New brakes for elderly Brompton.
01-25-20, 07:13 AM
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New brakes for elderly Brompton.
Hi,
I'm building up a bike from an old, short length Brompton frame, with 25.4 mm M type handlebars, and a fairly new wheelset with a three speed Sturmey hub.
Question one, is it better to have a separate gear shifter and brake lever?
(I don't even know if a combined shifter/lever exists for my handlebars)
And question two, will any newer calipers and pre 2017 levers do?
Plus, question 3, and any Brompton three speed hub shifter with a 24.5 mm clamp?
And, of course, question 4, I understand that I need shorter gear and brake cables, but will the ends be compatible with newer/current equipment?
Not forgetting, question 5, have you anything else to add?
Thanks in advance, Ted.
I'm building up a bike from an old, short length Brompton frame, with 25.4 mm M type handlebars, and a fairly new wheelset with a three speed Sturmey hub.
Question one, is it better to have a separate gear shifter and brake lever?
(I don't even know if a combined shifter/lever exists for my handlebars)
And question two, will any newer calipers and pre 2017 levers do?
Plus, question 3, and any Brompton three speed hub shifter with a 24.5 mm clamp?
And, of course, question 4, I understand that I need shorter gear and brake cables, but will the ends be compatible with newer/current equipment?
Not forgetting, question 5, have you anything else to add?
Thanks in advance, Ted.
01-26-20, 09:42 AM
#2
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Either separate or integrated brake levers and shifters will do depending on how much room you have on the bars. Mtn bike levers will fit BTW, and I think new pads are essential.
Brompton brakes pull down and although you could go with conventional sidepulls if the are long enough to hit the rim, the rear one would be awkward unless a downpull. The front will work with either.
I like the newer SA 3 speed shifters as they are sturdy and work well. They only work on 22.2 bars as M bars are.
Cable is standard mtn brake style and regular shifter cable works fine.
You can buy cabling and housing already cut to length from an LBS that carries Bromptons, or you can remove yours and have them cut to that length at an LBS for a lot less. I'd recommend Jagwire Elite for at least the rear brake since it incorporates both brake and shifter housing, and in my opinion, deals better with the curves and turns Brompton rear brakes require. Take a picture or two of the cable path before removing the cable so as to get it right when putting new cable on.
Other things you might consider are.......
a Shimano bottom bracket to replace the plasticity *** stock one.
Make sure the hinge for the rear triangle isn't loose. The bushing need to be replaced every so often.
If it doesn't already have one you can get some parts that allow the rear triangle to stay locked when you pick up the bike. You may also want a new elastomer for the rear triangle, especially if it seems too soft as they come in regular and firm. If it squeaks you can remove it and grease the bolt that runs through it.
If the bike chain skips it may be an adjustment problem with the hub, and there are YouTube instructions on the adjustment which you will need if you replace the shifter cable. It can also be due to wear on the sprocket, which can show up if you replace the chain, which is likely needed depending on the condition of th e bike when bought by you.
Actually, most of these procedures are on YouTube and are not very difficult. Good luck with your new friend.
Brompton brakes pull down and although you could go with conventional sidepulls if the are long enough to hit the rim, the rear one would be awkward unless a downpull. The front will work with either.
I like the newer SA 3 speed shifters as they are sturdy and work well. They only work on 22.2 bars as M bars are.
Cable is standard mtn brake style and regular shifter cable works fine.
You can buy cabling and housing already cut to length from an LBS that carries Bromptons, or you can remove yours and have them cut to that length at an LBS for a lot less. I'd recommend Jagwire Elite for at least the rear brake since it incorporates both brake and shifter housing, and in my opinion, deals better with the curves and turns Brompton rear brakes require. Take a picture or two of the cable path before removing the cable so as to get it right when putting new cable on.
Other things you might consider are.......
a Shimano bottom bracket to replace the plasticity *** stock one.
Make sure the hinge for the rear triangle isn't loose. The bushing need to be replaced every so often.
If it doesn't already have one you can get some parts that allow the rear triangle to stay locked when you pick up the bike. You may also want a new elastomer for the rear triangle, especially if it seems too soft as they come in regular and firm. If it squeaks you can remove it and grease the bolt that runs through it.
If the bike chain skips it may be an adjustment problem with the hub, and there are YouTube instructions on the adjustment which you will need if you replace the shifter cable. It can also be due to wear on the sprocket, which can show up if you replace the chain, which is likely needed depending on the condition of th e bike when bought by you.
Actually, most of these procedures are on YouTube and are not very difficult. Good luck with your new friend.
01-28-20, 05:46 AM
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The Brompton needs long reach brake caliper with the cable coming out on the left side down instead of the right side up as standard road bike caliper.
For the brake levers, be careful to choose levers for road calipers and not for V-brake. Most brake levers for flat-bar are made for V-brakes.
The bottom bracket of the Brompton is asymmetric to compensate the frame asymmetry.
Shimano doesn't have asymmetric bottom brackets. Besides the cheap bottom bracket mounted by Brompton there are only few others available. TI Parts Workshop has a special Brompton bottom bracket, Phil Wood has also asymmetric bottom brackets. Both are expensive.
For the brake levers, be careful to choose levers for road calipers and not for V-brake. Most brake levers for flat-bar are made for V-brakes.
The bottom bracket of the Brompton is asymmetric to compensate the frame asymmetry.
Shimano doesn't have asymmetric bottom brackets. Besides the cheap bottom bracket mounted by Brompton there are only few others available. TI Parts Workshop has a special Brompton bottom bracket, Phil Wood has also asymmetric bottom brackets. Both are expensive.
