# New project: Laminated wood mountain bike



## wardo78 (Apr 22, 2005)

After successfully building and riding my wooden gravel bike earlier this year (http://forums.mtbr.com/gravel-bikes/wooden-gravel-frame-1066231.html ), I decided to take on a wooden mountain bike frame. It will be a modern geometry (slack, long top tube) 27.5+ frame. It is formed by laminating 12-5mm lamello's, 6 per half. Subsequently, the frame tubes are formed by routing out the inside and rounding over/sculpting the exterior. Given the intended use, the frame is significantly reinforced with carbon/Kevlar hybrid cloth between the laminates and the inside of the frame tubes are lined with two layers of carbon fiber cloth. I expect the frame to weigh in around 6.5 pounds, not light, but I know from my gravel bike that it will ride lighter than the numbers indicate, with a nice balance of compliance and rigidity. The wood is walnut on the outside, one layer of cherry, then ash. Thanks to Vermont Plank Flooring for hooking me up!

Thanks,
Wardo


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## Drew Diller (Jan 4, 2010)

Oooo subscribed.

If you build your own stuff you know that the frame doesn't even need to be light, it's the light components that make more of a riding difference.


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## wardo78 (Apr 22, 2005)

Drew Diller said:


> Oooo subscribed.
> 
> If you build your own stuff you know that the frame doesn't even need to be light, it's the light components that make more of a riding difference.


That is true. My gravel frame is just around 6 pounds, and the total bike weighs 21. It is a dream to ride, and is literally my favorite gravel/road bike of all time. I suspect this will be much the same.

Wardo


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## armyofevilrobots (Oct 4, 2013)

Nice! Is that purpleheart? I love the stuff, but it's both gummy and abrasive on the CNC tooling.


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## wardo78 (Apr 22, 2005)

armyofevilrobots said:


> Nice! Is that purpleheart? I love the stuff, but it's both gummy and abrasive on the CNC tooling.


Walnut, which has ideal properties for a bicycle frame. It has a good weight to torsional rigidity ratio. Purpleheart actually looks pretty good in this regard as well, but I don't like working with it as well. I prefer local hardwoods although I do have a thing for Sapele. Here is an excellent website that discusses some of the engineering concerning using wood in bicycle frame construction: https://ligneusbikes.wordpress.com/why-wood/lets-talk-numbers/.

Wardo


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## J.B. Weld (Aug 13, 2012)

It doesn't seem very practical. Other materials seem better suited for the job. I love it!


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## golden boy (Oct 29, 2008)

Thanks for posting, keep us updated on your progress. I'm intrigued by wood bicycle frames. I'd love to ride one, I bet you can really feel the difference vs. metal.


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## scatterbrained (Mar 11, 2008)

Ooooooh. This is going to be good.


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## life behind bars (May 24, 2014)

This gives me wood. Pun intended.


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## armyofevilrobots (Oct 4, 2013)

Cool. Walnut is pretty sturdy as well.

As an aside, when I built my hickory and purpleheart handlebars, I stumbled upon this paper from the US forestry service:
https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf

It has some neat mechanical properties of a _vast_ number of different species of wood.


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## Drew Diller (Jan 4, 2010)

armyofevilrobots said:


> when I built my hickory and purpleheart *handlebars*


Your *what* now?! Post pictures!


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## Eric Malcolm (Dec 18, 2011)

Drew Diller said:


> Your *what* now?! Post pictures!


Oh Boy, did someone mention Handlbars........


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## armyofevilrobots (Oct 4, 2013)

*Handlebars.*









The two compound bends were a PITA.

IIRC; it's 820mm wide, 3 deg backsweep and upsweep.

380G or so.


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## Drew Diller (Jan 4, 2010)

Man that is friggin sweet. Great job.


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## wardo78 (Apr 22, 2005)

armyofevilrobots said:


> View attachment 1210985
> 
> 
> The two compound bends were a PITA.
> ...


Nice! I thought of making bars, but haven't gotten around to it.

Ward


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## armyofevilrobots (Oct 4, 2013)

wardo78 said:


> Nice! I thought of making bars, but haven't gotten around to it.
> 
> Ward


That's funny. I've been meaning to make a wooden bike, but... well... you can guess


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## slowrider (May 15, 2004)

That bar is solid wood? I've seen catastrophic carbon bar failures, how do you re-enforce single tube, wooden bar to take such stresses?
Looks amazing but I'd be scared to ride it.


