Author Larger front sprocket (Read 11742 times)

bobilovsky123 · **Reply #20 on:** 24 October, 2010, 10:17:16 pm

I wasn't aware that one could get a 42t rear sprocket for a biffer, the standard is a 43t and I knew a 41t was available.

bobilovsky123 · **Reply #21 on:** 24 October, 2010, 10:24:25 pm

Please forgive me "Biffer rider" if you initially meant the standard set up

Stevep · **Reply #22 on:** 25 October, 2010, 08:00:03 am

The 17/42 set up is same as Blackbird I think.
It also brings the speedo closer to a true reading as at the moment it runs about 5 to 6 miles a hour over the true speed.
On a recent trip to Poland and back my partners Deauville was recording about 6 mile a tank less than my biffer when travelling at same speeds with no additional detours taken.
Even with Tom Tom fixed at 70 my biffer was recording 76 mph.

bobilovsky123 · **Reply #23 on:** 25 October, 2010, 10:29:10 pm

The one thing I did notice when I had the 17T front sprocket on was that the front end felt looser and the steering didn't seem as precise. Why is this? :465:I know the Wheelbase is slightly shorter and one has a little less torque at the rear wheel, but I noticed a great deal of difference. Anyone any ideas.

Jumbo · **Reply #24 on:** 26 October, 2010, 05:43:56 pm

Originally Posted by bobilovsky123

.....I know the Wheelbase is slightly shorter and one has a little less torque at the rear wheel, but I noticed a great deal of difference. ...

Wheel base slightly shorter??? How is that??
You've lost me there.
Jumbo

johnstg2 · **Reply #25 on:** 26 October, 2010, 07:23:44 pm

Originally Posted by Jumbo

Originally Posted by bobilovsky123

.....I know the Wheelbase is slightly shorter and one has a little less torque at the rear wheel, but I noticed a great deal of difference. ...

Wheel base slightly shorter??? How is that??
You've lost me there.
Jumbo

I assume Bob means that the rear wheel is moved slightly forwards to get the correct tension on the chain, as it has to go around a larger sprocket. Wouldn't have thought a few mm's would have made a noticable difference to the handling though.

Jumbo · **Reply #26 on:** 26 October, 2010, 11:05:54 pm

Originally Posted by johnstg2

I assume Bob means that the rear wheel is moved slightly forwards to get the correct tension on the chain, as it has to go around a larger sprocket......

Ah, of course. Thanks.
In 40 years of interest in bikes and bicycles, it never occurred to me that every time we adjust our chain tension we are adjusting our wheelbase.... kind of, ish!
Likewise, every time we take our bikes out we have different gearing....... because we wear out tyres and replace them, which constantly changes the rear wheel diameter..... kind of, ish

Jumbo

johnstg2 · **Reply #27 on:** 27 October, 2010, 12:12:47 pm

Originally Posted by Jumbo

Likewise, every time we take our bikes out we have different gearing....... because we wear out tyres and replace them, which constantly changes the rear wheel diameter..... kind of, ish

Jumbo

On a similar theme.......every time you lean into a corner you are altering the final drive ratio as the edge of the tyre is a much smaller diameter than the centre.

Jumbo · **Reply #28 on:** 27 October, 2010, 02:33:19 pm

Originally Posted by johnstg2

On a similar theme.......every time you lean into a corner you are altering the final drive ratio as the edge of the tyre is a much smaller diameter than the centre.

Which is why we need to open the throttle a little to maintain speed in a bend

jumbo

Kevin t · **Reply #29 on:** 13 August, 2023, 10:11:53 pm

i know its an old post, but fitting the 17 tooth front sprocket do you need to alter the chain or will it just pull the rear wheel up more to the front,