Hammerschmidt
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Hammerschmidt
Post by 1440brad on Oct 7, 2008, 4:40pm
Oh Man ... I gotta get me one of these.
http://www.magicmechanics.com/#
Anyone have an idea of price?
Re: Hammerschmidt
Post by morris on Oct 7, 2008, 5:26pm
Your not the only one that wants one. I heard $800 as an after market. Trick is to get one on the next NEW bike.
Re: Hammerschmidt
Post by 1440brad on Oct 7, 2008, 5:42pm
That sounds like an excuse to look at a new bike!!!!
"Sorry honey, I have to by a NEW bike 'cause mine doesn't have the HAMMER".
How does that sound? Should I start to practice this line in front of a mirror?
Re: Hammerschmidt
Post by g on Oct 7, 2008, 6:11pm
$800ish is right on Mo.
Played with one at BTAC...Sweeet.
Rocky has it on the new Flatline Unlimited.
Santa Cruz will also offer it in the new year in a kit.
Very cool stuff.
-G
Re: Hammerschmidt
Post by admin on Oct 7, 2008, 8:00pm
![[image]](http://p1.pinkbike.com/photo/2557/med/mpbpic2557541.jpg)
http://www.pinkbike.com/news/truvativ-hammerschmidt-interbike-2008.html
Re: Hammerschmidt
Post by brad on Oct 7, 2008, 10:53pm
That is incredible!
Re: Hammerschmidt
Post by markhunter on Oct 8, 2008, 8:29am
Troy - forget the new gizmo approach. The secret to a new bike is the health angle. "Honey I'm not getting younger and you want me around for the retirement years. If I had a shiny new bike it would renew my enthusiasm for biking which is very good for my heart. Think of it as an investment in our future." Works for me
All that aside, the gizmo looks very nice.
Re: Hammerschmidt
Post by jackp42 on Oct 8, 2008, 8:49am
This looks pretty cool. Unfortunately my Supermoto doesn't have the required ISCG tabs. Time for a new bike? Tracy's not going to be happy!
Mark, I assume the Delirium is all set up for it!
I hear Nicolia is also working on a 2 speed crankset.
Change is happening to a true G-Boxx or CVT one small step at a time.
Re: Hammerschmidt
Post by 1440brad on Oct 8, 2008, 2:30pm
Oct 8, 2008, 8:29am, markhunter wrote:
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I here ya Mark. I'll give it a try.
Re: Hammerschmidt
Post by morris on Oct 8, 2008, 3:07pm
Understanding the ISCG tabs are required would the adapter work if your frame did not have the taps?
Re: Hammerschmidt
Post by brad on Oct 8, 2008, 4:50pm
Oct 8, 2008, 8:49am, jackp42 wrote:
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What the heck are ISCG tabs???
Re: Hammerschmidt
Post by 1440brad on Oct 8, 2008, 4:58pm
http://www.cannondale.com/bikes/09/cusa/model-9AFSDJFR.html
Take a look at the bottom bracket shell. Notice the 3 tabs.
Re: Hammerschmidt
Post by jackp42 on Oct 8, 2008, 5:08pm
Since the tabs are used to transmit/resist a fair bit of torque, I think any adaptor that simply clamps between the BB shell flange and the extrenal bearing cut isnt' going to work. I read that Truvative says the proper build in tabs are a must.
The good news is that this should inspire more frame builds to put these on in the first place, and not just on DH bikes.
Marco, can you set up shop and well on some tabs!
Re: Hammerschmidt
Post by morris on Oct 8, 2008, 5:28pm
Good to know the only option is a new frame with taps. Who will be the first to get one?
Re: Hammerschmidt
Post by marco on Oct 8, 2008, 6:08pm
Oct 8, 2008, 4:50pm, brad wrote:
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International Standard Chain Guide mount
Re: Hammerschmidt
Post by marco on Oct 8, 2008, 6:11pm
Oct 8, 2008, 5:08pm, jackp42 wrote:
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Nope - read my next comment.
Re: Hammerschmidt
Post by marco on Oct 8, 2008, 6:12pm
Oct 8, 2008, 5:28pm, morris wrote:
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I am with Mo on this one - why weld when you can by new.
Re: Hammerschmidt
Post by g on Oct 9, 2008, 9:40am
Oct 8, 2008, 5:28pm, morris wrote:
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....Hmmmmm.
