Preview: Truvativ HammerSchmidt

8/21/2008 : sicklines

, Preview: Truvativ HammerSchmidt
Truvativ HammerSchmit (AM)

It’s not every day that you get to ride something as unique as the Truvativ HammerSchmidt. What Truvativ has designed, a planetary gear system, is impressive to say the least.

, Preview: Truvativ HammerSchmidt

What HammerSchmidt does on the surface is replace a double ring setup with a single ring one that offers the same gear range, but there are many more benefits to it. Read more inside.

While the idea isn’t new to the transmission world, it is impressive to see the idea implemented in a crankset to effectively replace not only the double ring setup, but also acts as a bashguard and a chainguide all in one. Before we delve into the details of the ride here is a run down of the two versions available for after market purchasing.

HammerSchmidt will come in two flavors, an AM and a FR Version.

All Mountain (AM)

, Preview: Truvativ HammerSchmidt

  • Crank arm lengths are 170 and 175mm
  • Tungesten Grey finished arms made from AL 7050 TV
  • Versions for 68, 73, 83mm bottom bracket sizes
  • Gearing equivalent to a 22t/36t or 24t/38t
  • 15mm crank bolt

Free Ride (FR)

, Preview: Truvativ HammerSchmidt
  • Crank arm lengths are 165mm, 170mm, or 175mm
  • Galvanized Silver finished arms made from 7050 TV (optimized stiffness for FR)
  • 12mm crank bolt for increase stiffness
  • Versions for 68, 73, 83mm bottom bracket sizes
  • Gearing equivalent to a 22t/36t or 24t/38t

HammerSchmidt Bottom Bracket

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Installs with Howitzer tool on the non drive side, and an ISIS tool on the drive side

  • Proprietary to Hammerschmidt
  • Designed off of the Howitzer BB
  • Uses a double row bearing on the drive side specific to HammerSchmidt
  • Drive side tightens with ISIS tool, Non drive side uses Howitzer tool
  • Versions for 68, 73, 83mm bottom bracket sizes
  • AM version: 15mm (lighter)
  • FR version: 12mm (beefier stronger spindle)

HammerSchmidt Shifter

, Preview: Truvativ HammerSchmidt

, Preview: Truvativ HammerSchmidt

  • Specific to the HammerSchmidt and is available in X.O or X.9
  • The shifter actuates in reverse of a traditional SRAM front derailleur
  • Only two shifting points
  • Matchmaker compatible
  • X.0 version differs from X.9 in the same way as other X.0 / X.9 shifters (adjustable shift paddle, carbon cover, bearing vs . bushing for smoother shifts)

The HammerSchmidt setup runs on either a 22t or 24t chainring and once the overdrive setup is engaged, it multiplies the base gear by ~1.6 which gives an equivalent 36t if you’re running a 22t or a 38t if you’re running a 24t. So you’ve got the option to have either a 22t/36t setup or a 24t/38t setup.

, Preview: Truvativ HammerSchmidt
22t HammerSchmidt specific chainring

Riding the HammerSchmidt

SRAM setup an ideal testing ground for us in Pemberton, B.C. that highlighted just how well the HammerSchmidt would work in a very diverse area. From tight quick climbs to steep and rocky descents, the HammerSchmidt was put to the test for a few days.

Initial thoughts on the HammerSchmidt was quite positive throughout the test rides and after more and more time was spent on the system it was clear that the HammerSchmidt has clear advantages over a front derailleur system.

Installation was a breeze. It took no time to bolt up the system on the bikes SRAM selected. The system requires some specific ISCG tabs (03/05) and no you can’t use an ISCG adapter to circumvent this. The tabs require a good bit of strength to handle the torque generated so flimsy ISCG tabs might not suffice.

Another nice feature is that there is no more hassling front derailleur setup at any point whether it be in the shop, on a ride, or race. In a muddy race or tough climb situation, mud or grime won’t have you scared to shift into the lower gear. You’ll have reliable front shifting that will make you gain more confidence every time you ride it.

Overall the HammerSchmidt was durable, offered tons of clearance, and did not miss shift during the ride. There are tons of ideas for where these cranks can have a huge benefit for the rider and as more and more people install them, even more benefits will become apparent. I’ve outlined a few of the major benefits I felt with the HammerSchmidt below.

