# Total noob: building lugged MTB frame



## DoctorRad (Sep 24, 2009)

Hi folks,

I've decided I would like to have a try at silver brazing my own MTB frame with minimal outlay for tools. I have found the following book online:

http://bhovey.com/Masi/Scans/Talbot/index.htm

...which seems to cover the basics of building a brazed lugged road frame pretty comprehensively.

An MTB frame obviously has more issues with tyre clearance close to the BB shell than a typical road frame. What I'm struggling to work out at the moment is how to do a fully lugged construction - i.e. using a BB shell with chainstay ports - which will provide adequate mud and chainring clearances. Pointers and advice would be welcome, especially towards shells or chainstays available off-the-shelf which would help me out. Always love pictures, I'm a visual sort of person.

TIA,

Dr. Matt...


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## Walt (Jan 23, 2004)

*Slant 6*

You probably want some Pacenti Slant 6 lugs. Most normal lugs are intended for road bikes (as you've noticed) and the chainstay ports are the least of your problems - the angles on the entire lugset will tend to be way off what you need for a mountain bike.

Check out www.bikelugs.com. It doesn't appear that he still has any (does anyone know what's going on with Kirk?) but maybe if you email him he can find you a set.

That's the only MTB-specific lug set I know of. Anyone else want to chime in?

-Walt



DoctorRad said:


> Hi folks,
> 
> I've decided I would like to have a try at silver brazing my own MTB frame with minimal outlay for tools. I have found the following book online:
> 
> ...


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## unterhausen (Sep 28, 2008)

I'm assuming that tig is out of the question. Your life is going to be much easier if you go with fillet brazing and skip the lugs. You can get silver to braze fillets with if you really want to do that, but most people use brass. There are still MTB lugs out there to buy, but I wonder if anyone actually uses them.

Brazing with lugs looks to be easier than any other method, and it may be. But I am aware of at least one builder that is quite accomplished with fillet brazing and had a couple of lugged bikes that were not put together correctly.

I've never read Paterek, but that is the book that is cited most often nowadays. You can get an early copy online at Paterek's web site.

unterhausen, Ph.D.



Walt said:


> You probably want some Pacenti Slant 6 lugs. Most normal lugs are intended for road bikes (as you've noticed) and the chainstay ports are the least of your problems - the angles on the entire lugset will tend to be way off what you need for a mountain bike.
> 
> Check out www.bikelugs.com. It doesn't appear that he still has any (does anyone know what's going on with Kirk?) but maybe if you email him he can find you a set.
> 
> ...


 Henry James sells something he calls MTB lugs. The Slant 6 lugs are now sold by Llewellyn  
I couldn't find a direct link, you have to email, get the price list, send order and then pay with paypal. Bikelugs.com was easier, no doubt.


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## dbohemian (Mar 25, 2007)

DoctorRad said:


> Hi folks,
> 
> I've decided I would like to have a try at silver brazing my own MTB frame with minimal outlay for tools. I have found the following book online:
> 
> ...


You have actually chosen to embark on a pretty complicated project. For only some of the reasons you have already discovered. Lugged MTB;s are about as tough as they come.

Walt is correct. The only semi-suitable set right now is the slant six and is currently being sold by Ceeway and Darrel in Australia. The BB is one of the big issues in that finding the right clearance is dependent on finding the right chainstays and cutting them in just the right place as to maximize clearances.

Kirk is reorganizing to sell only Pacenti branded items. The slant six set is just being sold by the two people above now.

Personally, lugged construction on an MTB is so tough to do and leaves the geometry wanting typically that I would recommend that MTB's be built lugless. You can still do this with minimal equipment. I have built two MTB's that were fully lugged that did not have these issues but then again I made my own lugs

The only good advice I can give if you move forward with this is to lug the front triangle and then use a lugless BB. It will make your life a lot easier.

Dave


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## derek (Jan 13, 2004)

I built my second mountain bike using lugs:

http://forums.mtbr.com/showthread.php?t=375624

I could not agree with Dave B. more.



dbohemian said:


> The only good advice I can give if you move forward with this is to lug the front triangle and then use a lugless BB. It will make your life a lot easier.