I wonder.....??
-G
Re: Hammerschmidt
Post by g on Oct 18, 2008, 11:53am
I've got a deal cookin' on this one...
Watch the sponsor zone for more on this.
-G
Re: Hammerschmidt
Post by morris on Oct 20, 2008, 1:07pm
What's this I hear about after market taps that can be welded on?
Re: Hammerschmidt
Post by g on Oct 21, 2008, 10:25am
I'm trying to source them through a few different places that sell frame-building supplies. The places that sell dropouts, braze on's, BB shell's,..that kind of stuff. Not having much luck yet. I did find some...but you have to buy 100. That's probably more than we need. I guess most places just make their own. I have all the CAD drawings for the tabs, too bad I didn't know any machinists....
-G
Re: Hammerschmidt
Post by 1440brad on Oct 21, 2008, 4:41pm
Can the "tabs" be mounted to a "ring" that will fit over the bottom bracket shell?
There are many water jet CNC companies around.
Or should I look for another frame?....
Re: Hammerschmidt
Post by morris on Oct 21, 2008, 4:52pm
As Troy posted could we not use the 05 ISCG adapter that is held in place with the BB cup with an added bit that by way of the down tube or seat tube stop the forward rotation.
But I still have to ask how much torque will the Hammer put against the taps? All but one of my chain guides were/are held in place by the BB cup and they only moved if I lost my head and slammed the lower roller real hard against something solid.
Re: Hammerschmidt
Post by jackp42 on Oct 21, 2008, 7:27pm
I suspect the tabs will resist the full torque going through the geartrain which should be in a worst case the riders weight (assuming he has all of it on one pedal) multiplied by the crank arm length and divided by the radius to the center of the panetary gears. This would likely be somewhere in the 1000 lbs shear on the tabs. I doubt clamping with the BB cup would hold this.
I like Troy's idea of making a ring with the 3 threaded holes. This ring could then be stitch welded on to BB shell and with its added strength over 3 separate tabs, should help keep the BB shell from warping too much. The BB shell will have to have its threads chased and the outside refaced.
I'm currently in the process of setting up a small machine shop at work some making something to try shouldn't be a problem. Someone have an inexpensive frame to try it out on?
Re: Hammerschmidt
Post by 1440brad on Oct 21, 2008, 8:30pm
As Sprockets mentioned.....
What about this.
http://www.silverfish-uk.com/products/54....php?r=2m0d1b0s0
Re: Hammerschmidt
Post by wiggles on Oct 22, 2008, 12:29am
http://www.silverfish-uk.com/products/54....php?r=2m0d1b0s0
Available in:
* ISCG OLD
That's the problem...
This is the one we need:
http://www.beyondbikes.com/bb/itemdesc.asp?Ic=QCH1280
Re: Hammerschmidt
Post by marco on Oct 22, 2008, 10:21am
If welding is an option you are seriously considering then you will need to confirm the adapters base material. If made out of 6061 or 7005 - the aluminum standards for bike frames - then all is good. If made out of 7075 for increased mechanical properties (much like xtr and other high end chain rings) then welding is NOT an option. The weldability of 7075 is very poor and if cracks don't present themselves during welding they surely will during service.
That being said - who's frame, what adapter and when do we start welding?
Re: Hammerschmidt
Post by morris on Oct 22, 2008, 5:05pm
Forget the retro fit idea, other then the bling factor I am not convinced it would work all that great on a none current frame where the pivots have been relocated to work with a small chain ring.
Looks like we are back to getting NEW current model year bikes.
Re: Hammerschmidt
Post by jackp42 on Oct 23, 2008, 3:32pm
I would have a hard time believing that a frame manufacturer is going to optimize the suspension geometry to suit the Hammerschidt since the majority of his sales is still going to be to people installing coventional 2 and 3 ring cranks. Only in the case where they are selling complete bikes and the intent from the get go is to sell it and optimize it for the Hammerschidt would it happen.
I think that some suspension designs are going to be more tolerant of the change in chain ring size, but that there should be enough options to choose from on the market for the last few years that could accept it. Bikes that pedal well in granny should be fine for Hammerschidt conversion.