Easy setup

The HammerSchmidt was a piece of cake to setup with the given bikes. While it won’t work with every bike (requires ISCG (03/05) tabs and in a particular orientation), it is easier to setup than a front derailleur given comparable ideal setups. ISCG 03 is often also referred to as ISCG-OLD and sometimes just plain ISCG. ISCG 05 is also often called ISCG2005. To measure which tabs you have, you can refer to this chart as well. Regardless, the HammerSchmidt comes with both 03/05 plates as well as a template to make sure it will fit properly.

The HammerSchmidt installs in a few easy steps as illustrated below in some abbreviated steps. You can see the full set of installation steps and a video at MagicMechanics.com

1. Prepare frame and ISCG tabs

, Preview: Truvativ HammerSchmidt

2. Position and align HammerSchmidt collar plate

, Preview: Truvativ HammerSchmidt

3. Install shift cable

, Preview: Truvativ HammerSchmidt

, Preview: Truvativ HammerSchmidt

4. Install crank arms

, Preview: Truvativ HammerSchmidt

Increased clearance

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When you compare the HammerSchmidt setup to any typical double or tripple crankset, the HammerSchmidt system offers significantly more clearance in just about every direction. You get more clearance to the small ring which makes getting over logs and obstacles much easier.

If a frame were designed around a HammerSchmidt, it could prove beneficial by offering more flexibility on pivot locations, less front derailleur tubing variations / tweaks, beefier tubing options, additional tire clearnace, and much more.

In addition to the crankset area gaining more clearnace, the rear derailleur also can benefit as you can run a short cage derailleur which will improve clearance there as well without any loss of gearing.

Lastly, when you pick up the bike you won’t get the grease marks on your legs or clothes as the system is encapsulated quite nicely due to the smaller HammerSchmidt footprint.

All in one system

, Preview: Truvativ HammerSchmidt

The HammerSchmidt is a system and as such was designed to work as one unit. To get a comparable setup is a lot harder as all parts are not designed to work perfectly with every single part. By designing the HammerSchmidt to include all these in one package was a smart idea. The HammerSchmidt takes either a 22t or 24t main gear and uses either a 22t or a 24t HammerSchmidt upper guide that is included. There are multiple positions for the upper guide to be mounted that helps it fit a wide variety of bikes. The durability of the HammerSchmidt seems right where it needs to be and the synergy of the system worked well.

Hasslefree shifting

The HammerSchmidt system shifts under load, while backpedaling, or standing still. It is very quick and effortless. Compared to a front derailleur system, this system blows it away in how easy it is to shift in the last second without fail or chain griding.

, Preview: Truvativ HammerSchmidt

The system is smooth and is a vast improvement in terms of having reliable shifts no matter what the scenario is. With a typical front derailleur setup, you have to pedal to shift, the HammerSchmidt does not. This helps improve shifting as it is much quicker and easier to get out of rough situations with a quick push of the shifter.

While you can’t visually look down and see what gear you’re in, it is very easy to determine with a push of the shifter. The system shifts effortlessly and last minute shifts proved to be no problem for the HammerSchmidt.

Chain management

A big part of what the HammerSchmidt can do is manage the chain much better. It doesn’t have a lower roller to quiet the chain exiting the crankset, but it does have an upper guide that keeps the chain on the ring safely.

, Preview: Truvativ HammerSchmidt

The chain is also able to be cut much shorter so you get a tighter drivetrain that has less chainslap as well. A short cage derailleur can be used in this setup much easier without fear of cross stretching the chain or going beyond the rear derailleur’s capacity. In a typical 18 or 27 speed drivetrain, often there are gears that are shunned against using. With the HammerSchmidt system, the chain line is improved over a front derailleur system, and all gears are encouraged to be used.

Improved chain line

The chainline of the HammerSchmidt is an impressive benefit. There was no rub on the system in any of the gears and it allows the rear derailleur to do its job easier. During the test rides there wasn’t any mis-shifts and the rear derailleur tracked impressively well without fail.

Essentially what I found was that the HammerSchmidt encompassed a lot of single chain ring benefits and dual ring benefits into one clean rub free package.

