Modern Calipers on old frame??

David Waters said:

Hey folks. I am looking to put a set of shimano RX-100
calipers on an old (80's?) Reynolds 531 frame. Am I
going to encounter any problems or should they fit
without too many problems? (I am worried that the bolt
diameter may have increased and will not wit through the
frame an forks)

Let me know your thoughts, it is all appreciated.

Check the drop - i.e. the distance between the bolt and the
rim. It can be considerably larger on older frames than
current and if it is there are very few calipers available
today that will fit.

Tony

David Waters said:

Hey folks. I am looking to put a set of shimano RX-100
calipers on an old (80's?) Reynolds 531 frame. Am I
going to encounter any problems or should they fit
without too many problems? (I am worried that the bolt
diameter may have increased and will not wit through the
frame an forks)

Let me know your thoughts, it is all appreciated.

Cheers

David

I replaced the single pivot 105 calipers on #2RI (531 frame
& forks) which I obtained in 1989 with dual pivot 105s last
year. The original rear brake was a [censored] to get off, it had
siezed into the frame. I had to clean out the hole with a
drill, other than that no problems.

David Waters said:

Hey folks. I am looking to put a set of shimano RX-100
calipers on an old (80's?) Reynolds 531 frame. Am I
going to encounter any problems or should they fit
without too many problems? (I am worried that the bolt
diameter may have increased and will not wit through the
frame an forks)

Assuming they have enough drop, and clearance for mudguards
(if using any), the bolts will fit through the forks/bridge
but the holes may be too small to take recessed Allen nuts
if the new brakes use those. The holes can easily be
enlarged, though.

More info and options:
sheldonbrown.comgloss r.htmlOpen ↗ - Recessed
Brake Mounting

Note: Drop can be extended slightly by filing the slots if
the blocks can't /quite/ be lowered enough. Also, if
you currently have 27" rims and plan to eventually
upgrade to 700c, blocks will need lowering by 4mm.

Alhonga deep-drop dual-pivot nutted brakes are
available that would most likely suit your bike if the
RX's didn't work out.

~PB

Quoted message said:

Check the drop - i.e. the distance between the bolt and the
rim. It can be considerably larger on older frames than
current and if it is there are very few calipers available
today that will fit.

If you want Shimano do a search for these: BR-A550-57 brakes
here: shimano-europe.comcyclingOpen ↗

They have a 57mm drop, as implied in their manufacturers
code. Shorter Shimano calipers are 49mm drop.