Marco, I'm game to try and have a few spare (broken and repaired) Whyte frames that are 6061 that we can experiment with though ultimately I would prefer to have this on my SM. I can make the tabs or rings if you want to weld it. I assume G would have the tools to case the threads and face the BB shell when done?
I down loaded the CAD file for the geometry of the ISCG mount but didn't see information whether this was for the 3 or 5 standard. Does anyone know the difference?
Re: Hammerschmidt
Post by 1440brad on Oct 23, 2008, 3:51pm
Oct 23, 2008, 3:32pm, jackp42 wrote:
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Here is the difference.... http://www.e13components.com/support_iscg_explained.html
Re: Hammerschmidt
Post by morris on Oct 23, 2008, 3:58pm
My understanding is frame manufactures design the suspension around the middle chain ring. This being the case the use of granny or big big would be a compromise to the ride quality.
Re: Hammerschmidt
Post by jackp42 on Oct 23, 2008, 6:41pm
Thanks Troy. That link has all the info on ISCG we need.
I agree Mo that pretty much all bikes that are designed for twin or triple rings have their suspension optimized for the middle ring. That said, I believe some suspension designs are better then others for not causing suspension issues in the granny or big ring. These should prove better to handle the Hammerschmidt, though this may be splitting hairs for a well designed and proven bike. Possibly in time we may see frames/bikes coming out designed around Hammerschmidt, but I suspect this will take a while if ever.
Re: Hammerschmidt
Post by g on Oct 27, 2008, 11:39am
Oct 23, 2008, 3:32pm, jackp42 wrote:
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I have the tools...
I also ordered the ISCG tab facing tool.
I also have a few adaptors you could pattern from if needed.
My SXC doesn't have tabs either...gotta have'em.
-G
Re: Hammerschmidt
Post by jackp42 on Oct 27, 2008, 3:56pm
Let's talk. How about before, at or after next Tuesdays club meeting?
Re: Hammerschmidt
Post by g on Oct 27, 2008, 6:32pm
Sounds good.
Don't say anything to him...but we are still going to have to
bribe that "former-welder-guy"...we'll talk.
Just keep it quiet...
-G
Re: Hammerschmidt
Post by marco on Oct 29, 2008, 3:28pm
LOL - I'm pretty easy to bribe when it comes to welding.
Re: Hammerschmidt
Post by g on Oct 31, 2008, 3:46pm
I guess we blew it on keeping it quiet....
-G
food for thought
Post by thumbies on Nov 12, 2008, 11:21pm
Here's what Dave Weagle (from DW-Link fame) has to say about converting bikes designed around a multi-chainring setup to a single ring (such as the Hammerschmidt effectively is). This is taken from his blog:
"Bicycles have evolved in an interesting way over time. Over the first hundred or so years, the measurements of wheel diameters, bottom bracket heights, top tube lengths, etc. had just been empirically “figured out” by tinkerers. The geometry that we ride today in the grand scheme of things is not all that far removed from what people were on long ago. Sure, small changes make big differences in feel, but we are talking about really small changes at this point. (No adult is riding 10 inch rear wheels on their mountain bike.) Of course, this empirical geometry development was really just a systematic chain of choices based on what worked for human ergonomics. What felt right lived on, the Darwinian selection of cycling geometry if you will.
As bikes got more complex, gears were added, derailleurs, shifters, this original ergonomic heritage lived on. Drivetrain companies figured out through testing that a 22T front sprocket worked out well for climbing with an 11-32T and later 11-34T cassette. A 32T front sprocket felt good on flat ground with that same cassette range. A 44T front sprocket gave enough push for descending and getting up to speeds that would scare even the hairiest of men.
Then suspension came, and a whole new era of Darwinian selection began for cycling. Some designs were far ahead of their time, some were downright comical. A set of physical elements never before encountered were at work against cycle suspensions. Suspensions bobbed when riders pedalled hard, climbed hills, and did all kinds of other crazy things. Forces like gravity and anti-squat were acting on the suspension systems, yet few if any people in the world understood the how’s and why’s of why suspensions reacted the way they did.
One thing remained the same through this entire time. Drivetrains still used 3 sprockets, 22, 32, 44. It’s my opinion that the cycling public got extremely lucky here, as the variable front chainline is the savior of cycling suspensions.