Your going to have to braze the dropouts and seatstays anyways so you'll need to learn that.


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## themanmonkey (Nov 1, 2005)

Just so folks know the Henry James lugs only work with 32mm headtubes (1" steeers only). The MTB lugs at Ceeway look to have about 4 degrees of slope.

I built a MTB with the Slant-6 lugs and Columbus Zona that turned out great, but I also spent as much time designing as I did building. If you build it for a rigid fork it's not much of a problem, but a sus fork with more than 80mm travel can get weird.

To add to what Dave said the BB is a particular problem. Joe Bringheli had a BB shell that has chainstay ports, but no sockets for DT and ST. It's actually pretty neat and would work well for this project.


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## DoctorRad (Sep 24, 2009)

Thanks very much for the input folks, especially the pointer to the old Paterek manual which I had missed on his site. The headtube was the other point of contention for me, as I was having trouble finding 1-1/8" compatible lugs with MTB angles.

My reasoning for wanting to go the lugged route - as Derek correctly surmised - was to keep the amount of fillet-type brazing needed to a minimum. Also going with silver as I'd hoped to be able to get away with a cheaper torch due to needing a lower temperature.

Sooo... if I was to go down the lugless BB route, would I still be able to use silver? I presume the reason why silver is not readily used for fillet brazing is because of the cost of the brazing rods... any other reasons?

With regards to my choice of torch, what general type or specific model would you recommend for silver work? And how about if I was to go the whole hog and learn to fillet braze in brass?

Thanks again,

Dr. Matt...


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## themanmonkey (Nov 1, 2005)

I'm sure *dbohemian* will be in here and tell you about using Freddy Parr's Fillet Pro soon enough. I'll just give the teaser to the site. I've got some on order, but haven't used it personally. . . yet.


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## DWF (Jan 12, 2004)

dbohemian said:


> You have actually chosen to embark on a pretty complicated project. For only some of the reasons you have already discovered. Lugged MTB;s are about as tough as they come.
> 
> Walt is correct. The only semi-suitable set right now is the slant six and is currently being sold by Ceeway and Darrel in Australia. The BB is one of the big issues in that finding the right clearance is dependent on finding the right chainstays and cutting them in just the right place as to maximize clearances.
> 
> ...


Dave, have you ever used the Long Shen MTB lugs? I've built a conventional MTB frame with them no problem. Slack HTA, sloper, short fork. What's not to love?


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## unterhausen (Sep 28, 2008)

DoctorRad said:


> My reasoning for wanting to go the lugged route - as Derek correctly surmised - was to keep the amount of fillet-type brazing needed to a minimum. Also going with silver as I'd hoped to be able to get away with a cheaper torch due to needing a lower temperature.
> 
> Sooo... if I was to go down the lugless BB route, would I still be able to use silver? I presume the reason why silver is not readily used for fillet brazing is because of the cost of the brazing rods... any other reasons?
> 
> ...


There is no difference between the torch you need for brass and silver. Granted, people have made frames with silver and a MAPP torch. I would not ride those frames.
Silver isn't used much for fillet because it's expensive and you need special formulations to build the fillet. I say you need a real O/A torch either way.

And yes, that's going to cost you about $600. I figure you can always sell it for a reasonable price if that's a consideration.


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## dbohemian (Mar 25, 2007)

themanmonkey said:


> I'm sure *dbohemian* will be in here and tell you about using Freddy Parr's Fillet Pro soon enough. I'll just give the teaser to the site. I've got some on order, but haven't used it personally. . . yet.


Hi man Monkey. Nice introduction!

Yes, as was said before it is possible to silver fillet braze but.....I could not recommend that to an absolute beginner. It is a bit touchy. In his case more might end up on the floor than on his joint.

Also, I would reiterate unterhausen. that a good torch can do just about anything. I too got the feeling this guy wanted to braze with MAPP or some such thing. I cannot recommend that.