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## wardo78 (Apr 22, 2005)

slowrider said:


> That bar is solid wood? I've seen catastrophic carbon bar failures, how do you re-enforce single tube, wooden bar to take such stresses?
> Looks amazing but I'd be scared to ride it.


Although I can't speak specifically to evil robots bars, I can tell they are solid bar formed from laminates. They are likely steamed then put on a bending form. Once they have cooled, the laminates are put back on the form with adhesive, I am guessing epoxy. The process creates a very strong structure, there is tension between the laminates that adds rigidity, and by having different layers, you reduce the chance that it will fail along a grain line since each laminates grain pattern if different.

Wardo


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## armyofevilrobots (Oct 4, 2013)

Wardo78 nailed it. There are 70 pieces of wood in that lam-up, although, while solid, the thicker area contains a section of cedar at the center which is much lighter than the hickory and purpleheart.

Oddly, this is the third bar I created, and the glue used here is actually weld bond III between the laminates (although it has a coating of system III epoxy on the exterior). In testing, the weld-bond was actually stronger. In any case, the bond always failed in the wood instead of in the glue itself. I suspect the weld bond penetrates the wood better than the epoxy, and reinforces the bond boundary.

Also, this bar flexes FAR less than my ~250 gram Chromag OSX downhill bar. The first two were tested to failure, and the second failure test was weighted on one side with a very significant drop that actually bent the stem it was clamped in. While the test wasn't up to normal safety testing rigor, I am not concerned about getting injured using it as an XC/cruiser bar.


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## wardo78 (Apr 22, 2005)

armyofevilrobots said:


> Wardo78 nailed it. There are 70 pieces of wood in that lam-up, although, while solid, the thicker area contains a section of cedar at the center which is much lighter than the hickory and purpleheart.
> 
> Oddly, this is the third bar I created, and the glue used here is actually weld bond III between the laminates (although it has a coating of system III epoxy on the exterior). In testing, the weld-bond was actually stronger. In any case, the bond always failed in the wood instead of in the glue itself. I suspect the weld bond penetrates the wood better than the epoxy, and reinforces the bond boundary.
> 
> Also, this bar flexes FAR less than my ~250 gram Chromag OSX downhill bar. The first two were tested to failure, and the second failure test was weighted on one side with a very significant drop that actually bent the stem it was clamped in. While the test wasn't up to normal safety testing rigor, I am not concerned about getting injured using it as an XC/cruiser bar.


70 lams is considerable! I am interested by your glue results. I use epoxy not because I have tested it, but because it is what boat builders use and over the years I have learned to work with it. I use Weld Bond III for most of my normal projects, so I am glad to hear it performs so well!

Ward


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## phattruth (Apr 22, 2012)

This is a great thread, I love wood bikes. I remember seeing a Renovo road bike a number of years ago and thinking I need to make one. The tubes were massive. I've been working on my design for a while now. Many years of research and several design iterations have lead to this. I'm currently working on perfecting the tool paths for my CNC router. This version doesn't show all of the fillets that will be on the final product as they not going to be included in the tool paths.


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## wardo78 (Apr 22, 2005)

phattruth said:


> This is a great thread, I love wood bikes. I remember seeing a Renovo road bike a number of years ago and thinking I need to make one. The tubes were massive. I've been working on my design for a while now. Many years of research and several design iterations have lead to this. I'm currently working on perfecting the tool paths for my CNC router. This version doesn't show all of the fillets that will be on the final product as they not going to be included in the tool paths.
> 
> View attachment 1213700


I elected to take the opposite tack. I researched for a week, designed for a day and was riding my gravel bike 4 weeks later. I am not fluent in CAD, nor CNC, plus having spent years developing my pattern and jig making skills, these make sense for one off, or very limited production projects. If I were making a significant number of frames CNC would totally be my choice. How are you planning to bend the stays? Are you going to laminate the rest of the frame? What woods are you considering? I had to take a significant break from my project because I had an allergic reaction to the walnut sawdust, but I should have the frame ready for sanding by the end of this weekend.

