Author Topic: My Dunstall CB750 (Read 51713 times)

jaguar · « **Reply #100 on:** May 26, 2015, 08:23:46 AM »

Very cool swap.
Like that the bike keeps evolving.

CB_Jeff · « **Reply #101 on:** May 27, 2015, 07:48:05 PM »

Scott very nice work on the rear disk conversion. Well done!

Rookster · « **Reply #102 on:** May 29, 2015, 06:28:29 AM »

Thanks guys, much appreciated. I have some other "period correct" mods planned for the bike in the future so it will continue to evolve. One thing I have noticed is that the changes don't make the bike worlds better but incrementally improved. The cool thing is I like the bike as much today as I did when I started collecting parts to build the bike years ago.

I added the shorter brake line.

HurstAirheartMaster by Scott Rook, on Flickr

Scott

Rookster · « **Reply #103 on:** April 12, 2016, 02:44:25 PM »

This Spring is shaping up to be about brakes and suspension.

I started with some NOS Magura Power Levers.

Magura3 by Scott Rook, on Flickr

Genuine Magura for the clutch and brake not the cheap modern ones.

Magura by Scott Rook, on Flickr

Magura2 by Scott Rook, on Flickr

I installed Progressive Fork Springs kit 11-1104. The springs came with spacers that were 1-1/4" (white ones). I decided to use 1" spacers instead and see how the forks felt. I could either go up or down based on feel. The Progressives were the same length as the stock springs I pulled out. They were tough to compress with the spacers but a T-Handle made the job much easier.

PreloadSpacersProgressiveSprings by Scott Rook, on Flickr

photo_zpsyweoywrj by Scott Rook, on Flickr

The rear cast iron disk (AP Lockheed) was thinned and drilled by TrueDisk. These disks originally came with a chrome plating on them and some of it had worn through. The chrome was ground off and the disk trued.

LockheedDisk_Painted by Scott Rook, on Flickr

That's it so far. There should be some more updates very soon as I'm waiting for some things to show up and I have some items to send out.

Scott

slikwilli420 · « **Reply #104 on:** April 12, 2016, 03:57:13 PM »

This is looking great. I'm happy to see the result on that rotor. I need to get some rickman rotors cleaned up but many cannot do them due to the shape. God luck with your project!

Stev-o · « **Reply #105 on:** April 12, 2016, 06:19:17 PM »

Very clean mod, nice job!

Rookster · « **Reply #106 on:** April 16, 2016, 02:40:46 PM »

Spring Update Part 2:

I have been looking for a genuine Dredsa swingarm for years. I have come across a couple for sale but was never in position to buy when they were available. Of course when I did have extra money, I could never find one for sale. I even had these waiting for the opportunity to brand my genuine Dresda swingarm.

photo 2 3_zpsbkykchq1 by Scott Rook, on Flickr

Unfortunately I still haven't found a genuine Dresda but I did acquire a replica from a fellow board member. It was in as bought condition and never mounted.

Dresda4 by Scott Rook, on Flickr

I spent a few hours installing new shock bushings and fitting the new swingarm collar.

Dresda1 by Scott Rook, on Flickr

Dresda2 by Scott Rook, on Flickr

I might just get a few of these made up to make me feel better about not finding a real Dresda arm.

sw_zpsb6f8g0dj by Scott Rook, on Flickr

Thanks
Scott

Stev-o · « **Reply #107 on:** April 16, 2016, 02:46:51 PM »

Rookster · « **Reply #108 on:** June 13, 2016, 01:32:14 PM »

Spring Update, Part 3

The brake mods continue. I had my front disks drilled and thinned by Godfreys Garage. They came out great.