I think most of you guys know how I feel about that. It does cost some money to build a frame reasonably. Maybe not a lot but probably at a minimum 1k dollars and if that is too much to swallow then honestly, don't even get involved and leave it to a pro. You have to have a minimum level of commitment to learn this craft and do it right.

I have always thought for this reason that composites might actually be a better material for the beginner. There is no welding necessary. No machine tools or any fancy tooling to speak of. It would take a long time but they have that. The most money you would be looking at is material costs.


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## DoctorRad (Sep 24, 2009)

So would you say that a MAPP torch is not suitable even for lugged work in silver? If not, why not? I certainly wasn't considering one for fillet work.

Thanks,

Dr. Matt...


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## zank (May 19, 2005)

I've done a few mtbs with the Long Shen set and a few with the Slant Six set. As Don mentioned, the Long Shen lower head lug angle of 66 degrees is better suited to short forks. I like the way seat stay sockets on the seat tube lug of that set look. There is a set of Columbus triple bend 16 mm stays that work nicely in that application. The angle of the Slant Six lower head lug is much better for suspension forks. And that seat lug is nice because of the skirt on the back of it. You can fillet braze on just about any stay. I use the Fillet Pro for those.

The last mtb I did used the Slant Six head lugs and the Long Shen seat lug. I trimmed the points of the seat tube lug to match the look of the head lugs. I used Long Shen's BB shell for all of the mountain bikes. You need to blacksmith the CS ports a bit and you are pretty much limited to single bend CSs.

As others have mentioned though, I prefer to build mountain bikes lugless. Far fewer restrictions.


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## dbohemian (Mar 25, 2007)

DoctorRad said:


> So would you say that a MAPP torch is not suitable even for lugged work in silver? If not, why not? I certainly wasn't considering one for fillet work.
> 
> Thanks,
> 
> Dr. Matt...


Ah, the old MAPP thing

They see that 40 dollar torch in the home depot and think. Yep, that is all I need. So the short of it is, Yes, you can braze a bicycle with MAPP. It has a temperature close to Oxy/acetylene and should do a good job.

But, I think the biggest hangup is that the cylinders are small and the price of the fuel becomes an issue. I have heard of people going through 3-4 of them on a single project. That adds up quickly. The torches leave a lot to be desired in that you cannot typically adjust them much. Maybe it's o.k. for a lug but what about braze-ons and fillet brazing drop-outs to stays and the like?

If you are worried about acetylene you could always set up using propane or natural gas which is safer to transport and easier for many to obtain. I have found great equipment used with a little bit of effort. In fact I have a wonderful torch with all the tips I found for 75 bucks.

So IMO you should bag the MAPP. Other torches are much more useful and don't let the torch dictate what kind of construction you can accomplish, instead decided what construction method is best in your case.


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## DoctorRad (Sep 24, 2009)

*MAPP vs Propane*



dbohemian said:


> Ah, the old MAPP thing
> 
> So IMO you should bag the MAPP. Other torches are much more useful and don't let the torch dictate what kind of construction you can accomplish, instead decided what construction method is best in your case.


So - spot the naive newbie here - how is a propane/air torch more useful if it's around 1,000F lower in temperature than MAPP/Air? Would I, for instance, be able to get something big like a BB shell hot enough to fillet braze the chainstays onto it?

Thanks again for the input, really useful.

Dr. Matt...


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## dbohemian (Mar 25, 2007)

DoctorRad said:


> So - spot the naive newbie here - how is a propane/air torch more useful if it's around 1,000F lower in temperature than MAPP/Air? Would I, for instance, be able to get something big like a BB shell hot enough to fillet braze the chainstays onto it?
> 
> Thanks again for the input, really useful.
> 
> Dr. Matt...


Because I am suggesting using Oxy/propane not MAPP/air. It is the ****/air that is the issue. You have much more control when using an quality torch where you can control both the flow of fuel and oxygen.

The short of it is IMO is that you MUST invest in a quality gas welding setup. What gas that is is not so important but the simple gas/air things you get to do plumbing jobs are not suitable.


