Suntour LePree 3 pulley rear mech

[Gtpulse]

Apparently SunTour did the 3 pulley thing with Cyclone, XC, and LePree.

The arms definitely look similar:
Cyclone https://velobase.com/ViewComponent.aspx?ID=D408EFE6-545F-4553-823D-EE00300AB180&Enum=108&AbsPos=50
XC https://velobase.com/ViewComponent.aspx?ID=452F72A4-555E-4808-BC35-29E08352D7C9&Enum=108&AbsPos=95
LePree https://velobase.com/ViewComponent.aspx?ID=52F9FD31-AC22-41E4-9FDC-407610AE3B3F&Enum=108&AbsPos=67

I'd really like to see the specs for those variants - wrap mainly.
Velobase doesn't seem to know.

If you can read Japanese then Disraeligears has docs on there

 

[gounthar]

I asked a tool to summarize the whole story... I do hope it did not hallucinate.
Don't hesitate to tell me where it's wrong:

The Story of Suntour's 3-Pulley Derailleurs: Innovation and Interchangeability

Suntour's development of 3-pulley derailleurs represents one of the most innovative yet commercially unsuccessful ventures in cycling component history. These unique designs emerged during the mid-1980s as an engineering solution to the challenges posed by the growing popularity of mountain bikes and their demanding gear requirements.

Origins and Technical Innovation

The concept emerged from a fundamental engineering challenge in the early MTB scene. Traditional long-cage derailleurs, while capable of handling wide gear ranges, suffered from limited ground clearance and chain slap. Suntour's engineers developed a 3-pulley system to provide huge capacity with a shorter cage.

The third pulley disengaged when not needed, maintaining chain tension and adapting to gear selection. This approach was protected by patents, including US Patent #4,637,808 and Japanese patents from Kawamura and SunTour.

The Le Pree Series: Nishiki's Exclusive Partnership

The Le Pree derailleur was initially exclusive to Nishiki's ATB line around 1985–1986 (forum source). Some earlier versions were labeled “Le Preel.” It was designed to handle large cogs (34–38 teeth) while maintaining a short-cage profile—ideal for rugged terrain.

The XC Mountain Bike Series

The XC series was Suntour's follow-up to the MounTech line. The 3-pulley XC variant retained overbuilt, durable construction. It had a large spring housing, wider hanger bolt, and “3 Pulley System” stamped on the cage. More details are on Disraeli Gears.

Cyclone Variants and Evolution

To be checked, this looks like an hallucination:
> The Cyclone series also saw a 3-pulley version, notably the Cyclone 6000 in 1984. This marked a shift toward durability over lightweight finesse.

Interchangeability and Technical Compatibility

Suntour had two main 3-pulley cage systems:

• XC/Le Pree system: Large spring housing, wide hanger bolt, and cage stampings.
• ARX system: Smaller spring, no markings, compatible with Cyclone M-II cages.

Enthusiasts have discussed cage swaps and compatibility in this BikeForums thread. Note: finding replacement parts like the flat clock spring is a known difficulty.

Commercial Reception and Market Impact

Despite technical brilliance, the 3-pulley derailleurs were not a commercial hit. Their strange appearance deterred buyers. Meanwhile, Shimano's SIS (indexed shifting, introduced in 1984) began dominating the market. More on Suntour's decline can be found in this historical overview.

Conclusion

Suntour's 3-pulley derailleurs showcase innovation that fell victim to timing and aesthetics. They remain collectible gems today, admired for their clever engineering—but tricky to maintain.

Full Reference List
Reference Links and Further Reading

These links expand on the history, models, patents, and enthusiast discussions around Suntour's 3-pulley derailleurs:

1. Disraeli Gears - Suntour XC 3 Pulley System
2. BikeForums - Suntour 3-pulley action video thread
3. Restoring Vintage Bicycles - Suntour Components Overview
4. Disraeli Gears - Suntour XC Derailleur 6300
5. Disraeli Gears - Cyclone 6000
6. Disraeli Gears - Cyclone 6200
7. Disraeli Gears - The Cyclone Story
8. BikeForums - Cyclone M-II Cage Swap Thread
9. Cycling Vintage - Suntour Derailleurs for Sale
10. MOMBAT - Suntour Brand Page
11. Rene Herse Cycles - Book on Suntour
12. PDF: "The Sunset of Suntour"
13. Frugal Average Bicyclist - Suntour History
14. Velobase - Suntour Component 1
15. Velobase - Suntour Component 2
16. Velobase - Derailleur Component Details
17. SR Suntour - Company History (FR)
18. SR Suntour - Werx Camp Story
19. SS Cycle Works - Front Derailleur History
20. BikeForums - Derailleur Talk
21. YouTube - Suntour System Overview
22. YouTube - Suntour 3-Pulley Animation
23. YouTube - Derailleur Discussion Video
24. BuyCycle - Suntour Rear Derailleurs
25. VéloVintage - Suntour Enthusiast Thread (FR)
26. VeloVert - Suntour Derailleur Help (FR)
27. eBay France - Suntour Derailleur Listing
28. Cycles Fun Passion - Suntour Accushift
29. MadHornets - Pulley Conversion Kit
30. Disraeli Gears - Suntour Main Page
31. Disraeli Gears - Suntour Docs Archive

Have a favourite link or doc on this subject? Add it to the thread and keep the history alive!

 

[doctor-bond]

Despite the AI flowery language (“durability over lightweight finesse?”) that’s pretty good and useful!

There isn’t a pic of a 3 pulley cyclone on Disraeli gears as the link above suggests, but there is one Here :

 

[gounthar]

Thanks, let's correct that!

 

[bikeworkshop]

Trouble with AI is if you don't know the facts already you can't tell when it's fallen for marketing bullsh1t or just wandered completely off-piste into Nonsense Land.

 

[gounthar]

I can delete the post if you prefer.
I think most of it is correct, I'll have to double-check all the links.

 

[bikeworkshop]

I can delete the post if you prefer.
I think most of it is correct, I'll have to double-check all the links.

I don't touch the stuff myself - but i won't stop you...

Yet...

I think it's unlikely to destroy humanity, but will lock you out of your car, and spam you with emails and CG phone calls until the technology becomes useless.

I already don't answer my landline, although it still costs me £10/ month

 

[doctor-bond]

There are loads of issues with AI practically and ethically, but something like this gets you to 90% with traceable links on a non contentious subject - seems a good use and no more inaccurate than the human opinions, lost rememberings and heresay that many forums are awash with.

I guess a useful rule is to flag that it’s AI generated - as you have done - so people can tread carefully.

 

[Gtpulse]

My brain likes to meander towards what I was trying to find out otherwise the facts don’t lodge themselves. Faced with an information dump I’m more likely to move on or lose interest.

 

[bikeworkshop]

My brain likes to meander towards what I was trying to find out otherwise the facts don’t lodge themselves. Faced with an information dump I’m more likely to move on or lose interest.

Knowledge is an interesting journey, rather than an information "big mac with cheese"
Food used to be like that too, so I suppose it's the future.

There are loads of issues with AI practically and ethically, but something like this gets you to 90% with traceable links on a non contentious subject - seems a good use and no more inaccurate than the human opinions, lost rememberings and heresay that many forums are awash with.

I guess a useful rule is to flag that it’s AI generated - as you have done - so people can tread carefully.

A problem with the Internet is its hard to judge the quality of the source - AI is better than average, its true.

My HI generated answer:

The 3 pulley derailleur was a blind alley, an attempt to fix increasing complexity with increasing complexity, doomed to failure.

Partly why it's a super cool item