Christiaan

I'm working on my first rebuild (a 1999 Marin Larkspur) and need to get new forks, headset and stem.

I don't know where to start. See attached photo of existing. I think they're the most common size (whatever that is). My tyres are 37-622. The head tube is 150 mm long and 30 mm inside diameter.

So what do I need to keep in mind when ordering the correct kit?

Edit: the second image is of the forks in the head tube. It was a quill stem and the forks/stem had to be cut to remove the forks. But perhaps I'm jumping the gun on needing new forks? Are they still usable in some way do you think?

FBinNY 

OK, start with the fork. You need a 700c fork with cantilever bosses, to match your wheels. Steerer is measured from the base of the crown, to the top, so double check the 150mm dimension, and the diameter is the outside diameter which is probably 1-1/8" or 28.6mm. That doesn't jive with the 30mm ID you measured so re-check that. (32mm OD forks exist, but they're fairly rare.

Next you have decide whether you're going with a threadless headset or threaded. Since you're going new on both the fork and stem it's your choice, but I suggest you opt for threadless. Important - if you're replacing a threaded fork with threadless add at least 60mm to the steerer tube length to support an external stem.

Lastly the stem, decide on the extension and angle you prefer, then match the steerer diameter, and the handlebar diameter which I believe is 25.4mm on Larkspurs (I own 2, but they're from about 2003 or so).

That covers the basics, but it adds up to a decent cost to put into a Larkspur, so double check to see if any of what you already have is OK for re-use. I assume all this is because you bent the fork in a crash, because if the fork is OK I'd just clean it up and reuse it and whatever is OK of the other parts.

Christiaan

Thanks FB, I think you might have got in before I edited my post. I've added a photo and an explanation of why I'm replacing them (they had to be cut). Check out the second photo. What do you think? Reusable in some way?

It was the inside of the head tube that I was measuring at 30 mm. The steerer is 24.5 mm.

Head to crown—now that the steerer has been cut—is 170 mm. Don't know how long it was before being cut.

FBinNY 

OK, life is simple (almost) now. You need a 1" threaded fork (or you could go 1" threadless). For the length measure the headtube and add the stack height of the headset you plan to buy. It's listed as a spec and is usually 38-44mm. Headsets require a bit less than 1" of thread so you can buy a fork 1" longer than needed if it has the typical 2" of thread. When cutting the fork, err long by a millimeter don't forget to add for a cable hanger or any other stuff under the headset locknut. I usually cut all forks 44mm longer than the headtube, plus the cable hanger if there is one. I then use spacers to take up the excess, leaving the option for a taller headset in the future.

Again if you opt for threadless add 60mm to the steerer length for the minimum, and buy anything longer since threadless is easy to cut down.

Your headset is tricky, if you measured accurately you have a JIS headset which is harder to source than an ISO (British) whose head cups are 30.2mm. Even if you find a JIS headset, I doubt you'll find a JIS fork, so you'll need either a spare crown race, or a ISO headset, but that means bring the frame to a shop to have the head tube reamed out (figure $25.00 os so).

Then either a quill stem for the threaded fork, or a threadless stem (probably 1-1/8" with a shim) for the threadless.

BTW- when you add the reaming cost, to the parts it adds up to a decent chunk of change, and given the age and apparent condition of your Larkspur, you should give serious thought to buying new rather than saving.

fietsbob

I have favored longer forks , as spacers can go in between the 2 upper parts of threaded headsets.
in fact for V/cantilever brakes the hanger is a spacer.. I have a sleeve and a bell in the stack of my bikes steerer tube..

had the thread cut down further with the bike builders cutting die.

Christiaan

Thanks again. I take it this means my current forks are unusable?

FBinNY 

Your thread started with the premise that you needed to replace it. Then you mentioned that it had been cut. Most threaded forks have very little extra length, so if they cut more than a few millimeters off I'd assume it's scrap metal now.

But you could check, you need 38-45mm more than the head tube length. If you don't have it you're SOL.

FBinNY 

Christian, I have a question.

What genius (apologies if it was you) decided to cut the fork? and why?

and a suggestion,

Since buying new will likely bring the cost of the project above what the bike warrants, consider going on a scavanger hunt for a beat up bike with a good front end that will fit your needs. If you select carefully you should be able to find one with usable fork and stem, though a matching JIS headset may be too much to hope for.