Wardo


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## wardo78 (Apr 22, 2005)

After the extended hiatus due to my walnut sawdust allergic reaction, I am back at it. At this point, the frame is basically structurally complete, so final sanding and then finish application are next. With any luck it should be ready to be built up in a week. Here are pics as of today:

























Wardo


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## phattruth (Apr 22, 2012)

wardo78 said:


> I elected to take the opposite tack. I researched for a week, designed for a day and was riding my gravel bike 4 weeks later. I am not fluent in CAD, nor CNC, plus having spent years developing my pattern and jig making skills, these make sense for one off, or very limited production projects. If I were making a significant number of frames CNC would totally be my choice. How are you planning to bend the stays? Are you going to laminate the rest of the frame? What woods are you considering? I had to take a significant break from my project because I had an allergic reaction to the walnut sawdust, but I should have the frame ready for sanding by the end of this weekend.
> 
> Wardo


My plan is to laminate both stays. The seat stays and top tube are one piece. I'm going to make a handful of these and I'm looking to make them from oak, maple, ash and hickory. The plan is to make the first one out of doug fir with really thick walls as I can work out the bugs easier in a softwood. I will be machining all weekend to complete the first one.


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## phattruth (Apr 22, 2012)

wardo78 said:


> After the extended hiatus due to my walnut sawdust allergic reaction, I am back at it. At this point, the frame is basically structurally complete, so final sanding and then finish application are next. With any luck it should be ready to be built up in a week. Here are pics as of today:
> 
> View attachment 1214507
> 
> ...


Really nice work!


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## wardo78 (Apr 22, 2005)

phattruth said:


> My plan is to laminate both stays. The seat stays and top tube are one piece. I'm going to make a handful of these and I'm looking to make them from oak, maple, ash and hickory. The plan is to make the first one out of doug fir with really thick walls as I can work out the bugs easier in a softwood. I will be machining all weekend to complete the first one.


I look forward to seeing the results!

Wardo


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## wardo78 (Apr 22, 2005)

Although there are a few things that need to be resolved, it looks complete and I was able to ride it around a bit. I will wait to get some miles on it before I try to determine if it is a success or not. First impressions are that it rides like a mountain bike should, that the stand over is a bit high for my stature, but I knew that was going to be tough. I wanted to use a longish head tube to reduce the likelihood of structural failure, and that pushed the top tube up a bit. It weighs more than I anticipated (7+ lbs for the frame), but again I was structurally conservative... although it is only as strong as it's weakest bit, so it may be overbuilt in the wrong areas. I'll report back when it has a few real rides on it. Here are some pics:

























wardo


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## wardo78 (Apr 22, 2005)

phattruth said:


> My plan is to laminate both stays. The seat stays and top tube are one piece. I'm going to make a handful of these and I'm looking to make them from oak, maple, ash and hickory. The plan is to make the first one out of doug fir with really thick walls as I can work out the bugs easier in a softwood. I will be machining all weekend to complete the first one.


Did you make headway on the project?

Wardo


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## golden boy (Oct 29, 2008)

Congratulations, Wardo! Time will tell if the ride is to your liking, but it is certainly an aesthetic triumph! Love it!


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## sturge (Feb 22, 2009)

That is beautiful! Truely a work of art. Good luck with it.


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## Drew Diller (Jan 4, 2010)

Dang! Well done.


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## scatterbrained (Mar 11, 2008)

Personally, I wouldn't ride that. I'd hang it on my wall! That is gorgeous.


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## wardo78 (Apr 22, 2005)

scatterbrained said:


> Personally, I wouldn't ride that. I'd hang it on my wall! That is gorgeous.


Thanks, I built it to ride and that I will!

Ward


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## wardo78 (Apr 22, 2005)

Today, I took the new whip on a two hour ride on a trail system I know well and has an eclectic array of climbs, descents and technical features. I was delighted to be riding a mountain bike frame that I built from scratch, so that put a little spunk in my spin and of course my perspective is biased. At 28.5 pounds, it is the heaviest hard tail I have owned in a long time, but I had already adjusted my expectations from my usual racier hard tail to trail oriented one, and judged by the latter criteria it fit the bill perfectly. The wood frame is quite stiff laterally, but dampens some of the smaller chop. It climbed in and out of the saddle well and the rear wheel hooked up on the slippery bits. Interestingly, the head angle looks a bit steeper from the saddle than the 27.5+ bike it replaces. I am not sure why this is, the wheelbase, angles etc match the previous frame as was my intention. Maybe the rockers in the rear raise it up a tad (although I believe I accounted for this), or maybe it is just a visual illusion due to the taller head tube and thicker frame overall. It really doesn't matter as the real test is how it rode, and here I was very satisfied. It tracked sweepers well, flicked in the tight stuff and didn't feel pitchy on the drops. The headset loosened up a bit (probably the lower cup settling in a bit) so there was a tiny clunk on descents that had my stopping to do a safety inspection. A good start for the two of us, the pic is the bike meeting some of it's cousins.

