Originally Posted by
linberl
The shop tried that...we are talking about a 10cm difference (it was 9.87). And I ride in an aggressive position so the S bars are the only ones close to the right height. On my NWT, my bars are 2.5" below my saddle. So rotating the bars back on M, H, or P bars puts me too much upright. I've got some disc issues and in my case, being bent is what helps to open space between the discs; I know, most people with back problems like to be upright. I asked if I could put my Nitto allrounders on (like a smaller north roads) and they said it wouldn't work, it would screw up the fold and the cables and some other thing I can't recall. Because low north roads are the only way I think it could work for me. At some point, it is just too much trouble and too much after-market fiddling/cost.
Searching for less reach in combination with a low bar is a bit of an unusual problem on a Brompton. Here are some options:
1.) Buy a used MK3. It has the old mainframe, used from 1987 up to 2004, which is about 3cm shorter (wheelbase 101cm vs. 104 cm on the Mk4). Mk3 is better than Mk2 as, being the latest model with the old frame, it has the best components of the older models, thus not needing many upgrade parts. This means: Dual caliper front brake, better spokes and some other bits. I'd upgrade to the brake levers of the post 2013-bikes and install a rear frame clip (standard from 2008 on). The Mk3 was built from 2000 - 2004 and I would try to find one after 2002 as it already has the bolt on for the dreailleur on the rear-frame. Or you manage to find an early one with the five-gear S/A-sprinter on it (quite rare as only built for less than a year).
That leaves 7cm to go.
2.) Change and tilt your bars. As the Mk3 is always an M-model it as (together with the P) the lowest stem of all standard bromptons (valid for the M-model BEFORE 2017). Switch the bars to something lower than the standard (i.e. the new standard brompton-bars used from 2017 on) and tilt them towards you. Quick-release on the bolt makes the bike fold as usual. Should almost solve the issue. Works best with the M-stem as the stem itself has less of an angle than the P but the P should still be ok.
Alternatively you could also use a Dahon/Tern andros stem adaptor with a flat bar - it offers about 8cm of "negative" reach.
https://buy.ternbicycles.com/products/andros-stem
3.) Use the
Brompton seatpost-adapter-pin (part number QSAPA). This should bring the rest of the necessary limitation of reach w/o bringing the saddle too far forward. (BTW: This pin should always be pointing forward, never backwards as shown at nycewheels as this would stress the frame too much).
With a combination of all three you should be there.
As an alternative you could look at
this company from the netherlands. They could provide you with a custom made stem, usually used for getting higher bars. But you could obviously also use it for getting less reach, using an ahead stem the other way round (or possibly a traditional stem in the same way). This way you would possibly not have to deal with the saddle position but the folded size of the bike would become bigger.