Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

[Nexus 8] Riding without left hand-side dust cap?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

[Nexus 8] Riding without left hand-side dust cap?

Old 03-01-21, 05:51 AM
  #1  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
[SOLVED] [Nexus 8] Riding without left hand-side dust cap?

Hello,

To stick a Shimano Nexus 8 gear hub into a Brompton (OLD 112mm), I'm thinking of removing the left hand-side "dust cap unit" and shave 12mm (132mm → 120mm; 3.68mm could be further saved by replacing the LHS lock nut with its  RHS, thinner alter ego, and achieve an OLD of 116.32mm).

Do you think it's reasonable to ride without it in a moderately rainy region (Western Europe), even if it means squirting fresh grease on the bearing balls more often?

If not, is some kind of cap available?

Thank you.


Last edited by Winfried; 03-01-21 at 12:54 PM.
Winfried is offline  
Old 03-01-21, 05:56 AM
  #2  
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Posts: 7,950

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1297 Post(s)
Liked 759 Times in 532 Posts
I expect that the dust cap was put there for a good reason.
dsbrantjr is online now  
Old 03-01-21, 06:05 AM
  #3  
Amt0571
Senior Member
 
Join Date: Dec 2014
Location: Catalonia
Posts: 874

Bikes: Canyon Grand Canyon AL SL 8.0, Btwin Ultra 520 AF GF, Dahon Mu P27, Triban Road 7, Benotto 850

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 371 Post(s)
Liked 164 Times in 109 Posts
The dust cap does not only protect the hub from rain. It also protects it from DUST.

If dust gets in, it mixes with oil/grease and starts sanding parts down when they turn. It doesn't seem like a good idea to me.
Amt0571 is offline  
Old 03-01-21, 06:33 AM
  #4  
Geepig
Senior Member
 
Geepig's Avatar
 
Join Date: Sep 2020
Location: Eastern Poland
Posts: 525

Bikes: Romet Jubilat x 4, Wigry x 1, Turing x 1

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 147 Post(s)
Liked 126 Times in 99 Posts
Or, if you are or happen to know someone with decent engineering skills, you could try devising some kind of alternative.

For example, many bikes from the cheaper end of the market had pressed aluminium dust shields on either end of the BB as the sole protection against the ingress of dust and/or water, as do the coaster brake hubs from Velosteel.

I have never examined a Nexus in detail but, heh ho, life is short and engineering the final front door.
Geepig is offline  
Old 03-01-21, 11:44 AM
  #5  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
However, the BWR from Sturmey-Archer that powers the six-speed Brompton has no dust cap, just a lock nut + cone:

Winfried is offline  
Old 03-01-21, 11:47 AM
  #6  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
Another thing that must be addressed: After removing those parts on the left side, the hub will be moved to the left, so when cold-setting the frame, it should be pulled asymetrically so the right stay lies further to the right.
Winfried is offline  
Old 03-01-21, 11:52 AM
  #7  
phughes
Senior Member
 
phughes's Avatar
 
Join Date: Mar 2011
Posts: 2,069
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 576 Post(s)
Liked 478 Times in 286 Posts
Originally Posted by Winfried View Post
However, the BWR from Sturmey-Archer that powers the six-speed Brompton has no dust cap, just a lock nut + cone:

Well, it is a completely different hub, designed differently. Don't remove the dust cap, it is there for a reason.
phughes is offline  
Old 03-01-21, 12:54 PM
  #8  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
Got a reply from gear hubs expert Aaron Goss: "It is fine. We have done it. Yes grease more often."
Winfried is offline  
Old 03-01-21, 09:41 PM
  #9  
Reynolds 
Passista
 
Reynolds's Avatar
 
Join Date: Jul 2005
Posts: 7,186

Bikes: 1998 Pinarello Asolo, 1992 KHS Montaña pro, 1980 Raleigh DL-1, IGH Hybrid, IGH Utility

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 712 Post(s)
Liked 348 Times in 203 Posts
I think it's not really a dustcap, but it's there to cover the splines if you don't use a roller brake.
Reynolds is offline  
Old 03-02-21, 01:18 PM
  #10  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
It's how Shimano calls it: "Left Hand Dust Cap Unit (Y-34R 98100).

Regardless, it then opens a new issue: Using that trick, the rim would now be way too far to the left :-/
Winfried is offline  
Old 03-02-21, 05:34 PM
  #11  
Reynolds 
Passista
 
Reynolds's Avatar
 
Join Date: Jul 2005
Posts: 7,186

Bikes: 1998 Pinarello Asolo, 1992 KHS Montaña pro, 1980 Raleigh DL-1, IGH Hybrid, IGH Utility

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 712 Post(s)
Liked 348 Times in 203 Posts
Originally Posted by Winfried View Post
It's how Shimano calls it: "Left Hand Dust Cap Unit (Y-34R 98100).

Regardless, it then opens a new issue: Using that trick, the rim would now be way too far to the left :-/
Redishing should correct that easily.
Reynolds is offline  
Likes For Reynolds:
Old 03-02-21, 11:53 PM
  #12  
Winfried
Senior Member
Thread Starter
 
Winfried's Avatar
 
Join Date: Aug 2011
Location: Paris, France
Posts: 2,092
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Liked 58 Times in 49 Posts
Even after shaving 12mm from the left side?


https://www.flickr.com/photos/juddpa...7613358920756/
Winfried is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.