Frame mod question......CB450.

[ADS]

Hi just wondered peoples thought on this frame section shown in the photo with a white circle.

The back is due to be chopped, the battery going down near the swinging arm and wondered if things would look better without this section.

It was used for the rear mudguard and I presume it is also a strengthening member too.

I've seen bikes with and without it.

What's ya thoughts.

Cheers

Adam.

Sent from my iPad using Tapatalk HD

 

[Green199]

As I understand, the piece is there to act as a brace and to stiffen the rear as well as hold the mudguard. If it were removed, the rear would flex much more than from the factory.

Would it look better? Maybe.

Would it ride and handle better. No.

Id leave it be tbh.

 

[Rich Ard]

I think it could be replaced with a section of tubing in a less conspicuous spot - but that frame is flexible enough to begin with, I wouldn't say making it more bendy would help the handling much.

 

[cqyqte]

+1 on flexible

Also depends on if you are removing the rear upper cross support. If both are gone you will have zero frame rail to frame rail support allowing the shock towers to collapse inward. The CB450 frame is a sandwiched spotwelded joint design and after years of stresses the spots do weaken. I would be cautious of removing bracing unless you replace it elsewhere with stronger designs.

 

[teazer]

If that's the actual bike in question with those clown tires, it will never be far enough over to impart any stress to teh frame. The tires will slip a long time before the frame bends. [/sarcasm]

Assuming that the OP intends to fit actual motorcycle tires at some point in time, then the brace in question can be replaced with bracing struts to the down tube plus a cross member under the seat.

 

[ADS]

Thanks for the replies.

I don't actually mind it being there, I've seen a few with it removed and with very little if any bracing done at all.

Funnily enough this is not being built for speed.......



Sent from my iPad using Tapatalk HD

 

[teazer]

That is not an acceptable answer. It's not about speed. It's about safety- at any speed

 

[ADS]

That is not an acceptable answer. It's not about speed. It's about safety- at any speed

Oh dear oh dear ......

I thought I'd dip my toe into the forum world again after been out for some time......same old same old.

Goodbye.



Sent from my iPad using Tapatalk HD

 

[Green199]

Same old, same old?

This is a motorcycle forum, not one about creating pieces of fucking art. What is wrong with people. If it wasn't needed, why the heck did honda put it there in the first place!!

 

[rockcitycafe]

Motorcycle Frame [moh-ter-sahy-kuhl freym] n: a device, of no significant structural importance, from which to hang polished baubles.

See also: Christmas tree.

 

[ADS]

Same old, same old?

This is a motorcycle forum, not one about creating pieces of fucking art. What is wrong with people. If it wasn't needed, why the heck did honda put it there in the first place!!

PMSL half the bikes on here are getting cut up!

I was going to use a similar line to yours in my typical noddy quotes but decided not to....and look it has appeared!


Sent from my iPad using Tapatalk HD

 

[ADS]

As I said I'm quite happy for it to be left in I was just asking the question what people had done or what they thought as lots have been removed etc etc

What's disappointing is that bike building is new to me, no shit Sherlock some of you say! My background is mainly Lambrettas and two stroke tuning and expansion chamber design and build. My exhausts have been on sprint record machines and race bikes around the world. Selling hundreds of units and stocked in places all over the world such as Japan, Italy, Germany even dispatched them to Oz. I am hoping to bring what I have learnt in expansion design to another bike build in the near future. I'm pretty sure they too will be not as Suzuki or Kawasaki designed or intended. Having got a taste of forum life again I can see why I bailed last time.

So much aggression sat behind a keyboard.....

All the best

Adam..

Sent from my iPad using Tapatalk HD

 

[Green199]

PMSL half the bikes on here are getting cut up!

I was going to use a similar line to yours in my typical noddy quotes but decided not to....and look it has appeared!


Sent from my iPad using Tapatalk HD

Yes they are. And they are getting added bracing and support. Which is fine. If you plan to do that, go ahead and chop it, but don't base it all on looks. Just because you have seen a few with them chopped off, doesn't mean they we're braced and are safe.

Your initial response was the one that carried the anger and aggression my friend. Teazer, a very VERY knowledgeable man who I advise you to listen to is right, it is about safety at any speed.

I hope you stay around on this forum and don't get dishevelled by this thread, it really is one of the best on the web for help and advice, and we are occassionally friendly! ;D

 

[Rich Ard]

Calm down, Nancy. You asked a question and it was answered. You must spend a lot of time fighting aneurysms if that little bit got your jimmies rustled.

 

[teazer]

............. My exhausts have been on sprint record machines and race bikes around the world. Selling hundreds of units and stocked in places all over the world such as Japan, Italy, Germany even dispatched them to Oz. I am hoping to bring what I have learnt in expansion design to another bike build in the near future. ..................

Say more. Good to have you here. My last reply was short and blunt because people often use the "I'll not be going fast" rationale for all manner of bad decisions. Come on back and let's see those exhaust designs and what you have done with scooters. Most people that come here have little or no experience with bike modification or design and that leads them to make all manner of poor decisions.

Fortunately when I started modifying bikes and filing pistons and ports, there was no internet so on one knew about my bad choices along that learning curve. As long as we are trying new things, we continue to learn, and that is key.

 

[ADS]

If that's the actual bike in question with those clown tires, it will never be far enough over to impart any stress to teh frame. The tires will slip a long time before the frame bends. [/sarcasm]

When I actually said ...(new paragraph)....it's not being built for speed. It was a light hearted reply to the above quote, meaning clown tires are fine for what I need as it's clearly just going to be for plodding about. Unfortunately the attack switch was on and it was taken that I meant 'I can cut what I want out because I'm only going slow'......

ADS3 the torquiest performance pipe for the Lambretta. Touring pipe designed to peak at 7k on my motor.


Sent from my iPad using Tapatalk HD

 

[Green199]

Still, decent tyres will be beneficial at any speed...you should know that.

 

[teazer]

Nice pipe. I'm not too familiar with Lammy pipes since my cousin's 200 tried to spit me off years ago, so I stick to big wheels now. I looked at Kart pipes a couple of years back for a Kart racer. They had two pipes that others swore were the best on the market and one was super trick, but they wanted "more".

It must have taken me 50 -100 different designs before I settled on something a little different. After testing and a race season they came back and asked me to do another one for their new motor. That pipe only had 3 sections swapped out at the front end and it made between 0.4 and 4.0 seconds a lap improvement and they won their championship. Point is that pipe designs take a lot of work to get to something close to optimal. (that's a long winded, back handed compliment BTW, in case you missed it)

Point about crappy tires and going slow is that from my perspective at least, motorcycles are inherently dangerous and hard to control and anything that makes them harder to ride, or to reduce grip or handling is explicitly a bad idea. many people come here and say that they won't be going fast and that may be true but as long as that bike is on the street, the probability remains high that someone will ride it past its new (lower) safety limit and I hate it when people get hurt because of bad decisions by others in regards to what's safe or OK to do/use.

[/high horse]