Penton Owners Group

General Discussion => Penton Talk => Topic started by: tooclose racing on October 01, 2014, 09:05:04 PM

Title: 76 Ceriani forks on a 74.5 JP?
Post by: tooclose racing on October 01, 2014, 09:05:04 PM
I should probably just clean them up and sell them, but I have a set of the (black lower leg) 35 mm Ceriani forks that I removed from my 76 MC5 (and replaced with shortened 38mm Zokes).

I was reading/viewing that excellent 75 Mint 400 resto when people started pointing at the 76 Ceriani forks mounted on it. And I thought to myself..."Self, would it make any sense to shorten those Cherry's (to AHRMA vintage legal travel) and mount them on my Gary Ellis sourced Jackpiner 175?"  

As you all know, all the CMFs used 35mm in-line Ceriani forks beginning in 74 (I think). Which is what mine currently has.

I'm lazy and haven't looked at the rules book yet - but THAT aside:

Pro's:

1.  I probably CAN run them a little longer in travel? [8D]
2.  They might slow down the steering (response)a tad.
3.  Most important - they would look VERY cool.

Con's:

1.  They probably weigh more (haven't checked, but I'm presuming lower casting is aluminum,not mag)
2.  The might slow down the steering a bit.
3.  I'm too stupid to shorten them myself, so will probably pay one of the local suspension guys to do it for me.

Other thoughts from my POG racing brothers and sisters - OTHER than the usual cheater bike/anything to win/buy a clue remarks that I am already very accustomed to?

Thanks - hope everyone is having a nice Autumn.  We've had a great couple of weeks (no rain!) in the Empire state.

Title: 76 Ceriani forks on a 74.5 JP?
Post by: 454MRW on October 01, 2014, 09:53:29 PM
They are magnesium.They are probably longer travel and they might not pass inspection. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Title: 76 Ceriani forks on a 74.5 JP?
Post by: ALB on October 02, 2014, 11:24:21 AM
To shorten those leading axle Ceriani forks would be a sin.:(
They are excellent forks to put on a post vintage race bike.
Yes, they are Very cool looking.

Alan Buehner
Title: 76 Ceriani forks on a 74.5 JP?
Post by: 454MRW on October 02, 2014, 11:38:02 AM
Al is correct. I have a nice set of 74 straight leg Ceriani's that I would trade you for them though. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Title: 76 Ceriani forks on a 74.5 JP?
Post by: brian kirby on October 02, 2014, 11:52:12 AM
No, they will not be legal even if reduced to 7" travel. The only leading axle forks legal for AHRMA vintage are Betor (Bultaco Alpina/Sherpa T), Elsinore 125 or Maico, no other leading axle forks are Vintage legal. You could put them on the bike with the shocks in the 45 degree laydown position and race Historic 200, but you would have to use the straight triple clamps that go with it, the straight leg triple clamps will make the bike ride the Peter Fonda's bike in Easy Rider.

Brian
Title: 76 Ceriani forks on a 74.5 JP?
Post by: tooclose racing on October 06, 2014, 03:49:53 PM
Thanks guys.  I have regained my senses.  We'll stick with the 35mm straight legs that are already on my JP.  

But - next best thing? If I can't bring my leading axle forks to the Jackpiner - I'll bring my Jackpiner to the forks (so to speak).  I'm talking to Gary Ellis about building an MC5 175.  Maybe we'll use the leading axle Cerianis...

Get along, little doggies![8D]

Title: 76 Ceriani forks on a 74.5 JP?
Post by: brian kirby on October 06, 2014, 06:44:08 PM
That's what I would do.

Brian
Title: 76 Ceriani forks on a 74.5 JP?
Post by: 454MRW on October 01, 2014, 09:53:29 PM
They are magnesium.They are probably longer travel and they might not pass inspection. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Title: 76 Ceriani forks on a 74.5 JP?
Post by: ALB on October 02, 2014, 11:24:21 AM
To shorten those leading axle Ceriani forks would be a sin.:(
They are excellent forks to put on a post vintage race bike.
Yes, they are Very cool looking.

Alan Buehner
Title: 76 Ceriani forks on a 74.5 JP?
Post by: 454MRW on October 02, 2014, 11:38:02 AM
Al is correct. I have a nice set of 74 straight leg Ceriani's that I would trade you for them though. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R
Title: 76 Ceriani forks on a 74.5 JP?
Post by: brian kirby on October 02, 2014, 11:52:12 AM
No, they will not be legal even if reduced to 7" travel. The only leading axle forks legal for AHRMA vintage are Betor (Bultaco Alpina/Sherpa T), Elsinore 125 or Maico, no other leading axle forks are Vintage legal. You could put them on the bike with the shocks in the 45 degree laydown position and race Historic 200, but you would have to use the straight triple clamps that go with it, the straight leg triple clamps will make the bike ride the Peter Fonda's bike in Easy Rider.

