PDA

View Full Version : Need to lower a K75 for the Mrs.



90288
05-02-2004, 01:37 AM
We just picked up a K75 for Mrs. gsmetal and we need to bring it down about 1 inch or more if possible so she can get both feet down and balance the bike.

I've been to the IBMWR web site and read the (short) suggested mods.

Has anyone out there actually done the mods :dunno

Any suggestions on what to do from those who have already done it would be helpful.

deilenberger
05-02-2004, 04:16 AM
Originally posted by gsmetal
We just picked up a K75 for Mrs. gsmetal and we need to bring it down about 1 inch or more if possible so she can get both feet down and balance the bike.

I've been to the IBMWR web site and read the (short) suggested mods.

Has anyone out there actually done the mods :dunno

Yup. More than once - my legs haven't gotten any longer



Any suggestions on what to do from those who have already done it would be helpful.

Well... if you read the IBMWR tech pages - some of those I think I wrote.

What to do?

Lower profile tires (80 series instead of 90.. Bridgestone BT45's come in the right size) - gain of 1/2"

Short shock (Progressive, Works and Wilbers - in order of increasing quality) - gain of 3/4" or so.

Match front to rear (shorten spacer in forks, or move forks up in the triple clamp if possible) - gain of 1/2=1"

Narrower seat. You won't find ones that are rideable that are much lower unless you go with the low-seat kit. But width makes a big difference - your legs get longer as they are more vertical and at less of an angle to the bike.

Tall boots - pay attention to the thickness of the soles of the boots.. short (ummm... normal height) people need thicker soles. This sometimes excludes purpose built MC boots - I use Wolverine boots in a workman style. Expensive, but fit great, thick sole and they're waterproof (and made in the USA). There are lots of styles - look in a place that sells working clothes (or Sears, JC Penny).

That's about it. No magic to it. Lower the bike and make her legs longer. Combine the suggestions above to figure out what you want to do.

Oh - getting both feet flat is VASTLY over-rated. I've never managed it on a BMW, but being able to touch with both feet, even it it's just the toes/ball-of-the-foot IS a good thing. She will learn to watch where she stops the bike.

And a caviat - once it is lower - it WILL sit more upright on the sidestand, so you have to watch where you park it.. and it will be very difficult to lift onto the centerstand (I'd suggest forgoing the centerstand except in the garage, where you can make a small ramp to ride the rear wheel up on - about 1.5-2" works great).

Best,

BOBINILLINOIS
05-02-2004, 05:25 PM
A year ago I bought a 1994 K75 RT from a friend's brother. The stock set up did not work for me as I have a 29" inseam. My friend replaced the stock BMW seat with the low seat kit from BMW and also changed the BMW shock to a low Progressive shock. It made a tremendous difference. I now have a low Corbin seat and a Works short shock and, though the bike is not lower than before, the seat is much more comfortable.

Don is definitely correct about the challenge of using the center stand once the bike is lowered. But it is a reasonable trade off for getting both feet on the ground when stopped.

Bob

90288
05-02-2004, 07:05 PM
How much did the BMW "lower seat" cost?

BOBINILLINOIS
05-02-2004, 10:53 PM
Originally posted by gsmetal
How much did the BMW "lower seat" cost?

I was lucky because my friend knew of a low seat available with the necessary hardware for $100. My sense is that a low seat in good condition will cost anywhere between $100-200. But in order to make the conversion you need several pieces of hardware because the low seat is not hinged the way the stock seat is.

I noticed that there is a low seat plus some of the hardware on Ebay right now. You might want to look into it. Here is the URL:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7901088998&category=35612.

There is also a low Corbin seat available on Ebay. You will have to find the hardware separately, which is often harder than finding the low seat. The URL for this auction is:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7901149305&category=10065

Good luck.

Bob

CustomSarge
05-03-2004, 12:03 AM
P.O.V. difference.... I agree with all above but would add that a band saw, mig welder & powder coating facility available make changing the "touchy" side & "unusable" center stands just a consequence of lowering. I've cut down three Ks (2x75, 1100) & one R (1100). One thing that does get tricky is the rubber stops' new positioning. An upside is that now the sidestand can be fitted with a "foot" that won't sink in (custom shaped for fun!).

deilenberger
05-03-2004, 12:31 AM
Originally posted by CustomSarge
P.O.V. difference.... I agree with all above but would add that a band saw, mig welder & powder coating facility available make changing the "touchy" side & "unusable" center stands just a consequence of lowering. I've cut down three Ks (2x75, 1100) & one R (1100). One thing that does get tricky is the rubber stops' new positioning. An upside is that now the sidestand can be fitted with a "foot" that won't sink in (custom shaped for fun!).

Custom (Sarge?)

I'd be real interested in how you've done this. Some digipics would be great.

I've given it some thought and was never able to figure out two things:

1. How to keep the shortened centerstand from interferring with the sidestand (where the tang on the centerstand comes up next to the exhaust pipe)

2. How the shortened stand ends up in the recess in the muffler

Any hints, or even better, photos would be really useful!

