Brompton owners

A little lazy to google the details, but do those MTBs pivot at the BB, and hence maintain continuous distance from BB to rear hub, which is why they work there and not say not on a Brommie, as it pivots behind the BB, so distance between rear hub and BB changes throughout suspension travel.

My understanding (which is often wrong) is that belt drives often still have/use a tensioner/snubber so as to maintain strong tension on the belt to avoid belt slippage, as opposed to taking up slack created by moving rear wheel (not pivoted at BB).

TBH, it's been a good while since I looked into this. Tech/materials/techniques may have moved on this then!

but do those MTBs pivot at the BB, and hence maintain continuous distance from BB to rear hub

No - for the simple reason that there's a thumping great gearbox in the way.

And probably for the slightly more complex reason in that it's hard to build a good suspension platform that keeps chain length constant through the travel.

Colour me amazed. That looks awesome!

Thanks for the pic.

Yeah. I'd like to try one. I'm super curious.

Now let's get one a brompton...

Anyone currently riding a fg Brompton? Would you do it again, other than for the lols?

Yep, as @Howard has pointed out, my Brompton is fixed gear. Has been for a couple of years now. This is mine:

I would do it again - indeed, I will be doing it again on my next custom Brompton as it's the only way I'm going to get the gearing high enough with a track hub on the back. If I fit a freewheel then the gearing's going to be too low unless I fit a chainring so large it'll interfere with the fold. It's basically using a magic gear (50/14 I think) and as you say the tensioner only comes into play to take up the slack on the fold. I'm running it fixed because I've got a Powertap track hub on the back end (with custom end caps to reduce the OLN to 115mm) so that ticks another of your boxes. You can't skid it, as if you try the internals of the Powertap rear hub will undo themselves and the torque tube will try to exit stage left, but being a boring old giffer doing rad whip skids not really on my list of priorities. Can't say I've ever really had a problem with pedal strikes with 170mm cranks. You can get pedal strike if you really bank it over, but hey, Don't Lean.

Nice cranks (assuming those are the ones you got from me).

They are nice cranks, but actually these are different cranks I already when I got the equally nice ones off you. I was going to put your on my winter bike, but then got distracted and put some Fulcrums on. Yours may well go on the next Brompton though.

Hummingbirds (off of on here - https://www.lfgss.com/conversations/277334/ ) can be fixed and are going to come with belt drive I think. No disc tho' and would need a 'healthy' insurance payout.

Found your thread, outstanding work. Powertap looks to be the cleanest solution, but probably requires a better machine shop than I have (which looks more like a dremel and a clamp than your setup). If I abandon the belt drive, that should open up NDS crank or spider based power meters, but google is unclear as to whether the strain gauge would foul the frame, particularly on the NDS approach (4iiii, Pioneer, Stages). Pedal based PMs not acceptable because I'm not a monster.

Cheers. Making up the end caps does require decent tools - a lathe as a bare minimum - but that's why nice men with little machine shops exist. Once you have some 19mm hex bar stock it's a half hour job for a chap with a decent lathe, so it shouldn't cost too much to have someone make them up. You could even modify the stock ones, I suspect, with the same end result.

Think I've found the source of my creak.

Broken washer + dry suspension block.

Sorted the dry bit, where can I get a replacement easily? Brilliant Bikes have them but I don't need 6.

maybe worth having spares for the price

I maybe about to change jobs and my commute will take be into Brighton (25 miles from home). I cant sensibly commute there and back but would like to ride home. Sadly southern rails bike policy says no regular bikes on any service which terminates in Brighton between 7am and 10am so I cant even hop off at hove.
What is a sensible commute on a Brompton? Would the 25 mile trip home (pan flat) be a sensible option?

No

Concise

And correct

What's your route into Brighton? Trying to imagine a pan flat route in any direction other than out to sea is difficult!

If you ride west - you can get to past Chichester and never go up a hill

Would it be every day or just when you fancy it?

I’ve risen Dunwich Dynamo and London to Brighton on a Brompton

I want a brompton :(

I’d like to do it a couple of times a week in the winter and more in the summer. And @BunninZootius you are correct. It is indeed a westerly commute home. Although the swing bridge at Littlehampton has a metre or so elevation gain.

Check and see if there’s a Brompton Dock at Brighton station (I think there might be).
Rent one for a day and give it a go. Better to see for yourself than go on opinion. Also if you’ve never ridden one before you’ll get a true test.

Just bought a new Brompton from Evans.

1. M6L. Turkish green. OTP but swapped out the tyres for marathons. Added folding front basket. Picking it up proper later/tomorrow. Also ordered a K9 Sportsac for the dog. Look it up, it's fricking weird/awesome.
   
   

I'm so fucking excited, more so than I thought I would be. Basically I started a new job last week and HAD been excited about riding my fixed properly in London again... but the wait list for garage bike space is many, many waits. Little time for extra exercise, so needs to come from commute.

Note - we have an 11-year old Brompton (ML3, racing green) already in our household but the wife uses it to commute. I did pay for a brand new rear triangle hinge for it last year when I was using it...and every service... so that makes sense that I get the new one, right?! Hah!

Great idea, I hadn’t thought of that but there isn’t one there. I wonder if Evans will give me an overnight test ride.

If not try Cycle Surgery, they used to have demos of various models