'93 Marin Team / '94 Parkpre Pro825

[Anthony]

Oh go on, you could assume that the bb weighs 250g couldn't you? Wouldn't be that far out.

It's striking that neither of them is exactly under-built. There's a sort of double standard about mtb design where on the surface everybody talks up 'light', as if light = good. And yet designers build for stiffness and strength. And the marketing men get round the contradiction by claiming the frame is light anyway.

I hate to spoil the thread by mentioning something so sordid as a Kona, but my 97 Kilauea has a 28.6 top, a 28.6 seat and a 31.8 down. So the DT is the same size as the 825 - 31.8 x 8-5-8, but the TT is not just a 28.6 but a 7-4-7 to boot, so doubly lighter. Presumably the Kilauea is too flexy for some (not me), but still the light = good myth persists.

I really don't understand why the Marin takes such a thin post - it implies the walls of the seat tube are really thick. Maybe internal butting just at the top, but even so that's thick.

 

[Easy_Rider]

Now i'm stunned, get a load of this :shock:

Marin
C-C 455mm
C-T 485mm
T-T 590mm
H-T 120mm
Downtube 640mm
Rear to Centre 435mm

Weight with Titec BB (spindle and cups not outer nuts) 165g according to Marin catalogue.

2130 - 165 (to be safe leave the outer nuts) 1965g :shock:

According to the Marin catalogue my earlier tube diameters all match up.
28.6 0.8-0.5-0.8 Top
33.0 0.8-0.5-0.8 Down
28.6 1.3-0.6-0.9 Seat
All superlight.


Parkpre
C-C 435mm
C-T 510mm
T-T 565mm
H-T 115mm
Downtube 620mm
Rear to Centre 435mm

Weight 2090g

I'm very surprised that the Marin is lighter than the Parkpre, especially considering the Marin is larger. Maybe the chain/seat stays have a part to play :?

 

[WD Pro]

Must be that extra light chainstay

 

[crud]

Now i'm stunned, get a load of this :shock:

Marin
C-C 455mm
C-T 485mm
T-T 590mm
H-T 120mm
Downtube 640mm
Rear to Centre 435mm

Weight with Titec BB (spindle and cups not outer nuts) 165g according to Marin catalogue.

2130 - 165 (to be safe leave the outer nuts) 1965g :shock:

According to the Marin catalogue my earlier tube diameters all match up.
28.6 0.8-0.5-0.8 Top
33.0 0.8-0.5-0.8 Down
28.6 1.3-0.6-0.9 Seat
All superlight.


Parkpre
C-C 435mm
C-T 510mm
T-T 565mm
H-T 115mm
Downtube 620mm
Rear to Centre 435mm

Weight 2090g

I'm very surprised that the Marin is lighter than the Parkpre, especially considering the Marin is larger. Maybe the chain/seat stays have a part to play :?

you have a lot of patience, i would have got distracted after the c to c

 

[Easy_Rider]

Didn't take that long.

I'm thinking of drilling the other chainstay to match, might get it to 1.5kg too :shock:

 

[Anthony]

I'm very surprised that the Marin is lighter than the Parkpre, especially considering the Marin is larger. Maybe the chain/seat stays have a part to play :?

I must admit I was a bit surprised at first as well, but in fact the spreadsheet that I use to estimate frame weights comes close to those figures on quite plausible assumptions, so I can give you a possible explanation.

You say 1.965kg for the Marin and I say 1.95kg - if the frame is Superlight, except for an Ultrastrong seat tube. You say 2.09kg for the ParkPre and I say 2.06kg - if the main frame is Superlight and the stays are Prestige Concept. The differences are within the error factor inherent in the modelling, and in particular I can’t model the weight of the bulge butting on the ParkPre seat tube, so that will explain part of it.

For the greater joy of those who think it’s ridiculous to go into details, the differences between the two frames are:

a. the seat tubes are the biggest difference, the Marin arguably being a bit flimsy
b. I’m assuming that the chainstays on the ParkPre are plain-gauge, which could make c50g difference.
c. the top and down tubes weigh almost the same, despite the Marin being an inch longer, because the ParkPre has a fatter top tube.

