Topic: Cafe 400 Build

[ag12680]

Hi folks - have been lurking on this forum for some time and it's time to me to contribute to the great conversation...

I've got two 400F projects - one stock and the other a Cafe build with what was a parts bike.  I've had these bikes for 20 years and now getting around to the Cafe build first.

The Cafe goal is to upgrade the handling/braking, lightening the bike and adding a reliable power increase.  Started the project a year ago when a riding buddy who scouts for an MLB team pushed me into action during his off season.

I used to own a '75 with a Yoshimura 458 kit, bored carbs, lots of headwork and a Yosh hand bent pipe back in the late 70's which I sold unfortunately when starting a family.  When it comes to bikes, I tend to buy well and sell poorly…

Anyway, thought I would introduce the project with some photos of of the engine build pieces that are starting to trickle in from various places doing the work.

The cases were vapor blasted by Vapor Honing Technologies in NC.  I love the peened satin look.

The pistons are the 466 eBay variety coated by Evans Performance in GA.

The crank was lightened and balanced by APE.  I'm tempted to just mount it on a base so I can just see it all the time.

The original frame was bent to the point that I had to find another on ebay and had it delivered to Framecrafters in IL who is putting on a 750 front end and a Brembo brake set up as well as stiffening the swing arm and sorting other chassis items

It has been a very long time since I've been inside these motors so I'll be using the search function and asking questions.

Very glad to be part of this community.  Comments, input, suggestions, advice welcomed..!!

Andy --

[Godffery]

Welcome.

I have worked with the guys at Framecrafters a number of times, Tell' Godffery says hello!

[ag12680]

Sure, will do…

Andy --

[ag12680]

Well, I've run into conflicting opinions on the front end and I need to make a decision.

The frame builder is recommending that I go with a 750 front end with a 6 bolt hub that will accommodate a Brembo disk/caliper set up.  Get WM3/4 rims in 18" F/R with 40 hole front and 36 rear from Buchanan.  Rims alone are $500 for both with this set up and are much wider than stock 1.60/1.85.

Local builder who is lacing my wheels and has his own shop is suggesting that I go with a 19" front rim that will be cheaper to get and accommodate vintage tire availability and less expensive rims (which he already has on hand).  Plus, I already have $112 invested in his purchase of Buchanan spokes for a 36 hole 18" rim with the stock 4 bolt hub.  He says with a master cylinder upgrade and stainless brake lines - I'll have plenty of stopping power.  Plus, the issue is that most 18" rims he sources for this era are drilled for drum brakes not disks.  Not a problem for my rear wheel - no dice for the front.

The frame builder is saying that a 19" front will adversely affect handling and turn in on the bike - to stay with the 18".

Honestly, it has been so long since I have ridden a 400F that it's hard to sort out in my mind what the difference would be both in braking and handling except that I remember both needed improvement.

These are both very knowledge partners in my build with one who builds racing bikes with a deep understanding of frame geometry and the other who does more period restoration with some performance engine building.

So the decisions as I understand them are:

1. 750 or stock 400 forks?  I wanted stiffer than the 33 mm stock
2. Stock disk and caliper or Brembo? (upgraded master and lines for both - this is not a vintage restoration)
3. Ideal shouldered aluminum rim width over stock (thinking 1.85/2.15)?
4. 18" or 19" front rim?
5. Which tires to run with a preference for handling and grip over the vintage look?

Back to the original goal:  I want a good handling bike that will stop better and one that I don't have problems finding sticky tires for.  Love the look of the shouldered rims. 

I keep going back and forth in conversation with these guys and would sure appreciate any insights as I need to pick a direction and move the project down the road.

Thanks!

Andy --

[Godffery]

(1)&(2) If you go with the 750 (or even the 550) forks, you will have the option of running Twin disc.  (BTW; late model 77-78 will also give you taller sliders) with that you can even run stock calipers and still get a vast improvement over the original 400 single disc (which is also smaller) and the savings could fund your rims.  I would definitely go with a modern Master, 14 to 16mm.
If you'd like I can even provide you with updated Rotors & Caliper Pistons:
http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/95/

(3) As for your Rims; If you want a verity of performance tires to choose from, go with the 18". 
And Yes; 19" will not handle as well as the 18's.
"1.85/2.15" is fine.

(4) Tires; Totally your call, It's kinda like Pepsi VS Coke thing as long as you stick with the name brand tires.

Now, not to throw another "decision to be made" at you, But... You could also upgrade the rear hub and swingarm with a 550. That will give you matching 40 whole rims, larger brakes and most importantly, a stronger swingarm.

One last thing; have you seen this site: http://www.ttr400.com/

[ag12680]

Thanks for the very helpful reply…!  Some follow up questions:

1. What's better, single Brembo 320 disk and caliper (custom mount) or dual 750 disks with stock calipers (maybe thinned and drilled disks)?  I like the look of dual disks but both of my current partners say that single disk is better for combination of weight and stopping power.  I realize that dual disks have better range and feel…  Checked our your site - nice…

2. I take it that the 550 rear hub won't fit the 400 swing arm?  The plan was to add bracing to the 400 SW to stiffen it.  I like the idea of 40 spokes F/R.  Now you're making me wonder if 36/40 will be that noticeable…?

Yes, I know Kevin at TTR and have bought from him.  Good stuff.  Had a hard time with the expense of his swing arm though.

Thanks again,

[Godffery]

I am of the opinion that twin discs are better than a single. 
I like that the torque load is distributed evenly between the two fork lowers.
You can run smaller diameter / lighter rotors because you have two. Like the 550 rotors instead of the larger 750's.
And I have noticed with a single rotor, a slight drift to the rotor side; I assume may be to due to the uneven weight & gyroscopic effect.
There is no doubt that Brembo makes great calipers; the question is, will you be tasking them on a street bike hard enough to justify ?

No; the 550 Axle & spacing is larger then the 400.

Yes; Kevin at TTR sure has some goodies that could strain the budget!  = ]

[calj737]

Godffery has good advice. Kevin's swing arm is very nice, the shipping fees are what kills you. But the arm is a beauty and he's an awesome guy to do business with.

Another option on your setup:
18" fronts with stock forks, but new Progressive Springs, add a fork brace. You shouldn't need beefier forks unless your intended use is track or higher speed riding. Same is true for the swing arm. You could go to Hondaman for a swing arm rebuild, pressed in bronze bushings to improve the performance of it without modification.

But your rear shock are where you should spend you money, not the swing arm. Better shocks, upgrade the springs in your forks, add a brace, and drill your rotor for minor weight gains. Good SS lines and fully rebuilt caliper and pads, you should feel it to be a better bike.

Short of significant upgrades to modern suspension front and rear, it's still going to be a 40 year old bike. And behave that way...

Without cranking the HP way up, really is the braking insufficient? Probably not. Updated looks are really nice, but they are expensive. Go this route and determine what your real needs are. Swing arms and forks can easily be changed in a day/weekend later without much loss of expenditure on your stock components being updated. And your rear shocks will still be beneficial and useable with a new swing arm...