Brompton M2R New owner - Questions about QR on seat post and folding

[chriscross1966]

That looks like a clamp that has been overtightened I'm afraid. There are some aftermarket clamps that are stronger (and a lot that aren't, but are pretty).


In response to the person claiming the Brompton is a 200 quid bike, it's made by hand (including a lot of the actual frame welding) from a pile of almost entirely proprietary parts (which it needs to achieve the tiny fold) in a part of London where you could spend 200 quid on lunch and still be hungry to tolerances that have demonstrated that it's the quality of manufacture and not the overall design that counts whenever someone has tried to copy it in the last decade (since the patents ran out).... I'm mildly amazed they can do it as cheaply as they do.

 

[FolderBeholder]

Surely there are more of that same qr part correctly doing its intended job, than not. That tells me it’s design isnt flawed, nor is its execution. Could it be improved? Perhaps.

This product is more than the sum total of its (many) parts. Therein lies its value and it’s commanded price and those willing to pay it.

We are buying an entire Brompton...comprised of it’s many parts. Some of those will wear out, some will fail, some may not be perfect. Show me any machine thats any different.

I like funky machines, warts and all. The Brompton is indeed a funky machine.

 

[CaptainWheezy]

I dont think the part is poorly designed, it looks like its been overstressed by poor maintanance?

I disagree here. This is a cheap part that when it fails, lets the whole bike down (makes it unusable). Like I said, this part failed on my wifes bike, it had done less than 100 miles and had NOT been over tightened. The part is just plain poor design. There is too much slop around the nut to hold it securely, and once it does slip, its game over.

For what its worth, we have 3 Bromptons, all were bought new as S6L's. All have been of variable quality. I'm not saying its a £200 bike, but for the premium asked, there are certainly areas that could be improved, and quality checks seem somewhat lacking.

 

[TheDoctor]

The seat QR on my M6R has never needed tweaking in over a decade, and the only bits I've replaced are consumables - tyres, chain and sprockets.
It's not cheap, but it's the only bike I've got that I can take on Eurostar and then tour on it.
Planning on taking it to NZ next year *glees*

 

[chriscross1966]

Ive gone back to the stock clamp on my daily rider, an 11-speed that is a riot of titanium and carbon aftermarket parts.. ive tried several aftermarket ones and not found one as good.

 

[bence8810]

Maybe I was just unlucky then, will go to a brompton dealer here in Tokyo and get the part looked at and try my luck. This bike is nearly unused, totally spotless. I can’t imagine any abuse that might have caused that part to fail.

I think the brompton is brilliant and I don’t regret the large amount of money I spent on it. There isn’t a bike that’s this versatile out there as far as I know.

Having said that on my cheapo Dahon Metro 2010, the QR is much better.

Thanks again for all the help, I’ve just ridden the bike to my station here in western Tokyo (Mitaka) and parked it at my usual underground bike parking spot. The small wheels meant I couldn’t store it in the designated bike racks as the chain tensioner got caught in the guard rails.
No problem, folded the rear wheel under and parked like a boss at a corner that’s not utilized, the staff at the place was floored! Fantastic bike.

Thanks for all the help again!
Ben

 

[FolderBeholder]

Having said that on my cheapo Dahon Metro 2010, the QR is much better

Maybe the previous owner accidentally tried to ham-fist that QR in the wrong direction and caused that problem, who knows? But a new one....via warrantee or otherwise would likley put this whole issue to bed.

The QR/seatpost on MY $300 EuroMini folder hasn’t ever budged in quite regular use either. And I DON’T unweight the seat on that bike like I do on my S6L.

BUT...it doesnt fold as well, hold some type of decent resale value, or....did I mention it doesnt fold as well?

 

[bence8810]

So to bring this to an end, I took the bike to a local Brompton distributor who changed the clamp for me (albeit me needing to pay for it) and it works like a charm. There's no gap between the plastic housing and the nut and I haven't yet noticed the post slipping but I'll monitor that further. Most important is the clamp works and this new one indeed looks firm and is fit for purpose. I judged the quality based on the failed part, the new one looks good so far.

While there I also bought an extended seat post which is much better for my height and the dealer quickly replaced the bottom bracket for free as my serial was in that pool that qualified.

The dealer also inflated my tire saying it was too low, it is hard as stone now, put 100PSI in. I read that is the factory default, is that really necessary? The bike sure rides faster now but it gives an incredibly bumpy ride.

Thanks all for bearing with me with this issue, glad it is all sorted now!
Ben

 

[rogerzilla]

Generally you want to run high tyre pressures, yes, especially at the rear which takes more weight and has suspension to remove harshness. Check the tyre sidewall as 100psi is too high for some 16" tyres and you could blow it off the rim.

