chris folder

Hi guys I have not long bought a m6l can you tell me is this right im in say 4th gear im approaching a hill I drop into 2nd or 1st gear is it normal for the 2 lowest gears to make more noise When peddling? 3, 4, 5, 6 are quite just a little tick sound when cycling but in 1st and 2nd are louder is my bike ok should it be like this? Is your lower gears louder can you also feel them thought the pedals a bit

fietsbob

IDK You, have a wider ratio spread 3 speed (than the BSR), and 2 cogs on the end driver ,

what to you use for Lubricant in the hub & how often do you add more?

say what the gear is ,, hub H M L ? cog tooth count that the Big/ little ?

Lowest gear is Low in the hub and Larger of the 2 cogs..

Middle gear in the Hub drives the hubshell directly 1:1 so no planetary gears are engaged ..

High is an Overdrive gear, Low is a reduction gear Then, the hub shell and the cog turn at different rates.

dynaryder

You have to realize there are two different things going on. Your bike doesn't really have 6 gears,it has 3 low gears and 3 high gears. This is because you have a 3spd internal hub paired with a two speed derailleur. The derailleur shouldn't have any effect on sound,but which hub gear you're in will. All internal hubs make noise,some are louder than others. Many get quieter as they break in. I would ask the shop you bought the bike from to take a look and see if they think it sounds abnormal. If the bike is new,it might also just need the shifter cable adjusted do to initial stretch.

fietsbob

Its More or less a Half step . chain shover moves the pulley sideways. .. some noise as the chain Passes over those Pulleys ..




Where My mountain drive crank uses the same BSR 3 twice with a little gap in between so they are spaced out linear.

54, -'21.6t' [77, 58, 43_31, 23, 17"] (50 20 would be even numbers)

Yea the Meshing of the internal Planetary gears can be perceived. It's nothing a Passer By can hear .

radityajoko

i had this noise problems too. but cleaned the chain and now its gone.
the chain might get a little dusty from the storage and it makes it less flexible

tudorowen1

I have had 2 six speed Bromptons and they both did what you say yours is doing..After a couple of years the 1st and 2nd gears will get a little quieter.I simply think it is because you are putting more torque through the gears in the low gears...

chris folder

Hi its sounds like a prop plane when I ride up hills in 1st and 2nd gears is that how it should be then? That is good to hear others say there's are the same as I thought I had a odd bromptom not made right. it takes some getting used to that noise I dont get it the other 4 gears are quite

jur

Is it when the chain is on the biggest cog in the rear?

There may be at least 2 reasons,

One is that the chain pusher bracket is rubbing against the pulley due to incorrect adjustment.

The second is much more complex. I found that our 2 new Bromptons were making more noise compared to my previous one, when they are in the bigger gear in the back. I looked at the problem and found that the two chain tensioner pulleys are not coplanar with each other nor the cogs. When in the low gear (biggest cog), the pulleys run closer to each other, and the lack of alignment made the chain rub against the pulleys, producing an unpleasant additional noise. The tension pulls the pulleys in this direction of producing more noise.

So I disassembled the tensioner, and with careful heating with a hair dryer, and some bending and cooling, was able to get the pulley axles parallel to each other as well as properly perpendicular to the cogs, so that the cogs and pulleys are now coplanar. And the noise is gone.

So quite complex, I'm afraid, to fix. I think this is a manufacturing defect. Probably all new ones do the same. Somehow the mould for the tensioner is screwed up or something. Or maybe they are assembled and somehow the plastic relaxes a bit. Very annoying. At least mine is now perfect.

chris folder

Hi I will have a good look at that area of the bike wensday I cant see that noise is right Surely? Brompton told me all 6 speed bikes make a louder noise in the lowest 2 gears. Yet some tell me there quite. Its bugging me. I mite ride a few 6l demos in shops ride them in the low gears see if they make a noise

bhkyte

Pretty poor show if a simple gear shifter has a manufacturing fault like Jur describes. I thought you had 5 speeds now jur?

fietsbob

in the SEA Boutique Aftermarket Brompton parts Biz there is CNC Aluminum Chain tensioners in both types

6 & 2 speed . sideways shifted Pulleys , or 3 & 1 speed without sideways pulley motion.

jur

I have for the moment not used the 5-speed on my Brommie, will put it on when we go touring or something like that that requires wide gear range. Connie's bike does have it, plus the 2-speed shifter, for 10 speeds. Mine stays 2-speed for the moment.

chris folder

Hi jur your right I have noticed my chain pusher is rubbing on the little chain wheel. I have put gears all over the place tonight having a go at adjustment of chain pusher I had a small gap each side of the pusher in 1st as soon as I droppedIin 2nd it rubbed again so I adjusted pusher to clear again put back in 1st and then1st is out. What a do I will take time Monday afternoon to set the pusher correct I have downloaded bromptom manual on setting it. They dont give you much room each side of puser

BieneTVB

Hello,

here i am 7 years later with the exact same problem.
Just bought a 2022 Brompton 6 speed and have that "prop plane" sound just in 1st and 2nd gear... (2nd louder than 1st). Only when padeling.

What is the solution? Does the sound come from the chain pusher or tensioner or is something wrong with the hub?