Steve Parry's modified Brompton
Do not attempt any job on your cycle yourself unless you have
the knowledge and experience to do so - inappropriate modifications, or
incorrectly executed modifications could endanger your and other people's
safety.
The Mud Dock meting on 3 April provided the venue for the second showing
of Steve Parry's modified Brompton. The modifications have been extremely
well carried out and Steve is prepared to modify other Bromptons for
owners, or where appropriate supply the necessary parts, to bring their
bikes to this specification, or parts of it - more about this later. The
modifications are shown and described via the pictures below, but first
some comments based on a very short test ride.
The most striking changes are in the gearing and brakes, and these are
very evident on even a short ride. The V-brakes are very smooth and
powerful, inspiring complete confidence, and are a big improvement over
the standard Brompton brakes. The 7-speed Nexus gears are beautifully
smooth, with a very sweet gear change. The 7-speed hub has rather closer
ratios than the Sturmey-Archer and Sachs 7-speeds, and considerably closer
than than the Sturmey-Archer 3 and 5 speeds normally fitted to Bromptons.
I found this much more satisfactory; the gaps on most hubs are far too
wide for me - one moment you are pedalling like a maniac, then you change
up and the knees creak. I'm convinced the wide gaps on other hubs damage
my elderly knees. Although the ratios are closer than some competitors,
the total gear spread is still good, and wider than that of the 5-speeds.
The Steve has incorporated a barrel connector to make it easy to separate
the gear cable when removing the rear wheel, which overcomes one of the
principal drawbacks of this hub gear. Steve has also modified the chain
tensioner, with better idler wheels, and this certainly contributes to the
smooth running of the bike.
The modifications in pictures
The 7-speed Nexus hub probably just rates as the most significant change.
The hub is compact, and with the normal drum brake removed it fits into
the dropouts without modification to the rear triangle. Steve stripped and
rebuilt his Nexus, and reports that it now runs much more freely than in
its original form. Other detail changes are the fitting of a Moulton type
barrel connector in the gear cable which makes rear wheel removal much
simpler than is normal with this hub, and the fitting of better idlers in
the chain tensioner, which consequently runs much more smoothly.
The neat handlebar mounted gear change. A push on one lever changes 1 gear
up, while pushing the other lever changes down 1 gear.
The second major change is the fitting of V-brakes front and rear, as
shown in this and the next two pictures. These dramatically improve the
stopping abilities of the bike. In this first picture you can also see the
neater mudguards (Moulton) and more robust stays which Steve has fitted.
Front V brake, mounted behind the forks.
Some
detail changes: The original idlers are pressed into service in place of
the original Brompton jockey wheels, which avoids the common problem of
banging ones ankles on the jockey wheels while pedalling. This arrangement
means that the bike can't be pulled along on these jockey wheels any
longer, but most people don't use them - I don't think I have used them
for this purpose once in the 9 years I have had a Brompton, but I've
certainly banged my ankles painfully on them many times. Also visible in
the picture are the improved (Moulton) mudguards and more robust mudguard
stays. Also visible is the stainless steel jubilee clip around the rear
'suspension' rubber which stiffens it, and also allows adjustment of the
stiffness of the rear suspension. Attached to the end of the rubber is an
ingenious, concealed, catch which prevents the back of the bike swinging
down when the bike is lifted. Simply bending the rubber block allows this
catch to release when folding the bike. A carbon fibre seatpost is used,
but Steve has fitted this with an aluminium inner to reduce flexing when
ridden by taller and heavier riders.
Steve is also going to fit a suspension seatpost into the stem for
mounting the handlebars, thus giving a degree of front suspension. At the
time of this report he was still waiting for delivery of the post, so this
modification was not on show.
Although a number of the changes decrease the weight of the bike, these
are more than cancelled by the extra weight of other improvements, such as
the Nexus hub, more substantial mudguards and stays, and for the fully
equipped bike Steve was quoting a weight of 27lbs. Although it is a pity
that the weight has to increase, it is inevitable, and I would judge that
from my point of view and my type of riding the improvements are well
worth this fairly modest increase in weight
Conclusions
Overall I was highly impressed by the bike. The modifications have been
beautifully executed, and both the major and more minor changes have been
well thought out by someone who appreciates what is and isn't needed, and
what is practical. Steve is prepared to carry out similar modifications
for other owners, or, where appropriate, supply parts. He classifies the
modifications broadly into 4 stages:
- 7-speed Nexus gear system
- V-brakes
- Detail changes - eg suspension clip and rear triangle retention latch
and stem clip strengthener
- Stem suspension system - Steve is awaiting parts for this, so it was
not fitted on the test bike.
If you want to discuss modifications with Steve, and prices, you can
contact him on 01934 516158. Don't forget that Steve has also produced
some very useful improvements for Birdys (see report on the November Mud
Dock ride and the report on his front carrier bracket for Birdys and Bromptons), so you may want to contact him about these too.
If you have any information suitable for inclusion on these pages,
please contact us.
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Last updated: 4 April 1999
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