Yamaha forks on a BMW F650GS Dakar

[WayneC1]

Thanks is appreciated, and no I am not in an urgent hurry

[Barnman]

Originally Posted by WayneC1

Can those who have done the conversion measure the distance from the centre of the yoke post to the front edge of the upper yoke ?. I need the measurement to complete a diagram for the ignition switch mount

I know there are variations between some of the yokes which have been used so the more measurements the better to work out the max and min values likely to be encountered

Would greatly appreciate any assistance and measurements posted

Not easy to get a quick and accurate measurement, but it looks about 35mm with a tape measure on mine Wayne.

[Dan Alexander]

Will someone please once and for all make a top clamp that we can buy that works with the Yammy forks and OEM ignition. I've got a set of forks waiting



Plus it has to have the possibility of mounting a damper.

[Aquatic]

Originally Posted by Dan Alexander

Will someone please once and for all make a top clamp that we can buy that works with the Yammy forks and OEM ignition. I've got a set of forks waiting



Plus it has to have the possibility of mounting a damper.

What brand damper? Iow what configuration of mounting
holes?

[BobbySands]

Originally Posted by kubiak

has anyone tried to lower the yamaha forks besides sliding them up in the clamps? i have mine slid up in the clamps but i want another inch lower. i know you can have it profesionally lowered by shortening the parts but is there something i can do at home like cut a little off the spring?

When I went to my local renown suspension shop and described what I was doing. The fellow there had rebuilt forks with heavier springs for BMWs but wasn't sure why. After I explained everything he said, "do you want us to shorten the forks up to improve the geometry of the BMW?" Wow, never heard of that on any forum. I said, 'can we?'

Well, he had to order fork springs at 6.0 for the weight of the bike, my weight and luggage. He said he could order than shortened for a bit more dosh.

So I'll let you know what happens. We're shortening them 2". I had no idea how short to go since no one has ever mentioned this as possibility. It's only a matter of changing the fork springs out or they can even space the shorter spring if I don't like it.

[Kainic]

Originally Posted by Dan Alexander

Will someone please once and for all make a top clamp that we can buy that works with the Yammy forks and OEM ignition. I've got a set of forks waiting



Plus it has to have the possibility of mounting a damper.

House of Horsepower is supposedly working on solution.

[Dan Alexander]

Originally Posted by Aquatic

What brand damper? Iow what configuration of mounting
holes?

I had a Scotts on my Super Enduro and it was good and used ones seem to come up for sale fairly often.

[Dan Alexander]

Originally Posted by Kainic

House of Horsepower is supposedly working on solution.

I've gone to their website before but there wasn't really much info it seemed.

[nomad5326]

Originally Posted by Dan Alexander

Will someone please once and for all make a top clamp that we can buy that works with the Yammy forks and OEM ignition. I've got a set of forks waiting



Plus it has to have the possibility of mounting a damper.

Contact /email Highway DIrt Bikes. They will make one. Just send in your ignition pod so they can cut it. Have them make it two piece (ignition and topclamp). He said no problem and you can mount dampers, etc.

[nomad5326]

Originally Posted by BobbySands

When I went to my local renown suspension shop and described what I was doing. The fellow there had rebuilt forks with heavier springs for BMWs but wasn't sure why. After I explained everything he said, "do you want us to shorten the forks up to improve the geometry of the BMW?" Wow, never heard of that on any forum. I said, 'can we?'

Well, he had to order fork springs at 6.0 for the weight of the bike, my weight and luggage. He said he could order than shortened for a bit more dosh.

So I'll let you know what happens. We're shortening them 2". I had no idea how short to go since no one has ever mentioned this as possibility. It's only a matter of changing the fork springs out or they can even space the shorter spring if I don't like it.

Bobby, you may have missed it. To kep original OEM geometry 1" is all you need to go unless you keep the YAM height and respring/raise your rear 1". Most of us left full YAM height and resprung the rear to get full suspension travel. I still use my OEM Dakar fender and just upped the fluids to 10W

[WayneC1]

Barnman, thanks for the measurement, appreciated, that ABS/Flasher switch mount looks neat on your set up

The spring rate of 6.0 quoted by the suspension guy from the post above suggests he is not thinking of the differences between damper rod forks and cartridge forks, It would be a harsh old ride at that spring rate. A spring rate comparison chart is here http://www.f650gs.crossroadz.com.au/...tVspringKG.pdf

[BobbySands]

Originally Posted by nomad5326

Bobby, you may have missed it. To kep original OEM geometry 1" is all you need to go unless you keep the YAM height and respring/raise your rear 1". Most of us left full YAM height and resprung the rear to get full suspension travel. I still use my OEM Dakar fender and just upped the fluids to 10W

Missed it? I read for hours trying find actual numbers for length and couldn't find much but a lot of anecdotal talk about what seemed to work and not work.

The springs have been ordered and a new Ohlins shock with proper spring rate and valving for weight. I haven't made any adjustments in rear spring height to account for height of the new forks, just proper sag.

If 2" is short I'll have it brought to 1". Not the end of the world. But you can believe I'll have it all together this way and let you know the results. of a Ohlins shock sprung properly and forks shortened 2" sprung properly. If the bike feels divey or twitchy or the geometry is all wonky I'll put the fork back up an inch. My suspension shop is more than willing to tinker about and so am I.

[Kainic]

Originally Posted by Dan Alexander

I've gone to their website before but there wasn't really much info it seemed.

Send them an email or give them a call.

[nomad5326]

Originally Posted by Dan Alexander

I had a Scotts on my Super Enduro and it was good and used ones seem to come up for sale fairly often.

I'd read this first. Not many have had dampers on their bikes (but some have). Bike IMO just doesn't need it OEM or KYB front end if all is right in the front end world.

[Lupin 3rd]

I've been thinking about this swap for a while, I recently found a pair of '01 YZ 250 R forks and axle for a nice price on eBay and decided to start the gathering.

I get a lot of use out of the GS as my commuter and I'd really like to keep the ABS so I'm looking into options to use the stock wheels: except for Hawk engineering what other options are there? I think I did my homework and from what I've found in this thread it seems like people either get the kit or dump the ABS and use a 21" YZ or WR wheel. Just to clarify, I'm not here to put down the work by the guys at Hawk, but I like to experiment and try doing things differently.

Right now my main issue is the bearings: the GS has a 17mm axle and 17x40x12 (6203-2RS) bearings. The YZ has a 20mm axle, and the closest fit I've found to that is 20x42x12 (6004-2RS). Can the GS' wheel hubs be bored out from 40mm to 42mm to accept the larger bearings? Would this be a safety concern (not enough material on the hub leading to cracking)? I looked for 20x40x?? bearings, but they seem to be more rare than hen's teeth...

I found the front caliper and bracket from a WR250X and the disk rotor has the same diameter as the GS so that would be a perfect fit if I could get the wheel on...

Thanks in advance if anyone can help.