2 Chainrings on Brompton
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Personally, I don't care about e-Brompton, but would certainly be interested in Brompton offering new options, at lower prices than Kinetics/Vostok:
- disk or drum brakes: I'm tired of building/buying new rims every couple of years (they wear out fast when, like me, you occasionally ride on unpaved roads: Grit and rim brakes don't mix well, as shown in the attachment below)
- standard width rear triangle, so as to fit a Nexus/Alfine or Rohloff IGH
As for the double chainring: For close to two years now, I'ven been a happy user of the LitePro K clamp + Shimano braze-on derailleur + Sunrace M90 shifter combo. It provides the same meters development (1.79m - 7.32m, or 408%) as the Shimano Alfine 11 (409%)… at the expense of juggling with three shifters and the traditional issue of the derailleur getting stuck after riding on muddy paths.
FWIW, I changed the 50/34T to a more reaonsable 46/34T: The 50T is too big with a fully loaded bike (about 25kg), with 80-120km/day trips, and occasional 5-10% hills.
As for the bottom bracket, once the original, really el cheapo BB from F.a.g. wore out, I replaced it with a Shimano BB-UN55 in 73x118mm. I know it lacks the the asymetry provided by the original BB from F.a.g., but it hasn't bothered me and the double chainring works fine with that symetric BB.
Last edited by Winfried; 04-30-18 at 04:59 AM.
#27
Banned
I own a Bike Friday 'Season' Tikit now .. it takes the Brompton sized rim & has a 135 rear hub, not an 11 speed but it fits.. (has a Sram I-9)
their new Pakit is lighter than a Brompton, and they make several sizes and a long list of options on the build menu.. including Gates belt drive..
The wholesale Importer of Bromptons to Australia is Greenspeed , they re machine SA drum brakes for their recumbents and have re machined a 74 wide drum hub for Bromptons..
and Pakit/Tikits, that also use a 349 rim/74 axle front hub.
so a rear drum 4 or 8* speed SA hub is possible with Bike Friday Pakit
they're good at building with 24 spoke 349 rims and 36 spoke hole hubs too..
* SA 4 & 8 speed are 1:1 1st gear , so Ideal for small wheel bikes. 3 & 5 are 1 for middle gear and (b over a) and (a over b) ratios over and under drive..
[Been using my Bike Friday Pocket Llama all winter, on the Oregon coast]
..
their new Pakit is lighter than a Brompton, and they make several sizes and a long list of options on the build menu.. including Gates belt drive..
The wholesale Importer of Bromptons to Australia is Greenspeed , they re machine SA drum brakes for their recumbents and have re machined a 74 wide drum hub for Bromptons..
and Pakit/Tikits, that also use a 349 rim/74 axle front hub.
so a rear drum 4 or 8* speed SA hub is possible with Bike Friday Pakit
they're good at building with 24 spoke 349 rims and 36 spoke hole hubs too..
* SA 4 & 8 speed are 1:1 1st gear , so Ideal for small wheel bikes. 3 & 5 are 1 for middle gear and (b over a) and (a over b) ratios over and under drive..
[Been using my Bike Friday Pocket Llama all winter, on the Oregon coast]
..
Last edited by fietsbob; 04-30-18 at 09:10 AM.
#28
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As for the double chainring: For close to two years now, I'ven been a happy user of the LitePro K clamp + Shimano braze-on derailleur + Sunrace M90 shifter combo. It provides the same meters development (1.79m - 7.32m, or 408%) as the Shimano Alfine 11 (409%)
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In practise, I don't find the three-shifter solution really annoying, as…
Still, if Brompton or someone else offers an affordable way to add an Alfine 11 IGH (and non-rim brakes), I'll consider selling my B and getting a new one: Handling all the gears with one shifter + solving the derailleur issue (mud) would be great. Besides, I love how silent the Alfine 11 is on my regular bike.
- the Sunrace shifter is easy to use since it only handles two speeds, and
- I only shift down to the smaller chainring every once in a great while, when I ride in hilly areas.
Still, if Brompton or someone else offers an affordable way to add an Alfine 11 IGH (and non-rim brakes), I'll consider selling my B and getting a new one: Handling all the gears with one shifter + solving the derailleur issue (mud) would be great. Besides, I love how silent the Alfine 11 is on my regular bike.
#30
Banned
That some one is Ben Cooper in Glasgow Scotland, but you are wanting cheaper than his cost of doing business.