I will go out on a limb here and say that without the variable front chainline of the front derailleur 22, 32, 44 (or 48 whatever), the suspension bicycle would have died in its infancy. Sounds crazy, I know, but hear me out.
This is going to take just a little bit of physics, but its not going to be hard to follow I swear. Earlier, I mentioned gravity and anti-squat. You can’t have anti-squat without gravity. I’ll explain both briefly here.
Everyone reading this knows the feel of gravity. It’s acting on everyone on the planet Earth right now. Gravitational force is pulling you directly downward at the earth, right toward the core of the planet. When you ride your bike on flat ground, gravity is pulling you toward the earth at a 90 degree angle to the ground. When you ride your bike uphill, say a 10 degree incline, gravity is pulling you toward the earth at a 100 degree angle to the ground. Gravity is still pulling straight through the center of the earth, but the angle of the ground has changed in relation to gravitational force. When you ride your bike downhill, say on a 10 degree decline, gravity is pulling you toward the earth at an 80 degree angle to the ground.
You might be asking yourself, "What exactly is “anti-squat”? Anti squat is a force that balances the effects of mass transfer on the suspension, giving the best possible bump compliance, while at the same time providing excellent energy efficiency. There are two forces that combine to create anti-squat; chain pull and driving force. Chain pull force is multiplied through your rear cogs and wheel as a lever creating driving force. Because of this leverage, driving force is always the greater than chain pull force, but both are significant. If you hear someone talking about “chain pull force” without mentioning “driving force” in the next sentence, there is a good chance that they have a bridge to sell you somewhere.
OK, now for the tie in! The amount of anti-squat that a suspension can develop is based on (among other things) the angle of the ground that the bike is riding on and the angle of the chainline. It just so happens that as a bike is climbing a hill, the amount of anti-squat drops because the direction of gravity in relation to the bike changes. What this means is that if you are pedalling along in your 32-18 on flat ground and have just the right amount of anti-squat, then start to climb a steep hill, say 15 degrees or so, the amount of anti-squat is going to lessen. It just so happens that moving the chainline downward, say like if you selected your 22T cog, increases anti-squat. In an Apollo 13 like turn of events, people actually use their 22T cog when they climb hills as steep as 15 degrees (you basically have to). The two changing anti-squat amounts balance out, leaving the rider with very similar riding characteristics while climbing in the granny and riding on the flat in the middle ring. Amazing, huh? As you may have guessed, the same goes for descending with a larger ring.
Because of this, chainline variability made some very poorly designed suspension bikes that would have otherwise been unrideable at least reasonably useful enough that people eventually tinkered away and arrived at bikes that performed well enough for suspension to become a reality for the masses.
Variable front chainlines are ALWAYS going to be a good thing for mountain bikers who ride their bikes on variable terrains. Without them, suspension bikes might still be considered a bad idea, and I would most likely be riding motocross.
I design for optimization in the middle ring in the flats and light climbs, granny for the big climbs, and big ring for the descents. There is a lot of overlap there."
hmmm, you know he kinda makes a lot of sense. This is probably only a big deal if you plan on doing a lot of climbing on your new Hammerschmidt-equipped ride. Many of the people considering the Hammerschmidt are probably already running single-ring set-ups (or just never use the granny ring) anyhoo.
D.
Re: Hammerschmidt
Post by jackp42 on Nov 13, 2008, 8:32am
This all sounds great in principle but, there are a lot of bikes out there that don't have anti-squat geometry, some of which are still very good bikes. The saving grace for these is the advent of quality suspension dampers and stable platform dampers. I believe that Hammerschmidt will work well on many of these even though it only has the equivalent of the granny chain ring. Shock settings may need to be tweeked to optomize though.
The proof is obviously going to come out once these make there way on to bikes and we see what the reaction in.
I'm still quite interested in trying it.
Jack
Re: Hammerschmidt
Post by gixxerflier on Jan 13, 2009, 7:23pm
Gotta know. Did you guys try the retrofit? And the result?
Re: Hammerschmidt
Post by jackp42 on Jan 14, 2009, 6:13pm
A few of us are going to try a retrofit by welding on a custom made ISCG flange. Waiting for the Hammerschimdt to come in before making the flange, getting it welded on, and then machine the face to square it up and chase the BB threads.
Hope to have something together for early spring, but largely depends on when the Hammerschmidt parts show up.
We'll let you know how it works out.