Brompton X Rohloff
With a 526% range, one shifter and only a yearly / 5000km oil change you can see the attraction. It is not the cheapest option, but you will have gearing for any hill or mountain climb. Using this brilliant hub you can also fit disc brakes to your Brompton.
- The Stock BWR with 50t has a gear range of 302%, ratio of 1.99-6.03 with MPH per 90 RPM (cadence) at 8.9-26.9mph.
The gear range using 54t chainring and 13t would give 1.54-8.13m / 19-102" - (5.17-27.2mph) - this would be the most common choice.
Notes about the build;
To start, you need a suitable rear triangle. I have used Kinetics and Vostok (Vostok no longer in business) These are 135mm OLN and both have disc or caliper brake fitting options. Both fit on very simply with a spindle/screws change on the rear hinge.
Using a Rohloff with the 13t sprocket / wide carrier the chain line is slightly out but more than adequate.
When building with Kinetics I tend to leave the bottom bracket, however with Vostok, because you need to generally use their fork hook as well to fit the shape of the rear triangle, I go for a wider bottom bracket.
When it comes to the wheel build, Rohloff are happy as long as the one cross lacing pattern is used and the rim does not obstruct nipple movement to spoke angle. The build are use is a one cross pattern with the spoke heads facing out; this offers the best nipple spoke angle of entry to the rim.
I prefer to use an Allen key headed 5mm skewer for the Rohloff, using a Jtek tensioner insert that holds the tensioner in place and buts against the frame dropout. I have had great success with this and favour it. It requires no tensioner modifications and most pre-owned Rohloff hubs are QR.
For the axle nuts option, I use the standard Rohloff M10 nuts on non drive side. Under the tensioner I use a Rohloff axle serrated washer and on the outside of the tensioner I use an M10x17x5mm nut to secure, with the tensioner modified this fits perfectly flush to the edge of the axle.
When it comes to shifters I tend to favour the stock Rohloff twist shifter, they always build up with really smooth shifting and it’s super easy to blast through a whole number gears in one movement. There are aftermarket shifters and some of them are better than others but in classic Brompton style, I want the bike to be as functional as possible and if it takes a knock the Rohloff shifter probably isn’t going to come off too badly.
The S type handlebar works very well as there is no bend to it however the M type/H type handlebar has quite a short grip section. Two options for this are using a very short 60 mm grip - Sram do one that fits nicely or using an alternative handlebar such as the Joseph Kuosac mid rise. These are 600m wide, normally need 20/30mm cutting off to allow perfect fold less you’re using large easy wheels and/or rear rack, so allow a lot more room for a full-length grip and shifter.
The weight;
The Rohloff does weigh more that the BWR, there is no hiding that, but the overall bike weight is not much different and you can easily save weight elsewhere.
With the conversion, the main two changes are the hub and the triangle;
The BWR Hub is 940 grams whereas the Rohloff Speedhub is 1825 grams.
The rear triangles are 979grams for Kinetics over the stock steel one is 755 grams and 461 grams for titanium.
A stock M6L converted to Rohloff just changing the triangle and wheel was 12.97kg and a S6L with hydraulic disc front and rear was 13.24kg.
The stock M6L is 11.7kg, so roughly only a 1.27kg increase!
With a 526% range, one shifter and only a yearly / 5000km oil change you can see the attraction. It is not the cheapest option, but you will have gearing for any hill or mountain climb. Using this brilliant hub you can also fit disc brakes to your Brompton.
- The Stock BWR with 50t has a gear range of 302%, ratio of 1.99-6.03 with MPH per 90 RPM (cadence) at 8.9-26.9mph.
The gear range using 54t chainring and 13t would give 1.54-8.13m / 19-102" - (5.17-27.2mph) - this would be the most common choice.
Notes about the build;
To start, you need a suitable rear triangle. I have used Kinetics and Vostok (Vostok no longer in business) These are 135mm OLN and both have disc or caliper brake fitting options. Both fit on very simply with a spindle/screws change on the rear hinge.
Using a Rohloff with the 13t sprocket / wide carrier the chain line is slightly out but more than adequate.
When building with Kinetics I tend to leave the bottom bracket, however with Vostok, because you need to generally use their fork hook as well to fit the shape of the rear triangle, I go for a wider bottom bracket.
When it comes to the wheel build, Rohloff are happy as long as the one cross lacing pattern is used and the rim does not obstruct nipple movement to spoke angle. The build are use is a one cross pattern with the spoke heads facing out; this offers the best nipple spoke angle of entry to the rim.
I prefer to use an Allen key headed 5mm skewer for the Rohloff, using a Jtek tensioner insert that holds the tensioner in place and buts against the frame dropout. I have had great success with this and favour it. It requires no tensioner modifications and most pre-owned Rohloff hubs are QR.
For the axle nuts option, I use the standard Rohloff M10 nuts on non drive side. Under the tensioner I use a Rohloff axle serrated washer and on the outside of the tensioner I use an M10x17x5mm nut to secure, with the tensioner modified this fits perfectly flush to the edge of the axle.
When it comes to shifters I tend to favour the stock Rohloff twist shifter, they always build up with really smooth shifting and it’s super easy to blast through a whole number gears in one movement. There are aftermarket shifters and some of them are better than others but in classic Brompton style, I want the bike to be as functional as possible and if it takes a knock the Rohloff shifter probably isn’t going to come off too badly.
The S type handlebar works very well as there is no bend to it however the M type/H type handlebar has quite a short grip section. Two options for this are using a very short 60 mm grip - Sram do one that fits nicely or using an alternative handlebar such as the Joseph Kuosac mid rise. These are 600m wide, normally need 20/30mm cutting off to allow perfect fold less you’re using large easy wheels and/or rear rack, so allow a lot more room for a full-length grip and shifter.
The weight;
The Rohloff does weigh more that the BWR, there is no hiding that, but the overall bike weight is not much different and you can easily save weight elsewhere.
With the conversion, the main two changes are the hub and the triangle;
The BWR Hub is 940 grams whereas the Rohloff Speedhub is 1825 grams.
The rear triangles are 979grams for Kinetics over the stock steel one is 755 grams and 461 grams for titanium.
A stock M6L converted to Rohloff just changing the triangle and wheel was 12.97kg and a S6L with hydraulic disc front and rear was 13.24kg.
The stock M6L is 11.7kg, so roughly only a 1.27kg increase!
