Aluminum vs Steel Frame For Woods Riding?

[vic2340]

Does anybody know which frame is better for Woods/Enduro riding and why? Ive heard mixed things and I have never had solid evidence to tell me if steel is better than aluminum or vise versa. If anybody has a good opinion please share. Also can you interchange frames from 2000 to 2004 yz250's and 2005 to 2015 yz250's without much modification to components?

[cordlaw]

From my understanding 05 to 15 is almost exactly the same expect for few changes but not enough to the point where you would have to make mods

[rpt50]

Some things even interchange between frame types. For example, oversize tanks fit from current back to 02 I believe.

I have never owned a steel frame YZ and an aluminum frame YZ AT THE SAME TIME, but I have in the past and currently do own various steel and aluminum examples of the major brands. While it would never be a deal breaker in buying a bike, I prefer steel for the following reasons:

1. The smaller diameter steel tubing makes it easier to access parts of the bike for maintenance or tuning. For example, carb needle adjustments or pipe fitting are a PITA on my YZ compared to my KTM or RM. Not a huge deal, but very noticeable when you are working on both types.

2. Damage repair. It's been a long time since I've cracked a frame, but nevertheless I would have no problem finding competent repair services for a steel frame, probably on that same day! Not so sure about aluminum. I run a skid plate but I do worry about the rails on my YZ with every big rock crossing.

3. Mounting stabilizers. I don't like drilling and tapping aluminum.

I believe in the case of the YZ aluminum is lighter, so that would be a benefit, but others who have owned both at the same could tell you if it is noticeable.

Edited February 22, 2015 by rpt50

[vic2340]

Thanks for the replies, they give me a better understanding already. How about ride quality though? Does a steel frame ride better than an aluminum frame in the woods?

[bobbyward]

They claim the steel offers some flex, which should be easier for trail use.

[Woodzi]

Steel is actually about 3 times stiffer than aluminum. However, a steel frame can be designed to run at higher stresses, so it may feel less stiff.

Last steel YZ I had was a 1990, so I don't know how the newer ones compare with aluminum.

I would go for an aluminum frame with the SSS suspension. Most of us are quite happy with the aluminum frames and everyone loves the SSS suspension.

Try a KTM for a steel frame with bad suspension. No steel frame can make up for bad forks.

[Hans Schmid]

02-04 with SSS suspension, you just can't lose!

[GHILL28]

Steel frame is WAY more comfy.  Accessing the carb's on those older steel frames isn't nearly as easy as the later frames though in my experience.

[cwtoyota]

There's been a lot of discussion on these frames here in the past... Lots of opinion and hypothesis...
 

Before you read my opinion below, please know that I own both bikes, 2002 YZ250 and a 2010.

 

My opinion is that nobody really knows the truth of which frame is better, here's why:

 

1) Nobody to my knowledge has ever done a fair comparison.

2) Bike setup is typically a very personal thing... What works for one guy may not work well for another.

 

 

To elaborate on #1, I believe that to do an equal comparison of frame materials, you have to develop two bikes side by side with a group of test riders.  Each frame material will require it's own supporting components including fork tubes, triple clamp offset, swing arm design & material, tire selection, suspension valving, linkage curve, etc.
Obviously that's ridiculous and nobody can afford it.

So the closest thing we can do is to compare the two bikes side by side at the same tracks (or trails) on the same day with a group of skilled test riders.
I have done this on my own, however my 2010 was new with stock suspension while my 2002 had revalved/resprung suspension.  I felt that on rough hardpack MY 2002 was better at staying connected to the track while the 2010 (aluminum) was more precise in the sand and on rutted tracks.

 

Still, that doesn't mean anything to me... We all talkabout frame flex, but what about the fact that the 2002 has a 46mm KYB fork while the 2010 has a 48mm SSS?  What about the fact that the 2002 fork tubes are laterally closer to the centerline of the steering stem? The swing arm design changed in 2005 (or maybe it was 2006).  I ask you to consider that these items also contribute to a different flex character, perhaps more than the chassis.

