Retrobike Forum Index

It is currently Sat Dec 10, 2016 6:00 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 96 posts ]  Go to page 1, 2, 3, 4, 5 ... 10  Next
Author Message
PostPosted: Fri Mar 30, 2012 7:23 am 
Retro Guru
User avatar

Joined: Sun Mar 27, 2011 2:47 am
Posts: 327
Location: Cleethorpes
I've been trying to design a full suspension frame but with the abundance of shock mounting styles it's quite daunting trying to choose one.
I have been looking through different types and trying to decide which is best but without actually riding it's hard :roll:

My current design is based on the early Manitou FRS (the one that's the same as on of the Marins), so it has a fork type shock at the back, but I've modified it to be lighter.

I only want around 150mm travel, so what does anybody think? :)


Last edited by titch__16 on Fri Mar 30, 2012 8:28 am, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 7:28 am 
Old School Grand Master
User avatar

Joined: Tue Oct 19, 2010 9:55 am
Posts: 7058
Location: The land of Lea & Perrins
Single pivot and a platform shock (eg. Orange Patriot, 222, 223, 224 etc)

Simple, efficient, effective and can be built pretty much as light or heavy as you want it, hence the reason that Orange use predominantly the same single pivot design throughout their range.

I like the sound of the FRS back end though - just make sure that you make it stronger than Answer did!


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 7:58 am 
Retro Guru
User avatar

Joined: Sun Mar 27, 2011 2:47 am
Posts: 327
Location: Cleethorpes
I used the design of an FRS because it retains the strength of the full front triangle.

But the single pivot idea is another I considered, but in that design there is many different placements of the shock. For example;
Vertical
Image
Horizontal
Image
Among many others, but surely there must be an optimum position.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 8:56 am 
Retro Guru
User avatar

Joined: Thu May 08, 2008 4:18 pm
Posts: 2336
What are you making it out of?

Worth downloading Linkage to fiddle with pivot placements and rocker lengths to get your desired suspension characteristics.

(Shouldn't this be in post-98? ;) )


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 9:11 am 
Gold Trader / PoTM Winner / RB Rider
Gold Trader / PoTM Winner / RB Rider
User avatar

Joined: Thu Apr 10, 2008 4:16 pm
Posts: 9609
Location: brigg, home of the gypsies
Those frames are all multi pivot designs. And 150mm of travel is rather a lot.

I would be looking towards a host link design. Nearly all the major players were using them until specialized started threatening legal action.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 9:22 am 
Retro Guru
User avatar

Joined: Sun Mar 27, 2011 2:47 am
Posts: 327
Location: Cleethorpes
So single pivot is when there isn't the 'rocker' (?)

It will be made of Aluminium and will have Carbon fork parts.

Linkage? :P

This is my current design and I know it's not exactly 'pretty' but I really like 'different' (I own a PRS-T1) :lol:
Image
Image
Image
Image

If I use the single leg fork idea it will use a hub that I've designed for a trike I designed, along with probably a 12mm rear axle.

Also I will make one in the post 98 section if this conversion last longer than normal ;)


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 9:36 am 
Old School Grand Master
User avatar

Joined: Tue Oct 19, 2010 9:55 am
Posts: 7058
Location: The land of Lea & Perrins
Single pivot:

Image


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 9:48 am 
retrobike rider / Gold Trader
retrobike rider / Gold Trader
User avatar

Joined: Sat Jan 27, 2007 10:35 pm
Posts: 8423
Location: The desolate flats of Cambridgeshire
Interesting design with a mono stay rear end but I think your idea needs a lot of work or a major rethink.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 9:55 am 
Retro Guru
User avatar

Joined: Sun Mar 27, 2011 2:47 am
Posts: 327
Location: Cleethorpes
This is a basic first model. The next step will be the chainstays. Obviously they'll need to be able to take a bit of punishment and I'll make them bigger.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Mar 30, 2012 10:05 am 
Retro Guru
User avatar

Joined: Mon Aug 18, 2008 11:23 am
Posts: 295
Location: London, UK
I had a very long discussion with the guy behind the design of this bike:

Image

...the Pinnacle Tharpu Peak, similar design to several others. He thought that the best suspension designs kept the shock travel in-line with the suspension compression. There are an awful lot of other considerations, which is why Linkage is superb for playing with ideas:

http://www.bikechecker.com/home.phtml

When the Specialized patent over the four-bar or Horst link design lapsed, he expected more companies to adopt it - it's a convenient way to prevent the single-pivot arc problem of shortening the wheelbase as the suspension compresses. The shape the rear axle describes as it moves through its travel is important.

I like the idea of playing with suspension designs, but I have never really tried it, only spoken to a few people who have. I think I'd probably spend some time analysing what other people have come up with, and the strengths and weaknesses of their designs, before trying to come up with my own. And I'd probably look at downhill bike designs too, there have been some crazy bikes put together in the name of long travel, smooth travel or optimal axle path.

I'd be concerned that a 'one-legged' rear suspension design would have to be heavily reinforced to prevent the bike twisting under load, both suspension-compressing load and the forces of pedalling. 'One legged' motorbike rear arms are hugely strong; this isn't a problem when you can just fit a bigger engine, but it might present weight issues on a bicycle.

Anyway, good luck!


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 96 posts ]  Go to page 1, 2, 3, 4, 5 ... 10  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Koupe and 5 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group