He will ship a completed bike to you with that new fork & rear section, powder-coated to match , as I understand, as a Dealer He has to Buy the complete bikes from London, and resells the original parts ..
Bike Friday Ships (Pakit and new NWT) around the Globe, From Oregon..
those 2 are able to function without a chain tensioner..
..
He will ship a completed bike to you with that new fork & rear section, powder-coated to match , as I understand, as a Dealer He has to Buy the complete bikes from London, and resells the original parts ..
Bike Friday Ships (Pakit and new NWT) around the Globe, From Oregon..
those 2 are able to function without a chain tensioner..
..
Last edited by fietsbob; 04-30-18 at 12:18 PM.
#31
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I am amazed you are able to open his website. I hope that the website is not representative for the quality of his bike work - shiny when I catch a glimpse but not usable.
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I know several people who bought modified Bromptons from Ben Cooper and are very happy with them.
I, however, am not willing to spend that much money to get non-rim brakes and/or a wider range IGH.
Hence my suggestion to Brompton to offer those as options when ordering a new bike from them. It could only be cheaper than making and replacing those parts after sales.
But considering the vast majority of people only use the B for its intended purpose, ie. riding a few kms/miles in the city… I'm not holding my breath.
I, however, am not willing to spend that much money to get non-rim brakes and/or a wider range IGH.
Hence my suggestion to Brompton to offer those as options when ordering a new bike from them. It could only be cheaper than making and replacing those parts after sales.
But considering the vast majority of people only use the B for its intended purpose, ie. riding a few kms/miles in the city… I'm not holding my breath.
#34
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Adapter Update
After nearly 4 weeks from order, another derailleur adapter arrived, shown in the photos below. When a brand is indicated for this adapter it is mi.xim and the product identifier is NC-100. It is marketed for Dahon Speed P8 often as a 'disc' adapter and the latter seems to stand for chain ring.
Ebay Link
AliExpress Link
AliExpress Link 2
The adapter can be had for $8, 1/4 of the price of Litepro, it is heavier than Litepro, 74 vs 54g, and cruder. By being more bulky it is stiffer than Litepro and flexes less when the shift cable is tensioned. Also it is easier on the cable, see the photos. When using Litepro on Brompton, the cable gets awkwardly pinched to the seat tube on its way to the derailleur arm. Because the adapter is cruder, it is harder to adjust to arrive at best shifting than Litepro.
On the Scale
On the Bike
From Above
Ebay Link
AliExpress Link
AliExpress Link 2
The adapter can be had for $8, 1/4 of the price of Litepro, it is heavier than Litepro, 74 vs 54g, and cruder. By being more bulky it is stiffer than Litepro and flexes less when the shift cable is tensioned. Also it is easier on the cable, see the photos. When using Litepro on Brompton, the cable gets awkwardly pinched to the seat tube on its way to the derailleur arm. Because the adapter is cruder, it is harder to adjust to arrive at best shifting than Litepro.
On the Scale
On the Bike
From Above
#35
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The adapter can be had for $8, 1/4 of the price of Litepro, it is heavier than Litepro, 74 vs 54g, and cruder. By being more bulky it is stiffer than Litepro and flexes less when the shift cable is tensioned. Also it is easier on the cable, see the photos. When using Litepro on Brompton, the cable gets awkwardly pinched to the seat tube on its way to the derailleur arm. Because the adapter is cruder, it is harder to adjust to arrive at best shifting than Litepro.
Ideally, the cable should head straight for the derailleur, but I haven't had any problem in the almost two years I've been using this setup.
Also, I notice Ben Cooper now sells the Alfine 11 for £1,550: If I had to get a new Brompton today, I wouldn't bother with adding a doublechainring to the six-speeder and juggle with three shifters, as the Alfine 11 provides about the same gear inches.
Last edited by Winfried; 05-14-18 at 06:44 AM.
#36
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Thanks for the photo.
#37
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The Steel one I got from CM Wasson won't win the least grams competition, Vs Aluminum
but it incorporates the housing stop and a Italian style (most common type) FD mount..
but it incorporates the housing stop and a Italian style (most common type) FD mount..
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Hello,
A friend just bought a used Brompton.
In case he'd like to install a double crankset and get a wider gear range, I was wondering if someone had tried the "Litepro JP8 front derailleur set" for €50.
Thank you.
A friend just bought a used Brompton.
In case he'd like to install a double crankset and get a wider gear range, I was wondering if someone had tried the "Litepro JP8 front derailleur set" for €50.
Thank you.