Thanks!

CustomSarge
05-03-2004, 01:10 AM
I''l yield to the quandry to exhaust indent, that's where I've cut a shaped "foot" for the sidestand to both curvetrace the muffler and provide a larger landing. As for side/center conflict, it hasn't been an issue for me since I modify both and they're proportional. To your point though... the K11LTX would cross-glance each other, until I fixed the sides' pivot sleeve. I'll be happy to post/email pix, once I shoot 'em. The LTX is best candidate, K75KS would be comic relief, and #3 has been sold. I'll also acknowledge I go with the best answer within time allowed; errors & insights cause the process to be iterative.

deilenberger
05-03-2004, 02:55 AM
Originally posted by CustomSarge
I''l yield to the quandry to exhaust indent, that's where I've cut a shaped "foot" for the sidestand to both curvetrace the muffler and provide a larger landing. As for side/center conflict, it hasn't been an issue for me since I modify both and they're proportional. To your point though... the K11LTX would cross-glance each other, until I fixed the sides' pivot sleeve. I'll be happy to post/email pix, once I shoot 'em. The LTX is best candidate, K75KS would be comic relief, and #3 has been sold. I'll also acknowledge I go with the best answer within time allowed; errors & insights cause the process to be iterative.

Cool.. looking forward to seeing it. Would be nice to do away with my ramp for the rear wheel in the garage.

Thanks!

CustomSarge
05-12-2004, 01:52 PM
OK, the indent situation is obvious, it misses. I'm giving away about 1-1.5" clearance to each stand. It's close to the rear tire and only been a issue on grass/dirt, a couple 3 times. For me the upsides win. I'll take my hits from those who disagree with my changes (re: 5/04 MOA letters), but I rarely work on other peoples' bikes. Also note the rear wheel doesn't leave ground(shadow inferred in pict), so centerstand is very short.

CustomSarge
05-12-2004, 01:55 PM
The other stand...

deilenberger
05-12-2004, 05:09 PM
Originally posted by CustomSarge
The other stand...

Sarge - thanks.. of course the pics result in questions :-)

1. Is there a rubber bumper for the stands? If so - where?

2. It looks as if the centerstand isn't a standard 2-valve K bike centerstand.. it looks like the later straight leg stand BMW used when they started adding the catalytic converter. This so?

3. Does the sidestand have the self-retracting feature and does it still work?

CustomSarge
05-13-2004, 12:29 PM
1> no rubber stops, neither stand vibrates or clanks while riding, so it hasn't bugged me enough to make them. I really don't want to give up any more ground clearance either. I've thought about teflon pads/tubes but don't see how to hold them in place.

2> the LTX was a '93 K1100LT, so it is the later type with catalytic converter.

3> sidestand retractor works as originally.

I just finished assembling a '85 K100RT as a bone stock unit from a drop & slide incident. Only body work required (17 pieces!). Its' stock characteristics remind me why the LT became LTX. The LTXs' only downside is the lack of a 6th gear or lower rear end ratio. I wish I could drop the rear to about 2.75-2.80 and spread the trans ratios to accomodate, but I'm not a good enough machinist to make tranny gears. I wouldn't even try for a 6th.

deilenberger
05-13-2004, 01:18 PM
Originally posted by CustomSarge
1> no rubber stops, neither stand vibrates or clanks while riding, so it hasn't bugged me enough to make them. I really don't want to give up any more ground clearance either. I've thought about teflon pads/tubes but don't see how to hold them in place.

2> the LTX was a '93 K1100LT, so it is the later type with catalytic converter.

3> sidestand retractor works as originally.

I just finished assembling a '85 K100RT as a bone stock unit from a drop & slide incident. Only body work required (17 pieces!). Its' stock characteristics remind me why the LT became LTX. The LTXs' only downside is the lack of a 6th gear or lower rear end ratio. I wish I could drop the rear to about 2.75-2.80 and spread the trans ratios to accomodate, but I'm not a good enough machinist to make tranny gears. I wouldn't even try for a 6th.

RE: 1 - OK. I suspect that both of us are deaf enough not to hear it..

RE: 2 - Cool. I know that trying that stand - not shortened - on an earlier K leads to it tangling up with the sidestand. I think it's a better design than the curved leg stand, if for no other reason than it doesn't tend to break like the curved leg stand. I've also noticed it's easier to get the bike ON that straight leg stand.

I don't think it's an option for me since my stand is already modified to clear the wider tire and rim I have on the back.. I don't think the staight leg stand could be cut away like the curved leg one can be (with the necessary reinforcement welded in)..

http://www.eilenberger.net/K75S/K75S.html

RE: 3 - Cool also. I know some people found that an issue with the straight leg stand (don't remember exactly why..)

Thanks!

CustomSarge
05-13-2004, 06:03 PM
To your point on side / center lever conflict, the K75KS' stands are SO short the only place for center lever is the opposite side!