How to fit a rear rack on a full suspension bike?

[Andrieprima]

I've got a dropper post on my full suspension bike. Is it crazy to think about attaching a seat post rack to it? I wouldn't attach it to the moving part - see this mock-up below:

View attachment 43426


I won't be carrying a lot of weight - probably just a tube, tire irons, patch kit, & something to eat. I'm worried that putting too much compression on the fixed part of the dropper post will interfere with the dropper action.

Thoughts?

why not. Those bike repair stand clamp on exactly what you used. And they can support 50 lbs ebike even sideways or turned. That being said, if you just need space for tube, something to eat, why Not just get cyckit? Much more compact and lighter.

 

[BillH]

So Old Man Mountain got back to me with a fix for the rear rack for BH bikes. The rear thread for BH bikes is 1.0 and the standard rear bike thread is 1.75. This is why their axles won't work with BH bikes.

They suggested to buy the Salsa Split Pivot Service Kit:

Split Pivot Service Kit | Salsa Cycles

salsacycles.com

And swap out the axle stud, driveside, on the BH bike with the one in the kit. The axle stud in the Salsa kit is 1.75 thread, which works with their fit kits.

Unfortunately, you have to buy the whole Salsa kit just to get that one axle stud part, but I don't care about that (their racks are worth every penny).

Also, they said that the length of the Salsa axle stud is 19.5mm, whereas the BH one is 19mm, so some very gentle angle grinding is needed to be taken to the axle stud to get it to fit in the BH bike.

Apparently a customer has done this successfully on his BH bike, and the OMM rear rack works fine on his BH (maybe that person is on this forum??)

Here is a schematic of the part in question, the part is #9 on page 3:

https://salsacycles.com/files/tech/7783_SAL_SP_Service_Kit_INST_V5.pdf

What do you guys think of this? I don't have any mechanic skills, but I do think they make a great rack and would love to have their rear rack. There is really no other rack even remotely like it on the market.

Does this sound easy/doable? Thoughts? I would probably have to find a bike shop willing to help. Don't want to settle for the Topeak Tetra Rack, when OMM is superior.

@FlatSix911 @BillH @Ravi Kempaiah @Mike TowpathTraveler

To be honest I was just hoping they would have machined a thru axle with a 1.0 thread pitch that would work on our bikes without us having to deal with swapping out the axle stud.

 

[bikeman242]

How does one swap out an axle stud? Is this a simple thing to do?

I'm not really sure what an axle stud is.

 

[Mike TowpathTraveler]

How does one swap out an axle stud? Is this a simple thing to do?

I'm not really sure what an axle stud is.

Bill, as 911FlatSix noted above, you've done a great job staying up on this, which is to the benefit of all BH Emotion owners. Well done!

My Haibike frame does not have this axle stud as your BH does. Haibike has their thru axle go directly through the rear drop out, which is drilled and threaded to that 1.75mm pitch. The derailleur is mounted on another drilled and threaded boss that was cast on the rear of that triangle; altogether a completely different mounting set up for the thru-axle and derailleur. I like your BH design better, for if a problem arises in a problem with the thru axle or derailleur hanger threads, the repair will be a Heli-Coil type set up (I believe), whereas your design is just remove and replace with new.

That axle stud you ask of has to have it's inside diameter cut and threaded for the 1.75mm pitch thread of the OMM thru axle.

The only true way to know what you have to have done, is to have these parts in hand to see what work needs to be done. I'd like to know the outside diameter of the BH thru-axle and compare that with the OMM thru axle which replaces it. Same diameter? It seems to me that if their OD's are the same, then the non-drive axle stud on your BH stays. If larger, then it seems to me that Item 10 of that kit, the non-drive axle stud will need replacing as well.

It all depends if these 2 thru axles are the same OD or they are differently sized.

I'd talk to your local bike shops to get a feel for which one would seem the most comfortable in doing this installation job for you of the axle stud(s). It's just replacing parts in kind with the other and taking 5mm off the one axle stud, something they can do with their tools on hand with no issue.


When this thing is all said and done, do a good write up with plenty of pictures detailing what needs to be done to get an OMM rack installed. I'd imagine the OMM folks would like to have that write up, as well.


Not to confuse the issue, but add some food for thought, this is what my Haibike rear cast drop out looks as I was installing my OMM thru axle. On this bike, the rear drop out casting is drilled and threaded for the 1.75mm thread pitch, versus a replaceable axle stud that is held in place with a locknut on your BH application.

 

[FlatSix911]

How does one swap out an axle stud? Is this a simple thing to do?

I'm not really sure what an axle stud is.

The axle stud will adapt your frame to the new thru-axle... it is a quick and easy job for your LBS.

 

[bikeman242]

The axle stud will adapt your frame to the new thru-axle... it is a quick and easy job for your LBS.

View attachment 55883

I tried googling the job of replacing the axle stud on a bike, but came up empty handed.

How big of a job is it to replace the axle stud so the OMM rack would work with our BH Split-Pivot bikes?

Does replacing the axle stud require drilling or any permanent modifications to the bike, or anything else that may damage the frame?

Say I wanted to go back to the old axle for whatever reason, is it possible and simple for the bike shop to put the old axle stud and thru axle back in?

 

[FlatSix911]

I tried googling the job of replacing the axle stud on a bike, but came up empty handed.

How big of a job is it to replace the axle stud so the OMM rack would work with our BH Split-Pivot bikes?

Does replacing the axle stud require drilling or any permanent modifications to the bike, or anything else that may damage the frame?

Say I wanted to go back to the old axle for whatever reason, is it possible and simple for the bike shop to put the old axle stud and thru-axle back in?

No worries... here is the schematic diagram that will show what needs to be done to convert to a new axle thread size.
Take your time... it's very straightforward.

1. You will just be replacing parts 3, 9, 10, and 11 on rear swing arms of the suspension.
2. First remove the rear wheel and the old Axle nut(11), Axle stud(10), and Bearing(3).
3. Next insert the new Axle stud(10) through the frame and Bearing(3).
4. Then tighten the new Axle nut(11) and make sure the rear suspension moves freely.
5. Repeat the process for the other side of the bike frame and insert the rear wheel.
6. Finally, insert the new Thru-axle from the Salsa kit with 1.75 thread.
7. Congratulations you are now done... pour yourself a cold beverage!

 

[bikeman242]

I have yet to move forward on the rear OMM rack on the BH Rebel Lynx, but OMM said that two people have done this fix with the Salsa axle stud and said it works fine.

Are either of these two people on this message board, perhaps? Would like to hear how it works for you.

 

[FlatSix911]

I also have a BH Rebel Lynx and would be interested in seeing the final product... mounted rack with OMM axles and Salsa studs.

You may want to post in the BH forum.

 

[Stefan Mikes]

Topeak Tetra Rack M2. Works with any full suspension/dropper post e-MTB up to 2.8" tyres.

 

[FlatSix911]

View attachment 58870
Topeak Tetra Rack M2. Works with any full suspension/dropper post e-MTB up to 2.8" tyres.

This is a great solution if you don't require a heavy load rating for bike-packing, etc.

 

[bikeman242]

This is a great solution if you don't require a heavy load rating for bike-packing, etc.

I had one of these and returned it. It seemed to be good enough, but does not compare to old man mountain racks. Just some velcro holding it together. The bolts are hard to get at without a ratcheting tool, and seem like they will strip easily.

 

[Leon S. Kennedy]

Also from Arkel

 

[FlatSix911]

Also from Arkel

Interesting design... looks very sturdy, but not sure that it would work with a dropper post.