## Is this too much clay for a pump track?

Hi Lee,

I purchased your excellent book Welcome to Pump Track Nation v2 (hardcover) because my son and I are building a pump track in our backyard. I was wondering if I could ask you a question. I’ve gotten a dirt sample from a friend who’s got an excavator and can deliver it to me. I did your ball jar dirt test, and while I clearly see the clay (62.5%) it’s above another layer (37.5%), which is undifferentiated. I can’t figure out, by looking at your photo in the book, whether that bottom layer sand or silt. Or could it be both? If you could check out this photo and let me know what you think, I would be super grateful! (I wish I lived in Boulder so I could take one of your lessons – I may head out that way next summer anyways, so I might be able to squeeze one in). Also, I live in VT, is 62.5% clay too much for an environment where it can rain a fair amount?

## Pump track: sandy dirt for a wet climate

Hi Lee,

I’m building a pump track in the PNW where the soil is essentially always wet. What do you think an ideal soil mix would be? Would 60% sand / 40% clay be a good balance? Could I go with even more sand?

Thanks!

Alex

## Formula for sweet drops

Hey Lee,

I enjoy reading through all of your articles on your site, I have a question though that I have yet to find an answer to.

Is there a formula or proper way to figure how many feet away “y” the landing should be from the end of a man made drop that is “x” feet tall? I know that it has many factors such as speed, form, huckability, etc but I was just looking for a general rule of thumb on if it’s best to be 1:2 ratio, or what.  (1’ height drop, landing 2’ from lip)

Thanks!

Jordon Mallett

## Making tools to make rollers and berms sweet

Our friend Liam made some cool tools to help him make his pump track parfect.

Check ’em out …

## Pump tracks: simple is good

Hi Lee

I thought I would get in touch and I hope you are doing ok in these difficult times.

I have been dreaming of a backyard pumptrack for a few years and with the coronavirus lockdown here in the UK I am trying to find the silver lining and so am planning a build!

I bought your great book Welcome to Pump Track Nation v2 and have taken to design package inkscape to try to plan out a track. I have a long but relatively narrow space which is on flat land and currently simple turf. I plan to bring in a mini digger but don’t have access to bring dirt in easily so will dig down to get the dirt and then put in drainage from the low points.

The design is attached and includes a simple oval with an s-bend berm in the middle and a mixture of simple rollers and a couple of bigger ones to try to give the chance for jumps – including in and out of the s-berm. The track will be used by myself (38 and a bmx/mtb rider since a teenager) and my two kids (11 and 5 yr olds).

It would be amazing to get any thoughts you have.

Thanks
Joel

## Designing a jump for a Slip ‘N SLide

Hey Lee,

I am thinking about building one of those giant slip n slides that uses a bungee cord to get people up to speed and sends them off a ramp at the end. I was thinking about doing a ramp somewhere between 45 and 60 degrees because I feel like going for more height than distance would be fun but I also don’t want to lose too much distance. Just wanted your opinion on that. Also I don’t have a clue how to do the curve of the ramp so any advice on that would help. At the moment I don’t know how fast we would be hitting the ramp because I can’t find a big enough bungee cord with a spring constant to do some calculations.

Nolan

## Roller spacing for a kids’ pump track

Hi Lee,

I bought the v2 of the pump track nation book. Gotta say super well written. I’m planning on building one in the back yard to keep my kids busy. They are 3 1/2 (good at strider) and almost 6 (he’s got a nice 20” bike and can ride mellow mtb trails)

My space in the yard is 35 feet wide and 32 feet deep but the SW corner has a shed so need to keep entrance clear so will likely do a trapezoid shape. That includes room for the back of berms.

My main question has to do with the 10 foot peak to peak number you mention as ideal for rollers. How tight can I make rollers. I assume since the kids are on small bikes they can handle tighter spacing. What’s a smaller spacing that would still be manageable for me. I’m advanced rider on a dj bike. I can pump my way around a pump track without pedaling but by no means an expert. Though I’d like to practice now that I have time. We are working from home for the next foreseeable future and we have the kids home too. All schools and daycares are shut down here for the next 2 months at least. Our local pump track will also be shut down for the foreseeable future.

Thanks
Bogdan

## Pump tracks: Different radii in the interchanges?

Hi Lee,

I’ve found your “Welcome to Pump Track Nation v2” e-book to be a great resource. The pictures and steps regarding interchanges listed on page 49-50 have been helpful but I am not fully confident with the exact design of my interchanges. My main question is, is it okay that the interchange berm has a different radius than the adjacent berm? I have drawn out a plan that I hope will work well. Is there anything that stands out that needs changing?

Thank you,
Dan

## Roller height on the PumpTopia pump track?

Hey Lee,

Just purchased the Pumptopia Track Plan and was reviewing some of the sheets while comparing some things in your ebook “Welcome to Pump Track Nation v2” and had a few questions.

In the ebook it mentions 12″ high rollers with 10′ from peak to peak for the rollers.  However, in the plans it shows 18″ for what looks like 10′ peak to peak on rollers?  Is there a reason for this?  Will it be faster or slower?

Sean

## Here’s a sweet Sweet Little Track pump track

Hi Lee,

Just wanted to circle back with you (finally) as we built the Sweet Little Track back in late June. It turned out great and your plans and overall instructions were very helpful to this end. It’s a blast to ride and as you note it really freaks you out when you first experience the speed of pumping! Such a workout too, reminds me so much of steep fall line skiing.

Here are some pics after we first built it. Since then we have seeded the backside of the berms with grass for erosion protection.

There’s a few flat spots between the interior berms. OK for now as keeps the speed in check. The gap between the 110 berms is our entry point. Might do a bit of shaping with the rollers here a some point but fine for now. I ride it with a 20″ BMX bike and its great!

Hope you have a great Christmas season with your family and all best in the New Year!

Dean

## Berms in a very narrow pump track

Hey Lee,

First off id like to say i love your building style and your website.Recently i have been reading up on pump tracks when i came across your website which i might add is amazing.Whilst reading i noticed that you said a backyard pumptrack could be as small as 20 x40.Ive been wanting to build one for the longest time yet only have about 15 feet x 42ish feet.Do you think this could work and be fun?Also what kind of roller spacing and berm radius do you use?

Many thanks
Fraser