Additional insight

  • While I can’t speak on behalf of maintenance, the system itself is one that doesn’t need much according to Truvativ. Essentially it will be a lube your chain and you’re ready to go with some routine maintenance to make sure the HammerSchmidt continues to flourish.
  • To shift into an easier gear, you need to pull cable (push the big thumb lever). This is the reverse of what is normally done but it is less of an issue as there is only two ways to shift, and if you do make a mistake it is a quick shift to recover since HammerSchmidt shifts so quickly and requires no pedaling.
  • I would’ve personally liked to see a two piece style crankset and external bottom bracket setup personally but the test setup proved to be issue free.
  • There is currently only one mounting setup to install the HammerSchmidt shift cable. Top pull derailleur frames and even some bottom pull frames will have to rework how to get the shift cable to the HammerSchmidt. In addition, the position of the HammerSchmidt cable entry while I didn’t experience any problems with could potentially be less than ideal in the event of an ill placed obstacle.
  • While in the lower gear (22t/24t) the bike pedals like a normal crankset without any feel of drag. Once the shifter is pressed and overdrive is engaged I did feel some drag in the system that didn’t feel quite as effortless as a non HammerSchmidt setup. The system we rode was a pre-production version and brand new so some of this smoothness could be alleviated once the system breaks in.
  • The overall system weight of the HammerSchmidt will come down over time but currently it is a bit portly when compared to lighter setups.
  • The HammerSchmidt is built around 22t/24t setup and as such means that your suspension will react similarly to riding in the granny ring. If more bikes are designed around the granny ring this will be a mute point but currently there are some designs out there that don’t pedal ideally in the granny ring and the HammerSchmidt will suffer in those designs.


*All weights below provided by SRAM  (check out weights page for our measured weights)

Part Year Claimed(g)
2009 HammerSchmidt AM 175mm
Collar Plate 2009 217
Mechanism 2009 866
Non-Drive Arm 2009 246
73mm HammerSchmidt AM BB 2009 295
Total 1623
Part Year Claimed(g)
2009 HammerSchmidt FR 175mm
Collar Plate 2009 217
Mechanism 2009 922
Non-Drive Arm 2009 287
73mm HammerSchmidt FR BB 2009 360
Total 1785
Savings Year Claimed(g)
Additional Weight Savings
7 less chain links -36g
Mid-cage to Short Cage Derailleur -5g
Total -41
  • Compared to a Truvativ’s Stylo two ring setup with XR Guide the HammerSchmidt AM weighs 172g more.
  • Compared to a Truvativ Holtzfeller 2.2 two ring setup with XR Guide the HammerSchmidt FR weights 11g more.



Q-factor is defined as the distance between pedal mounting faces of left and right crankarm, measured in a direction parallel with the BB axis.

Truvativ HammerSchmidt Freeride is essentially the same Q-factor as a Holtzfeller OCT and Blaze. HammerSchmidt AM is 8mm narrower than the FR version and is in the class of Stylo’s Q-factor (1mm wider). HammerSchmidt Q-factor is symmetric about the centerline plane of the bicycle frame.

*Q-factor numbers provided by Truvativ

Part Center to Left Center to Right Q-factor
2009 HammerSchmidt FR 88.5 88.5 177
2009 HammerSchmidt AM 84.5 84.5 169
Stylo (GXP) 83 84.5 167.5
Blaze (Howitzer) 88 88.5 176.5
Holzfeller OCT (Howitzer) 88 889.3 177.3

, Preview: Truvativ HammerSchmidt
Bryan Bos – Truvativ Product Manager

The Truvativ Engineers will without a doubt keep improving this already impressive system. Any rider can appreciate the benefits of this system and the bottom line is that HammerSchmidt will change the way you ride. Now if they can make the rear end work similarly!

We’ll try to get a HammerSchmidt to ride a bit more and see how they hold up but so far our thoughts is that it is a very impressive system. If you’ve got any questions feel free to ask away and we’ll try to answer what we can.

Be sure to check out the gallery as we’ve included a lot of detailed pictures of the intricacies of the HammerSchmidt.

You can also check out the HammerSchmidt website at www.magicmechanics.com.

[HammerSchmidt Gallery]

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