To be clear, I’m not saying that this proves that the tubesets are what I assumed, I’m just saying that your observed weights are consistent with the assumptions.

It’s worth emphasising that if the assumptions are right, the ParkPre designer has chosen those heavier tubes to make a better, faster frame – it hasn’t saved him money to any great extent. While on the other hand the Marin design is slightly pushing the envelope – that flimsier seat tube wasn’t available within the Superlight options, implying that Tange thought that the other Superlight tubes needed the bulge-butted seat tube to keep everything stiff enough, but the Marin designer thought that wasn't necessary.

It’ll be interesting to see how they compare in back to back testing – you could yet find that the heavier frame is faster as a race bike. It should only take you a few days to build them up, I reckon.

 

[Easy_Rider]

That's some excel program you have there, those calculated weights are pretty good!

I think your assumptions are probably right. The Marin does have the "afterburner" stays so i'm guessing according to Marin thoery it should be a stiffer rear end, but a slacker frame?

When i was building the Parkpre SS I weighed the frame and that was 17xxg but it was a 17" frame and it's got a bit missing (long story).

I would love to build these up to see how they ride, but short term lack of funds and time are quite hampering.

I had a decent go on my 17" Parkpre Pro 825 yesterday (yes i have 3 ) , on hardpack gravel/stone. I am stunned at how quick it was, especially on the descents, really flew over the bumps and made me ride much faster than I normally would.
I'm guessing what your suggesting might be a little more scientific?

 

[legend1]

hi,

i am just starting to hunt around for a marin team issue 92 frame (yellow decals) and got a bit confused of the sizing.

@easy_rider: is there any possibility, that your frame could even be a 17,5" size in the marin-typical measurement?? as far as i remember, marin measures the sizes from center of the BB to CENTER of top tube - which would roughly match making it a 17,5"? rode some team issues back in the days and definitively had the size of the frame you posted...just would like to be sure asking for the right "official" size when looking for a frame...

thanks!

 

[Easy_Rider]

hi,

i am just starting to hunt around for a marin team issue 92 frame (yellow decals) and got a bit confused of the sizing.

@easy_rider: is there any possibility, that your frame could even be a 17,5" size in the marin-typical measurement?? as far as i remember, marin measures the sizes from center of the BB to CENTER of top tube - which would roughly match making it a 17,5"? rode some team issues back in the days and definitively had the size of the frame you posted...just would like to be sure asking for the right "official" size when looking for a frame...

thanks!

Hi,

I got the Marin frame size from the frame number (the Parkpre has a sticker, so easy).
Anyway, this is the code for the frame numbers.

http://www.retrobike.co.uk/forum/viewto ... me+numbers

I have more answers...

Take my frame number

M74HAB182

The M is the factory.

M is Marvel, F is Fairly and T is Ti sports

7 is the model number. Exclude the Ti bikes and work down the list eg.

1 Team Issue
2 Team Marin
3 Pine Mountain
4 Eldridge grade
5 Bear Valley
6 Muirwoods
7 Palisades Trail
8 Bobcat Trail

4 is the year ending number. That would be 1994.

HA is month and date, but you will need the Enigma machine to decode these. Not really relevant either!

B is the size centre to centre.

A is 14 inches
B is 15.5 inches ( this makes it 17 centre to top)
C is 17 inches
D is 19 inches
E is 20 inches

182 are production numbers that are factory use only, and again require the Enigma machine.

So, from that you can calculate the year, model and place it was made.

Seems I have a 94 Palisades Trail frame and forks. The frames were all the same up to Eldridge and then they used Tange prestige or Superlight tubing.

So my frame number of M23BAC004 means I have a 17" frame :shock: :? looks like you were right, how did i think it was a 19" before...? hmmm

Now i understand when people have said marin sizing was on the large side...

 

[legend1]

thanks! yeah, i think its a 17,5" marin size then...which would be a 19" measured from C-T. this would match with the table above and the known marin "big sizing".

then i will go after a 17,5. just checked some old racing pics of my team issues , its exactly the size you have. the head tube of the next size is significantly longer. and the more i think about it 17,5" sounds familiar :mrgreen:

the parkpre size sticker of course is the best way avoiding any size guessing


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