[by]photo 1_zpsvr4dmdsb by Scott Rook, on Flickr

I slotted the pads and deglazed them with some 400 grit.

photo 2_zpsqd6ktghr by Scott Rook, on Flickr

I replaced the wheel bearings and buttoned up the front wheel.

photo 4_zpsrjbly90w by Scott Rook, on Flickr

I also replaced the rear master cylinder with a more modern unit from MCP. The Hurst Airheart master cylinder never quite felt right.

photo 1_zps4bgmdjga by Scott Rook, on Flickr

It should be back together by this weekend and I will report how the suspension and brake changes feel: Dresda replica swingarm, Progressive fork springs, drilled and thinned disks front and rear, genuine Magura power levers, and a new MCP rear master cylinder.

Scott

slikwilli420 · « **Reply #109 on:** June 14, 2016, 07:54:35 AM »

Very nice looking. Been a fan of this one for a while. The front brakes look excellent.

Rookster · « **Reply #110 on:** June 25, 2016, 10:40:07 AM »

Thanks slikwilli, your Vintage Speed Parts Mashup and DHolda / Seeley Mashup are awesome.

Spring Update, Part 4
I still haven't been out on a test ride yet. Tomorrow morning is going to be the first test with the new suspension and brake parts. I will report back. The bike is finally back together. Here's the recap:

Replica Dresda Swingarm - Drilled Rear Disk - New MCP Master Cylinder

DresdaSwingarm-LesterWheel by Scott Rook, on Flickr

Progressive Fork Springs with a 1" Spacer - Drilled and Thinned Disks

LesterWheel_DrilledDisk by Scott Rook, on Flickr

Genuine NOS Magura Power Levers

MaguraBrakeLever by Scott Rook, on Flickr

MaguraClutchLever by Scott Rook, on Flickr

Scott

Tews19 · « **Reply #111 on:** June 25, 2016, 08:31:15 PM »

The levers are gorgeous! Mind if I ask what they run?

754 · « **Reply #112 on:** June 25, 2016, 08:54:30 PM »

Just picked up a nice clutch side.
Used to run a 72 and down rt side switch, no e start, that was used for horn.left side lever only...like this..nice parts..

Rookster · « **Reply #113 on:** June 25, 2016, 08:57:47 PM »

They were about $20 each + shipping. The problem is finding them. Here is an ebay auction for the brake lever:

http://www.ebay.com/itm/QUALITY-MAGURA-FRONT-BRAKE-LEVER-HONDA-CB350-360-400-450-500-550-750-GL1000-/331539917897?hash=item4d3151ac49:g:Av4AAOSwpDdVPTx2&vxp=mtr

The clutch lever is a little harder to find. The good thing is the same levers were used on many different bikes across the Honda range. You just need to find a left hand Honda lever

Scott

Rookster · « **Reply #114 on:** June 26, 2016, 11:25:40 AM »

Summer 2016 Ride Report:

I took the Dunstall for a decent ride this morning. The rear brake was immediately more responsive with the hard chrome ground off the cast iron disk. The Magura levers were noticeable right away. The clutch lever felt great and pulled right back to hug the grip. It was much more comfortable than the stock Honda levers. The brake lever was easier to reach and seemed right at hand when needed. The brake lever doesn't pull back to the grip but like the clutch lever it felt much more comfortable. The Progressive Springs seemed to smooth out the bumpier sections but I didn't notice any major handling improvements. Brake dive wasn't as pronounced but the Progressive Springs didn't transform the front end into something completely different from the stock front end. The front suspension was improved but not by a huge margin. I didn't notice any difference between the Dresda replica swingarm and the stock swingam. I think they are probably comparable in stiffness. The rear end of the Dunstall is stiff due to the Hagon shocks and this didn't change. The Dresda replica does lift the lower shock mount about 3/4" over the stock swingarm which wasn't noticeable while riding.