#39
Stardust
Hello,
A friend just bought a used Brompton.
In case he'd like to install a double crankset and get a wider gear range, I was wondering if someone had tried the "Litepro JP8 front derailleur set" for €50.
Thank you.
A friend just bought a used Brompton.
In case he'd like to install a double crankset and get a wider gear range, I was wondering if someone had tried the "Litepro JP8 front derailleur set" for €50.
Thank you.
#40
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Since it's meant for Dahons like the other Litepro clamps, why would it be wider than the K, P, or B clamps?
Is JP8 the model of the clamp or the name given to that kit?
--
Edit:
"JP8" = "Dahon Jetstream P8".
It's too long in the back for a Brompton. So it looks like I'll have to get a P/K/B clamp and a two-speed derailleur.
Is JP8 the model of the clamp or the name given to that kit?
--
Edit:
"JP8" = "Dahon Jetstream P8".
It's too long in the back for a Brompton. So it looks like I'll have to get a P/K/B clamp and a two-speed derailleur.
Last edited by Winfried; 08-02-19 at 04:56 AM.
#41
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In the bike pictured in LitePro photos the seat tube ends ahead of the bottom bracket shell, justifying the need for pushback for derailleur. In Brompton the seat tube ends behind the bottom bracket shell. So no, this adapter does not seem suitable for Brompton. As to the seat tube diameter, for other possible adapters you need to put some shim as well. One extra concern that I have about the JP8 model is of the mounting stud being seemingly secured to the clamp with only one small bolt that does not seem to go very deep into the material. Other Litepro adapters also came with one bolt but at least there as a threaded hole there for a second bolt, so you could make the setup more secure.
The linked Jetstream P8 seems to have a different arrangement around the bottom bracket, so I suspect that its identification as JP8 is incorrect. While I can find some other Dahons where the seat tube ends ahead of the bottom bracket, e.g. Bullhead, NBA083, IOS, I cannot find though any other 8-speed with a name starting at J. Talk about the garble of Dahon models! I wonder why LitePro does not finally make a dedicated Brompton adapter.
The linked Jetstream P8 seems to have a different arrangement around the bottom bracket, so I suspect that its identification as JP8 is incorrect. While I can find some other Dahons where the seat tube ends ahead of the bottom bracket, e.g. Bullhead, NBA083, IOS, I cannot find though any other 8-speed with a name starting at J. Talk about the garble of Dahon models! I wonder why LitePro does not finally make a dedicated Brompton adapter.
#42
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Oh, OK, here is a Jetstream that looks like in the LitePro photos. I.e. Dahon is not even consistent within their declared models! This one is also named Dahon Dragon and there is also a third frame around under JP8 that looks like neither of the two.
https://www.shpock.com/en-gb/i/WXaRn...-p8-20-sram-x7
https://www.shpock.com/en-gb/i/WXaRn...-p8-20-sram-x7
#43
Stardust
Since it's meant for Dahons like the other Litepro clamps, why would it be wider than the K, P, or B clamps?
Is JP8 the model of the clamp or the name given to that kit?
--
Edit:
"JP8" = "Dahon Jetstream P8".
It's too long in the back for a Brompton. So it looks like I'll have to get a P/K/B clamp and a two-speed derailleur.
Is JP8 the model of the clamp or the name given to that kit?
--
Edit:
"JP8" = "Dahon Jetstream P8".
It's too long in the back for a Brompton. So it looks like I'll have to get a P/K/B clamp and a two-speed derailleur.
#44
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Yes, it's wider by 2mm for the K clamp at least, which was easily solved by using a bit of inner tube as shim.
So the conclusion is: Don't buy that kit. Get a K/P/B clamp and a two-speed derailleur independantly.
So the conclusion is: Don't buy that kit. Get a K/P/B clamp and a two-speed derailleur independantly.
#45
Full Member
Anyone tried using a Shimano E-mount front derailleur? Seems to be a much easier way for 2 chain rings. The der would be placed in the proper position for shifting. The e-mount ders are held in place by the fixed cup of the bb axle. There are a number of different versions.
#46
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I looked at the option and it was a no-fly pretty soon. A folder provides more constraints than a regular bike - it must fold small, be light and withstand all kinds of banging up. This kind of mount builds up an extended structure that is heavy if out of steel and else needs to be bulky to be strong if out of alu. In either case it takes unnecessary space by the seat tube. In addition you are going to be stuck with one outer ring size. My practical experience was trying out such a steel mount and it was a complete mismatch - beasts from different animal worlds.