truvativ hammerschmidt

[Tumbleweed]

if only they could make one light enough for cross country' date=' then we'd be getting somewhere...[/quote']

 

isn't the weight gain of the planetary gears offset by the fact that you're only using one ring and doing away with a front derailleur? 

[Thug]

So for all the lazy asses out there who couldn't be bothered with watching videos, what makes this crank so special ?

[intern]

No sleep til Hammerschmidt...

[Dirtbreath]

 

So for all the lazy asses out there who couldn't be bothered with watching videos' date=' what makes this crank so special ?

[/quote']

 

Chain line stays the same. Gearing in the crank changes the ratio of pedal cycle to chain ring cycle. 1:1 standard and 1:1.6 overdrive if I'm not mistaken.

 

As for running this with a Rohloff, that's like putting a spear on the end of a cruise missile!

 

[Tumbleweed]

Chain line stays the same. Gearing in the crank changes the ratio of pedal cycle to chain ring cycle. 1:1 standard and 1:1.6 overdrive if I'm not mistaken.

sounds like something out of the da vinci code.

As for running this with a Rohloff' date=' that's like putting a spear on the end of a cruise missile!
[/quote']

nicely put. was just pulling your socks

 

No sleep til Hammerschmidt...

 

that a beastie boys remix?

[Dirtbreath]

 

 

As for running this with a Rohloff' date=' that's like putting a spear on the end of a cruise missile!

[/quote']

nicely put. was just pulling your socks

 

c/o Lenny Henry............It's automatic officer but I still gotta be here.

 

[TiBones]

However Dirtbreath, consider this if you will - One of the so called major advances in Bike drivetrain technology has been the testing of HTD (Hi Torque Drive) belts to replace the chain. As a drivetrain supplier, designer and manufacturer, I feel that the belt has to be a better option. The problem up until now has been how to shift.

Now with a HS in the front, a Rholoff at the back and a belt in between, the chainline remains constant at all times. There is no chain growth, no derailleur jump and the entire drive can be enclosed and sealed against the elements. Belts are not nearly as susceptable to dirt, require no lubrication,have equal or better wear characteristics etc. etc.

The only thing that has stopped me building such a machine has been a severe lack of funding. Not only do you need an 18K rohloff but an HS and, at about the same cost, a frame,bb,crank combo to suit the HS. Anybody got some tom for a bit of R&D and a coupla beers?

 

[ridesleeprepeat]

if sram can get a handle on the weight, you could effictively have a compact xc crank set up with all the advantages of no shifting, being able to run a short cage mech, tighter chain line and increased bash clearance... but again - the weight is the issue and some people would rather go light than go smart...

[Tumbleweed]

However Dirtbreath' date=' consider this if you will - One of the so called major advances in Bike drivetrain technology has been the testing of HTD (Hi Torque Drive) belts to replace the chain. As a drivetrain supplier, designer and manufacturer, I feel that the belt has to be a better option. The problem up until now has been how to shift.
Now with a HS in the front, a Rholoff at the back and a belt in between, the chainline remains constant at all times. There is no chain growth, no derailleur jump and the entire drive can be enclosed and sealed against the elements. Belts are not nearly as susceptable to dirt, require no lubrication,have equal or better wear characteristics etc. etc.
The only thing that has stopped me building such a machine has been a severe lack of funding. Not only do you need an 18K rohloff but an HS and, at about the same cost, a frame,bb,crank combo to suit the HS. Anybody got some tom for a bit of R&D and a coupla beers?
[/quote']

 

i got beers!

i think dirtbreath may also have been referring to chain feedback on suspension bikes?

 

[TiBones]

 

However Dirtbreath' date=' consider this if you will - One of the so called major advances in Bike drivetrain technology has been the testing of HTD (Hi Torque Drive) belts to replace the chain. As a drivetrain supplier, designer and manufacturer, I feel that the belt has to be a better option. The problem up until now has been how to shift.

Now with a HS in the front, a Rholoff at the back and a belt in between, the chainline remains constant at all times. There is no chain growth, no derailleur jump and the entire drive can be enclosed and sealed against the elements. Belts are not nearly as susceptable to dirt, require no lubrication,have equal or better wear characteristics etc. etc.

The only thing that has stopped me building such a machine has been a severe lack of funding. Not only do you need an 18K rohloff but an HS and, at about the same cost, a frame,bb,crank combo to suit the HS. Anybody got some tom for a bit of R&D and a coupla beers?

[/quote']

 

i got beers!

i think dirtbreath may also have been referring to chain feedback on suspension bikes?

 

 

Lets start with those then, we can design drives later!

