Advice on modernising a 90s Marin

[Stanflashm4n]

Hi, long time lurker/reader , first time poster, so please forgive me if this is in the wrong section of the forum or any other faux pas I’m committing! I started tinkering with a 1992 Marin bear valley during the first lockdown, that got me hooked and I bought a slightly worse for wear 1991 palisades to overhaul shortly afterwards, re sprayed the forks and bars revamped it a bit back to working order. I then bought a semi dismantled 1992 Eldridge grade at about the same time and I’ve only just got round to having a go at doing it up . My idea is to use the frame but modernise it , put suspension forks on and make it 1x drivetrain ideally. I’m realising it’s not as simple as what I’ve done previously. Would more modern 26inch forks be the wrong geometry for the frame? The bottom bracket that came out of it was a shimano BB-UN53 68 1.37 x 24. I’m unsure as to which of these numbers Is going to help me to get a new one? And lastly (sorry for the very long post haha) I’ve bought a 26inch wheel that will fit up to a 10 speed casette, with the idea of going 1x9 or 10. What do I need to consider when choosing a bottom bracket , crankset , cassette etc? If anyone could give any tips, would be much appreciated. Cheers

 

[Motomax]

I had a bike from year 2000 that was in very good condition but needed updating. I wanted bigger tires but had to lace new rims to fit them. Found a new Suntour Radon fork for cheap and a set of discontinued Shimano disc brakes. Got a bar and stem handed down from my modern bike. Kept the original 9 speed cassette but got rid of the triple up front and installed a single narrow/ wide ring on the original crank. I ended up with a bike that rides much better than stock but spent a LOT more than I should have. I would suggest the first change be the bar/ stem combo to get rid of that OTB feeling from the long stem. Then mount the best tires you find that will fit the stock rims. For drivetrain just get rid of the triple and buy a single ring to fit the existing crank. Keep the rigid fork for now as you try out the other changes. You should be able to do these mods without breaking the bank.

 

[Gtpulse]

Hiya, I did a Marin 1x11 for my brother a couple of years ago. Used the original cranks and a narrow-wide chainring. With the bottom bracket the 68mm is a key number, the other is the axle length. The main consideration with axle length is getting it so the cranks don’t catch the stays at the same time getting a chain line that is not too wonky when you move up and down the cassette. I’d get it built with the existing bottom bracket and see if that works, you can then work out if it needs to be narrower or wider.
Forks on a bike that age more modern suspension forks may make the geometry a bit weird as I don’t think they are suspension corrected. Key number here is axle to crown measurement, likely to be lower than on modern forks to keep the geometry of an older frame in check.

Best to have a play around and you’ll get there!

 

[Tootyred]

Marins cope pretty well the 80mm travel forks due the seat tube angle and steep head.

You will raise the bb a bit, but again should be ok. The 92 frame is the same geometry as the slightly latter models, that came with an option to upgrade to a 80mm travel fork.

Have a play.....you will be fine...nice to see some unused kit back on the trails.

 

[Stanflashm4n]

Thanks for the replies . Can anyone recommend a half decent 80mm travel fork? I see an RST delta comp 80mm travel on eBay £50 , is that any good? Also I’ve been looking for a narrow wide chainring that’ll fit the cranks I took off but not having much luck , it’s a 5 bolt - most seem to be 4. Do they exist? This is the crank

 

[FluffyChicken]

I can tell you you bottom bracket length will be 122.5 and probably has the marking D-NL on the axle on the ring side, if you look for it.

But that means nothing if ever you change cranks.

They're 110 BCD chainrings (you may see it as BCD) so search on that.
It also became a common road bike format, their 'compact' size.


See what deals CRC/Wiggle have in the sale for shifters and mechs.

*CRC = chainreactioncycles

 

[novocaine]

you could leave the middle ring on and use a chain guide.

 

[2manyoranges]

Pssst……here are some secrets.

If the ttube is short for you then there’s not much you can do to get really good trail peformance. If the bike feels a bit long currently then HURRAH you can do something.

Suggestions (from 30 years of messing with them…)

1 if tt is longish for you, shorten the stem. This gets the c of g back.

2 run early Judy’s or Manitou if you can find some. Judy’s with SpeedSprings are excellent.

3 radical: get proper length rigid forks but get the widest rims you can in there and the biggest tyres. Run them tubeless. You’ll be amazed at what you can achieve with wider rims and bigger tyres. But you will need the clearance on the fork - this might mean running a modern fork (shock horror) with the right axle-crown length - but note that older Orange F2 forks have huge clearances - you can even run a modern carbon fork (eg Exotic) with a disc - then you can get hyper wide 26 inch rim on the front with a mahoosive tyre - run at low pressure and you will be astonished at the bump-eating performance. Fine for a trail bike…and no suspension dive to try to throw you over the front. People will laugh at the big tyre on the front and weeny skinny thing at the back. They will stop laughing when you trash them on both climbs and downhill. I have a COTIC SIMPLE (26inch wheels) with 36mm internal rims and 2.35 tyres. They are big. And absorb loads. Run 2,35 at the front on a wide rim and 2,10 at the rear on a narrow rim to get the clearances through the chainstays.

4 if tt is longish shorten the stem, get an inline post, run the saddle forward. Combine with the above.

5 get some wide riser bars … And combine with any of the above (if it was good for JMC……) wide riser bars effectively reduce your tt length (so you can then run a shorter stem and put the saddle forward) since you are more upright, your body is shorter due to your arms being wider. By wide bars I mean in the region of 760mm. I am a short-arse and run 760 bars.

This a JMC replica - note the bars. Cheap and radical adjustment to your bike. Go wide.





This is the SIMPLE. It is bump eating when running a rigid fork - no need for a suspension fork most of the time. And yes that’s a 35mm stem.

 

[hamster]

Superstar Components do 5-arm 110mm narrow-wide rings. Very good they are too, lasting well on my singlespeed.
https://www.superstarcomponents.com/en/raptor-chainring-110bcd-narrow-wide.htm

 

[Stanflashm4n]

Thanks for all the advice! im going to order a narrow wide ring, leave the bottom bracket that was in there to see how it all lines up once I’ve got it set up and get a shorter stem and wide bars. I’ve got a set of rockshox J3 forks but I’m fairly sure they are too big. This is probably a silly question but to work out the ‘travel’ do you measure the from the top of the lower part to the top? These seem to be about 115mm so would they been 110 or 120 mm travel? This may not be how travel is measured at all… I’m guessing