17x 3.5" Wheel Swap to Accommodate Sticky Buns ;)

DesmoRonin

DesmoRonin

Joined
Feb 27, 2025
Messages
101
Age
59
Location
Southern California
Bike
ST1100
Have any of you successfully swapped the stock 18-inch front wheel on the ST1100 (preferably non-ABS) with a 17" wheel? I've seen the "other defunct forum" post about using a front wheel from a CBR600F2, but I also welcome any feedback or advice from someone who has actually done it.

The time has come to make the hard decision to keep/sell/donate the ST... it's a great bike that has more than served it's purpose, but alas, I really like it, but I don't love it. I think I can turn like ---> love, but it will likely cost me more than a considerable amount of money for that love ($10k? including wheel swap), and I perhaps risk it losing too much of the ST character. I'm not opposed to this per se, and I do love me a challenge, but it might be better that I put that time and money into one of my better suited passion projects. But if the wheel swap works as intended, it could be the start of a very interesting project indeed.

Thanks in advance.
 
I know of one rider that put a 17" front on his standard ST1100 but he is no longer active on this forum.
IIRC, he had to shorten the sidestand and make custom brackets for the 'new' front calipers.
I don't remember if he swapped out the forks or not.
 
Thank you, I'm not worried about having to modify/fabricate/replace necessary items. Perhaps ok 25+ years ago, but brakes and suspension are two areas that could stand to be improved on the ST today. But without having access to sticky rubber, it would be kind of moot for me.

CBR600F2 wheels are readily available, and proper spacers are easy enough to make. Speedo drive from the bike of the donor wheel is supposedly accurate enough. Rotor bolt pattern is the same, but require shimming to align rotors with calipers. And some caliper material has to be trimmed for clearance (though realistically, calipers would be upgraded to allow access to better brake pad options -- 4-pot better still) I'm curious about how much the geometry change might affect handling and what may have been done to compensate, if necessary.
 
DesmoRonin said:
Thank you, I'm not worried about having to modify/fabricate/replace necessary items. Perhaps ok 25+ years ago, but brakes and suspension are two areas that could stand to be improved on the ST today. But without having access to sticky rubber, it would be kind of moot for me.

CBR600F2 wheels are readily available, and proper spacers are easy enough to make. Speedo drive from the bike of the donor wheel is supposedly accurate enough. Rotor bolt pattern is the same, but require shimming to align rotors with calipers. And some caliper material has to be trimmed for clearance (though realistically, calipers would be upgraded to allow access to better brake pad options -- 4-pot better still) I'm curious about how much the geometry change might affect handling and what may have been done to compensate, if necessary.
Click to expand...
FWIW, He was not a 'quick' rider but I never heard him complain about the handling or exclaim about the handling. ;)
 
Many people do things to their bikes, seemingly with "little point."
Some just like to tinker, and some do well with fabricating, and some do it for other reasons.
But your concern is valid... Will there be any actual payoff, or are you simply creating a money suck?
It's easy enough to do with motorbikes, even if you stay within the original design parameters... saddles, grips, lighting, luggage, and the endless quest for the ultimate farkle.
And there is little point to my rambling post here.
 
Larry Fine said:
It seems that the simplest swap would be to find a complete 41mm fork-to-wheel assembly.
Click to expand...
Interesting idea! But if I were to change the forks, I'd prefer them to be fully adjustable. Only Honda that might fit that bill (41mm/adjustable/hopefully similar triple clamp to fit ST steering head) is the RC45 (RVF750) that I know of. Hens' teeth... This would obviously be easier if I made a custom triple clamp, but then further down the time and money rabbit hole we go...
 
Uncle Phil said:
A stretch but maybe - the ABSII front forks are 43mm - might give you some more 'tire' room.
The triple-trees are interchangeable - BTDT. ;)
Click to expand...
120/70-17 is target tire size. No extra room necessary ;)

If I have to change forks, I would prefer rebound/compression damping adjustability. But I think I would be ok with cartridge emulators on stock forks initially.
 
