Question about 4L0 Wheel Upgrade Options

[geoffb]

Happy Sunday!

Although I am not new to LCs, I am new to the idea of hybrid conversions.  I love what some of you guys have done with your hybrid bikes but wondered if there is a simple wheel upgrade and rear disc brake option (including wider tyres) but without having to change forks, yokes, swinging arm, etc.?

Cheers

Geoff

[midlifecrisisrd]

Hi Geoff

The rear has a few options as there were a lot of 15mm spindle "skinny" hub wheels and the LC swinger can be spread quite easily

Front is the tricky one as the fork spread and twin disc set up doesn't suit many wheels

Even if you found an rz250 3hm1 front wheel it still needs an extra 10mm between the forks

I've picked up a few bits for a possible "half arsed" attempt at a mild hybrid. Not put much thought into it or measured anything yet but basically thinking spoked 17 inch wheels again but you can get them made in wider 18 inch rims easily enough

TDR 250 hub is 15mm spindle and not too wide but still has a cush drive

Rd250/400 aircooled hub would do as well but rarer and think it's 17mm spindle

Front hub is tricky for twin disc

I've done a front end with an sr500/xs650 hub and 4 pots but that needed a lot of room and complex disc/hub spacers to get it to fit

Latest thing I picked up is an SR125 early disc brake wheel

It is a narrower, thinner spindle hub with same Yam disc pattern

It was a single disc but the other side has the holes but no threads and the disc face only has some casting marks that just need cleaning up in a lathe then the holes threaded

Not looked at measurements but hoped it would fit in easier and use slide type calipers (like standard LC) so no disc/spoke/caliper clearance issues

Think I paid £30 posted for the sr125 wheel so no big gamble

Steve

[geoffb]

midlifecrisisrd Thank you so much for this Steve 👍

[4l04ever]

You can fit 3 spoke Yamaha wheels with a bit of work.



TZR125 3PC front wheel and TZR125 4FL rear wheel. Needs caliper adapters, spacers and modifications to sprocket carrier, but it fits nice :-)

[steve63]

I'm going through my stash of bits with the loose plan of putting at least one of the LC's (4L0) back on the road.

I've got a set of F2 wheels and forks and yokes with original calipers and clip ons and a half baked idea of  using them on one of the LC's. I'm pretty sure I've seen the wheels fitted to a 4L0 race bike somewhere before.

The F2 wheels are a bit wider and lighter than the 4L0. I don't think they allow the fitment of much wider (if any) tyres exactly but the tyres should work better on the wider rims.  Purely from memory 1.85" rims for the LC and 2.25" for the F2 (I'd be amazed if that is right ) and the forks are a bit wider and should be better. The twin piston calipers should be a bit of an upgrade as well.

I think the yokes should fit the LC frame but it's just wishfull thinking!

The caliper mount on an LC swinging arm will be the biggest job but I was a sheetmetal worker in a previous life so I'll be fine to do a bit of welder/fabricating.

[dusty350]

A Ypvs front end will fit straight into an Lc. Stem on the yokes are the same dimensions as Lc. F2 forks are longer as the clip ons bolt to them above the top yoke, so if you wanted to use Lc type bars, then you would want a 31k top yoke with bar risers the same as an Lc, and earlier, shorter Pv forks. All Ypvs forks, regardless of model, are 35mm diameter, Lc are 32mm, so Pv forks are a bit beefier. Later F2 forks will allow fitment of more modern calipers due to their 83mm mounting centres.
A Pv rear wheel will go in an Lc swingarm with some milling to the caliper carrier, and centralising of the wheel. I would get a bracket welded to the Lc swingarm to keep the caliper and carrier above the line of the wheel spindle - it looks so much better - but otherwise Pv into Lc is relatively easy and cheap compared to other options

Dusty

[midlifecrisisrd]

Ypvs wheels will comfortably take a 100 front and a 120 rear and keep a good profile

Any bigger just balloons

There is the wider FZ rear which takes a 130 but then your into possible issues with spindle size and the hub width being bigger

Steve

[steve63]

Jan 12, 2021 8:26:30 GMT 1 dusty350 said:

A Ypvs front end will fit straight into an Lc. Stem on the yokes are the same dimensions as Lc. F2 forks are longer as the clip ons bolt to them above the top yoke, so if you wanted to use Lc type bars, then you would want a 31k top yoke with bar risers the same as an Lc, and earlier, shorter Pv forks. All Ypvs forks, regardless of model, are 35mm diameter, Lc are 32mm, so Pv forks are a bit beefier. Later F2 forks will allow fitment of more modern calipers due to their 83mm mounting centres.
A Pv rear wheel will go in an Lc swingarm with some milling to the caliper carrier, and centralising of the wheel. I would get a bracket welded to the Lc swingarm to keep the caliper and carrier above the line of the wheel spindle - it looks so much better - but otherwise Pv into Lc is relatively easy and cheap compared to other options

Dusty

Thanks for the info.

I guess there's nothing much cheap in the LC world anymore but seeing as I have most if not all the bits it's the easy bit that appeals to me! I had some dropped type bars on the LC all the time it was on the road before, along with an F1 top fairing so it kind of mimicked the F1/2 riding position and it felt fine. Good enough to do a 3,000 mile round trip to Spain with the Mrs on the back in '87. I would use the F2 clip ons this time.

My lad has a downhill mountain bike in the garage that he built on a Nukeproof frame. It has Marzocchi forks on it that make the LC forks look like pipe cleaners! Mind you it cost more to build that my LC's cost me back in the day. The caliper on the front is a four pot.