Lots of folks have had great success melding two bikes into one, or three into two. This is standard fare for a number of groups stateside who scavenge bikes and refurbish them for charity.

skilsaw

I'm a dad who bankrolled a couple rebuilds for my sons. The objective was to teach them about bikes. Both rebuilds cost more than the bike was worth but that was OK because the objective was to teach...

Let me repeat again the first advice you got on your first post on this project:

Christiaan - " I'll be replacing everything and having the frame repaired and resprayed."

FBinNY - "Before you start, get a good estimate on the total cost. Odds are it'll be more than you paid for the bike, and more than a better bike can be bought for today."

Right off the bat, buying a new fork is going to start you on an expensive rebuild. Maybe you can get parts from a bike shop that specializes in used bikes and rebuilds. Otherwise your bike will cost you more than it is worth. This isn't the first time a rebuild got started and abandoned when interest and money ran out.

Otherwise, go for it, if your objective is to learn, and you have deep pockets with lots of spare cash.

motobecane69

I somewhat disagree, here in the states a replacement steel fork can be had for $50 and a replacement kinesis carbon fiber fork can be had for $100. thats not crazy expensive. OP, I'm not sure what you said your intended use for this bike was going to be but if it's going to become a commuter, don't repaint it, leave it as is so it looks like a piece of crap but get it mechanically functioning well. then you won't be a target for thieves.

FBinNY 

Your numbers are OK, now add a headset and stem, and possibly having the headtube reamed since it seems to be JIS. suddenly you're talking serious dough. A Larkspur is a lower mid-range bike, probably replaceable these days for $350 or less new. That buys you all new, with an aluminum frame (at least in 2004) and all new components. Obviously this is more than the low end of the repair cost range, but even in the best case scenario, he ends up with an expensive old bike (look at the photo).

Add tires, brake shoes, and 4 cables all stuff it's likely to need soon enough and the gap closes.

Learning projects are great, but part of the process is knowing when to quit, lest you end up with a money pot you can't walk from because you have too much in it already (think Volvo). For projects like this the 2 used bikes into one makes the most sense all the way around creating both good learning and real value with minimum cost.

skilsaw

Good advice on not repainting. For an idea of how much is going to be replaced, on top of the fork, and how much this could cost, look at this quote from Christiaan's first post from January 30/11. "I'll be replacing everything and having the frame repaired and resprayed."

FBinNY had a great suggestion: "Since buying new will likely bring the cost of the project above what the bike warrants, consider going on a scavanger hunt for a beat up bike with a good front end that will fit your needs. If you select carefully you should be able to find one with usable fork and stem, though a matching JIS headset may be too much to hope for.

Lots of folks have had great success melding bikes into one, or three into two."

jimc101

That fork is toast as the threads have been cut, it's will not fit your frame as it's now too short, You will struggle finding a suitable replacement fork if it is a 1 inch, forks have moved on, and anything decent will be 1 1/8, a good choice would be a Kona Project 2, but again, these are only in 1 1/8.

Skilsaw, guess the avalibility of used parts is much better in Canada / the US than the UK, over here, there ebay, there anything good it will fetch a premium, there are very few places which actually re-cycle bikes, can only think of 2-3 in the county, the only places you can really do a "scavenger hunt" for bike part in London will be Police acutions, where they dispose of found / recovered bikes and markets, like Brick Lane, where the chances are the bike was stolen, Pawn shops do sell bikes, but these are at the top end of their worth & normally basic bikes; 2nd had shops will normally have only very basic bikes in, nor have never seen any in charity (goodwill) shops anywhere in the UK

Christiaan; the more pictures you show of that frame, the worse it looks, it was low end to start with, and you will just be throwing money at it, and it looks as though you will end up with a very expensive cheap bike. FBinNY is totally correct, walk away, by the time you have got this powder coated (£75-100) the frame re-finished, taping & facing (£30-50) new fork if you can get one (found one on ebay which may fit) £50, A-headset & stem £40, thats around £200 and you haven't started on the groupset & wheels, even for budget, and Shimano Alivio is about as basic as you can get at a consumer level in the UK unless you want pressed steel parts which will last a few weeks, that another £150, a basic set of 700c wheels will be another £100, tires and tubes £30, saddle, H/bar, seatpost, grips £75, odds & ends like cables, rim tape £20-50, that £550+, you will no doubt need some tools, which you don't have for these parts, add another £50-300 for the these, or workshop labour, in London, will be at around £40 per hour, would imagine you would be billed arround £200 to build

