4130 and 853, how big of a difference?
 

Rephrasing as the question of the steel is more interesting (to me, at least) than the question of the specific bikes.

I've ridden old steel (1980s Tange 2) and recent aluminum, but don't have a feel for the difference between the 4130 and Reynolds 853.

I am looking at a Space Horse (612 select, which is a variation of 4130) and a 2015 Kona Kapu, which is Reynolds 853.

I live in a hilly area. I ride on relatively quick but not group-ride quick ~30-50 mile rides with friends. I have a long commute to work (27 each way) I do once or twice a week with a light load. I ride some forest roads. I can imagine doing some light touring (very light) and possibly gravel races. No road racing. No cylocross (I do it, but I have a bike for that).

A new Space Horse is about $1,500. Tiagra. Heavy wheels. Cantis. Tire clearance 40+, maybe 40 with fenders (as far as I can tell). Longer wheelbase, but I'm not sure that's a plus or it's going to feel too slow at the expense of stability.

A 2015 Kona Kapu is available in my area for $1,500. This is without any negotiating yet. It is 105 with an Ultegra RD, Aksium wheels, nice long reach brakes. It is fitted with 28s, and although I can't find any confirmation on the 2015 model, it looks like it could fit fenders with the 28s and maybe 30s without.

The question: Is this as easy a decision as it seems … go for the better frame and components and give up a thin margin of utility? I know 4130 is not as thin, etc. But, if anyone has ridden both (and I know design has a lot to do with it, but humor me), is that dropoff to 4130 significant enough to make a noticeable difference.

Thanks

The only significant difference in the riding is the weight. Stronger steel like what is used in 853 tubing allows the tube to be thinner and therefore lighter. Weaker steel like not-heat treated 4130 (aka chrome-moly or CrMo) requires a thicker tube wall for the needed strength. Stiffness of the two types of tubes should be adjusted to be similar by the tube diameters, larger for the thinner wall tube to stiffen it. Not always, but that is the object in steel bike design. So it is just a difference in weight.

If you don't count weight, the idea that 853 tubes are better than 520 tubes (made of 4130) is just wrong. I know that is heretical, but hey, this is Robert talking. What do you expect?

Tubing Article ? Nothing is better than a bike that fits

tl;dr; The only easily predictable effect of a different tubeset is weight reduction. The additional strength of higher grade tubesets can actually hurt the quality of the ride if the frame design doesn't compensate for it. When you're comparing two different frame designs, there's no point even looking at what tubeset was used because it doesn't guarantee any particular quality or characteristic.

3277.

Geometry and fit will affect your ride more than the steel in the tubing...

OP, I forgot to mention that you are mixing your terms. 4130 or CrMo refers to the steel that the tube is made from. 853 is a model of Raleigh brand bicycle tubing which means it has specific wall thicknesses, butting profiles, and cold working and heat treating histories that greatly affect its strength and ride characteristics. Unless you know who made the tubes from the 4130 and what the design characteristics were, you really can't compare the two. But even so, what I said about weight being the only resulting difference, still SHOULD be the case.

The Kapu looks like a better bike all-round to me, from tubing to components. Of course we're talking about used vs new here, so only you can determine if the bike is in good enough condition to warrant the price. They went for $2000 new in 2015 I believe.

I'd have my doubts that it would fit fenders with 28c tires though, you'd want to get verification of that if that's a requirement. I note that it does come specced with 28c tires out of the factory though, and come with long reach caliper brakes, so maybe.

EDIT: This review:

http://www.gravelbike.com/?p=3564

suggests that the brakes can cope with 28c and fenders, but that doesn't guarantee the frame can.

Cool. Thanks for the insight.

And, naturally, I am still on the fence. Now I'll go ponder components vs. tire clearance for a few hundred hours ... .

Just ask yourself the question whether you want to spend more money either for a lighter frame or for bragging rights re: the 853 sticker. I probably would pay for that, but I am a well-known weight weenie. YMMV. It is your choice.

One other semi-relevant thing: I am about 6'3" 215 lbs. Sometimes the weight thing feels like splitting hairs to me. And while I have heard the Space Horse is not flexy (in the good way), I am not sure that's something I'll notice. Or that it would even be bad if I did notice.

I built up a Traitor Wander recently with hydro disc brakes (Ultegra level) and the rest of the bike 105, and it cost me a total of about $1400. If you go with a similar, cheap non disc frame I would bet it would cost even less, and possibly have better components. Just something to consider, since you have other bikes to ride. I have taken mine on road rides and singletrack, and it is a blast to ride. Far as I know, plain ol' 4130 tubing.

"Steel yourself" a guide to the most popular metal for bike frame

Here is a decent article about steel used in bikes and it doesn't go completely into techno-garble with over explanation.

