Ski-Doo Snowmobiles Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
1,801 Posts
i hope BRP hasn't ''detuned'' the clutchs to keep the springs from breaking, like they did on the 850's to prevent belts from coming appart...
 

·
Banned
Joined
·
7,722 Posts
I have Dalton torsion springs for both of my turbo's and that's what I will stay with. I will give back the stock Doo springs for the new ones but will only use them for spares.

I think this is a temporary fix and have always felt that torsion springs are better than compression springs. The only reason to use compression springs is for the rer on the 2 stroke models.
 

·
Super Moderator
Joined
·
17,983 Posts
Brp has been changing these yearly since the 1200 first came out in 09.. when are they going to either get a good Torsion spring manufactured that doesn’t break or pick a good compression setup for a fourstroke!
 

·
Ski-Doo Guru
Joined
·
13,819 Posts
I have never replaced a roller in a QRS going on what 12 years now the QRS has been out???

Personally I would started out stock or tuned with a Dalton Red secondary spring with two swivel washers.

The Dalton red is an excellent replacement spring and it tends to allow the QRS to shift into OD easier than the doo purple compression spring.

Still if it were ME with a 2020 I would be drilling the helix to accept the dalton torsion spring.
 

·
Registered
Joined
·
469 Posts
Brp has been changing these yearly since the 1200 first came out in 09.. when are they going to either get a good Torsion spring manufactured that doesn't break or pick a good compression setup for a fourstroke!
This comment interested me..... FWIW: Looking at the design of the so-called torsion spring, it looks like it is going to get stressed in an unusual way. The spring wire in a compression spring gets twisted around the wire axis, and not bent. For a torsion spring, the wire actually does get bent, and in this application, that torsion spring gets both twisted (in compression) AND bent (in torsion).

With the tapered diameter on the spring design here, the degree of torsional bending on the wire is going to vary across the length of the coil when bent in torsion... thus the strain on the wire varies and it would be expected to fatigue and break more readily at one end than the other. So I'm not sure 'non-breaking' is ever going to happen...at least at first thought. This is an odd design where the wire gets both bent AND twisted at the same time, along with the strain varying across its length.
 

·
Banned
Joined
·
7,722 Posts
This comment interested me..... FWIW: Looking at the design of the so-called torsion spring, it looks like it is going to get stressed in an unusual way. The spring wire in a compression spring gets twisted around the wire axis, and not bent. For a torsion spring, the wire actually does get bent, and in this application, that torsion spring gets both twisted (in compression) AND bent (in torsion).

With the tapered diameter on the spring design here, the degree of torsional bending on the wire is going to vary across the length of the coil when bent in torsion... thus the strain on the wire varies and it would be expected to fatigue and break more readily at one end than the other. So I'm not sure 'non-breaking' is ever going to happen...at least at first thought. This is an odd design where the wire gets both bent AND twisted at the same time, along with the strain varying across its length.
Torsion springs were on all sleds with few issues until the reverse running engine on two strokes.
 
1 - 13 of 13 Posts
Top