Grades
Magura Power Levers - A+ / Huge improvement in comfort and control over stock
Progressive Fork Springs - B / Marked improvement over stock springs but I had hoped for more
Drilled Disks - B / They look great and remove some unsprung weight but I didn't notice any braking improvement
Hard Chrome layer removed from rear disk - B+ / Big improvement over the stock Lockheed chromed disk
Dresda Replica Swingarm - C / No real change from stock and it was a pain to fit but it looks cool
MCP Master Cylinder - B+ / Worthwhile only for the improvement in design and reliability over the Hurst Airheart Master

I ended my ride by rolling through Chestnut Ridge Park. I came across 2 guys on vintage bikes which is rare. One was on a Triumph T140 and the other on a 70s BMW. We exchanged thumbs up and I headed home after a few pics:

DunstallChestnutRidge2 by Scott Rook, on Flickr

Scott

slikwilli420 · « **Reply #115 on:** June 26, 2016, 01:19:00 PM »

That's a proper machine in all respects. Everything is so well done and a dunstall kitted bike is something special. Any plans for others modifications?

Rookster · « **Reply #116 on:** June 26, 2016, 04:55:31 PM »

Thank you. Much appreciated.

There are some things I would still like to do. I wanted to do some head work with a mild cam, slotted sprocket, HD studs / nuts, and stronger valve springs. I was never happy with the paint work either, so at some point I would like to get it painted again. There are always thoughts of different wheels, possibly 19" aluminum rims and stainless spokes or different mags. There always seems to be something else I want to do to it.

Scott

754 · « **Reply #117 on:** June 26, 2016, 05:28:49 PM »

You will notice huge improvement. Of brakes in the rain.. My undrilled single,in the rain, .I ride dragging the front brake all the time so that it will work when I need it..

Stev-o · « **Reply #118 on:** June 26, 2016, 05:50:15 PM »

Beautiful.....

SOHC4 Cafe Racer Fan · « **Reply #119 on:** June 27, 2016, 01:33:40 AM »

Gorgeous bike.

Rookster · « **Reply #120 on:** June 27, 2016, 09:39:54 AM »

Thanks for the kind words guys.

Scott

Rookster · « **Reply #121 on:** June 30, 2016, 03:51:57 PM »

I had noticed the front master cylinder was weeping a bit around the piston. Not enough to leave a puddle anywhere but enough that I had to wipe the lever off every day. So it was time for a rebuild. I also decided to 86 the black turned purple anodizing. Easy Off oven cleaner softened the anodizing but I still had to use a scotchbrite pad and a brass brush to get it all off. Once the purple was gone I used the Dremel and a brass wheel to give it a uniform look. It's not highly polished like the cap and the top tree but it looks decent.

Before:

MaguraBrakeLever by Scott Rook, on Flickr

After:

RebuildMasterCylinder by Scott Rook, on Flickr

PolishMasterCylinder by Scott Rook, on Flickr

PolishMasterCylinder2 by Scott Rook, on Flickr

Scott

Rookster · « **Reply #122 on:** August 03, 2016, 03:44:59 PM »

I just picked up a set of Henry Abe mag wheels. They are 19" front and 18" rear.

photo 1_zpsi8pyifgy by Scott Rook, on Flickr

They are in good shape but it looks like someone painted them all silver. My plan is to polish the outer lip and have the rest of the finish be powder coat. I think I will stick with a silver color. I like the 19" front 16" rear Lester wheels but there's always that voice that says real cafe racers had 18" rear wheels. I didn't notice any ill handling effects with the 16" rear and I like the width of it. I think the 18" Henry Abe is going to look skinny but that's OK.

photo 3_zpspcmepa9m by Scott Rook, on Flickr

I hit the outer edge of the rear wheel with some Tripoli on a buffing wheel just to see what it would look like. Not bad.

photo 2_zpsvliodvbz by Scott Rook, on Flickr

Scott

SOHC4 Cafe Racer Fan · « **Reply #123 on:** August 03, 2016, 03:51:38 PM »

I have the 19/18 Lesters on my CB550 and I went with a beefier rear.

Rookster · « **Reply #124 on:** August 03, 2016, 08:14:28 PM »

What size tire is that? It looks good.

Scott

News:

Author Topic: My Dunstall CB750 (Read 51713 times)