I recently bought a steel mountain bike and the brand or type of steel used in the frame was a bit down on the want-list, but I wanted it fairly light. To do that in steel, usually a higher quality steel tubing set is used. Incidentally, that bike uses Reynolds 853 tubing. It is also a complete blast to ride.

My last road bike that I bought that was steel never said what the tubing was (Rivendell Roadeo) but the frame wasn't all that heavy, so I'm assuming it was relatively higher quality. The company making the bike never really says what tubing they use except to say that they mix and match tubing for desired performance aspects. That bike felt livelier than my other steel road bike which used Reynolds 520 tubing. Design and geometry probably had more to do with handling differences than tubing, but the weight between the two frames was different.

you can get fine riding bikes using CroMo or higher quality steels. Frankly, the Kona looks like the better bike for you, IMHO.

Reynolds 853 is an air-hardened steel. It combines the durability of steel with the light weight of titanium, at a significantly lower cost.

The ride is sweet... of course nothing wrong with plain ol' cromoly. It still has a good weight to price ratio which is why its used in all but high end bike builds.

Weight of 853 frames matching Ti frames is a slight stretch...assuming similar design characteristics and not even considering the weight of paint. IMO you would need to go to one of the slightly stronger stainless varieties.

You might consider going between the horns of the dilemma and finding another bike that you will be even happier with.

28s might be a little disappointing for some of your riding.

I have an 853 OS (I had 16 steel bikes). Hard to tell. for the time the 753 was by far the most incredible ride.

I've talked with frame builders who have worked with 853 and with various 4130 tubing. They all say that the 853 is amazingly tough and resilient.

Some people say that most 853 frames are 853 in the main triangles only.

What does tough and resilient mean to you? Is 4130 not tough and resilient enough for the bike you want? I assure you that 4130 will resist denting much more than 853 will, not because of metallic differences, but because of wall thickness.

Ultimate yield strength. Young's modulus/modulus of elasticity. Spring.

Yes, 4130 is good enough. 853 is better though. To me. For me.

I would have to disagree with your assessment of relative dent resistance.

853 can be both thinner walled and more dent resistant. It depends on just how much thinner the walls are. In actual, real world, in-use bike tubing, 853 is more dent resistant, at least in some cases. Jamis Dragons (853) have been known to be markedly more dent resistant than similar 4130 frames.

I suppose including both the butted portions and the the thinner unbutted portions would help complete the comparisons.

You may disagree, and that is fine. If you can present some evidence that would be meaningful, I would enjoy seeing it. I would like to know exactly where the wall thicknesses coincide.

For the OP, and others for that matter, the actual wall thicknesses of the bikes under consideration, both 853 and others, would be one starting point for determining relative dent resistance.

If anyone happens to have the numbers (ultimate yield strength and others) for the different materials, that would contribute to the discussion and to the topic.

Say what you want, it still comes down to a weight difference only. The 853 bike is being lightened to be only as strong as the 520 (4130 bike), so all the steel strength you gain is being given back by thinner walls. That is just the way it is. What you say about dent resistance being related to wall thickness (but also diameter) is correct. But paying for a bike made out of 853 steel with tube walls as thick as normal 4130 tubes would just be stupid. Your unsupported claim about a single brand of MTB (we are talking about road) is irresponsible. Clearly you aren't talking about scientific test data.

PM to [MENTION=38510]Scooper[/MENTION]. He has a chart with all the data you are looking for.

I think this is all a marketing hangover from the days when all bikes were steel and the tubing manufacturers needed a way to differentiate. IMO, there's absolutely no practical difference in terms of performance between various grades of steel. 853 might be "stronger" than 520 in absolute yield strength but both are so far above the demands of cycling that it doesn't matter, at all. Both will be plenty tough. 853 might save a quarter pound over 520, but who cares? Also, the idea that 853 might be "harsher" than 520 is strange to me. Surely things like chainstay lengths and tire selection are far more important than the specific tubing a bike is made out of when discussing compliance and comfort. I might pay more for stainless (maybe... I also think being concerned about rusting frames is a red herring) but that's it.

I think you are mistaken on a few things. First tubing made from higher strength steel is downgauged to save weight. Whether the frames are strong enough or not, they are not made as strong as possible without regard to weight. Second the the weight savings is more like 2 pounds in the frame only, no fork. Third thinner tubes are stiffened by increasing their diameter. If that is taken to extreme, as it used to be in aluminum bikes, there is no question that a harsh ride can result.

Other than the weight comment, I'm struggling to identify what any of this has to do with my post. Also, I'm not sure I buy your two pounds estimate.

You suggested the steels were way stronger than necessary. I am saying they are compromised by design factors such as weight goals and bikes are made as strong as they need to be, not way more. And classic 531 and 520 frames weigh around 5 lb. Higher strength steels like what 853 and 953 tubes are made from can yield frames in the 3 lb area. That sure sounds like 2 lb to me.