Wardo


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## wardo78 (Apr 22, 2005)

I dragged the fleet of wooden bikes out for a family portrait as well. The balance bike is for my grandson, but it is his Christmas present so it is living with us until then.

Wardo


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## Cornfield (Apr 15, 2012)

Beautiful bike(s), Wardo!

I do a bit of woodworking myself, but that's on another level!


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## wardo78 (Apr 22, 2005)

Cornfield said:


> Beautiful bike(s), Wardo!
> 
> I do a bit of woodworking myself, but that's on another level!


Building a wooden frame isn't that difficult if you have the right tools and the time. Mostly it takes the Chutzpah to just start!

Wardo


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## kyle_vk (Jul 25, 2011)

Do you have any process photos of the balance bike? I've got a 3 month old at home and work at a millwork shop, so I've got enough time to mess a few try's up before he's old enough to ride one


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## wardo78 (Apr 22, 2005)

kyle_vk said:


> Do you have any process photos of the balance bike? I've got a 3 month old at home and work at a millwork shop, so I've got enough time to mess a few try's up before he's old enough to ride one


Sorry, I didn't take any pictures of the process. I basically took the dimensions off an existing bike, drew up some plans, made a form the matched the plans, cut the laminates and glued them up. The "chain" stays were done seperately and glued on after the main spar was drilled for the seat post and headset. It is really pretty easy if you are handy... it took me a few days of part time fiddling.

Wardo


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## wardo78 (Apr 22, 2005)

A couple of better pictures:

























Wardo


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## kyle_vk (Jul 25, 2011)

Thanks, i appreciate it! Looking forward to your next project!


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## wardo78 (Apr 22, 2005)

I realized I really hadn't done an update on this frame in a LONG time. Last Autumn, I took a 10 week hiatus from work and headed to the Southwest. I rode Fruita, Moab, St. George, Sedona, and Taos. I also have a Cannondale Habit 1, so the riding got split up a bit, but the wooden frame now has many hundreds of miles on it. Ordinarily, if I am riding by myself, I chose to ride wood. It is a more enjoyable ride, the feel is unique and this frame fits me like a glove. Numerous people have ridden it and returned to say that it felt to have the best balance between rigidity and compliance of any hardtail they have ridden. The frame has held up beautifully despite numerous biggish drops, little jumps and the usual XC abuse. It had one very significant crash here in Vermont. I was running my w-i-d-e Western bars and caught the bar end on a sapling while descending briskly. The frame landed 15' from where it started and was last seen before impact flying at 5' off the deck. Both of us were crazy lucky and walked away unscathed. The right chain stay has a significant ching from a Sedona rock, but you just sand it out and put new finish on and you are good to go. If it weighed in at 24 pounds (4.5 lbs less than actual), it would be the best hardtail I ever have ridden. As it is, it is the funnest and since I ride 90% of the time solo, that's all that counts. Feel free to ask any follow up questions.

Wardo


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## nemesis256 (Aug 16, 2014)

Great update, very jealous of your workmanship.

How did you get the headset cups and BB in the frame? Are they pushed into the wood? Similar question with the seat post, is the internal diameter just right so it slides in?


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## wardo78 (Apr 22, 2005)

nemesis256 said:


> Great update, very jealous of your workmanship.
> 
> How did you get the headset cups and BB in the frame? Are they pushed into the wood? Similar question with the seat post, is the internal diameter just right so it slides in?


Those are key questions, as is the BB issue. For the seat, I bought a light piece of frame tubing, routed it's OD in the frame and glued it in. For the HT, I bought a 44mm ID tube and routed a channel equal to its OD, plus a tiny bit for some CF cloth. The BB is a Paragon T47 steel shell with a 2" OD. I used an 84mm width to give myself a little more glue surface on the chainstays. When building, once the halves are glued up, I used a 2" forstner bit to drill each side separately for the BB shell. Then the shell was inserted for indexing after that. I did glue the races directly into my gravel frame, and have had no issues after 2 years, but was concerned about the forces on this frame would cause the HT tube to fail, so went with the heavier, but stronger route.

Thanks,
Wardo


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