Jamis Hudson bolt sizes for rack mounting?

General Discussion about electric bicycles.
Post Reply
MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Dec 23 2019 2:39am

The Hudson is sort of a pedal forward, foot touch when you stop bike. To me it appears to be between a Townie and a conventional bike design.

I bought a used Hudson and am now trying to mount a rack for the battery. M5 .8 bolts don't seem to work, M4 is too small. Anybody know what bolt size the Hudson is drilled and tapped for?

Thanks

User avatar
MadRhino   100 GW

100 GW
Posts: 6115
Joined: Sep 03 2010 5:28pm
Location: Montreal QC Canada

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MadRhino » Dec 23 2019 3:46am

Maybe it is not metric. ?
Make it fool-proof, and I will make a better fool.
Current bikes
Street: https://s20.postimg.org/ewrvugywt/Session_04_2015.jpg
Dirt: https://s20.postimg.org/lbqwr55ml/IMG_0157.jpg

MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Dec 25 2019 1:33am

Might not be metric, but a M5-0.8 did fit into the front fork dropout, though with some difficulty.

I'll call a Jamis dealer in a few days.

User avatar
E-HP   100 kW

100 kW
Posts: 1172
Joined: Nov 01 2018 9:20pm

Re: Jamis Hudson bolt sizes for rack mounting?

Post by E-HP » Dec 25 2019 12:55pm

MikeSSS wrote:
Dec 23 2019 2:39am
The Hudson is sort of a pedal forward, foot touch when you stop bike. To me it appears to be between a Townie and a conventional bike design.

I bought a used Hudson and am now trying to mount a rack for the battery. M5 .8 bolts don't seem to work, M4 is too small. Anybody know what bolt size the Hudson is drilled and tapped for?

Thanks
An M5 tap is $4 at the hardware store, in case you want to convert it to a known size, or if the threads weren't cut very well in the first place.

MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Dec 26 2019 8:02pm

It might be thick paint in the threads, a tap would fix that.

If I knew it was M5-0.8 I'd run a tap through it. Pretty sure I have that tap size.

Anyway, I was trying to install a rack for the battery bag, but have used a seat tube clamp rack for now. A regular rack provides a place for the controller but such place is not there for the seat tube rack I'm using.

Seems like "it's always something".

MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Dec 28 2019 1:44am

The rear dropout has two screw holes, a top one and a lower rear one. The lower rear hole is M5-0.8, the top hole isn't, it's smaller diameter or so it seems. Perhaps that top hole is a #10 fine or course pitch.

The adventure continues.

MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Jan 07 2020 2:49am

Bought bolts and did trial and error, found the answer.

Lower and more rearward holes are M5x.8 pitch. The upper and more forward holes are 10x32.

10x32 screws will fit in the M5x.8 holes but are loose. M5x.8 screws are a bit too large diameter to fit in the 10x32 holes.

User avatar
amberwolf   100 GW

100 GW
Posts: 28940
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: Jamis Hudson bolt sizes for rack mounting?

Post by amberwolf » Jan 08 2020 12:33am

that just seems wierd.

i wonder if they intended the holes for different types or brands of accessories, whcich each commonly use different bolt sizes?

User avatar
E-HP   100 kW

100 kW
Posts: 1172
Joined: Nov 01 2018 9:20pm

Re: Jamis Hudson bolt sizes for rack mounting?

Post by E-HP » Jan 08 2020 1:06am

The holes are just messed up. Tap everything to M5 and make your life easier. I've had a couple of Jamis bikes and all the nut and bolts are metric. Extremely unlikely that they'd use US machine screw sizes on it; but pretty likely they screwed up the manufacturing by not changing their tooling when required.

MikeSSS   100 W

100 W
Posts: 180
Joined: Jul 31 2016 10:52pm
Location: San Antonio, TX

Re: Jamis Hudson bolt sizes for rack mounting?

Post by MikeSSS » Jan 16 2020 10:09am

Removed the temporary seatpost mounted rack and installed a dropout mounted rack. I used the M5x.8 holes in the rear dropouts.

Now there is room for a Thudbuster Long Travel seatpost. That's why I wanted to not use the seatpost mounted rack.

Thanks for the help.

Mike S

User avatar
E-HP   100 kW

100 kW
Posts: 1172
Joined: Nov 01 2018 9:20pm

Re: Jamis Hudson bolt sizes for rack mounting?

Post by E-HP » Jan 16 2020 12:03pm

MikeSSS wrote:
Now there is room for a Thudbuster Long Travel seatpost. That's why I wanted to not use the seatpost mounted rack.
A worthy cause!!


Sent from my iPhone using Tapatalk

markz   100 GW

100 GW
Posts: 8469
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Jamis Hudson bolt sizes for rack mounting?

Post by markz » Jan 17 2020 6:47pm

Very odd

Made in China
Slave worker "we are all out of this size"
supervisor "just get whatever size and get the bso outta here"

Post Reply