Converting Spec 25mm to 20mm

I wish someone could make axles. I have a design in mind and it wouldn't be hard to do.

Basically you put a reducer sleeve in the left leg to make the 25mm opening just 20mm. Cut a 1/16th slit down the length so it can compress when you tighten the bolt on the fork leg.

Then the axle is 25mm where it's in the right leg and steps down to 20mm to slide through the wheel and reducer sleeve. I believe you can still use the original threads in the fork leg.

20mm spacers will not work, they are only 20mm Inside diameter, you need 25mm inside diameter.

As for the two piece front axel design, do you really want to go there??

I would say if Kelstr with his handy dandy pocket lathe (that every man should own) would be the one to skunk work a 25mm to 20mm axel contraption.

The axle would be a single piece the FULL width of the hubs and legs so I don't know why you are concerned about a 2 piece design.

The other price is a reducer so it's as much a part of the axle as a wheel bearing is..... It's not part of the axle.

Get it?

tonyxcom said:

The axle would be a single piece the FULL width of the hubs and legs so I don't know why you are concerned about a 2 piece design.

The other price is a reducer so it's as much a part of the axle as a wheel bearing is..... It's not part of the axle.

Get it?

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If you found someone to make the conversion kit, how many prices would you be holding in your hand? My problem with a two piece design is that it will be heavy, there are twice as many points of potential failure, and very expensive to machine.

Think about it: The reducer price would need to have outside threads, and possibly inside threads, you are talking about 2 to three hours of a machinists time to make that one piece, plus initial set up cost, so that one reducer would cost you at least $100. Then your solid piece (heavy) conversion axel is another $100 or so.

Post pictures when you find someone to make this for you and let us know your actual costs.

PB Matrix said:

20mm spacers will not work, they are only 20mm Inside diameter, you need 25mm inside diameter.

As for the two piece front axel design, do you really want to go there??

I would say if Kelstr with his handy dandy pocket lathe (that every man should own) would be the one to skunk work a 25mm to 20mm axel contraption.

Click to expand...

Not sure I understand what you're saying. Forget the 25mm. I want to run a different fork that is 20mm and wanted to know if I can convert my 25mm hub to accomodate the new fork.

the question still remains.................

Yes, you can convert it with 37mm OD x 20 ID bearings. But, the 20mm spacers have to be the correct width once the new bearings are in the old 25mm hub.

So, buy 2 6904-2RS bearings, put them in tight, then put the spacers on both sides of the hub, then put a 20mm axel thru the hub and spacers, make it tight, mark the axel with a pencil where the spacer stops, measure this distance, if it is less than 110mm add 37mm OD 25mm ID shims inside the bearings to get it to 110mm. If the distance is more than 110mm, reduce the width of the spacers. Get it?

PB Matrix said:

Yes, you can convert it with 37mm OD x 20 ID bearings. But, the 20mm spacers have to be the correct width once the new bearings are in the old 25mm hub.

So, buy 2 6904-2RS bearings, put them in tight, then put the spacers on both sides of the hub, then put a 20mm axel thru the hub and spacers, make it tight, mark the axel with a pencil where the spacer stops, measure this distance, if it is less than 110mm add 37mm OD 25mm ID inside the bearings to get it to 110mm. If the distance is more than 110mm, reduce the width of the spacers. Get it?

Click to expand...

Do I get it? Yes I do.

shift96 said:

Do I get it? Yes I do.

Click to expand...

I will say the Roval wheels are set up very nice , they enable a QR , 20 and 25mm axle to be used and they come with all the spacers .

A guy can run whatever fork set up he needs to and the spacers stay sealed right in the hub and do not fall out.

I have made up some axles and spacers for this change over and it is alot of work and exspensive, PB is correct on using the 37x20 mm bearings and making spacers to fit from there , its not to bad doing it this way

Cool thanks. I think it would just be easier to get a hub and relace my wheel. I like building wheels anyway:thumbsup: or look into the Roval wheel.

It's definitely doable. I actually bought a wheel with the 25mm front hub, and the seller shipped it with the stock 25mm end caps and a set of "plug-in" 20mm end caps as well. They fit perfectly, and the hub is spaced perfectly without any extra shims. Problem is, I haven't been able to track down the make. I've tried to find out, because I'd like to find some 15mm conversion caps to run the wheel with a fox 32. I can take some pics if they'd be helpful to figuring this out.