Retrobike Forum Index

It is currently Mon Dec 05, 2016 3:37 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 56 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6
Author Message
PostPosted: Thu May 09, 2013 2:03 pm 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8204
Location: New Forest, UK
My ownership experience with Rapid Rise was bad - with age the mech (identical to yours) would ghost shift under load. The problem is that only the spring stops it from going to a smaller cog (which it wants to do under chain tension) unlike a conventional mech when the shift cable tension prevents it.

My suspicion is that it's the cassette which is worn in a few gears, but I binned the mech, returned to a conventional one and the ghost shifting disappeared immediately.

Rapid rise is a fundamentally flawed idea - it works in the showroom, but when the spring ages it becomes useless.


Top
 Profile  
 
PostPosted: Thu May 09, 2013 2:14 pm 
Gold Trader | rBoTM Winner
Gold Trader | rBoTM Winner
User avatar

Joined: Fri Oct 19, 2012 12:30 am
Posts: 2389
Location: London
hamster wrote:
My ownership experience with Rapid Rise was bad - with age the mech (identical to yours) would ghost shift under load. The problem is that only the spring stops it from going to a smaller cog (which it wants to do under chain tension) unlike a conventional mech when the shift cable tension prevents it.

My suspicion is that it's the cassette which is worn in a few gears, but I binned the mech, returned to a conventional one and the ghost shifting disappeared immediately.

Rapid rise is a fundamentally flawed idea - it works in the showroom, but when the spring ages it becomes useless.


I suspect you're right
The cassette is new as is the chain and all correct
The hubs are good and only thing I can point to is the mech as no amount of experimentation solves it. In the "lab" all is fine, on the road or trail, slippage and only on certain cogs .

I will scrap the mech


Top
 Profile  
 
PostPosted: Thu May 09, 2013 7:06 pm 
Retro Guru
User avatar

Joined: Mon Mar 28, 2011 9:29 pm
Posts: 1877
Location: Somerset
gtRTSdh wrote:
Pierre wrote:
It looks like you've routed the cable over the top of the clamp bolt on the rear derailleur. It's designed to be routed round the underside of the bolt


It looks like a rapid rise rear mech, is it? if it is pressing the thumb shifter makes the gear harder (smaller cassette sprocket), I'd be interested in taking it off your hands.

And regarding the above, if it's rapid rise the cable is the right side of the bolt, do you agree Pierre?


Dibs on the mech :)


Top
 Profile  
 
PostPosted: Thu May 09, 2013 8:06 pm 
Gold Trader | rBoTM Winner
Gold Trader | rBoTM Winner
User avatar

Joined: Fri Oct 19, 2012 12:30 am
Posts: 2389
Location: London
gtRTSdh wrote:
gtRTSdh wrote:
Pierre wrote:
It looks like you've routed the cable over the top of the clamp bolt on the rear derailleur. It's designed to be routed round the underside of the bolt


It looks like a rapid rise rear mech, is it? if it is pressing the thumb shifter makes the gear harder (smaller cassette sprocket), I'd be interested in taking it off your hands.

And regarding the above, if it's rapid rise the cable is the right side of the bolt, do you agree Pierre?


Dibs on the mech :)



Make me an offer and it's yours :)
Will send pics this weekend


Top
 Profile  
 
PostPosted: Thu May 09, 2013 9:04 pm 
Retro Guru
User avatar

Joined: Mon Mar 28, 2011 9:29 pm
Posts: 1877
Location: Somerset
A tenner posted sounds fair as it's suspect?


Top
 Profile  
 
PostPosted: Fri May 10, 2013 9:06 pm 
retrobike rider
retrobike rider
User avatar

Joined: Fri Aug 08, 2008 2:36 pm
Posts: 16747
Location: Yorkshire, England
Details, make and model of everything?
Then it'll stop people guessing what things are.

Is anyone else near to have a look at simple thing.

Exacly what gears does in do this in, not just 'some'.

Can you fit another rear wheel to test that out. You don't need a brake.

Then try different chain if you have one (SRAM are quick link normally)

Check the rear drive train setup to Shimano documents, they are all on their website under Technical. Just look for the rear mech code.

Better close up pics would help to.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 56 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6

All times are UTC [ DST ]


Who is online

Users browsing this forum: Bing [Bot], Si_33, sztopi17 and 43 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