I have now set up my new site, I will now proceed to transfer the information over and grow that.
Many changes, many new things, see it here;
Thanks!
Thursday 29 August 2019
Wednesday 10 July 2019
Brompton X Rohloff
Brompton X Rohloff Speedhub 14
With a 526% range you can see the attraction. Its 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.
To start, you need a Vostok or Kinetics rear triangle.
So 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.
Using a 54t chainring the following ratio / speed is found;
16t would give 0.942-4.95 / 4.20-22.1mph
17t would give 0.88-4.66 / 3.96-20.8mph
Notes about the build;
Using a Rohloff with the 13t sprocket / wide carrier the chain line is quite far out and you have two options. Either leave the chain ring where it is and run a slightly sub optimal chain line or use a 122mm bottom bracket and potentially affect the fault.
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 the 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.
For the axle nuts, I use the standard Rohloff M10 nuts on non drive side however underneath the tensioner I use a M10x5x15 nut. This nut ensures the wheel is held securely, that the tensioner is held separately with the outer nut and just takes away any
concern that the wheel isn’t secure as it should be. 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 real 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
With a 526% range you can see the attraction. Its 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.
To start, you need a Vostok or Kinetics rear triangle.
So 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.
Using a 54t chainring the following ratio / speed is found;
13t would give 1.16-6.09 / 5.17-27.2mph - this would be the most common choice.
14t would give 1.08-5.66 / 4.8-25.3mph - for someone looking to climb mountains with a loaded bike
15t would give 1.00-5.28 / 4.48-23.6mph16t would give 0.942-4.95 / 4.20-22.1mph
17t would give 0.88-4.66 / 3.96-20.8mph
Notes about the build;
Using a Rohloff with the 13t sprocket / wide carrier the chain line is quite far out and you have two options. Either leave the chain ring where it is and run a slightly sub optimal chain line or use a 122mm bottom bracket and potentially affect the fault.
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 the 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.
For the axle nuts, I use the standard Rohloff M10 nuts on non drive side however underneath the tensioner I use a M10x5x15 nut. This nut ensures the wheel is held securely, that the tensioner is held separately with the outer nut and just takes away any
concern that the wheel isn’t secure as it should be. 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 real 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
Tuesday 8 January 2019
Two speed + larger chainring
The two speed is an obvious choice to save weight, but with the limited gears you need to pick you options well or be left churning a massive gear or spinning out too quickly!
The stock ratio / MPH for RPM/cadence of 90 is - 3.38-4.5 / 15.1-20.1 mph.
It is very common to increase the chainring size, 60t seems to be the biggest option without too many issues. Larger hits the front fork hook / the chainstay. On my personal bike I now use a 122mm BB to stop the chainring contacting the chainstay when folded.
The following ratios and MPH90C are per increased ring sizes;
56t - 3.5-4.67 / 15.6-20.8mph
58t - 3.63-4.83 / 16.2-21.6mph
60t - 3.75-5.00 / 16.7-22.3mph
The 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.
So with a 60t x 12/16 you would need to pedal at 108.5 RPM to equal a BWR hub using 50t 13/16 at 90 RPM.
Tuesday 11 December 2018
2 Speed Hub Drivechain Alternatives
A page about various non stock gearing systems..
Converting a 2 speed to 3 speed - non IGH
Stock hub - simple and easy
Simply using a thinner snap ring will allow a third sprocket to be fitted to the stock hub!
Stock snap ring is 2.2mm and the replacement needs to be 1.5mm.
This allows you to then use a combination of sprockets such as 12-14-17 making a 2 speed ratio a lot more usable!
You can simply use a friction shifter or other shifters may work depending on the set up. It is common to need to modify the cable run, with an inner cable going straight through the spring of the anchorage and fastened with a barrel nut / grub screw.
- On a Ti triangle you are limited in sprocket size to 18t without modification.
Hubsmith hub - 11t capability!
Using a Hubsmith rear hub, you can replace the free hub body to one that accepts a locking, such as on traditional cassettes, rather than a snap ring.
This allows you to fit an 11t Shimano style cog, meaning you can widen that gearing range!
http://www.brommieplus.com/portal_c1_cnt_page.php?owner_num=c1_343119&button_num=c1&folder_id=44131&cnt_id=708310&search_field=&search_word=&search_field2=&search_word2=&search_field3=&search_word3=&bool1=&bool2=&search_type=1&up_page=1
Converting a 6 speed to 9 speed
Simply convert the external cogs from 2 to 3 and change the shifter - see - "Converting a 2 speed to 3 speed - non IGH"
Suitable for BWR hubs, or BSR*/SRF3*/SRF5 hubs that have been converted to a dual sprocket driver.
* These hubs offer ratios of 0.75, 1.1 and 1.33, compared to the BWR which offers 0.638, 1.1 and 1.567.
Converting a 2 speed to 3 speed - non IGH
Stock hub - simple and easy
Simply using a thinner snap ring will allow a third sprocket to be fitted to the stock hub!
