What should I do?
- Thread starter Mastiff Rider64
- Start date
TapioK
Well-Known Member
Doesn’t look like it fits our Dogs. Or I’m wrong again. The one I meant is just 2” stainless rod with male/female thread that screws into top of the fork tube.
roadie1389
Well-Known Member
Stupid phone - They have a 2" as well.
But for $100 or so you can get longer tubes. BUT you need to take them apart. I am just a provider of info I do not condone any type of modification to your bike. You do so at your own risk. Hey HD is being sued for a hot engine......
But for $100 or so you can get longer tubes. BUT you need to take them apart. I am just a provider of info I do not condone any type of modification to your bike. You do so at your own risk. Hey HD is being sued for a hot engine......
TapioK
Well-Known Member
The top doesn’t look like it fits to our the triple tree. Anyways parts can be cheap. A friend with a lathe is cheaperStupid phone - They have a 2" as well.
But for $100 or so you can get longer tubes. BUT you need to take them apart. I am just a provider of info I do not condone any type of modification to your bike. You do so at your own risk. Hey HD is being sued for a hot engine......
K9 would benefit of 2” rise more anyway. The flow of K9 is not perfect. Chopper model flows better. At least to my eye.Made extension is good and easy way to see and try how it would or wouldn’t work...
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Here is 2 pictures of the Mastiff with the 23 inch wheel on it. And just so everyone knows this is the stock wheel design just in a 23 instead of a 21 in. Derrick has this same wheel on his Mastiff.
![20190428_000810[1].jpg](https://www.bigdogbiker.com/data/attachments/61/61160-1e7381254fd843b31326892fbf20947a.jpg "20190428_000810[1].jpg")
![20190428_000738[1].jpg](https://www.bigdogbiker.com/data/attachments/61/61159-c792301a20299c7e9b61cea0959baf6f.jpg "20190428_000738[1].jpg")
Took some more pictures and went to a website that told ke the height difference just in tire size. The 21 inch wheel on my bagger is running a 120-70 the 23 on the mastiff is running a 130-60. The site says theres a 1.53 inch difference in just the height of the tire. And here are some more photos to so the difference in how the bike is. 
TapioK
Well-Known Member
So bigger tire rises the front axle about 0.8” forks are more or less 45 degree angle, that means triple tree rises about 0.5”?
It the shop installed 2” shorter tubes the front should be lower than original. ...Your pic says it 1” higher. Is Mastiff frame supposed to be horizontally even? If yes my logic says someone is bullshitting someone. You sure they didn’t install 2” longer tubes?
Or my thinking has a major flaw somewhere.
It the shop installed 2” shorter tubes the front should be lower than original. ...Your pic says it 1” higher. Is Mastiff frame supposed to be horizontally even? If yes my logic says someone is bullshitting someone. You sure they didn’t install 2” longer tubes?
Or my thinking has a major flaw somewhere.
I'm thinking the shop left original fork tubes on installed the 23 inch wheel with this tire raised the rear shocks to make the bike ride level and gave it back to me even tho they say they compensated for the wheel.
My question is what do I need to do to get the bike back to the original ride heigth. And what is the orginal ride heigth.
mleach72
Well-Known Member
This is gonna be hard to explain, but you actually only lifted the front of your bike 3/4 of an inch. That's why something else is wrong. The shop put longer tubes on or something. The first number is the width of your tire in millimeters. The second number is the profile aspect. It's a percentage of the width. So your original mastiff tire, which is the same tire on my pitbull and your bagger is (120÷25.4)×.7=3.3 inches high. You 23" tire is (130÷25.4)×.6=3.07 inches high. Yes, the 23" tire is 1.5" taller because 3.07+3.07+23=29.14. Your original tire is 3.3+3.3+21=27.6. But you only gained half of this in heighth, because it's from the axle to the ground. You gained 1" from the rim, but lost 1/4" in tire profile.
I understand what your saying there. I know the mastiffs came with +2 inch tubes originally. So you're thinking I now have +4 inch tubes?
You will really need to just take the tubes apart and measure them. Then we should be able to help you with the math. I think what we need to know is what tubes the guy used, he said they were right, but obviously not.
It's overall a pretty easy and not very expensive fix just will take some time. New tubes will only be about $150. Will need new fork seals too as you gotta take the lowers apart to measure the tubes.
If you don't measure the tubes, we will just be guessing what ones to order. And maybe just going back to stock tubes will be your best option because if you go with 2" less tubes it will be even lower than stock height. You can get custom tubes made but obviously would cost a bit more.
You could also fairly easy just cut the tubes you have down with a pipe cutter. That may be a great option at this point. Saves money and then you'll know for future reference.
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TapioK
Well-Known Member
Manual says ground clearance is 4.5” on pic your bike is leaning left, so its hard to say what you have. Not far from that it looks like.
Looking at pic
it does kind of look like there is bit more ground clearance in front...
I wouldn’t do anything to the bike. But take it for a spin and show everyone, “look my new big wheel”. You’ll get used to more like 0.5” difference in 2 miles. I would think. Or start burning money, your pick.
You can always put a 2by4 on floor and rise rear tire 2” look how that looks. I suppose that more or less equals 3.5” shorter front tubes. Or you have 1” whatever use that. Should be pretty close.
I’m too lazy to start playing with geometry... but frame angle is 37 deg, neck is 3 deg.=40 degrees. You’d still need total length from neck to axle to make precise calculations...
Looking at pic
I wouldn’t do anything to the bike. But take it for a spin and show everyone, “look my new big wheel”. You’ll get used to more like 0.5” difference in 2 miles. I would think. Or start burning money, your pick.
You can always put a 2by4 on floor and rise rear tire 2” look how that looks. I suppose that more or less equals 3.5” shorter front tubes. Or you have 1” whatever use that. Should be pretty close.
I’m too lazy to start playing with geometry... but frame angle is 37 deg, neck is 3 deg.=40 degrees. You’d still need total length from neck to axle to make precise calculations...
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Well as you can see in the picture of the kickstand the whole frame is sitting higher. The bagger and Mastiffs kickstand both should be at the same height when the bikes are being stood up but yet you can tell there is a big difference in them. Even if I were to lower just the rear of the mastiff then the bike would seem to be riding up hill.
TapioK
Well-Known Member
There also are different length kickstands.. measure the frame bike standing up. Is it 4.5 at lowest point?
Both have the same kickstand