Current Marin Larkspur can be picked up for £450, will have a warranty, no need to assemble, and have a post sale service. guess which I would choose from these 2 options

motobecane69

no disrespect to you, but you are clearly always budget conscious. if the frame hasn't been compromised, whats the difference between spending 500 to fix an old bike up like new or paying $500 for a new bike? both will ride great. Also, fixing up an old bike gives one the opportunity to fully customize With that said, if someone does want to learn to build a bike, you can buy frames from nashbar for $90 all painted and ready to go which is what I did recently specifically because I wanted a few very custom options. lets not forgot that money spent on parts for an old bike can always be taken off and used on other bikes.

I fixed up an old hi-ten bike last summer as my first project and spent close to $500 to do it. I rode it for 3 months and enjoyed it then sold it for $300! technically I lost $200 on the deal, but I learned a ton and had the enjoyment of riding it. can't go wrong there.

cheap headsets and stems are $20 items but I do agree with you, if it's a JIS headset, that begins to make it a pain in the ass.

jimc101

Motobecane69, the problem with this example, it that frame is a wrecker, it looks as though it has been dragged out of a canal, it's going to take a lot of work to fix, and a huge amount of money, even with budget components. Also, your idea of re-using part from an old bike is flawed, there are so many standards out there, take Bottom Brackets, Square taper, ISIS, Octalink, HT2, BB30, BB90, the list goes on, and then there are different sizes for some, the chances are that any parts needed to fit this old frame would not be able to be used on any other bike; most bike components can substitute for the BB; for this specific bike, it used an obsolete 1 inch fork, very hard to source, and no one uses 1 inch any more except for ultra low end

Remember the original question was asked by someone in the UK, the market for 2nd hand bikes in the US sounds a lot stronger than the UK from your experience, at the moment Marin's are not an 'in' brand, they were 10-15 years ago, but now, you don't see many, and you wouldn't notice if they weren't here, resale value for this when finished would be £50-100 max, that's a lot less that you got.

You can get far better bikes for less than half what the minimum cost of any refurbishment would be; the Boardman range of bikes for example, you can google them.

There is a time and place for re-furbishing old frames, classic road bikes, early (retro) mountain bikes, custom builds, it's not for a cheap mass produced hybrid that's a few years old, that a wreck to start with.

Christiaan

Thanks for all the good advice guys.

The (4130) frame may look a bit worse for wear but nothing a good shot blasting won't fix. I'm doing this for fun, to keep a bike out of the tip and to learn. So if I make a few of mistakes all the better. And if those mistakes cost me it's no big deal. I've spent more on a big weekend out. The main thing I've learnt from this is that it's a good idea to strip the bike *entirely* and check the frame for integrity *before* buying new components.

So I took it to the local bike shop because I couldn't get the bottom bracket off. I didn't have a big enough wrench for the headset so I asked them to take the forks off too. I came back the next day and they said they couldn't get the forks off. According to their advice the only way was to cut them off. They advised against this but I said to go for it. Could they have cut them off without cutting the steerer? I don't know. I asked for the forks back but didn't think to ask for the stem as well. I have a hacksaw so I should have just done it myself.

To give you an idea of what I've spent and where it's going:

£36 on an Ice Toolz Essence Tool Kit, but I needed this anyway (for my new bike). The only thing it didn't have that I needed is a big wrench.

- £8 on new rear derailleur pulleys
- £10 casette (Shimano HG30 7 Speed)
- £17 chain (SRAM PC-890)
- £60 is what the powder coating will cost (Armourtex)
- If I don't find something secondhand I'm thinking about a Brev chainring (£18), crank (£45) and peddles (£25).
- I need new brake and gear cables (although only rear gears as I'm leaving front derailleur off)
- Brakes and brake pads are fine. Wheels are fine (although I might replace rear hub). Tyres are near new Marathon Plus.
- Handlebar is fine, but I'll get new grips.
- Saddle and seat post are fine but I might be tempted to find something else.

So we're talking between say £120-225.

