Drop bolt for rear brake caliper?

[Tpbiker]

Just bought an old dynatech frame and the calipers were goosed so replaced with some 7700 beauties. Unfortunately the pads dont quite clear the tyre, they are about 3mm short

I’m not so keen on the offset pad holders as they don’t look all that safe, so looking at a drop bolt. However only one I can find has 2.5 cm of drop, which is too much

Are there any other options available? I don’t have the means to make my own.

Ta

 

[jim haseltine]

Think I know the thing you've found - it's called a 'single to dual pivot adaptor'. A traditional drop bolt won't work with dual pivot calipers because of the design of the centre bolt. I'd be inclined to get one of the adaptors and drill a second mounting bolt hole closer to the caliper mount or contact the manufacturer and see if they make a shorter drop version.
Or just buy some different calipers.

 

[sjcprojects]

I was also a bit sceptical about the brake shoes with a longer drop, but I've recently tried some and they do the job perfectly. They feel just as well made as the regular Shimano ones they replaced - so I don't think safety is an issue at all, should you need to go down that route. They cost about £10.

 

[Tpbiker]

Good to know. Which ones did you get? I’ve seen some expensive ones for 30 quid, or the ones on eBay which are about a tenner

Like these

https://www.ebay.co.uk/itm/28456799...ar=586162586268&widget_ver=artemis&media=COPY

 

[oldandslow]

I've used drop shoes, but the only thing is the effect on the mechanical advantage of the brake - it may not perform so well as with a normal shoe.

 

[sjcprojects]

These are the ones I've used:

https://www.ebay.co.uk/itm/285395676789
I use them with modern 105 brakes, and only a few mm lower than they would otherwise be, so the loss of mechanical advantage isn't really an issue. It might be more so with older brakes, I guess, although if you're only 3mm off I would think you'd be okay.

 

[oldandslow]

That auction has ended, but I managed to snatch a glance and they look identical to the ones I have. No issues with fitting blocks or in use. In fact, I've currently got them fitted upside down in a set of brakes that needed the blocks a fraction higher (and the performance of those brakes is probably the best on any of my bikes, as you might expect!)

 

[Tpbiker]

Perfect. Thanks folks it’s for the rear wheels so should be fine, it’s not as if I’ll be descending big mountains on the bike given it’s got a 39-23 easiest gear!

Have bought a set!