Short Reach Brakes versus Long Reach Brakes
The best part of designing bikes is coming up with solutions. Often this comes about from an offhand comment from a rider. When I hear it, I realize I can bring more to the bicycle design than either of us planned on originally. Here’s an example. I recently built a Georgena Terry Gale Force bicycle for a rider who mentioned that the roads in her area were really rough. Steel bikes are great at absorbing road shock, but a wider tire can help as well.
The problem is that a traditional road bike uses a “short reach brake”, which may limit the width of the tire that can be used. It’s often not possible to use tires wider than 25mm (1 inch) with this kind of brake. As the tire gets wider, it gets taller. And there’s the rub — literally. The wider tire is too close to the underside of the brakes. Imagine picking up a small stone and having it jam between the tire and brake. Not good.
“Long reach brakes” solve this problem. The arms of the brake are about 8mm (.3 inch) longer than the arms on short reach brakes. If a bike is specced with this brake, the rider can use wider tires. So when my customer mentioned rough roads, I offered her the option of long reach brakes so she could put wider tires on her bike. A simple solution that added versatility to the bike. Unfortunately, you can’t just swap out your short reach brakes for long reach brakes to solve this problem. The bike has to be built for one style or the other.
Does a Small Front Wheel on a Bicycle Make You a Slow Rider?
One question I commonly hear is “Will I go slower on a bike with a small front wheel?”
The quick answer is “no”. Suppose we have two identical bikes, one with a 24″ front wheel and a 700c rear wheel and one with 700c wheels front and rear. If the gearing on the two bikes is the same, then one turn of the pedals will turn the rear wheel on both bikes the same amount and the two bikes will travel at the same speed.
It is true that smaller wheels have more rolling resistance because when the tire deforms under the weight of the rider, more of a small tire’s circumference will deform than that of a larger tire. But this resistance is tiny and not significant. A smaller wheel rotates more rapidly than a larger wheel, but it weighs less, so maintaining its momentum really isn’t an issue either.
So, if you ride a bike with a small front wheel and you feel slow compared to your friends, consider some other reasons why that might be the case. Perhaps they’re stronger than you are — not unlikely when comparing a man to a woman. Perhaps your bike doesn’t fit properly. Or maybe their bikes are substantially lighter than yours; this is more likely to have an effect during rides in hilly rather than flat areas. And then there’s always the psychological side: if you think you’re fast, you are!
What Size 24″ bike tire do I need?
I get lots of questions about understanding and sourcing 24″ tires and tubes. We use this size on our smaller bikes. Here’s all you ever wanted to know about the 24″ size. And if it’s not — leave a comment and I’ll be glad to help.
First, let’s talk about tire designations. 24″ is a very broad term. It’s best to refer precisely to the tire/tube size. This is done by referencing the bead seat diameter — the diameter of the tire’s bead, which rests inside the wheel rim.
You can tell what tire size your bike uses by reading the impressions on the sidewall of the tire. Typically, they will look like this: XX-YYY. The first two numbers are the width of the tire in millimeters and the second three numbers are the bead seat diameter in millimeters. This applies to all sizes of tires, not just 24″.
For instance, if your sidewall reads 25-520, your tire is 25mm wide (about an inch) with a 520mm bead seat diameter. Armed with this information, you can order the correct tire/tube for your bike.
This tech page from Schwalbe explains much more about the size markings on tires.
Terry has used two 24″ road sizes — 600A, with a bead seat diameter of 541mm and 24″, with a bead seat diameter of 520mm. The 541 size was used very briefly on only one Terry model — the Precision — for a limited time in 1985 – 1986. Later Precisions and all other Terry road bikes which are built with a 24″ front wheel use the 520 size.
Terry hybrid/mountain bikes using 24″ wheels front and rear have a 507 bead seat diameter.
ROAD BIKE TIRES/TUBES
Most Terry bikes use 24″ wheels with a 520mm bead seat diameter.
Terry Bicycles carries a variety of 24″ (520) tires/tubes which can be found here.
Your local bike dealer can order 520 tires/tubes from Quality Bicycle Products, 800-346-0004 (wholesale only).
Here is a list of some 24″ tires that are available:
Panaracer Pasela 25-250
Terry Tellus 32-520
Schwalbe Durano 23-520
Older Terry Precisions used a tire size popularly called “600A”, which has a 541 bead seat diameter.
Schwalbe RightRun 25-540 (part number 10282387). More information available here.
The Schwalbe RightRun comes closest to the Wolber Rallye 22mm tire originally specced on the Precision. The fit is quite tight (because it’s 1mm smaller than the original Wolber), but it will work. Schwalbe also carries presta valve inner tubes (part number 10519213) which can be found here.
HYBRID BIKE TIRES/TUBES
Schwalbe Kojak 40-507 (1.5″ wide). This tire is a slick, but rides beautifully! Unless you’re on gnarly roads, it’s the best. – Information can be found here.
Schwalbe Marathon Plus 47-507 (1.75″ wide) A very robust tire. Not light, but bomb-proof! – Information can be found here.
Inner Tube Source:
Schwalbe offers a variety of 507 inner tubes with either presta or schrader valves — AV10 and SV10. See here for more information.
REPLACEMENT WHEELS (520 or 507 size)
Do you need a replacement road or hybrid wheel? You or your dealer can obtain these from Velocity USA (800-453-6126). Velocity supplies all the wheels for my hand-built bicycles.