I did a little fork modification on my 1990 ST1100. You should know that stock, the left TRAC leg is a damper rod and the right is a cartridge damper. The latter can be improved by fitting Racetech Gold Valves. I found a spare right cartridge and installed that in the left leg with more Gold Valves fitted, that bolted right in but I had to leave out the bottoming cone, and it rendered the TRAC obsolete. Adjustable fork caps from e.g a VFR800 can be used to give preload adjustment. Some decent springs will kepe the chassis steadier when pressing on.

The brakes can be made better by installing a smaller-bore master cylinder and braided lines, I used a VFR800 piece. You get a bit more lever travel but much more grabbing force at the disc; EBC HH pads were also part of the upgrade.

As for the 17" wheel, I get that there are endless tyre choices for that size, but putting a super-sticky tyre on the 1100 will probably just result in grounding out hard parts in corners, she's a big old girl and not really designed for apex attacks. The modern sport-touring tyres like Road6, Bridgestone T33 have much more traction than I have courage or skill and should be available in 18" size.
 
TerryS said:
I did a little fork modification on my 1990 ST1100. You should know that stock, the left TRAC leg is a damper rod and the right is a cartridge damper. The latter can be improved by fitting Racetech Gold Valves. I found a spare right cartridge and installed that in the left leg with more Gold Valves fitted, that bolted right in but I had to leave out the bottoming cone, and it rendered the TRAC obsolete. Adjustable fork caps from e.g a VFR800 can be used to give preload adjustment. Some decent springs will kepe the chassis steadier when pressing on.

The brakes can be made better by installing a smaller-bore master cylinder and braided lines, I used a VFR800 piece. You get a bit more lever travel but much more grabbing force at the disc; EBC HH pads were also part of the upgrade.

As for the 17" wheel, I get that there are endless tyre choices for that size, but putting a super-sticky tyre on the 1100 will probably just result in grounding out hard parts in corners, she's a big old girl and not really designed for apex attacks. The modern sport-touring tyres like Road6, Bridgestone T33 have much more traction than I have courage or skill and should be available in 18" size.
Click to expand...
Thank you! The Racetech Gold Valves were the emulators to which I was referring earlier. Your solution sounds more interesting and something I'd like to research further. Springs are a must for me, as is proper setup. Assuming I do the wheel swap, proper preload adjustment and setting static sag would be next. Current setup would not allow that.

I use a lot of higher end Brembo components and usually have a set of adjustable MC's around. If not, I have good access to the whole catalog, so that's where I've been leaning. I have sintered EBC pads on a couple of bikes... not my favorite, but they do work well, and I get them at a large discount. And I'm friends with a high end brake line manufacturer, and they used to make me custom lines all the time... also a must have for any bike I ride with enthusiasm ;)

To be fair, the tires don't have to be super sticky... I would like them to be a bit more confidence-inspiring, especially at the occasional trackday (sh!ts and giggles, not laptimes). If I don't hang off, I'm already grinding hard parts in the corners on the Michelin Road 6's that came with the bike. They have more than enough traction for the street, maybe almost enough for the track, but I've had more than a couple of not so confident moments on them and having more options is not a bad thing. Plus almost all of my performance bikes are shod with 17" tires, and there is a case to be made for essentially "free" takeoffs since there is usually plenty of center tread remaining. Owning a tire machine makes a stronger case for this.

I realize that this is more than a bit unorthodox, but it's part of the whole like --> love thing I think I can make happen. I totally agree... she is a big old girl (who also doesn't get up to speed very quickly and one who I wouldn't mind putting on the moto-Ozempic plan, if possible). I'd just like to give my hippo a better selection of ballet shoes... ;)
 
The Michelin 6 is a great tire, and I wore them before going Double Dark.
The 1300 is admittedly porky, but steers easily and confidently,
I've never wished for more cornering room and find it to be a superb sport touring bike.
That's one reason I plan to keep it until *I* am the one that's all used up.
 
You must log in or register to reply here.
Back
Top Bottom