I suggest that the frames need to be compared on equal suspension components to make any realistic assumptions about what the frame material does to handling.

To elaborate on #2,  What I prefer as a 5'9" 160lbs Intermediate on a motocross track may not be the same as a 220lbs 6'2" Novice, or a pro.

I have heard Chad Reed, David Vuillemin, and Tim Ferry. on Matthes' podcast talking about their factory bikes when the frames changed to Aluminum...
Each of them stated that they preferred the Steel bike from 2003-2004 to the 2005 alloy frame.  What they don't talk about is the fact that they are pushing these frames to the limit in supercross way more than us amateurs are at the local track or on the trail.


In conclusion, my opinion is that there isn't enough difference between the 2002 - 2015 YZ250 bikes steel vs aluminum, etc to even worry about it.  But if you must, find a set of the older 46mm forks from 2003 or 2002 and run them on either type of chassis with the swing arm and linkage from the 2009 YZ450F.  That should give you the most flex if that's what you think you want.
 

[BDubb106]

Steel does offer more flex, that is true... but the honest answer is that 99.9% of the people to ever throw a leg over a dirtbike will not ever notice the difference. More flex does not automatically mean a better ride. Proper suspension set up as well as adjusting geometry with things such as linkages and clamp offset and controls will yield greater benefits than either frame. 

 

As cwtoyota mentioned above... it takes the fastest riders in the world pushing the bike to the limit to even make mention of the difference. 

Edited February 23, 2015 by BDubb106

[vic2340]

Thanks for all of your replys, I guess I shouldnt really be to worried about my aluminum frame on my yz250 for Enduro type riding. I did have a 2009 yz450f and that thing, after being totally set up for the woods was fantastic. (Its aluminum frame felt very mellow) It was stable and soaked up the trail amazingly. The only reason I sold it was it was too heavy for my 150 pound body. I mainly started this thread because I also had a 2003 yz250 which from my memory I was the fastest on. I havent really had the chance to ride my 2006 yz250 yet, after I have the suspension revalved and I de tune the engine a bit im sure I will be better on it than I was on my 2003 yz250. I guess wanting to throw my 2006 on a steel frame was a silly idea, I probably would not benefit from the steel enough to make it all worth while. 

Edited February 24, 2015 by vic2340

[shagger]

While not earth shattering. The steel frame is a nicer woods frame. I rode one of three 2007s for years. Last spring I bought a 2004. Since then I have ridden them back to back often. They work and feel very similar until you get to a place that has roots and rocks or whatever. You'll see a formation that you know from experience is about to give you a big jolt from the aluminium frame. That jolt is just a regular bump on the steel frame. If where you are riding has a lot of that stuff. It could add up to a pretty big deal. The average area of good trail just sort of makes you happy knowing the jolt from those rocks are not going to happen because you are riding the steel framed bike. Could you have a crash didn't crash scenario? Well, you'd never really know for sure. But if you are racing an enduro you can certainly have a get tired sooner or later scenario.

 

For ice racing the steel frame makes a pretty big difference because you are doing nothing but tipping the bike way in over bumps all day. You can go faster through a given bumpy corner without getting rattled or loosing traction.

 

The situation reminds me of the difference between the 1999 and 2000 CR250 Honda. The 1997-1999 aluminium frames were really stiff. Get on a 2000 and the bike feels exactly the same until you hit a corner. Then the "tuned flex" really became very apparent.

 

I think the main issue with the YZ250 is that it is basically running a first generation aluminium frame that was designed very quickly to fit in the same space as the steel frame that it replaced. There are few parts other than the frame itself that differ between 2004 (steel) and 2005 (aluminium). The racers hated it. Why? Because they go really fast on tracks that are whipped to crap. That is exactly the sort of terrain that the aluminium frame doesn't like. They also found that the aluminium frame was very sensitive to what skid plate was on it and that sort of thing. There is an interview with Chad Reed someplace. He makes it VERY clear that he did not like the aluminium frame.

