28 replies to this topic

[doostroke]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

[LeeL]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

i have seen it done first hand with over 2000 miles with no probs,if i were you i would put the ring gear on it .the one i had here had it on.they work real nice imo way better the the big heavy p.o.s tra.throttle response is crazy amd real good back shift,

[CVCOBRA1]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

A lot of good response from the PB80 on the XR 1200's. You might want to go over to the XR forum and do some looking around.

[DITCHBANGERPRO]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

with proper maintenance this will not happen...im almost at 8000 miles of off trail riding,changed a few parts at 6000 miles and new ramps this year(dynamo joe rocks)..although i am interested in the pb80 as i run the trailbloc(pb80 smaller bro)on my quad and it flat out works great...very happy

[one_fast_x]

Not sure how u guys get off calling the TRA a POS.... The PB-80 is much easier to work on given a 5 yr old could rebuild 1 but is MUCH less adjustable than a TRA, but like everything else... they require maintenance.

[doostroke]

Thanks guys. Yes the ring gear is mounted bud. The balance washers came out of TRA and chewed the governor cup.etc at 3600 miles of trail. Personaly seen them need a rebuild at 1k miles so the TRA is not an option for me. I am not rich, or blind

I will test 3k miles with it this winter. My only concern is the dampening puck? Nice to hear 2000 miles have been done on 2 stroke and 20k miles on xr

11-008
11-015 Are they the same with different calibrations?

[doostroke]

Blowing belts is hard on a clutch and so is heat, balance, alignment, vibration so we will all get different results. They are only aligned at 45mph unless you DooDR it but no sled is the same always variation from BRP. That is why many small co like Doc, smitty, cv tech have troubles re-engineering. How do you make a brace fit when a tower moves around and pulls out 1-99%.

[LRD]

I was introduced to the PowerBlock 50 on my 05 Summit 550 fan in July 04. I had such great succes with it that when I got my 08 TNT one of the first mods in building it into a 365 lb mtn sled was putting the TRA III on the shelf and buying a takeoff Powerblock 50 from a 600HO SnowHawk. Went from a 12 lb TRA to 8 lb PoweBlock and the throttle response is amazing, tuning is easy with my ShockWave helix. Can change weight washers in the Powerblock in about 5 minutes, spring change about 10 minutes.

The new slightly larger Powerblock 80 with the ring gear on should be even better if you have a big shaking long stroke engine like the 800's.

My setup for a recent trip to So Wy in 3 to 4 ft of sugar, lots of climbing up and down tight steep tree north facing slopes and draws.

100/260 primary spring, engagement 2850,
8 thin 3.8 gram washers put it at 7800 to 7900 rpm.
QRS sec, green spring, 180/303,
Shockwave helix, one turn out, about 37.5 degrees (straight arms)
My new track, 15 X 141 X 2.25, Hp 115 to 120 HP guessing
Geared 19/45 with Avid 7 tooth 3" pitch, Will gear up to 20 next trip as the belt Completely wiped all magic marker off all the way to the top
of the primary sheeves

These settings made it a snow tractor in the sugar without trenching down and it could near waterskip on top of the sugar climbing sometimes.

Amazing clutch. Keep it simple stupid is a great engineering principal. Unlike all other clutches it has very little weight hanging out 8 or 9 inches from the end of the crank at the largest diameter of the clutch. Probably has the lowest inertia (Not just from its low weight) of any clutch out there and more forgiving of crank runout if you figure out how it works.

I don't know which style of helix is best with it, straight or normal progressive. I had Hyperlite secondarys with progressive helix on the fans and Shockwave with the straight arms on my 629 TNT big bore. Both have worked awesome.

I do prefer high rate primary springs in it. A high rate spring will be shorter with thicker wire compared to a low rate spring. The 2010 race manual list all the doo springs with their rates besides normal lbs start and finish.

The clutch has good belt grip at engagement and can go all the WAY into full overdrive if your geared low enough.

Here is a two page thread Clutch Tutorial I wrote on the PowerBlock a number of years ago http://www.dootalk.c...pic=140014&st=0

On reliability the 4 strokes have less powerstrokes compared to 2 stroke twin and thats why they tear up the TRA. On the 4 stroke forum you can find you tube video of the Poweblock kicken TRA Heiny!!!


Good Luck

Attached Files

•  post-5760-1205194215(2).jpg   17.58K   3 downloads

[doostroke]

Nice LRD. Also the holding key with entire pb80 is $600 with free shipping. Then the BRP puller works or clutch bolt water trick. I feel alot more confident this clutch is better for crank bearings/seals being lighter/balanced and smoother but it can always be better.

I wonder if cv tech or someone could easily fab a dampening puck or similar to further help the clutch bolt/washer sending any vibes to the crank. A puck 1/4 the size

[CVCOBRA1]

http://www.box.com/shared/c9qek9vyj4

Here is some more info I found while researching the PB 80. First half is in French, second in English.
This was last year, I doubt much has changed.

[Schmotz]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

The Powerbloc 80 has a torsional dampener in the cover if that is what you are asking.

[dwulf]

I got a PB80 clutch from cvtech for my 800R and wanted to ask if any others have experience with it especially higher miles.

The pb80 is much lighter, balanced, $40 to rebuild, instead of $1200 which it was gona cost for tra 7 parts. Many TRA 7's are also shot after 2k miles so that means a rebuild mid season.

It doesn't have a dampening puck tho for the clutch bolt like the tra7. Any wisdom?

How is the clutch working out so far?

[dwulf]

[quote name='dwulf' timestamp='1326938124' post='3693428']
How is the clutch working out so far?

TTT

[doostroke]

Thanks for the info schmotz.

Yeah much cooler, quicker throttle response, no belt wear. My rpm is high though at 8500rpm I will work towards 8100 and post my results. I always prefer to rev a little lower, they work better.

[tree ape]

I was pulling 8100rpm on perfect conditions with PB80(table top smooth with little resistance but enough lube to keep things cool). If the conditions were loose (freshly groomed or powder, slick or loose) it will over rev? You may have to find the happy medium or target for the conditions you primary ride in. Keep in mind tach's can be off. Setting up in semi good conditions yields the best results as it will sightly over rev in loose conditions and slightly under rev in perfect conditions. The tra clutch gave you the option to target your rpm in the conditions you encounter with easy trail side adjustment. I know the tra was not an option for you though. How many miles have you put on it so far? Keep an eye on the belt deflection. Curious as to your findings on how the clutch reacts to conditions with rpm.