My new Bromptnot

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brommieinkorea

Senior Member
Location
'Merica darnit
Every bike I've bought has needed the gearing lowered, surprises me that 54 teeth is too low, Id top out in the 50 mph range with that gearing ! I'd be interested to hear what the entire spec is. Do they have their own rear hub or is it a Sturmey Archer ? Is it light weight ? Does it use the same rear pivot as Brompton, or have they improved it ?
 

brommieinkorea

Senior Member
Location
'Merica darnit
Regular derailer, sorry hadn't looked close enough. Lots of questions though still. Did Bona Bikes retain the awful plastic seatpost sleeve ?
 
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dimrub

dimrub

Über Member
Every bike I've bought has needed the gearing lowered, surprises me that 54 teeth is too low, Id top out in the 50 mph range with that gearing ! I'd be interested to hear what the entire spec is. Do they have their own rear hub or is it a Sturmey Archer ? Is it light weight ? Does it use the same rear pivot as Brompton, or have they improved it ?

Well, in terms of drivetrain, we have:
- H&H Studios 7 speed 11-32 cassette
- A newly installed 58T chainring
- A gold-anodized 11s chain, to fit the narrow cassette (KMC I believe)

In terms of gear inches, this gives us a range of 29-84. For comparison, my gravel bike, a Sonder Camino, 1x12 setup, has a range of 25-112. So yes, definitely shifted towards the lower side of the range. But the gravel bike was chosen for good performance on steep climbs while fully loaded. I don't need any of that for a Brompton - I could have gone much higher... except I'm all maxed out. I can't go smaller than 11 on the sprockets - and I can't go bigger than 58 on the chainring. As it is, it's borderline in terms of interfering with the folding, so I'm quite lucky I didn't go for 60 - that would have been too much. I still spin out on the descends, but I'm fine with it.

The wheels are by LitePro, and I don't know which hubs are they using, but it's definitely not SA. By the rear pivot - do you mean the rear triangle folding mechanism? If so, I think it's pretty much the same, I haven't noticed any difference.

About the seatpost sleeve - yes, it's there, and I'm a bit fearful of the moment it starts falling apart - I think it's a safe bet that it will.
 

CXRAndy

Guru
Location
Lincs
Take it out, use sand paper to rough the surface of the seat post. If that doesn't work get the post knurled to provide friction
 
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dimrub

dimrub

Über Member
I had to tinker with it some more. At some point an awful creaking sound appeared. It took me forever to narrow this down, but it turned out to be the interface between the non-drive side crankarm and the spindle. The splines were too wide, and the crankarm - probably undertightened. I replaced the crankset with a new one, with narrow splines, and tightened it well. I've also rewaxed the chain once. The bike is eerily quiet now. I've also switched the chainring again, down to 56: 58 was a tad too much in terms of getting in the way of the folding. Oh and I got me a rear rack. I'm not sure theirs is similar to Brompton's: it's very wide in its rear part. It's also very light, so I don't mind the added weight, but the bike is now rock-solid when folded.

I like the knurling idea, but haven't had the chance to do it yet, will do when I get around it - it's a cool idea. It's the only issue now, and a minor one, since reapplying the assembly paste solves the problem for a while.
 
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