Edited February 24, 2015 by shagger

[shagger]

Thanks for all of your replys, I guess I shouldnt really be to worried about my aluminum frame on my yz250 for Enduro type riding. I did have a 2009 yz450f and that thing, after being totally set up for the woods was fantastic. (Its aluminum frame felt very mellow) It was stable and soaked up the trail amazingly. The only reason I sold it was it was too heavy for my 150 pound body. I mainly started this thread because I also had a 2003 yz250 which from my memory I was the fastest on. I havent really had the chance to ride my 2006 yz250 yet, after I have the suspension revalved and I de tune the engine a bit im sure I will be better on it than I was on my 2003 yz250. I guess wanting to throw my 2006 on a steel frame was a silly idea, I probably would not benefit from the steel enough to make it all worth while. 

That depends on the amount of time you are going to keep the bike. I'd do it in a heart beat. Think of all the things you do and money you spend for a suspension upgrade. This is one of those things that is a suspension upgrade that you can't get from a tuner. I remember when I got an 18" rear wheel for my 1993 YZ250. It was like I suddenly had a much better shock. The effect is much less on the newer bikes. But it is still an advantage on nasty terrain.

[Shawn250]

I would think having the correct suspension set up is going to give far better results that using a steel frame. 

[shagger]

Both however is best. And I wonder about the suspension. Provided it's sprung for you weight. I find the stock Yamaha suspension to be pretty good. A steel frame might have a better net result. You gain something that no tuner can give you.

[rpt50]

You didn't mention your height, but if seat height is an issue at all, don't forget to work that into the equation. It's amazing how just a minor seat height difference can improve your concerning confidence in tricky conditions and reduce knee tweaks.

I've been tinkering with my 06 YZ (re valve, re spring, lots of sag settings) and I'm finally got it to the point where it works as well in the woods as my KTM and RM, but the seat height is just a little to high. I was planning on some minor seat shaving, but I did not take into account how the oversize tank changed the angle of the seat at the front. Looking back, I should have had the suspension limited a tad when it was apart for the re valve.

[YamaLink]

While this isn't an answer I know a local A rider who has a garage full of bikes, and his 250 two stroke favorite is a steel frame YZ with a ton of mods. I asked and he said the steel frame fits his needs and riding style the best.

[vic2340]

That depends on the amount of time you are going to keep the bike. I'd do it in a heart beat. Think of all the things you do and money you spend for a suspension upgrade. This is one of those things that is a suspension upgrade that you can't get from a tuner. I remember when I got an 18" rear wheel for my 1993 YZ250. It was like I suddenly had a much better shock. The effect is much less on the newer bikes. But it is still an advantage on nasty terrain.

Thanks a lot for your input, I am going to go through with my plan on building my yz up to a woods weapon. My last mod will be a steel frame conversion. That might be some time in the future and I will see if it might benefit me then, you never know what the future will bring. It would be cool also because I could buy a steel frame, say a 2002 for about 200 bucks. Then I could sell my aluminum one for double that. Anyways would that conversion work, and would the parts fit and be interchangeable? If you know of anything that would not line up let me know. Im curious if this is in the realms of worth doing. 

[vic2340]

You didn't mention your height, but if seat height is an issue at all, don't forget to work that into the equation. It's amazing how just a minor seat height difference can improve your concerning confidence in tricky conditions and reduce knee tweaks.

I've been tinkering with my 06 YZ (re valve, re spring, lots of sag settings) and I'm finally got it to the point where it works as well in the woods as my KTM and RM, but the seat height is just a little to high. I was planning on some minor seat shaving, but I did not take into account how the oversize tank changed the angle of the seat at the front. Looking back, I should have had the suspension limited a tad when it was apart for the re valve.

I am 6 ft tall. My choice of seat is a medium density foam made by guts. It is much softer than stock yet not too soft and I ride with a gripper seat cover. I once tried a tall seat foam however it was terrible. I feel right at home with standard height.  

[shagger]

I stand most of the time. So seats aren't very important to me. I'm 6' tall and have some stock seats and some MSR, I think, seats. I use a seat for Ice racing if I want it softer. I had my own track. So a season of ice racing would soften a seat quite a bit. So much so that they would become a bit "hard" for ice racing.