That leaves forks, headset and stem. If my steerer column is 25.4 mm and my head tube is 30 mm. Isn't that a 1" ISO rather than a 1" JIS? I presume they're just as rear? My best bet, I guess, is another Marin Larkspur.
https://en.wikipedia.org/wiki/Head_tube

motobecane69

I think JIS really has to do with the crown race and the lower bearing race. sizewise they are the same size or close enough to the same size that they willprobably fit into the head tube without much issue but I'm far from an expert on this. I would think you could contact Marin directly and find out.

I think your on the right track, if your able to reuse that many parts from the original bike like the brake levers, shifters, etc, you are okay

JIMC, it doesn't matter if the bike LOOKS like it was dragged out of a canal, all that matters is did the time spent in the canal render the bike structurally unsafe? if not then there is no reason why it shouldn't ride as good as any new bike once complete. yes there are a lot of different standards out there but in the case of a bottom bracket, there is really only a couple of standard sizes and typically bb shells are 68 and english threaded on a bike from that generation. i had an 83 nishiki that had cup and cone bb and steel spindle. I replaced it with an isis bottom bracket and crank easily. it's really not that hard.

Again, I don't know why everyone thinks rebuilding a bike is always about doing it on the cheap. for many of us it's the sense of accomplishment of riding something you made yourself or knowing that you brought something back to life and kept it out of the dump. nothing wrong with that.

FBinNY 

JIS and ISO headsets are different both at the crown race, and the head tube dimensions. The internal dimensions of the headset are the same so you could use a JIS headset on an ISO fork by replacing only the crown race.

As I posted earlier the OP can either try to source a JIS fork, or have a shop ream his 30.0 head tube to 30.2, or buy a JIS headset plus the matching ISO crown race. Given that JIS isn't that common in the UK, he's best off biting the bullet and having the head tube reamed if he decides to go ahead. A decent shop can do this at a price not out of line with what he's spending overall.

BTW- the assumption that his frame hinges on the OPs 30.0 measurement. if he didn't measure it carefully, he should knock out the head cups, which he'll need to do anyway, and measure them more carefully to verify if they're 30.0 or 30.2mm.

motobecane69

one thing the op will learn is that there are certain jobs best left to the lbs to perform. for example, unless you know your going to be doing a lot of bike builds, buying a headset press doesn't make sense when an LBS will install the headset for you for about $10. this is a case where I would have the lbs figure out what headset is needed and install it.

fietsbob

Ah the aluminum quill stem seized in the fork steerer.

If the cut was at the top of the headset, just the old stem was cut, the aluminum
can be drilled and cut out like a pie.in sections, then the fork re used..

A threadless 1" fork is a possibility, different headset and stem.

jimc101

If you can get a headset fitted in London for less than £20 (approx $32) would be very supprised, Evans Spitlefields charge £37.50 ($61) you can buy a Cyclus headset press from Wiggle for £34.19 ($55), so will pay for its self after a couple of uses

Christiaan

The cups are long gone. I'm pretty sure it's 30 mm but it's very difficult to tell because the inner edge of the head tube at each end has a slight chamfer. Any tricks for measuring more accurately?

Ha, that's not what I wanted to hear! Oh well, it's done now.

motobecane69

a set of calipers will get you the measurement you need.

FBinNY 

head tubes tend to ovalize, so measure twice 90° apart and average the results. If you use a caliper, most have an undercut near the base which will clear the lip and allow a correct reading.

If you or a local shop have a JIS head cup, it can be used as a guage, as it will be a slip fit in a 30.2 ISO frame, and a press fit in a 30.0 - not counting ovalization, but you can tell by feel anyway. The other way is to knock the crown race off your fork. If it's original it'll be to the same JIS or ISO standard as the frame, either 27.0 or 26.4 respectively.

FastJake

I'm all for keeping old bikes on the road, but only when it makes financial sense. The difference between spending $500 on the frame pictured and buying a $500 new bike is that you'll actually have a brand new bike that won't look like junk. If you want something that looks bad, buy something cheap.

I see your point about learning and the sense of accomplishment. But if you want that, get a bike that is old and dirty. Give it a complete overhaul (bearings, cables, brakes, etc.) Not one that needs a complete set of parts. Your example shows what I mean. I'd rather wait for a good deal and maybe if I do a good enough job cleaning it up and fixing it I can make $100 when I sell it. That's more of an accomplishment for me, rather than sinking a ton of money into something then selling it at a huge loss.

Your plan only makes sense for those with money to throw away.