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## Smokebikes (Feb 2, 2008)

The big problem I had with the MAP/air set-up was the tanks where too small and tended to use up too much fuel too soon, running out of gas ($$) in the middle of the project..........yes, it was hot enough to braze (barely) but heat control was less than optimal and parts with higher thermal mass (HT, BB, DO's) required much more heat and control that the MAP/air kit provides.


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## themanmonkey (Nov 1, 2005)

*DoctorRad* I think a through read of this forum's FAQ, the archives for the Framebuilders listserve at bikelist.org, and a good perusal of the Paterek Manual will do you a world of good before asking these questions. This whole thing has been done over repeatedly in these various places. What questions you have after your research can then be answered or clarified quite easily.


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## DoctorRad (Sep 24, 2009)

Thanks guys, the more I learn, the more I realise I have yet to learn. I'm currently veering towards getting myself on a framebuilding course to see if I enjoy the process before I invest in my own equipment.

All the best,

Dr. Matt...


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## unterhausen (Sep 28, 2008)

dbohemian said:


> It does cost some money to build a frame reasonably. Maybe not a lot but probably at a minimum 1k dollars and if that is too much to swallow then honestly, don't even get involved and leave it to a pro. You have to have a minimum level of commitment to learn this craft and do it right.


It's a little troubling how many people seem to want to start framebuilding because they want to save money. To me, even a hobby is worth an investment of $1000 because I know I'm going to spend that much anyway. I hate to think about how much money I have invested in woodworking, just as one example. I started framebuilding when I was a broke high school student. I had the same attitude about tools then as I do now -- buy the best or buy it twice. Back then they had these little O/A setups in the hardware store where you could burn a tablet and get an oxidizer out of it. It was fairly easy to see that the gas costs of that far outweighed the cost of tanks.


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## themanmonkey (Nov 1, 2005)

When I talk to folks who want to build a frame I figure the first frame will cost you at least $2500 and each one after that will be $1000. This of course doesn't count time spent.


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## DoctorRad (Sep 24, 2009)

themanmonkey said:


> When I talk to folks who want to build a frame I figure the first frame will cost you at least $2500 and each one after that will be $1000. This of course doesn't count time spent.


In that context, a course with an expert for £849 = US$1380 (plus materials) seems like a very good deal.


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## GrayJay (May 16, 2011)

Bringing this thread forward couple of years, I see that NOVA is now selling a sloped tube lugset that will take a 36mm headtube (1-1/8" steerer) they have named as slant-6. I assume this is just a ripoff of the Pacenti derived name but not his lugs?

NOVA LUGS SLANT SIX OS ROAD NOVA 36MM HT FOR SLOPED TOPTUBE :: LUGS :: Nova Cycles Supply Inc.

They also have a MTB specific bottom bracket with 10° angle between round 22.2mm chainstay ports, should allow for a bit better tire clearance as compared to using a road shell?

STANDARD MTB BB :: BOTTOM BRACKETS :: Nova Cycles Supply Inc.

Alternately for larger diameter main triangle tubes, ceeway is selling Llewellyn XL compact lugs: 
P3 Top Lug 36x31.7 79°. 
Bottom Lug 36x35mm 60°. 
Seat Lug 31.8x31.8mm 79°. 6° Slope 
https://www.framebuilding.com/NEWPARTSPAGES/NEWIMAGES/XL-Compact-Data-Sheet.jpg

Above could be paired with the ceeway C79 bottom bracket that uses ovalizes chainstays with 14° angle between ports; 
C79 - 34.9x31.8x30/17mm Tubes
63.30x68.30x14° angles.

For even more flexibility with geometry, ceeway also offers a BB that has ports for 30mm/17mm chainstays but allows for the DT and ST to be fillet brazed to the BB.

I am from more of a road and cyclocross bike building background, anyone see a major issues or geometry compromizes with using either the nova or llewellyn lugs/BB for a fully lugged MTB? I would probably be looking at a large size 29'er with moderate (100mm) XC front suspension.


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## G-reg (Jan 12, 2004)

I got some of the llewellyn lugs to work out and I'm as newb as it gets. I didn't use a bb lug though, just too restrictive with too many variables to account for with a MTB.


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