Overtight cones will become destroyed and definitely bind the spin.
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Old 12-04-19, 11:13 AM
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Originally Posted by candan View Post
When the wheel turns (with or without pedalling), I hear the friction noise.

By the way, do you work for schwinn?
I liked the suggestion to take it out of the frame and spin it. That way you can tell if it is from the hub. Was the mechanic you brought it too, at the the shop where you purchased the bike? The dealer should sort this out for you particularly if it is a defect.

Schwinn was big in the 1950's when I was a kid.

Last edited by Schwinnsta; 12-04-19 at 11:20 AM. Reason: Change to the text
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