Manitou 2 Coil/Elastomer FrankenFork Build Thread

[Juanabe]

Re:

You do know that springs have no damping properties at all right?

This mean that what elite says about them kicking back hard cannot be cured with another spring to replace the rebound bumper you need a damper in there which is usually hydraulic fluid. The beauty of the elastomer was that they had inherent damping properties (ie they don't just return to the same shape as quickly as they deformed, like a spring does, the energy is dissipated through the material and they return slower to their original shape) which kept these early forks light as it serves as both spring and damper in one light unit. They were far from perfect but springs change them for the worse, which is not just my opinion it's a scientific fact.

Easy case in point is have you ever seen a car or motorbike with no dampers?

Sorry, you have just created this:

Carl.

Well.. Though I do appreciate the reply, I'm not so sure that there was anything of any constructive value there. I'm not so sure why you would think that by basically telling me that my project inherently sucks, you are somehow helping or being encouraging.

Now granted I do know about suspensions to some degree and their function, I completely understand the limitations of what it is I am trying to work with here, and am happy to operate within those parameters. This fork pushes a very mild 1.5" of travel as I have it set up and seems to suffer from no perceived topping out as well as minimal pogo effect. I used a slightly taller than average oem soft rebound bumper and that seems to help cushion and slow down the rebound somewhat. With that aspect I am mostly satisfied.

Again, I am not out to reconfigure this to be the perfect fork as much as I am simply trying to recycle good old bits for some future fun. As for, that I think with experimentation and constructive input from others that can be the case

Ps. Your image link is broken.

 

[lrh]

Re: Re:

Thanks for sharing that picture of your setup. Im curious about your coils. Who made those springs?

They're some generic compression springs off eBay here in the UK. Annoyingly the advert suggested they had flat ends but they didn't when they arrived so I had to grind them down.

Here's the dimensions compared to other fork springs I've got (length x diameter x wire thickness):

eBay Springs................60mm x 19mm x 2.5mm
Rock Shox Type II 100.....52mm x 18mm x 3.0mm
RST Mozo Pro (1997).......55mm x 20mm x 2.8mm
Manitou Spyder (199.....50mm x 21mm x 3.0mm

As you can see the stiffness/travel of my springs are very similar to those included in later elastomer-based forks. I'm also a lightweight guy and want a soft action on the road and mild terrain... Those later RST/Manitou forks above barely move under my weight.

I think our and many other people's experience is that these conversions work well for us and you'd have to go to extremes with a very soft/long spring to have the front-end bouncing up and down!

 

[Juanabe]

Sweet info irh.. If this setup works well I plan to emulate it with another paid of manitou 2 lowers I have, and will be needing some similar springs.

I think your right about the latter part of your post. I think a fully serviceable short travel fork is a huge plus for tinkerers such as ourselves. It's wonderful to know that when the time comes to rebuild I won't have to send this thing off to a specialist somewhere.

 

[Mr Crudley]

Sweet info irh.. If this setup works well I plan to emulate it with another paid of manitou 2 lowers I have, and will be needing some similar springs.

I've just impulsively picked up some pre-loved Manitou1's today that I'll rebuilding. I'm keen fiddle with these forks.

I have a pair of M4's on another bike that I replaced the factory elastomer stack with a spring, elastomer and MCU shish kebab. The smaller bump compliance improved but could be due to the factory elastomers not being so great to being. I liked the simplicity of Manitou's approach to early forks at a time when blown seals/cartridges were common.

I wondering what to do with these M1's and want to experiment a bit. I think a coil / MCU might be the ticket. I'm not worried about the lack of damping for such short travel. My M4's seems to have free 'air' compression dampening.

I did open oil bath my old pair of White Brothers SC90's and that made a big difference in smoothness. I'm wondering if a eensy splash of some weight oil might help these too if I went purely coil spring. There is probably a zillion good reasons not to but need to get my hands on these first before I can do the 'what if'. Might be bad idea and the oil might not work with the rest of internals - but it is experiment time and I'm thinking out loud here.

Any sources of replacement springs in a medium spring rate would be appreciated. I'll check the measurements first and see what could be substituted. I'll update you all of likely contenders I find. It sounds like the elastomer shish kebab size is pretty common across the M1->M4 range which has to help.

 

[james1985]

I think I can use most of this info for bodging my Shocktechs.

 

[Gruff]

Re:

James
Pace elastomers fit Shocktech forks

http://www.ebay.co.uk/itm/Pace-Retro-Fo ... SVg6yPOAag

 

[james1985]

Re: Re:

James
Pace elastomers fit Shocktech forks

http://www.ebay.co.uk/itm/Pace-Retro-Fo ... SVg6yPOAag

OOOH. Cheers, that's good to know. I might rebuild my Pace with new bits, put the old but usable stuff in the Shocktechs and see how they fare. I want to get them a bit softer than the forks on the proflex.