 

[FolderBeholder]

So to bring this to an end, I took the bike to a local Brompton distributor who changed the clamp for me (albeit me needing to pay for it) and it works like a charm. There's no gap between the plastic housing and the nut and I haven't yet noticed the post slipping but I'll monitor that further. Most important is the clamp works and this new one indeed looks firm and is fit for purpose. I judged the quality based on the failed part, the new one looks good so far.

While there I also bought an extended seat post which is much better for my height and the dealer quickly replaced the bottom bracket for free as my serial was in that pool that qualified.

The dealer also inflated my tire saying it was too low, it is hard as stone now, put 100PSI in. I read that is the factory default, is that really necessary? The bike sure rides faster now but it gives an incredibly bumpy ride.

Thanks all for bearing with me with this issue, glad it is all sorted now!
Ben

All’s well that ends well.
Thanks for the update.

 

[bence8810]

Generally you want to run high tyre pressures, yes, especially at the rear which takes more weight and has suspension to remove harshness. Check the tyre sidewall as 100psi is too high for some 16" tyres and you could blow it off the rim.

I checked the tire - it’s the stock brompton - and it says on the tire itself to inflate to 100PSI! I could never do that with the little hand pump.

I have the firm suspension and with this high pressure, the brompton gives a very bumpy ride but it’s sure enjoyable.

I hear a lot of road noise, is that normal for the brompton tires? Specially since it’s been inflated according to the specs.

Another thing I noticed that the whole drivetrain in general is very noisy when comparing it to my old Dahon. Is that normal?

Thanks
Ben

 

[TheDoctor]

You'll want a track pump to get up to 100 psi in a reasonable timescale. The small pump that comes with Bromptons really is a get-you-home item at best.
Can't say I've noticed the drivetrain on my M6R being all that noisy - there's a ticking noise from the rear hub gear, but you won't have that.
Is the chain lubed?

 

[rogerzilla]

A track pump is a life-changing purchase.

The little pump, as mini-pumps go, is ok but not much fun to use. Kimble did some experiments to prove a 16g CO2 canister wouldn't blow any currently available* Brompton-fit tyre off the rim, so that's an option for roadside repairs.

*the old 28mm Stelvios would probably not cope

 

[12boy]

There are several things that can cause noise ...you haven't said what your drivetrain is. If you have a 3 speed hub, they do make a bit of noise. I put a few ccs of 5-20 synthetic oil in mine whenever it gets noisy, and although it slowly oozes out it is much quieter. When it isn't I put another few ccs in. The polymer suspension block needs to be greased if it is the noise maker. I've noticed it compresses more with a vigorous push on the pedals than it does on a bumpy road. Hold the bike so it can't go forward and press hard on the pedal to see if it is creaking.The seat post will creak if it isn't tight, but only tighten it to the point it doesn't slide down. Too much can ovalize the post. I prefer leather saddles and they too can creak a bit. Finally, the hinge for the rear triangle can also make noise if the bolts are loose, the bushings shot or it isn't oiled where the nylon washers sit on the bike. Hopefully you keep your chain well lubed as a dry chain isn't quiet. I have in the past had trouble figuring out where noise is coming from, since it seems to travel up the seat post. BTW, I only put about 75 PSI in my tires as whatever speed I've lost is made up for by comfort.

 

[TheDoctor]

There are several things that can cause noise ...you haven't said what your drivetrain is. If you have a 3 speed hub, they do make a bit of noise. I put a few ccs of 5-20 synthetic oil in mine whenever it gets noisy, and although it slowly oozes out it is much quieter. When it isn't I put another few ccs in. The polymer suspension block needs to be greased if it is the noise maker. I've noticed it compresses more with a vigorous push on the pedals than it does on a bumpy road. Hold the bike so it can't go forward and press hard on the pedal to see if it is creaking.The seat post will creak if it isn't tight, but only tighten it to the point it doesn't slide down. Too much can ovalize the post. I prefer leather saddles and they too can creak a bit. Finally, the hinge for the rear triangle can also make noise if the bolts are loose, the bushings shot or it isn't oiled where the nylon washers sit on the bike. Hopefully you keep your chain well lubed as a dry chain isn't quiet. I have in the past had trouble figuring out where noise is coming from, since it seems to travel up the seat post. BTW, I only put about 75 PSI in my tires as whatever speed I've lost is made up for by comfort.

The OP has an M2R - that's a 2 speed cassette and no hub gear.
Good call on the chain though - I was out earlier and someone cycled past with a chain that sounded like a very upset hamster.