Stock snap ring is 2.2mm and the replacement needs to be 1.5mm.
This allows you to then use a combination of sprockets such as 12-14-17 making a 2 speed ratio a lot more usable!
You can simply use a friction shifter or other shifters may work depending on the set up. It is common to need to modify the cable run, with an inner cable going straight through the spring of the anchorage and fastened with a barrel nut / grub screw.
- On a Ti triangle you are limited in sprocket size to 18t without modification.
Hubsmith hub - 11t capability!
Using a Hubsmith rear hub, you can replace the free hub body to one that accepts a locking, such as on traditional cassettes, rather than a snap ring.
This allows you to fit an 11t Shimano style cog, meaning you can widen that gearing range!
http://www.brommieplus.com/portal_c1_cnt_page.php?owner_num=c1_343119&button_num=c1&folder_id=44131&cnt_id=708310&search_field=&search_word=&search_field2=&search_word2=&search_field3=&search_word3=&bool1=&bool2=&search_type=1&up_page=1
Converting a 6 speed to 9 speed
Simply convert the external cogs from 2 to 3 and change the shifter - see - "Converting a 2 speed to 3 speed - non IGH"
Suitable for BWR hubs, or BSR*/SRF3*/SRF5 hubs that have been converted to a dual sprocket driver.
* These hubs offer ratios of 0.75, 1.1 and 1.33, compared to the BWR which offers 0.638, 1.1 and 1.567.
Tuesday 21 August 2018
Aftermarket Brompton Components + Weights
A list of common additions / upgrades and their weights!
Pedals:
Chainrings:
Litepro 53t with bash - 105 grams
Cranks:
Ti Parts Workshop - Forged, 53t, with bolts, - 477 grams
Thorn Triple Solo Alloy - no ring/bolts - 140mm- 1673L140 - 484 grams
Bottom Brackets:
Shimano BB-UN55 - 309 grams
Front Hubs:
Jtek superlight - Xgrams
SP dynamo - sv-9-fb - Xgrams
Rear Hubs:
Hubsmith R015R 28h - 227g
Rims:
Joseph Kuosac 38mm Carbon - 28h - 342 grams
Spokes:
Front Wheels:
Rear Wheels:
Sturmey Archer SRF3 / Jtek spokes / Sun CR18 - 1410 grams
Wheel Fittings:
Jtek Allen key skewer - Front - 26 grams
Tyres:
Nexo - 37mm - Solid - 420 grams
Tubes:
Rim Tapes:
Jtek Yellow Tape 349mm - 10 grams
Seat posts:
Seatclamp/clips;
Ti Parts Workshop - easy large handle - 53 grams
Saddles:
Joseph Kuosac - wide - 273 grams
Brooks Cambium S17s carved - 404 grams
Suspension Blocks:
Easy wheels:
Racks:
RJT Alloy - 190 grams
Handlebars: (All 25.4mm)
Joseph Kuosac - flat - 195 grams
Joseph Kuosac - full rise - 239 grams
Litepro Ghost - 580mm - 144 grams
Grips:
Joseph Kuosac - 75 grams
Brake levers:
Shifters:
Sturmey Archer - SL30 3 speed - 79 grams
Brakes:
Headsets:
Joseph Kuosac - sealed bearing - 100 grams
Derailleurs:
H&H Derailleur + fittings - 9 grams
Hinge Clamps:
Joseph Kuosac knobs - 124 grams
Other;
Ti Parts Workshop Ti hinge spindle/bolts - 23 grams
Tuesday 24 July 2018
Stock Bike Weights
One of the most common questions is how much does it weigh? So here we are, all of the weights are the standard bike, with Marathon Racer tyres, mudguards and a standard seat post.
S1 - 10.7kg
S2 - 10.9kg
S3 - 11.5kg
S6 - 11.6kg
P1 - 11.3kg
P2 - 11.5kg
P3 - 12kg
P6 - 12.2kg
H1 - 11kg
H2 - 11.2kg
H3 - 11.7kg
H6 - 11.9kg
M1 - 10.8kg
M2 - 11kg
M3 - 11.5kg
M6 - 11.7kg
Electric!
Fitted as stock, marathon tyres, lighting, mudguards, standard seat post/saddle.
M2 - 13.7kg (16.6kg total with battery)
M6 - 14.6kg (17.5kg total with battery)
H2 - 13.8kg (16.7kg total with battery)
H6 - 14.7kg (17.6kg total with battery)
Battery - 2.9kg
Monday 9 July 2018
Notes
- The Brompton two speed hub uses:
6900-2RS in the non-drive side
6901-2RS in the drive side
And in the freewheel body:
6900-2RS
6000-2RS
Brompton SL front hub bearings:
6900 / 61900 - 1 either side
6900-2RS in the non-drive side
6901-2RS in the drive side
And in the freewheel body:
6900-2RS
6000-2RS
Brompton SL front hub bearings:
6900 / 61900 - 1 either side
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