Breaking rear mudguard on my HP SMGT

[glasgowcyclist]

I know from the bike's previous owner that it was prone to breaking rear mudguards. This was believed to be due to a lack of vertical support stays, there being only a pair of stays extending horizontally from the axle to the tail of the guard, and the nose of the guard being bolted directly to the frame.

The mudguard would shear just above this forward mounting point, so previous owner resorted to using cable ties to fix what was left of the mudguard to the cross-members of the rack. Not pretty but it worked.

Two weeks ago I fitted a new Bluemel SKS rear guard and supplemented the supplied stays with another pair of stays to give this missing vertical support. It broke today.
However, this time it tore the support stay mounting from the tail of the guard, leaving a hole there.

Is this a common problem? Is there some trick to fitting guards on a 'bent?

I have some doubt about the rear shock and that (despite me cranking it up as stiff as I can get it) it is reaching full travel occasionally and I think the rear rack may be fouling the guard.

This brings me to my second question: assuming the rear shock needs serviced/replaced, could I take the Fox Float shock (3" travel) from my Trek Fuel 80 and fit that instead?

 

[henshaw11]

Pretty sure this has come up before, either here or yacf - the standard HPVelo-supplied SKS mudguards (probably blumels but I'm not sure) have the vertical supports:
http://www.bicycleman.com/recumbents/hp_velotechnik/hp_velotechnik_street_machine.htm
- I've a speedmachine and they're pretty much the same (if not identical) - and the mudguard's in perfect order, with no sign of wear after 3 years or so's use.

If it's smacking the rack, that really won't help..as far as the shocks concerned - I dunno. What you actually need to do is find the shock stroke (not the rear wheel travel, which'll be different), and eye-to-eye length (ie between shock bush centres. I expect it'll be on the hpvelo website, mebbe in the user manual - I've had a brief google but couldn't find it.

If you fit a different shock you'll also need spacers so that the shock fits the frame mount points - in the case of DTSwiss shocks they probably need machining to size - at least they do on the Speedmachine (generally that's included in the shock+mounts purchase price). 'Fraid new shocks aren't cheap, unless you put another DV22 (?) on there. The DTSwiss units are servicable, dunno about the DV22 - think they may be fit/forget.

 

[glasgowcyclist]

If it's smacking the rack, that really won't help..as far as the shocks concerned - I dunno.

I've had a good look at it and come to the conclusion that the spring is way too soft. The sag when I sit on the bike takes the rack to within 1.5" of the mudguard and it doesn't take much more flexing to get it to strike it.

What you actually need to do is find the shock stroke (not the rear wheel travel, which'll be different), and eye-to-eye length (ie between shock bush centres. I expect it'll be on the hpvelo website, mebbe in the user manual - I've had a brief google but couldn't find it.

If you fit a different shock you'll also need spacers so that the shock fits the frame mount points - in the case of DTSwiss shocks they probably need machining to size - at least they do on the Speedmachine (generally that's included in the shock+mounts purchase price). 'Fraid new shocks aren't cheap, unless you put another DV22 (?) on there. The DTSwiss units are servicable, dunno about the DV22 - think they may be fit/forget.

The Fox shock was only a few millimetres out in eye to eye length but the eye diameter was much narrower so that scuppered my idea. I'll confess I hadn't thought of stroke length so thanks for pointing that out.

I removed the SMGT shock (it's a 450lb version) and tightened it up a good six full turns. I couldn't get it that stiff on the bike due to the restricted access. It's not so stiff as to not give on bumps but it barely sags when I sit on it. I find that a great improvement over the very soft setting it was at before. I'll run it like that for a while to see if that's it sorted.

Can I ask you about front suspension?

My bike has Ballistic 450 AII shocks which I think are elastomer based. They are very, very stiff with no noticeable change throughout the range of the adjustment. Are these easy to service or am I as well looking at changing to something more modern and effective? If so, what sort of cost will that be? I'm happy to buy second hand.

Thanks for your help.

GC