Brian
Title: 76 Ceriani forks on a 74.5 JP?
Post by: tooclose racing on October 06, 2014, 03:49:53 PM
Thanks guys.  I have regained my senses.  We'll stick with the 35mm straight legs that are already on my JP.  

But - next best thing? If I can't bring my leading axle forks to the Jackpiner - I'll bring my Jackpiner to the forks (so to speak).  I'm talking to Gary Ellis about building an MC5 175.  Maybe we'll use the leading axle Cerianis...

Get along, little doggies![8D]

Title: 76 Ceriani forks on a 74.5 JP?
Post by: brian kirby on October 06, 2014, 06:44:08 PM
That's what I would do.

Brian
Title: 76 Ceriani forks on a 74.5 JP?
Post by: Mike OReilly on June 02, 2017, 12:11:36 PM
Currently rebuilding a set of the leading axle 35mm Cerianis.

Does anyone have a suggestion for quantity and weight of fork oil?

Thanks,
Mike
Title: 76 Ceriani forks on a 74.5 JP?
Post by: Larry Perkins on June 02, 2017, 12:20:54 PM
Brian is on why they are not AHRMA legal.  I have seen several try it to get jilted in Tech Inspection.

Larry P
Title: 76 Ceriani forks on a 74.5 JP?
Post by: Rocket on June 02, 2017, 12:21:10 PM
Quotequote:Originally posted by Mike OReilly

Currently rebuilding a set of the leading axle 35mm Cerianis.

Does anyone have a suggestion for quantity and weight of fork oil?

Thanks,
Mike

1978 GS6    Ceriani Leading Axle   35mm   240mm   230cc   215cc   10wt
1978 MC5   Ceriani Leading Axle   35mm   265mm   270cc   250cc   10wt
1978MC5 250/400   Marzocchi    38mm   270mm   380cc   360cc   10wt
1978 MC 5 125/175 & All GS6   Marzocchi    35mm   250mm   280cc   265cc   10wt
1977 GS6 & MC5   Marzocchi    35mm   220mm   240cc   220cc   10wt
Late 1977 MC5   Marzocchi    35mm   240mm   265cc   250cc   10wt
1976 Cross Country or MC5   Ceriani Leading Axle   35mm   220mm   230cc   215cc   10wt
   Marzocchi    35mm   220mm   240cc   220cc   10wt
1975 All Models   Ceriani Straigh Leg   35mm   190mm   235cc   220cc   10wt
Title: 76 Ceriani forks on a 74.5 JP?
Post by: Mike OReilly on June 04, 2017, 11:44:06 PM
Rod:
You are indeed the suspension guru. Thanks for such a comprehensive answer.
As noted the bikes 1975 thru 1978 came with a whole variety of forks and the manuals did not keep up.
I have printed this out to include with my manuals, and I expect that a bunch of POG members will do the same to keep as reference.
Thanks again,
Mike
Title: 76 Ceriani forks on a 74.5 JP?
Post by: Rocket on June 05, 2017, 09:18:00 PM
Quotequote:Originally posted by Rocket

Quotequote:Originally posted by Mike OReilly

Currently rebuilding a set of the leading axle 35mm Cerianis.

Does anyone have a suggestion for quantity and weight of fork oil?

Thanks,
Mike

1978 GS6    Ceriani Leading Axle   35mm   240mm   230cc   215cc   10wt
1978 MC5   Ceriani Leading Axle   35mm   265mm   270cc   250cc   10wt
1978MC5 250/400   Marzocchi    38mm   270mm   380cc   360cc   10wt
1978 MC 5 125/175 & All GS6   Marzocchi    35mm   250mm   280cc   265cc   10wt
1977 GS6 & MC5   Marzocchi    35mm   220mm   240cc   220cc   10wt
Late 1977 MC5   Marzocchi    35mm   240mm   265cc   250cc   10wt
1976 Cross Country or MC5   Ceriani Leading Axle   35mm   220mm   230cc   215cc   10wt
   Marzocchi    35mm   220mm   240cc   220cc   10wt
1975 All Models   Ceriani Straigh Leg   35mm   190mm   235cc   220cc   10wt

The first number with the amount is if a total take down and clean, the second amount if it is a drain and refill.