 

[Tumbleweed]

However Dirtbreath' date=' consider this if you will - One of the so called major advances in Bike drivetrain technology has been the testing of HTD (Hi Torque Drive) belts to replace the chain. As a drivetrain supplier, designer and manufacturer, I feel that the belt has to be a better option. The problem up until now has been how to shift.
Now with a HS in the front, a Rholoff at the back and a belt in between, the chainline remains constant at all times. There is no chain growth, no derailleur jump and the entire drive can be enclosed and sealed against the elements. Belts are not nearly as susceptable to dirt, require no lubrication,have equal or better wear characteristics etc. etc.
The only thing that has stopped me building such a machine has been a severe lack of funding. Not only do you need an 18K rohloff but an HS and, at about the same cost, a frame,bb,crank combo to suit the HS. Anybody got some tom for a bit of R&D and a coupla beers?
[/quote']

 

i got beers!

i think dirtbreath may also have been referring to chain feedback on suspension bikes?

 

Lets start with those then, we can design drives later!

 

imagine the designs we could come up with after a few cold ones!

[droo]

However Dirtbreath' date=' consider this if you will - One of the so called major advances in Bike drivetrain technology has been the testing of HTD (Hi Torque Drive) belts to replace the chain. As a drivetrain supplier, designer and manufacturer, I feel that the belt has to be a better option. The problem up until now has been how to shift. Now with a HS in the front, a Rholoff at the back and a belt in between, the chainline remains constant at all times. There is no chain growth, no derailleur jump and the entire drive can be enclosed and sealed against the elements. Belts are not nearly as susceptable to dirt, require no lubrication,have equal or better wear characteristics etc. etc.The only thing that has stopped me building such a machine has been a severe lack of funding. Not only do you need an 18K rohloff but an HS and, at about the same cost, a frame,bb,crank combo to suit the HS. Anybody got some tom for a bit of R&D and a coupla beers?[/quote']

 

?

 

i got beers!

 

i think dirtbreath may also have been referring to chain feedback on suspension bikes?

 

?

 

 

 

Chain growth could be easily dealt with - just add an idler. If the chainline's constant, no problem!

[TiBones]

You also want beer?

[Dirtbreath]

With a Rohloff you effectively get similar gear ratios to a 27 speed setup. What would a Hammerscmidt achieve on the front? Pointless I think. I would be interesetd to see a belt driven Rohloff though.

 

I agree with you guys on the beers though. Cant do any R&D without beers.

 

Whats the HS ti?

 

Have you seen the Nuvinci drivetrain? Google it. Very interesting.

 

[Thug]

A review on MTBR...

 

http://reviews.mtbr.com/blog/truvativ-hammerschmidt-pro-review/

 

[Iwan Kemp]

So I emailed SC asking how it might change the ride,here's what I got back the next day...

 

Their Response:

The very short answer is- some people notice a difference, and some don?t.
It depends on your riding style to a certain extent, and the terrain you are
riding.

The long answer is- yes, it does pedal differently, but only if your
hammerschmidt is in the higher gear. The lower gear will pedal the same as
any granny ring. Basically, chainring size will affect any suspension bike,
as the location that your chain is pulling from changes as the chainring
diameter changes. The larger rings will have a tendency to pull the wheel
up- compressing the suspension, while a smaller ring will have less of that
compressing force, or possibly an extending force (this is a vast
generalization; it really, really depends on the bike). In general we
design bikes to pedal perfectly in the middle ring, with slight compromises
in the small and large rings (The Nomad is designed to be optimal with
around a 32-34t chainring). Pedaling hard (standing) in the small ring on a
Nomad will have a slight tendency to extend the suspension, which is
something some people feel, and some don?t. So, as the hammerschmidt is
always using a small ring, you are always a little compromised.
Here is where it gets a little more complicated. Not only does the
chainring size affect the suspension, but the torque that you are putting
into the chain affects it as well. You are able to put more torque on the
chain in a lower gear, making that extending force on the suspension
greater. The high gear on the hammerschmidt puts the same force on the
chain as a standard middle ring, so it will not extend the suspension as
much as using the lower hammerschmidt gear or traditional small chainring
will. So, you are pulling from a different spot compared to a standard
middle ring, but the pulling torque is the same. So the end result is
pedaling characteristics somewhere between that of a traditional granny gear
and a middle ring.
Basically, it isn?t ideal; but it probably isn?t too bad either. The other
thing to consider is the tolerances required by the hammerschmidt. There
are a lot of very tight specs for flatness and perpendicularity of the ISCG
tabs that we may not meet at this time. SRAM has a facer for the ISCG tabs
to get them perfectly flat, but I have a feeling that tool is hard to come
by.

Thanks for choosing Santa Cruz, and let me know if you have any other
questions.

Scott Turner - Santa Cruz Bicycles