Monster Pete

I dug the old Raleigh Scorpion out of the garage at my parents house yesterday and gave it a tune-up. It has single-pivot caliper brakes of the long-reach type, typical of those found on older BMXs. They stop the bike ok, but having got used to cantilevers, I'd like it if the performance could be improved somewhat.

There are no bosses for cantilever brakes and I'm not confident in my ability to fit them, so that option is basically out. My question therefore boils down to this:

Can the performance of the brakes be improved by fitting better pads and/or more robust levers?

Would disk or drum brakes be a viable alternative?

Could 700c wheels be installed with shorter-reach calipers?

Pete

bradtx

Pete, I think a new set of brake pads would be a good starting place. Those single pivot brakes just aren't going to have the power of some of the other designs. The other items just depend on will the available space and how much you wish to spend. If a dual pivot brakeset like those from Tektro will fit it'll improve braking.
Brad

krome

Dual pivot caliper brakes have impressed me. I recently converted a Raleigh Marathon from single pivot to dual pivot. Braking performance was greatly improved. Easy centering. No fuss. No regrets on my end.

Edit: I used Tektro 539's to convert from 27" rims to 700c for the Marathon.

rothenfield1

While buying a more modern dual-pivot caliper would improve the power of your braking, I find that people often forget to clean their rims from time-to-time. Over time, the brake pad rubber will embed in the rim surface making the brakes less effective. You may not even notice it, but you would be amazed at how much black comes off the braking surface if you clean them with some rubbing alcohol and a scouring pad, or even wet sand them with a fine sandpaper. I'd go with new pads made of a soft rubber such as the salmon colored Koolstop pads, clean the rim braking surface, make sure the wheels are true, and adjust the brakes properly before buying new brakes.

fietsbob

and replacing cables and housing clean and grease.. the frame/bolt center pivot..

I have a bike with Sturmey Archer drum brake hubs ,
they have been low maintenance, trouble free for 20 years.

krome

Is it a Raleigh Scorpio or a Scorpion. Scorpio is a 70's road/touring bike. I've seen pictures of a Scorpion MTB. Any MTB with caliper brakes I shy away from, it screams "low end".

Either way, Disk brakes require new hubs, which require new wheels or lacing new hubs into existing rims. Ditto with drum brakes. I see dual pivot caliper brakes as the lower cost alternative to the other two. Disk brakes also require disk brake mounts, which do not bolt on. Drum brakes have a reaction arm, which can clamp to the fork (bolt on)

Edit:

Also, steel rims or aluminum? Upgrading to aluminum will improve performance, but requires a new wheel or existing hubs laced into a new rim.

jimc101

Basing this on you want to improve the stopping power of your brakes -

Your best option for this would be to scrap, and start with a new bike, most Raleigh bikes are very low end, and if it has calipers and is in MTB, this indicates that it's late '80s / very early '90s, and most parts will not be compatiable with anything you can buy today.

There is very little / no point in upgrading, it most likely has steel rims, drum and disc are no goes, as the frame was not designed for them, and it is probably made of very heavy / Hi-Ten with solid stays, and it would cost far more to retro fit them, than would ever be viable, the brake levers will be plastic & the flex will not help the braking, and the frame wil not fit 700c wheels, also the gearing is mostlikly 5 or 6 speed on a 126 hub, so would involve a lot of replacement.

It's Easter weekend, that means sales, go to Halfords, and have a look at their Subway & Boardman series of bikes, or similar from a LBS, this will be a far more cost effective than putting a single pound into the old bike.

Or just ride it as is, till it dies.

Monster Pete

It's a Raleigh Scorpion that used to belong to my dad (he can't ride anymore so I claimed it). The rest of the bike I'm perfectly content with, and the old gearing shifts surprisingly well- it's a 2x5 shimano SIS setup with thumb shifters, which I actually prefer to gripshift or triggers.

I'll try cleaning the rims (I believe they're aluminium) and replacing the pads and cables to begin with, as it seems disks/drums/700c is more trouble than it's worth. For the brake pads, I assume threaded stud v-brake type pads would be ok to use here?

jimc101

these may work, but would take one of, and go to say Wilkinson or similar store, and look at the cheapest they do; and it will most likely be the same type; they also do good cheap cables.

Steev

You need to check the clearances between the fork legs and the rims at the front if you want to use the longer V brake pads. They will not always fit in there. If they do, it does help improve braking.

Chris Chicago

see if a magnet sticks to the rim. if it does, it is steel.