Help & FAQs    Search BCF    Members    Groups    Events Calendar
Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


Making a hole bigger!

 Reply to topic
Bike Chat Forums Index -> The Workshop
View previous topic : View next topic  
Author Message

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 21:01 - 29 Jan 2006    Post subject: Making a hole bigger! Reply with quote
My metal work knowledge is pretty poor. Confused

I'm going to fit a new swingarm to my project bike, only the new swingarm spindle is 20mm, and the old one was 16mm.

So, the hole in the frame for the original swingarm pivot bolt needs taking out from 16mm to 20mm.

How can I do this and what do I need?

Cheers

Thumbs Up
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Bezzer
World Chat Champion



Joined: 14 Apr 2005
Karma :
PostPosted: 23:15 - 29 Jan 2006    Post subject: Re: Making a hole bigger! Reply with quote
Barry_MC21 wrote:
My metal work knowledge is pretty poor. Confused
How can I do this and what do I need?


If it is poor forget it and get it looked at professionally. Might not be even possible as you would lose strength and integrity at the pivot, might have enough meat on it to do it but then again the companies never use more metal than is necessary so it might not and leave you with a death trap. You're going to need new bearings as well and possibly have new seats cut for the pivot shaft and nut to sit on, are they recessed in the frame? if so the access hole might not be big enough for the larger socket needed to fit the bigger nuts.
I'm not putting you down at all but if you don't know make sure you consult someone who does know the bike you're working on first, saves any hassle in the long run.
____________________
I used to be indecisive but now I'm not quite so sure.
 Back to top
View user's profile Send private message You must be logged in to rate posts

stinkwheel
Bovine Proctologist



Joined: 12 Jul 2004
Karma :
PostPosted: 23:27 - 29 Jan 2006    Post subject: Reply with quote
I'm no engineer either, but it would stand to reason that the original 16mm spindle is designed to be strong enough for the bike. The frame will also be designed to take it, machining the holes out might well weaken the frame itself.

By my way of thinking it would be better to sleeve up your original spindle to suit the swingarm. Get someone to machine up and sweat-in a couple of bushes to take the standard size bearings. You might even get away with sitting it on phosphor bronze bushes with grease nipples in place of bearings.

If you look hard enough, you might even find there is a bigger bearing with a 16mm I/D and an O/D that will fit the swingarm.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 09:21 - 30 Jan 2006    Post subject: Reply with quote
There is plenty around the current hole to take it out another 4mm, I wouldn't be doing it otherwise, I said my metalwork knowledge was poor, I'm not an idiot, I'm not going to do something that is going to risk the strength of the frame.

I'm extreemly competent mechanically, all I wanted to know was is there was a tool that would allow me to easily take a hole out by another 4mm.

Stink, your idea of sleving the swingarm I did think of, but might look into the bearings stuff...
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Bezzer
World Chat Champion



Joined: 14 Apr 2005
Karma :
PostPosted: 09:59 - 30 Jan 2006    Post subject: Reply with quote
Barry_MC21 wrote:
I'm not an idiot, I'm not going to do something that is going to risk the strength of the frame.

..

Yes you are( risking that is Mr. Green ), taking 4mm out is compromising the frame strength from it's original spec. So it's a bigger swingarm?, heavier?, bigger tyre etc?- heavier? different length?- force angle changed. All this has a bearing on the stresses involved, most get away with it but they don't mess about with original holes which aren't just a "hole" they are a mounting point, they bush,reduce or change bearings keeping the frames original integrity. Anyway what frame and swingarm are we talking about?
____________________
I used to be indecisive but now I'm not quite so sure.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 10:30 - 30 Jan 2006    Post subject: Reply with quote
Thanks so much for your help. Thumbs Up

Rolling Eyes
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 10:35 - 30 Jan 2006    Post subject: Reply with quote
Bezzer wrote:
[............Anyway what frame and swingarm are we talking about?


That should have been your first question, before you went jumping to conclusions! Laughing
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

bidman
Crazy Courier



Joined: 01 Oct 2005
Karma :
PostPosted: 11:18 - 30 Jan 2006    Post subject: Reply with quote
Hey, have you thought about just gettin a 16mm spindle and jst altering the frame sides so that it is easier to fit? Dan
____________________
Don't ride it, RAG IT!!
 Back to top
View user's profile Send private message You must be logged in to rate posts

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 11:56 - 30 Jan 2006    Post subject: Reply with quote
Dan,

The frame will already take a 16mm spindle, but the swingarm needs a 20mm. So i'd need to either change the swingarm bearings, or drill out the frame mounts by 4mm.

Got a couple of contact numbers now and I'll speak to them later about it.

Thumbs Up
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

BFG
Brolly Dolly



Joined: 14 Feb 2005
Karma :
PostPosted: 14:17 - 30 Jan 2006    Post subject: Reply with quote
Barry_MC21 wrote:
all I wanted to know was is there was a tool that would allow me to easily take a hole out by another 4mm.


No. Nothing hand-held will do the job.

You need to get the frame securely jigged and clamped onto a drill-stand at the very least or better still a milling machine. If the hole is currently a precision fit, the new hole will need to be reamed.

Also, unfortunately there are just as many cowboy machinists as there are in any other profession, so word of mouth counts.

However, forget all that and go for stinkwheel's suggestion. Just look in yellow pages for bearing suppliers and give them the sizes.
Change the bearings and there is no risk. This is also the easiest if the sizes are available. But if they aren't, get some made. They don't need to be roller bearings if you put a grease nipple in.

Re-work the frame and you risk changing the alignment of the holes. 1/4mm out one side and your wheels will never be in line. Then the only way to fix that is to start again from scratch.

Hint: "Metalwork" is what you learnt in school. Wink
 Back to top
View user's profile Send private message You must be logged in to rate posts

Barry_M2
World Chat Champion



Joined: 09 Sep 2004
Karma :
PostPosted: 14:24 - 30 Jan 2006    Post subject: Reply with quote
Laughing

School was a long time ago for me! Wink

Cheers BFG, good advice, thanks. Thumbs Up
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts
Old Thread Alert!

The last post was made 19 years, 215 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> The Workshop All times are GMT
Page 1 of 1

 
 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 vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 
Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.18 Sec - Server Load: 2.43 - MySQL Queries: 14 - Page Size: 70.68 Kb