Have finally started to get out a bit on the R80 street scrambler (see here) after having to get the gearbox unexpectedly rebuilt (thanks Bob!) as well as getting the exhaust thread repair on the right side head fixed yet again...
The heavily refurbed engine (new mains, big ends, timing chain, valve seats, valve guides and valves) is running nicely.
But something isn't quite right in the handling department, and I'm wondering which of the many things that could be the cause is the culprit.
The handling is fine at speed. But when I brake, the steering becomes increasingly heavy - if you brake hard to a stop you really have to put some serious muscle into the bars to persuade the front wheel to deflect at all from straight ahead. It's most noticeable at very low speed, but this just may be because I never find myself braking hard at speed while trying to turn the bars (!). Typical scenario is you're rolling to a stop at a junction and trying to position the bike as you roll up (instead of stopping completely square to the junction), or turning slowly into a side road, trying to balance steering and braking at the same time - but I just end up thrupenny-bitting as I shove the bars hard, then have to back off, as once the wheel has started deflecting the resistance quickly decreases.
It didn't used to do this before I rebuilt it, though I used to use the rear brake much more than the front in its previous incarnation (and using the rear now doesn't cause the symptoms described)
It's easy enough to ride around, but I'd like to improve it if at all possible.
I changed a lot of things around the front end when I rebuilt the bike, and I'll probably experiment with refitting the original wheels and/or tyres soon to try to eliminate some of these factors. But the suspect list is currently as follows:
- TKC80 knobbly tyres giving a completely different feel to previous standard road tyres (BT45s)
- Wirespoke wheel replaced snowflake wheel - may be a bit lighter/ give a different feel?
- Rebuilt forks are still very sticky and slow to reextend after compression (new damper rod rings are not bedded in yet, also the inside surfaces of the "new" off the shelf rechromed stanchions may take some time to smooth down)
- Forks possibly twisted in yokes when reassembled, or other schoolboy error when rebuilding / refitting front end and new steering head bearings
- much wider bars completely changing the feedback and feel of the front end
Or possibly all of the above!
Thoughts?
The heavily refurbed engine (new mains, big ends, timing chain, valve seats, valve guides and valves) is running nicely.
But something isn't quite right in the handling department, and I'm wondering which of the many things that could be the cause is the culprit.
The handling is fine at speed. But when I brake, the steering becomes increasingly heavy - if you brake hard to a stop you really have to put some serious muscle into the bars to persuade the front wheel to deflect at all from straight ahead. It's most noticeable at very low speed, but this just may be because I never find myself braking hard at speed while trying to turn the bars (!). Typical scenario is you're rolling to a stop at a junction and trying to position the bike as you roll up (instead of stopping completely square to the junction), or turning slowly into a side road, trying to balance steering and braking at the same time - but I just end up thrupenny-bitting as I shove the bars hard, then have to back off, as once the wheel has started deflecting the resistance quickly decreases.
It didn't used to do this before I rebuilt it, though I used to use the rear brake much more than the front in its previous incarnation (and using the rear now doesn't cause the symptoms described)
It's easy enough to ride around, but I'd like to improve it if at all possible.
I changed a lot of things around the front end when I rebuilt the bike, and I'll probably experiment with refitting the original wheels and/or tyres soon to try to eliminate some of these factors. But the suspect list is currently as follows:
- TKC80 knobbly tyres giving a completely different feel to previous standard road tyres (BT45s)
- Wirespoke wheel replaced snowflake wheel - may be a bit lighter/ give a different feel?
- Rebuilt forks are still very sticky and slow to reextend after compression (new damper rod rings are not bedded in yet, also the inside surfaces of the "new" off the shelf rechromed stanchions may take some time to smooth down)
- Forks possibly twisted in yokes when reassembled, or other schoolboy error when rebuilding / refitting front end and new steering head bearings
- much wider bars completely changing the feedback and feel of the front end
Or possibly all of the above!
Thoughts?
.
