Topic: clutch springs?

[Don R]

  The Rat Race bike has reeeeal stiff clutch springs. They need to go, what's available these days?  Are old stockers the go to spring? I see Barnett, Vesrah, EBC, and even
Sirius $9.99 delivered on ebay. 
  Does anyone have a preference for mostly normal street riding?

[PeWe]

My K2 has Barnett CB750 springs. Middle number -56-
Work fine, not hard for clutch fingers

My K6 with  +100whp must use the  stiffer Barnett with middle number -66-
They are for the smaller CB's.

Slip with the weaker Barnett springs despite glass beaded metal discs, later clutch from an F2. Tested twice.


These made my clutch fingers really tired. It helped to lubricate the clutch cable with  teflon cable spray.

Next step was "dog leg" type of  clutch lever,  more comfortable.

Both my bikes got them for clutch and brake.

GP style here https://vintagecb750.com/products/clutch-lever-gp-style

Stock type of clutch lever under the dog leg type that is more comfortable, flatter closer grip.

The golden spring, the weaker for CB750. -56-
Black the stiffer with middle number -66-

[HondaMan]

  The Rat Race bike has reeeeal stiff clutch springs. They need to go, what's available these days?  Are old stockers the go to spring? I see Barnett, Vesrah, EBC, and even
Sirius $9.99 delivered on ebay. 
  Does anyone have a preference for mostly normal street riding?

The normal Vesrah or OEM springs work fine for me up to 80 HP. Does the bike have OEM clutch plates, or something else?

[Don R]

  The Rat Race bike has reeeeal stiff clutch springs. They need to go, what's available these days?  Are old stockers the go to spring? I see Barnett, Vesrah, EBC, and even
Sirius $9.99 delivered on ebay. 
  Does anyone have a preference for mostly normal street riding?

The normal Vesrah or OEM springs work fine for me up to 80 HP. Does the bike have OEM clutch plates, or something else?

  It's not likely over 80 HP, but it is a K1 ported and cammed 836 with Mikuni carbs. It has a set of frictions that were advertised as oem Honda but when they arrived, they were obviously not. The friction material and adhesive were sloppily applied, and I had to clean the tabs off to use them.  So my answer is that they are likely Chinese junk. (Not the boat) The steels were sanded with a DA. It does have a newer clutch, basket etc. in it with a later cover.

[PeWe]

I used Cruzinimage low priced clutch plates with 836cc, 80whp on dyno. K6 clutch, no double metal plate. Glass beaded metal discs.
Those plates work fine despite made in China.

My almost stock K2 has a K2 set. 58whp a few years ago. Runs better now, maybe a little more at top.
61.50 392 CI pistons.

[Don R]

 It does have Magura levers, the collections of old parts that I bought out had some really nice finds in them. I'm sure that the sellers have some level of remorse now that I've made use of what they didn't.

[Don R]

 I ordered a set of the Barnett springs with the 56 middle number. I have others of unknown brand here that I can compare them to. I found a picture of the Magura levers that came with a truckload of stuff I stumbled across a couple years ago. 
 The cable tie on the grip was to hold the clutch lever open when the new plates stuck together. Notice the silicone plug caps and carbon core wires on the Gerex ignition.

[willbird]

When I was redoing my CB750K2 back 1992ish I had made acquaintance with a guy at Action Fours. I had called him to see if they had any headers avail like my 1970's vintage action 4 header, sadly none avail but he did have a big bin of Action 4's clutch springs. No idea what they are but your post made me remember :-). You know when you pull the clutch in that they are not stock. I used a Barnett clutch back then. Might get back into there one of these days.

Bill

[Don R]

 I had my hands worked on a few years back and am in no hurry to aggravate the old trigger fingers. The Rat Race bike has a little too hard of a pull. I'm wondering if they might be inner valve springs lol.

 I got the set of Barnett springs with the 56 middle number.

[Don R]

 The bike is back in the shop now, I'm planning to check the clutch for the mystery (cam chain maybe?) noise, someone here had the back of the clutch pressure plate rubbing on the clutch outer, I did use a newer clutch in an early engine so it might be worth a look. I need to swap the springs anyway.

[dragracer]

The bike is back in the shop now, I'm planning to check the clutch for the mystery (cam chain maybe?) noise, someone here had the back of the clutch pressure plate rubbing on the clutch outer, I did use a newer clutch in an early engine so it might be worth a look. I need to swap the springs anyway.

Use stock OEM springs. Add shims as needed. Works for me. I seriously doubt you'll be pushing the limits to the extent that I do under full race trim.

[seanbarney41]

lol, I have still yet to find a reason to tear into a clutch cover on a cb750...or most other 1970's Japanese bikes for that matter.  My kz1000 has the real hard pull indicative of some stiffer aftermarket springs.  It does make it not so pleasant to ride.  Guess I gotta learn how all that stuff goes together sooner or later.

[Don R]

  I appreciate the input, I'm sure you're using your bike to the max and have as much experience as anyone. The springs in there now are nasty strong, they have to come out, the clutch friction plate seller quoted me Honda numbers, but they clearly are not OEM Honda clutches either. I want to see how they have worn in, if they don't look right they come out too.

[dragracer]

  I appreciate the input, I'm sure you're using your bike to the max and have as much experience as anyone. The springs in there now are nasty strong, they have to come out, the clutch friction plate seller quoted me Honda numbers, but they clearly are not OEM Honda clutches either. I want to see how they have worn in, if they don't look right they come out too.

I now have a collection of old clutch baskets/hubs. I pulled out all of the springs to visually compared the coil diameters and its all over the place. I intend to pick a few random heights, put each spring in a spring checker and pull them down for a reading. I'll separate the weakest from the rest and test them in the monoshock bike at some point.

[BenelliSEI]

Don….. I’ve got lots of old springs saved fom “parts engines”. I measure them up and if they are even close to the factory minimum height spec, I toss ‘em. The rest I reuse. No strain on the hand and never had an issue……

[Old Scrambler]

My CBR has red Barnett springs (no number) that were repurposed from may brother-in-law's poor attempt at building an 836 to run at faster highway speeds. They work great

[PeWe]

My K6 has hard springs as I wrote earlier.
I forgot to mention that it work fine from this season after I checked how clutch cable was routed.
The steering damper bracket was an obstacle and the tach cable. Moved straps holding clutch cable to frame.

Huge difference. Now OK, no pain.
- Dog leg  levers
- Lubed the clutch cable.
- Cable routing and straps around frame  moved.

[dragracer]

PeWe, you touched on an extremely important part regarding the stiff feeling from the clutch. Many times it's not the springs themselves but the actual cable thats creating drag. Both lubrication and proper routing can change the entire feel on never pull. I replace my cable with new ones periodically and it does help when trying to have consistent launches on my dragbike.