Dual pivot brake upgrade

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Archie_tect

De Skieven Architek... aka Penfold + Horace
Location
Northumberland
The brakes on my old Dawes are awful, so bought a pair of Shimano R650 dual pivot brakes from Ribble Cycles on line. They've arrived and look the bee's knees, but to fit I need to drill out the fixing hole in the steel frame to 8mm on the allen head side to accommodate the increased width of the restraining sleeved nut. Ribble assure me that the 1mm shoulder on the allen head will be safe enough to hold the bolt in place but I wonder whether I should avoid drilling the frame to 8mm and use a longer bolt with conventional 10mm head nut and washer.

Anyone any experience of drilling out the steel frame to use the modern allen head fixing on an old bike?
 

tyred

Legendary Member
Location
Ireland
I did this on my Carlton and there have been no problems. The fork crown was unbelievably hard to drill though.
 

gbb

Legendary Member
Location
Peterborough
Are you fitting the rear too Archie ?
I had to open up the brake bridge (tubular) to accept an allen fit caliper. At first i thought i may have 'gone a bridge too far' and not left enough meat for good strength, but its been ok for 2 or 3 years. Still wished i'd used the proper nutted variety tho, just for complete peace of mind.
 
OP
OP
Archie_tect

Archie_tect

De Skieven Architek... aka Penfold + Horace
Location
Northumberland
Are you fitting the rear too Archie ?
I had to open up the brake bridge (tubular) to accept an allen fit caliper. At first i thought i may have 'gone a bridge too far' and not left enough meat for good strength, but its been ok for 2 or 3 years. Still wished i'd used the proper nutted variety tho, just for complete peace of mind.


Intended to, but looking at the size of hole required it makes me wonder! Could just buy the longer bolts as Baggy suggests, if I take the assemblies apart to get to the bolt heads. I've being putting off the decision by riding my hybrid since!

At least no-one's shouted, "Don't, under any circumstances, drill out!" which is reassuring.
 

RecordAceFromNew

Swinging Member
Location
West London
I used Sheldon's option 1 for rear and 3 for front - when I did mine I found that the cavity inside the fork is long enough to swallow the allen sleeved nut, so no drilling and no long bolt and it was a cinch to tighten the nut because the allen key can reach the nut from the hole at the back of the fork. If the cavity inside the crown is not big enough for the allen nut, I don't see why a nylock nut or two "inside the fork" would not serve the same purpose as the allen nut.

Despite bolting on to just the front of the fork crown and not the back, the brake has been rock solid with no issue - given the crown is like 5mm thick there I am pretty sure alloy brake calipers would shear before the steel crown ever gives.
 
OP
OP
Archie_tect

Archie_tect

De Skieven Architek... aka Penfold + Horace
Location
Northumberland
Chickened out and decided to go with the long through bolts but then discovered the steel rims are the real issue not the difference between single or dual pivot... stops much better with the new, larger pads so, as I don't want to alter the appearance of the original fundamentally I've gone back to single pull which, with the new Aztec PBA2002 pads fitted, are good enough. Unless I relent and get new 27" wheels but that's a step too far [yet]!

Looking forward to a good day out on it for the 66 mile Cyclone tomorrow. I'll be the slow one! [Number 1963!]
 
OP
OP
Archie_tect

Archie_tect

De Skieven Architek... aka Penfold + Horace
Location
Northumberland
Right, after pushing the Dawes up the Ryals
sad.gif
.... I need a new small chain ring [52/40 is crazy], even with 14-32 freewheel, so need to check the range to see whether 36 or 34 would suit. Oh, and get fitter and lighter.
 
OP
OP
Archie_tect

Archie_tect

De Skieven Architek... aka Penfold + Horace
Location
Northumberland
This is how it's turned out but now with SPDs and Aztec blocks \/ Bit fuzzy taken with my phone.
 

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